High Efficiency Speaker Asylum

Need speakers that can rock with just one watt? You found da place.

Return to High Efficiency Speaker Asylum


Message Sort: Post Order or Asylum Reverse Threaded

Electro-Voice Regal lll

107.4.191.216

Posted on December 17, 2016 at 14:48:38
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013



Hi,
I am attempting my first DIY speaker restoration. I picked up a pair of vintage Electro-Voice Regal lll's. I was going to re-cap the crossover but discovered that the crossover is inside a "can" container. I can't figure out how to get the "can" open. Anyone know how to get it open?

 

Hide full thread outline!
    ...
RE: Electro-Voice Regal lll, posted on December 17, 2016 at 16:58:32
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Similar EV and Altec xovers in a can that I've opened had a metal cover on the bottom that has a flange or apron all around it that holds the cover into the can. They were press fit into the bottom of the can and I used a thin blade screwdriver to pry the cover out.
Try working around all four sides to see if you can pry the cover out kind of evenly. Too much prying on one side can bend the edge of the can.
The Altec xover had some hard black stuff covering the components and I used an Exacto Knife and needle nose pliers to pick away at it. The hard goop was just a covering over the components and didn't fill the can.
The EV xovers I opened were from 1978 and the only black goop in those was holding the coils in place to the top of the can but you have a pot mounted up there so that may not be the case in what you have.

 

I would ask EV for a schematic and build from new in a box outside the speaker, posted on December 17, 2016 at 21:08:44
Timbo in Oz
Audiophile

Posts: 18572
Location: Canberra - in the ACT - SE Australia
Joined: January 30, 2002
Contributor
  Since:
June 25, 2014
and use lots of space on the board.

use a trim pot on the treble.


Warmest

Tim Bailey

Skeptical Measurer & Audio Scrounger


 

RE: I would ask EV for a schematic and build from new in a box outside the speaker, posted on December 18, 2016 at 10:12:29
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Timbo in OZ, Thanks for the idea. I've been searching the web for a schematic to no avail. Never thought to try to contact EV directly.

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 10:16:52
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013



DaveV, Here is what the bottom of the can looks like. I did try a razor knife but it snapped the blade. Didn't want to continue without knowing more about how to get into it.

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 11:59:28
dee eye why
Audiophile

Posts: 517
Location: so. ohio
Joined: March 20, 2003
Google "electro-voice crossover specifications" and you will find plenty of info. It is most all PDF files which I am not able to post here.


.
Freak out...Far out...In out....

 

EV is quite good about legacy documentation , posted on December 18, 2016 at 14:05:03
mhardy6647
Audiophile

Posts: 11038
Location: New England
Joined: October 12, 1999
Contributor
  Since:
October 23, 2016
A quick search turns up datasheet with XO for the Regal 300; not sure if it is the same or different, but certainly seems worth a look.

datasheet:

http://www.electrovoice.com/downloadfile.php?i=971409

manual:

http://www.electrovoice.com/downloadfile.php?i=971408
all the best,
mrh

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 14:24:03
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
The pic does show that the cans have the press fit bottom cover.
I'm not surprised that a knife blade broke because those covers are in there pretty tight.
That flange or apron on the bottom cover is up into the can by about 1/4 inch and is pressing against the bottom edges of the can.
I used a flat blade screwdriver with a blade flat enough to be tapped into the groove between the bottom cover and can but not delicate enough to snap when using a prying motion.
Just be careful how much you tilt the screwdriver to pry up because you can put a dent or kink into the bottom edge of the can.
Working around all four sides a little at a time is advisable or maybe a putty knife would work?
Those are nice speakers. I have a pair of similar EV Esquire 200's that I don't use right now but I will never part with in the event I end up in a small retirement condo or apartment. The size is right and they blow lots of newer expwnsive speakers out of the water.

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 15:41:05
dcal40@aol.com
Audiophile

Posts: 8
Location: NY
Joined: July 30, 2016
I also have a pair of EV Esquires, and I agree....they are shockingly good, and well suited towards a lower powered tube amp too.

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 17:42:17
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Thanks, dee eye why. I have searched all those and came up empty.

 

RE: EV is quite good about legacy documentation , posted on December 18, 2016 at 17:46:58
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
mhardy6647, thanks but the 300 has different drivers and crossover.

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 17:52:05
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
DaveV, So, if I build a new crossover based on what is in the can I don't have to worry about wrecking the can. Just cut the can open and duplicate and forget about the can?

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 18:29:19
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Building a new xover not in the can would be your decision but you can pop the bottom cover with minimal to no damage to the can if your careful.
The inductors (coils) in the can are probably air core and should be reusable. Unless they really saved a buck but my 1978 EV xovers still had air core inductors in them.
The side edges of the can with the mounting flange would be a bit stronger so maybe you can confine the prying to those two locations?
Yes, the 300 has different drivers and crossover than the 200 but they should still sound good.
The 200 low end crosses over lower. I think around 400HZ and to an 8 inch cone mid driver but the high range crossover is the same at 3500HZ.
The Esquire and Regal had at least a couple of revisions. I believe the older Regal had a mid and high level pot and yours seems to have one pot, probably for the tweeter.
If that's the case you may find that if you recap with new film & Foil caps you may need to add a resistor in the mid line to cut it back a little. Maybe .25 to .50 ohms? Or it may be OK with you as is.

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 18:48:52
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
I just had a thought. If you don't want to use good screwdrivers, go buy a couple of cheap thin flat blade screwdrivers and lightly tap the blades into the sides with the mounting flange where the crack is between the bottom plate and side of the can. If you get the blades in about an 1/8 of an inch and tilt the drivers outwards for a pry motion, the bottom plate may just pop off.

 

I was afraid of that; sorry :-( (nt), posted on December 18, 2016 at 18:55:17
mhardy6647
Audiophile

Posts: 11038
Location: New England
Joined: October 12, 1999
Contributor
  Since:
October 23, 2016
nt
all the best,
mrh

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 19:01:19
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
DaveV, It has two pots. Brilliance and Presence.

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 19:02:19
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
DaveV, I'll give it a try.

 

RE: Electro-Voice Regal lll, posted on December 18, 2016 at 19:42:38
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
The first time I looked at the pic of the interior of the speaker I was looking at the xover and didn't notice the pot on the other side.
I thought it was strange that the mid horn wouldn't have had an adjustment too.

 

RE: Electro-Voice Regal lll, posted on December 19, 2016 at 15:31:12
Coner
Audiophile

Posts: 1776
Location: S.W. Washington state, USA
Joined: November 17, 2001
No reason to "cut" the can up, just take a small blade screwdriver
and slowly work the 4 corners out, it'a actually easy to do,
I never had a problem.

 

RE: Electro-Voice Regal lll, posted on December 19, 2016 at 15:45:18
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Coner, I'll give it a try. Probably won't be able to get to it until after Christmas.

 

RE: Electro-Voice Regal lll, posted on December 20, 2016 at 09:04:24
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013



I got a few minutes to try an open the can and that's all it took was a few minutes. Popped open easily without damage to the can. Not what I expected to find inside. I don't see any value markings or leaking. Remember I am a newbie. This is my first project. I did email Electro-Voice for a schematic; no response yet. What should I do next?

 

RE: Electro-Voice Regal lll, posted on January 4, 2017 at 09:12:28
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Electo-Voice has no schematic/info for this speaker. It was destroyed during one of the business purchase transitions. Anyone know of anyone that might have some info. Any EV historians out there.

 

RE: Electro-Voice Regal lll, posted on January 4, 2017 at 14:40:45
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
C

The crossover has a part # rather than a model # (which would have begun with an "X" like the later EV crossovers: X8; X36 etc) indicating that you have an early model. Check with a Volt Ohm Meter to see if the woofer is a 16 Ohm unit (which is likely for early ones though it will probably not be marked on early units). The crossover can looks like it has the crossover freqs marked as 1000 Hz and 3500 Hz. With this and the driver's impedance known you can use one of the online crossover calculators to design your own crossover, and a second order (12 dB) Butterworth should work fine (though it all may not fit into the original can). While you are at it check the other drivers too just to see that they match the woofer as 8 or 16 Ohm units, if not this will have to be factored into the crossover design. It's hard to tell from the pic but the T350 looks more like a later version from it's black finish. A 16 Ohm T350 will measure about 12 Ohms with a VOM, an 8 Ohm one will measure about 6 Ohms, but use 8 or 16 for the crossover calculator.

Easiest way/long shot solution: if you know someone with an ESR (effective series resistance) meter, have them check the capacitors in the original crossover to see if they are still functional. Using the similar Regal 300 8 Ohm crossover as an example you may be able reverse engineer what the cap value should be and then replace them, if you can solder. The original inductor coils should still be useful.

Hope this helps

Paul

 

RE: Electro-Voice Regal lll, posted on January 4, 2017 at 16:32:17
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Paul,

I started to look into building a new crossover. It seems to be pretty complex from what I found on the web. Not sure I want to tackle it. I'll look into it some more. I did find info that the W12s woofer is 4 ohm and the T35B tweeter is 16 ohm. I have no idea what the mid horn is.

Craig

 

RE: Electro-Voice Regal lll, posted on January 4, 2017 at 21:29:20
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
It is confusing because the available schematics for the EV Esquire 200 and Regal 300 are the same and your saying Regal 111 with a horn mid. The 200 and 300 both have an 8" cone mid but the instructions to adjust the two level controls are different for some reason.

When I got done writing this response I'm now thinking that the crossover for your version of the Regal is not the same as the 200 or 300 with the cone mid driver because of the pics of your crossover with the crossover frequencies and what looks like a missing cap.
But it does look like the mid and tweeter have a simple crossover like the 200 and 300 because there's only two coils or inductors I see in the pic.
Maybe you can follow my progression below on that conclusion.

As for the Esquire 200's I have, I would have never guessed that the woofer was 4 ohm, the mid 8 Ohm, the tweeter 16 ohm and that the woofer was wired out of phase with the mid and tweeter? The schematics for the 200 and 300 do actually show the woofer wired that way once you stop being confused by the low-high marking and go by the + - markings next to the drivers to see where those wires go.
It looks like there's a letter stamped on your woofer after the 12W so that's a tip that it's probably not 16 ohms like you'd expect with an older brown colored 12W.

The 200 and 300 data is on line as a download from EV/Telex by doing a search for EV esquire 200 or EV regal 300.

That so called mid/presence pot as shown in the schematics control the level of both the mid driver and tweeter so as to "shelf them" relative to the woofer output.
The HF pot just adjusts the tweeter level and the instructions for adjusting the pots makes more sense in the Esquire 200 directions.

You seem to have later Regals with a horn mid and because your actual crossover reads 1000 and 3500, that 100uf cap on the mid/presence pot doesn't make sense. If the crossover to the horn mid was 1000HZ and it was 8 ohm, I'd think that cap would be around 19 uf.

The 2.84 cap in the tweeter line is after the cap to the mid/presence control so your tweeter is protected from low frequencies.

The 100uf makes sense with an 8" cone midrange that can actually be a full range speaker and that suggests a crossover from the woofer to mid of around 300HZ.

Either wait to see if EV/Telex has the schematic for your Regals with the horn mid or you are probably going to have measure the DC resistance of the drivers to see if they are 4, 8 and 16 ohm.They will measure below those values but readings of 2, 5 and 10 would show you if they are different.

The other unknown is, did EV change the crossover setup for the Regal with the horn mid so that there is actually a mid level and tweeter level pot that work independently of each other?
Maybe if you carefully look at the crossover you can draw the connections on paper?

I believe the tweeter cap being 2.84 with a 16 ohm T35 or T35B tweeter but if your horn mids are 8 ohms and the crossover is 1000HZ, then I'd question if the cap across the woofer in your Regals is 140uf as the schematics show. UNLESS they didn't use a cap there to roll off or bypass the HF response of the woofer because the crossover to the mids in those Regals is 1000HZ.

If your going to be dabbling in this kind of stuff in the future you might think about buying a multimeter that checks capacitance. If you break the connection at one end of each cap you should be able to see what the caps in there are. Maybe they drifed in value but it's a rough guide.

From the pic you supplied it looks like two caps in your crossover unless one is a dual cap or one is hidden. If those two caps are a single value each then there may not be a cap across the woofer in your Regals because of the higher crossover point with the horn driver.

A dual cap of that type would probably have a wire on one end and two wires on the other end.

The other issue would be if EV wired the woofer out of phase in your version of Regals because the overlap of the woofer and the mid with a higher crossover point than that of the cone mids may not be a concern.
That should be fairly easy to trace out if there are + - markings or a red dot for plus on the the woofer.

If not, just remove one wire from the woofer and jump the ends of a 1.5 volt flashlight battery across the woofer terminals. The plus side of the battery makes the cone move out and the minus side makes the cone move inwards so mark the terminal that makes the cone move out when the plus side of the battery is on it.

 

RE: Electro-Voice Regal lll, posted on January 5, 2017 at 09:31:37
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Craig

The mid horn driver looks like an EV T25. It's hard to see from the pic of the crossover can contents, but are there only 2 caps and 2 coils in there? If so this would indicate that it's a first order 6 dB crossover. A 4 Ohm 12W seems unlikely, but you won't know unless you measure it. The red surround on the woofer indicates it's an EV cone and not an aftermarket re-cone. BTW Radio Shack has a pocket sized self ranging multimeter on sale for under $20. In the pic the woofer is wired in standard polarity with the blue wire going to the woofer plus terminal which is identifiable by the redish (faded) washer at the base of the terminal, while the negative has a faded blackish washer. With a first order crossover the mid and tweeter are wired in standard polarity, but with a second order crossover the mid is wired in reverse polarity. The wiring polarity to the mid, plus the crossover parts count, would indicate what's actually going on there.

Crossover design is "a piece of cake" nowadays once you know the driver impedances and the crossover points (see link). If the original crossover is a first order one, you can easily reproduce a sim of that too. EV used second order crossovers in their later X series so the link here is to that type.

The mystery deepens! (also see Dave's comments below.)

Paul

 

RE: Electro-Voice Regal lll, posted on January 7, 2017 at 08:48:37
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013



Thanks to both Dave & Paul. I wish I could say I understand what you're talking about, this is all new to me. I do appreciate it and it is inspiring me to learn more. I did get up the nerve to take apart the crossover and lo and behold values!

 

RE: Electro-Voice Regal lll, posted on January 7, 2017 at 08:49:23
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013



2nd one

 

RE: Electro-Voice Regal lll, posted on January 7, 2017 at 10:43:25
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
If your goal was to change the capacitors, now you have the values.

I'm having a hard time trying to figure out the 5.7 uf for the mid horn but there it is from the factory and EV choose that value for a reason.

When they got more into the bookshelf speaker market they did have different drivers that were not a part of their normal driver offering so it does get confusing unless the full specs of all the drivers are known.

A friend had a pair of EV bookshelves, EV Two's I think and the mid horn looked liked yours but I don't think they were T25's because the output was so low and I think the magnet structure was smaller.

I wouldn't replace the inductors (coils) but that's up to you.
Without a schematic or way to check their values it's not possible anyway.

Don't go nuts trying to find those exact cap values because they probably never were those exact values due to the manufacturing tolerance factor of either plus or minus 10 or 20%.

I found a Clarity ESA cap from Madisound that was close enough to the 2.84 but never had to locate a 5.7uf.

If you parallel two caps they sum, so a 3 and 2.7 would be 5.7. The voltage rating isn't a problem because most of what your going to find today will have a voltage rating that exceeds 50 volts.

If you end up using two caps in parallel to make the needed value, I'd use the same type of cap.

If the speakers sound good to you now, save the old caps because new and better isn't always better sounding. They aren't electrolytic caps so they may be old but not bad.

I find that changing caps can indeed alter the "voicing" of speakers and amps and those old caps can sound pretty darn good compared to some new ones that have better specs on paper but ultimately it's personal sonic preference.

Your not dealing with a high voltage electronic circuit where an old coupling cap is a time bomb in the output section and can damage the output tubes if one fails.

About 6 months ago I hooked up some 1950's EV drivers and their associated crossovers that are 100% original and they sounded fine to me without the urge for "better."

If your going to be working on "vintage speakers" then find a copy of Hi-Fi Loudspeakers and Enclosures by A Cohen. That book taught me a lot back in the day. There's a copy on E-Bay now for $22 and change.

You can get a new speaker design book but it will most likely be dealing with zobel networks, EQ networks,new driver design/technology and other things that don't apply to most speakers before 1968.

 

RE: Electro-Voice Regal lll, posted on January 7, 2017 at 11:16:21
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Thanks for the book recommendation. I am doing one speaker at a time just so I could compare the sound. I was told the caps would be electrolytic and would be bad after this many years. You said "They aren't electrolytic caps so they may be old but not bad." So that I can learn; how did you discern that? Would the following new caps be a good choice?

https://www.parts-express.com/dayton-audio-dmpc-27-27uf-250v-polypropylene-capacitor--027-416

https://www.parts-express.com/dayton-audio-dmpc-56-56uf-250v-polypropylene-capacitor--027-425

 

RE: Electro-Voice Regal lll, posted on January 7, 2017 at 11:47:23
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Craig

It looks like you have a first order crossover in the Regal 111. This is to say that the capacitors and coils in the crossover will limit the drivers to overlap into each others territory by a 6 dB per octave (first order) roll off, and the drivers will be primarily limited to the frequency range they perform in best.

The 2.84 MFD (micro-Farad or uF) capacitor would indicate that it's for a 3500 Hz crossover point for an 8 Ohm tweeter. The 5.7 MFD capacitor indicates that the mid driver is probably a 16 Ohm unit, though about 10uF would be a more likely value.. It's unlikely that the coil inductors will have the values printed on them (in milliHenrys), but they are likely still usable. One of the coils will start limiting the upper end of the woofer response at 1000 Hz, while the other will start limiting the upper end of the mid response at 3500 Hz. It's advisable to replace the 2.84 uF and 5.7 uF caps with new ones, try Parts Express and use the nearest standard value good quality caps.

Do you know how to solder? It's time to learn! You should be able to find soldering instructions online. The Regal 111 should prove to be a nice vintage speaker with a re-cap, just resist the temptation to play it super loud with a high powered transistor amp or you risk blowing a driver. A modest powered tube amp would be ideal. A test with a multi meter would indicate if any of the drivers are already blown which would complicate the project to say the least., and you don't indicate if you've tried to play the speakers already. If the treble and mid volume controls (L-pads) are scratchy or problematic you may be able to clean them with Caig Deoxit, but if you replace them they must match the impedance of the driver (i.e. 8 or 16 Ohm units). The values may be printed on them. BTW the link I provided in the previous post will not work with a less than 3 octave spread with a first order crossover as it's optimized for direct radiators and not for horns.

Good luck and welcome to the Electro-Voice Brotherhood

Paul

 

RE: Electro-Voice Regal lll, posted on January 7, 2017 at 12:21:40
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Electrolytic caps were and still are pretty common in xovers.
They are non polar and don't have a plus or minus side like an electrolytic in say a power supply circuit of an amp so they can be installed without regard to "polarity."

The non polar lytic for a speaker xover has to pass an AC signal, not filter it or block it.

"Conventional wisdom" says that if can use a film and foil cap, like the Daytons or a paper in oil cap in place of a lytic, it's a good thing.

But when your talking about higher values, the size and cost is a consideration and the lytics are smaller and less expensive.

When your talking about a 2.8 uf and 5.7 uf, that isn't an issue and even back when those speakers were made the 2.7 UF and 5.7 UF values weren't large enough so that a lytic was the only practical choice in size or price.

Lytics are usually obvious because they are in a sealed metal package sometimes with a plastic like wrapping on them that has the data printed on it.

The cap values in your xover didn't need to be lytics because of cost or size and they appear to be some kind of film and foil not of the lytic variety due to the way they are packaged.

My EV Esquire 200's has two lytics in the xover but those values are much higher, 40 uf and 140 uf I think. At the time a film and foil cap of those values would have probably been unavailable or just too nuts to think about and the use of paper in oil caps like motor run caps with those higher values wasn't by any means common place due to size and price so they were non polar lytics and still are, but new ones.

Unfortunately I didn't save the old 2.84 caps to compare to any new cap in the tweeter. That was before I discovered that new caps can change the sonics for some known and some still debated reasons.

The Daytons of 2.7 uf 250V and 5.6 uf 250 V should be fine. They would most likely be lots closer to the stated values of the caps in there now.

I've never read anything bad about the Daytons so give them a try. Not to say that another brand wouldn't sound different but that's where mind set over price and specs and sonic taste come into play.

A friend bugged me to replace the caps in his Warfedale W70 speakers because he was convinced new caps would sound better.
I choose the Daytons because of price and the fact that I had never read anything bad about them.

We did one speaker and couldn't hear any difference between the two. He listened for a couple of days and concluded that we should do the other speaker so that the caps were new in both. Net gain zero other than having new caps so draw your own conclusions because I have no answer other than the old caps were good and the new Daytons provided the same sonic signature.

Yes, like Paul says, it's generally advisable to think about new caps for a couple of reasons but that can open a can of worms with sonics. Just because the new cap is the same value as the old one it may not automatically sound better to you than the good old cap.

Designing xovers isn't rocket science but you have to know all the parameters of each driver and that's still an unknown here.
Then there's the actual listening test to hear what you designed using those parameters.

Speakers like the EV 200, 300 and 3000111, were at the time, sort of budget speakers or speakers for those that wanted decent and almost full range sound at a good price or that just didn't want BIG speakers.
And of course marketing came into play because other companies were offering bookshelf speakers and EV's mainstay had been the larger systems.

That meant sticking to a price point and using some tricks in design to achieve a result that was satisfactory. It's hard to second guess those designs as to why they were done that way.

The same holds true today with price points versus design and performance.


 

RE: Electro-Voice Regal lll, posted on January 8, 2017 at 16:17:41
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Paul,

The speakers do work. I have know idea if they sound the way they are supposed to. I was going under the assumption that they had electrolytics and they would have deteriorated by now. DaveV says not necessarly so. I bought a Klein MM400 multimeter and measured the drivers. The 12Ws cone woofer measured 2.3, the mid horn measured 4.7 and the T35B horn measured 7.3 L-Pads are quiet. I was planing on hooking them up to my RCA console just like this one: https://www.youtube.com/watch?v=uRY0Ssibaho

 

RE: Electro-Voice Regal lll, posted on January 8, 2017 at 16:22:12
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
And thanks for the welcome to to the Electro-Voice Brotherhood. With the multimeter I have is there a way to measure/know if the caps are still good?

 

RE: Electro-Voice Regal lll, posted on January 8, 2017 at 16:46:29
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Dave V,

Thanks for the education. I'm with you on preserving the the original sound. Since this is my first project it still interests me to try to "improve" the original. I know these speakers were lower end; good first project.

 

RE: Electro-Voice Regal lll, posted on January 8, 2017 at 17:21:51
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Your welcome Craig

Those speakers aren't that low end. I've heard new speakers that cost over $2000 a pair that don't sound as good to me as my Esquire 200's.

What I meant was that EV's lineup of larger systems were more straight forward in design for the day and used their standard drivers and crossovers.
Those systems are more efficient, better balanced overall, have a more extended low end due to the driver and cabinet size/venting and they didn't need to use what I call tricks to do that.

The cap thing is your call. I just cautioned you not to toss out the original caps just in case.

I remember when I got my Altec Model 19's and I searched around the Internet to see what people were doing about the caps.
There was the camp that said to put better caps in and the camp that said they still have the originals and they sound fine to them and were afraid to change the original voicing in this classic speaker.

The camp that changed caps had different favorites from metallized and non metallized film and foil to paper in oil so it's very doubtful they all sounded the same in the end.

Some changed the inductors too because the originals aren't air core and they have a higher DC resistance than air cores made with a heavier gauge wire.

I did a quick survey of Model 19 owners and asked them if they had measured the values of the original inductors. The responses I got showed exactly what I found. The actual inductance of all three inductors was different than what was shown on the schematic so the people that changed the caps and inductors were listening to three changes,not just the caps.

So when people offer their opinion there can be more involved too.

If we're not talking about replacing a truly faulty part with a good part then "better" is in the ear of the listener.

 

RE: Electro-Voice Regal lll, posted on January 9, 2017 at 11:50:10
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Craig

If the speakers are working (with lows, mids and highs coming out of the appropriate drivers) then definitely listen to them for awhile, you'll at least establish a base to evaluate any changes. I concur with Dave's take on a re-cap in that it may make a difference, or it may not. The Klein MM400 has a capacitance mode from what I see online, but you'll have to unsolder the caps from the circuit to measure them for accuracy, and as the speakers are functional you have to decide if that's worth the trouble. The MM400 doesn't have an inductance function so you won't be able to check the coils for accuracy, but this is likely a non-issue.

Did you disconnect the drivers from the crossover before you measured them with the DMM? If so it looks like your 12W's are indeed 4 Ohm units. The 2.8 uF cap on the bottom end of the mid horn crossover is still puzzling. You would need a circuit resistance of some 55 Ohms to use a cap of that low a value for a 1000 Hz crossover point. Perhaps this resistance can be accounted for in the coil and/or the L-pad circuit to pad the mid horn down. Horn loaded drivers tend to test low with the DC of a multi meter as this type of static measurement does not account for the acoustic resistance of the horn as seen by the driver in operation with a music/test signal. So it would seem that a non-standard impedance was assumed in the design of the crossover for the mid horn circuit, however the tweeter cap is right on the money at 5.7 uF for 3500 Hz with an 8 Ohm driver.

Anyway, how do the speakers sound? If working well they should be a big improvement over the small magnet drivers in that vintage RCA console. Just avoid getting the tweeter and mid too strong with the L-pad adjustments, and the Regals should be comparable or better than many recommended list speakers as Dave observes.

Paul

 

RE: Electro-Voice Regal lll, posted on January 9, 2017 at 13:26:54
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Paul,

Did you accidentally switch the cap values in your post?
The 2.84 is the tweeter cap and the 5.7uf has to be for the midrange. I questioned that 5.7 for the mids too and assumed it was one of those tricks I referred to because the xover can't be 1000HZ on both sides with that value.

The 2.84uf is the same value as in the Esquire 200 and Regal 300 with a 16 ohm tweeter.
I just checked with an on line calculator and the 2.84 seems correct for 3500HZ 6db/octave with 16 ohms.

 

RE: Electro-Voice Regal lll, posted on January 9, 2017 at 16:21:54
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Dave

For a 1st order crossover high pass I'm using the following:

159,155/F(Z)=C

This is where F=the crossover freq. in Hz; z= the driver impedance in Ohms; and C= the capacitor value in uF.

The assumption that the Regal 111 has a 1st order crossover is based on the parts count of two capacitors plus two inductors in the crossover can (hope this is right!).

So for a 3500 Hz high pass with an 8 Ohm driver I get a 5.68 uF cap, and with a 1000 Hz high pass with an 8 Ohm driver I get a 19.89 uF cap.

There were some problems with the online calc I first linked to here as applied to the task at hand. It won't allow you to specify a frequency spread of less than 3 octaves, and when you enter data with a crossover spread of say 2.25 octaves like the Regal 111 has, it changes one of the crossover frequencies to match the 3 octave spread: i.e. if you put in a 1000 Hz mid high pass, it will bump the tweeter high pass up to 8000 Hz with a 2.84 uF cap. I linked to this particular calc because it featured a nice schematic which I hoped would be clear for Craig, but it's definitely from the direct radiator driver persuasion and not useful for mid horns like the one in the Regal if someone (like me) is not paying attention

There still seems to be a mystery here, and we seem to be missing some information.

BTW you didn't think the mid driver was a T25. and you may be right The mid in the Regal has 4 screws on the back, but I have a pic of the T25 showing only 3 screws, on the back and another pic of a T25 showing 4 screws on the front! I have to confess I have never seen a T25 in real life, and it's strange that the driver in the Regal has no badge on the rear like the T35B.

I'm still scratching my head on this one! Maybe someone else has something to add.

Paul.

 

RE: Electro-Voice Regal lll, posted on January 9, 2017 at 17:21:53
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Paul,

The calculator I use is linked below. I still come up with 2.84 for the tweeter cap. Same as what was used in the Esquire 200 and Regal 300 with a 16 ohm T35B tweeter.

Using this calculator I'm also getting the 18-19uf for an 8 ohm midrange and that confused me from the beginning because the cap in there is 5.7uf and it appears to be original.

I think where we are getting crossed is that I'm assuming the tweeters are 16 ohms. Craig said at least one measured 7 point something ohms and that sounds like it is more than 8 ohms.

His 12W woofer does appear to have a number or letter stamped after the 12W like what EV did with the 15W/15WK Drivers to designate a different impedance for different enclosures like the Regency or Georgian.

And with the readings Craig provided I have to assume that the 300011 also has a 4 ohm woofer, 8 ohm midrange and 16 ohm tweeter.

In my friends EV Two's from around the same period I don't remember seeing any badge or designation on those mids either but I do know they didn't put out much. I even sent them to EV when they were still in business because I thought they were faulty but they said they were OK.

The woofers in my Esquires aren't marked with a model or impedance and they weren't in the usual EV lineup of drivers. I think they are 12BW or 12BWS and they are 4 ohm.

Seems to me that EV came up with some special drivers for some of these bookshelf speakers because they are infinite baffle types of enclosures.

The woofer is less efficient and the mid didn't have to compete so why toss in a more expensive T25 to only cut it back so much?

The T35B was already less efficient than a T35 so they probably let that fly because it did give you the option for more "sparkle" at the top.

That 4 ohm woofer, that may have a longer throw, must have lead to using
different impedance drivers to get a workable system balance.

Pure speculation on my part but I can't come up with anything else.

 

RE: Electro-Voice Regal lll, posted on January 10, 2017 at 09:00:39
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Dave

Digging through my archives here I ran across an old download from the EV discontinued products website of the spec sheet for the 12W, 12BW and 12WK. The same pic represents the 12W and 12WK with their big 3 lb magnets, but the 12 BW is different in that it has a smaller 1 lb magnet. The nominal impedance for all three is 16 Ohms, however the DCR for the 12W and 12BW is listed at 11.6 Ohms, but the 12WK is listed at 3.2 Ohms! It's mentioned that the 12WK is intended for a "Klipsch type enclosure" but that still seems quite a bit of a stretch.

The wiring schematic for a 3 way (which is kinda hard to see, or I'd post a scan) shows a T25 or a T10 mid driver on an 8HD horn, and it shows the mid wired with reverse polarity indicating a 2nd order crossover, and it looks like an X8 (800 Hz) and X36 (3500 Hz) are used though it's hard to see. I dunno why they didn't call the mid crossover an X35, but there may have already been another former model with that appellation.

There's another hint in the operation section: "The 16 Ohm impedance of the driver units is a standard RETMA rating and is indicative of the voice coil impedance at crossover frequency. A mismatch by as much as 40% may be made without affecting the reproduction or efficiency of the unit". I guess they didn't figure the audiophiles of the future would be so picky about this stuff.

Paul

 

RE: Electro-Voice Regal lll, posted on January 10, 2017 at 12:20:26
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Paul,

I sent you an e-mail bypassing the Asylum because I didn't want to confuse Craig while we tried to figure out an old design,why they choose those cap values, woofer model numbers and T35B impedance.

But for Asylum Archive purposes, I did forward a link to a past E-Bay sale for Esquire 200 components and the woofer was a 12BWS with the S stamped into the plate after the printed letters.

My own original Esquire paperwork says that the system contains a special 12" woofer, the EV 12BWS with a one pound six once ceramic magnet and my Esquire woofers have a DCR reading that looks like a 4 ohm unit.

The EV stated frequency response of the Esquire 200 is 40-19000CPS (HZ)
The stated response for the Regal 300 is 33-19000CPS.

The Regal was a more expensive model and there's something stamped on Craigs woofer after the 12W. An S maybe?

Since Craigs DCR reading shows that his woofer is a 4 ohm unit then EV must have made a special 12W that kept all or near the same parameters except for the impedance.

Since Craig wants to experiment with new caps then I think the best course of action is to replace them with the same values that are in there now because they appear to be original from the factory.



 

RE: Electro-Voice Regal lll, posted on January 10, 2017 at 14:22:43
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Paul,

I did remove all three drivers before testing them.

I had the speakers hooked up to a vintage Marantz receiver in an office at work listening to the radio. I never had them setup for critical listening. They didn't sound that good to me; not terrible but certainly nothing to get excited about. I never did hook them up to the RCA console. I will hook-up the one that is still together and see if it sounds better with tubes. I do like the sound of the RCA. My main system has Magnepan MMGs and before that I had Dahlquist DQ10s. I like the dipole sound more than boxes.

Craig

 

RE: Electro-Voice Regal lll, posted on January 10, 2017 at 14:52:14
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Dave,

Yes, there is an "s" stamped after the 12W.

Craig

 

RE: Electro-Voice Regal lll, posted on January 10, 2017 at 15:21:41
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Dave

If we could get the values of the coils in milliHenrys in the crossover of Craig's speakers, or a schematic of the crossover with this info, this may provide some insight into the mystery. It's possible that the mid or tweeter could have been re-diaphramed, or swapped with another with a non-original impedance not matching the original crossover. From this reverse engineering project I've learned that I have a lot to learn about vintage EV boxes with horn mids and tweets.

Paul

 

RE: Electro-Voice Regal lll, posted on January 10, 2017 at 15:28:12
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Dave,

What you and Paul are discussing is over my head but I do enjoy the puzzle. I went to the crossover calculators posted but they were for 2-way systems, shouldn't it be for 3-way systems? I found this one:

http://www.kbapps.com/audio/speakerdesign/calculators/ThreeWayCrossoverSchematicCalculator.php

Do L1 and L2 represent the coils? Do they affect the capacitor values? It's too bad the calculator won't let you input the knowns to determine the unknowns.

What started out in my mind as a fairly simple DIY restoration has become an intriguing puzzle. Rather than replacing the caps with the same values why not use what the calculators suggest? Not knowing what the coils measure, yet, they may need to be replaced.

Craig

 

RE: Electro-Voice Regal lll, posted on January 10, 2017 at 16:57:09
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Some other things I have been considering in this restoration is:

Cabinet sealing, bracing, damping, & stuffing. Re-wiring & terminals. This speaker has no sealer caulk, damping material or stuffing.

And what about the horn diaphragms? Do they slowly go bad or just go until they quit?

I am considering taking the crossover out of the can and mounting it on a board like Bob Crites does and I am leaning toward the Sonicaps that he uses.

I know this is Sacrilege to the purest. I am not dead set on doing this. My motivation was to add current knowledge & technique to maximize the original.

What are your opinions on these subjects?

Craig

 

RE: Electro-Voice Regal lll, posted on January 10, 2017 at 17:58:12
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Craig,

The calculator link I posted was for Paul to see how I was getting the 2.84 value for the tweeter by assuming the tweeter was 16 ohm and knowing that the standard crossover to an EV T35, T35B or T350 tweeter was 3500HZ.
And that 2-way calculator was for the 6 db per octave that is in the Regal with just a cap in series with the tweeter.

Your link and two others I tried for a three way system wouldn't accept a calculation for xovers of 1000 and 3500 HZ. The xover points had to be 3 octaves apart.

The one I used went from 2-way 6 db per octave to a calculator for 3-way 12 db per octave so that didn't help either because with just two caps and two coils you have 6db per octave.

Yes, the "L's" are the coils or inductors.

No, it's not possible to calculate cap or coil values just based on one or the other. They are chosen based on the parameters of the drivers used, the actual crossover frequencies and the slope being 6,12 or 18 db per octave.

The xover can says 1000 and 3500 but I question the 1000 being the actual xover frequency at which point the woofer higher frequencies start to fade out and the lower frequency of the mids start to kick in.

Not being an engineer, what I see is that we aren't dealing with a text book speaker system where everything should fall into place better.
They tried to make a full range system in a small box with woofers that were meant for a vented enclosure or much larger enclosure and they jury rigged it from there to the midrange.

I can believe the 2.84 cap for the 3500HZ xover to the tweeter BUT that reading you came up with of 7 point something is a bit on the low side. I would have thought if the tweeter was 16 ohm the reading would have been at least 10 ohms. Although Paul did find that blurb about actual impedance at the xover.

Paul suggested a diaphram being replaced but those caps sure look factory original to me and I've seen the insides of several old EV and Altec xovers. Plus you had to unwrap them and the pic you first posted looked like a neat untouched factory package.

If EV used a non standard impedance T35B of something other than 8 or 16 ohms, those caps still look original and making the 2.84 the midrange cap would be even more of a mystery.

At this point I'd say it is what you see and go with the cap values that are in there. Measuring the coils for inductance would add missing data but I'm not sure if that would solve the mystery or not.

You said the speakers didn't sound all that good so you should change the caps to see if new ones make an improvement.

I know what the Esquire 200 sounds like but not the Regal 3000111.
I suspect the Regal with the 8" cone mid might sound better to some people but I wouldn't think EV would have had their next up in line from the Esquire not sound as good even it it had that horn mid.

Judging by the other speakers you mentioned, these may not be your cup of tea but they should sound better than RCA console speakers.

 

RE: Electro-Voice Regal lll, posted on January 10, 2017 at 20:22:11
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Craig,

My "opinions" regarding anything audio are based on working for three audio equipment companies and one speaker manufacturer. All well known, plus having the field as a hobby for over 50 years and having had and worked on more equipment and speakers than I care to list.

You bring up some valid issues but IMHO it's not worth the money or effort to do all those things with those speakers unless you just want to see for yourself what each "improvement" may or may not do. If you want to spring for those caps for peace of mind then go ahead. I'm just saying that I don't think you should go nuts with those speakers with a mind set that all those things will make them something are aren't.

When I saw the name Crites, the first thing that came to my mind was that he has a business selling parts and mods to people that aren't happy with their Klispch Speakers as they came from the factory. But being bigger more expensive speakers with some good bones to work with, it probably makes more sense to swap out parts to your liking than to buy new ones.
Many times people like something about a speaker but learn to hate something else about it and there you have it.

But to address your list:

1.Anything electrical should require a mechanically strong, clean and well soldered or well fitting connection.

2.Cabinet leaks alter the low frequency response and overall function of the woofer to some degree depending on the woofer design. My Esquires don't have a gasket on the lip where the back panel rests but the backs fit snug and tight so I never went any further.
However, if your upgrades prove to be successful in bringing about a sound your more pleased with but the bass seems a bit flabby or off,that's the time to try better sealing. But the woofer, xover and cabinet size are what they are and they have limits.

3. Damping on a horn may or may not be needed and you may or may not hear a difference. Depends more on the material the horn is made of and how it's mounted.

4.Stuffing changes how the woofer responds in the cabinet and at the very least there should be some sound absorbent material covering the back speaker panel to help cancel standing waves from the back of the woofer. Adding stuffing where there was none can change the sound depending on how much you add and it may sound better or worse to you.

5.Bracing will change the inherent resonace of the cabinet and that may or may not sound better even if in theory it's correct. When your marketing a $10,000 speaker you better mention bracing because it's expected but with a bookshelf speaker that's not an acoustic suspension design that's driven at high levels I don't put much importance into it as long as your working with a cabinet that isn't coming unglued at the seams and the back panel is tight.

6.Cap brands and types to me are like what flavor ice cream you like or how much you think you have to spend for a tire for your car. Crites deals with horns so maybe he found that the Sonicap flavor works well with horns. Others may tell you that horns need paper in oil caps.
As above, new expensive speakers sold to a niche market are expected to have caps that are perceived to be better or "auiophile" grade caps. That holds true with the electronics too.

7. Not knowing what diaphrams are in the mid horns I can't say if they go slowly or all at once. If they are phenolic like the T35B I'd say that they either work or they don't. But the voice coil is attached to it so if the coil has some shorted windings it can change the impedance of the driver and can change the performance.

8. Your not working with a "Classic" that has a big resale value in original condition or with one of those outstanding Japanese reworks so making a new breaboard xover or "Bob Crites style" is fine. Just make darn sure you take pics of the connections or don't take the other xover a part and use that for your pattern of connections or you can blow the mid or tweeter with wrong connections.

Five other people can do what I just did and disagree with me on some or all of my opinions but that reflects how diverse opinions are on what you believe to be true and/or your own experience.

 

RE: Electro-Voice Regal lll, posted on January 11, 2017 at 16:57:21
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
I hooked-up the one speaker that is still intact to my RCA tube console and gave it a good listen. It does sound much better than when I had it hooked-up to the Marantz receiver in the office. Does it sound better than the RCA? As I said before, I like the sound of the RCA. The RCA is not your typical console with left and right channels in the same cabinet. It is not boomy like others I have heard from the 60's & 70's. It was one of the first (1958) if not the first to offer a stereo option. It could be purchased as a single mono/stereo unit with the option to add on a second speaker cabinet to allow it to do stereo.

The console is a little more open/airier in its sound. The EV is more powerful with punchier bass. The EV does have that box sound; the RCA less so. I do like the EV and I am more excited to complete the restoration.

I really appreciate your wisdom regarding the other upgrades I listed and I completely understand what you are saying about "it's not worth the money or effort to do all those things with those speakers unless you just want to see for yourself what each "improvement" may or may not do." As I said before this is my 1st DIY project. It's a learning experience for me and it's a hobby/project for me to do during the Minnesota winter. I have already refinished the cabinet and will replace the grill cloth and caps. I probably will add some foam liner and fill just to see what happens.
Thanks again to DaveV, Paul and all that have contributed.

 

RE: Electro-Voice Regal lll, posted on January 11, 2017 at 18:53:54
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Craig,

What your saying doesn't really surprise me.

My Esquires sound better with a tube amp too and the debate continues as to why that is but I really never got involved with that because I've always preferred the sound with tubes so that's a useless debate for me to take part in or worry about.

I have two transistor amps, one 60 watts per channel and the other 200 watts per channel that only come out of the closet when I want reconfirm that I prefer tubes and so do the speakers I have.

My Esquires sound "full" all the time like there's upper bass that never goes away. With real deep bass in the source they sound like they are going deeper than they really are and the effect is quite convincing.

I attribute that to the overall design and trying to get a reasonably full ranged speaker at a price point into a small sealed box.

The T35B Tweeter with the pot at full should pierce through all that and give some "sparkle" or a sense of air but the full sound is still there.
Maybe the new caps will change that?

Without seeing the RCA speakers and how they are in their enclosures I can't comment on those other than to say that I'm not surprised that you say they sound somewhat more open or airy. But you'll probably find that the Regals are more capable of doing real deep bass better.

The renewed interest in the AR3A bookshelf speaker with a pair going for $1000 plus is an example of a speaker that I wouldn't call open or airy but it does deeper bass well and it has a sound that some may call linear because the bass, mid and treble blend well for a smooth sound without anything jumping out. You could also call the boring or un-involving.

There's a compromise in lots of speakers old and new and some companies pulled it off better than others. The Infinity Qb bookshelf speaker comes to mind from around 1978 that compromised the deeper bass while retaining a good bass presence that sounds clean and fast, the mids are open and clean and the highs come through with detail without harshness.

On another topic, but one that is directly related to how your speakers sound, if your Marantz and RCA still have all their original components they probably aren't doing what they could do.
In the Marantz at least the power supply caps would be suspect and in the tube RCA it would be power supply caps, the rectifier and related cap in the output tube bias supply if there is one, output tube coupling caps and the tubes themselves.

So basically you want to have the amp provide the punch and available power it was meant to deliver and without the distortions due to parts that have passed their useful lifetime. In this case we are talking about electrolytic caps and output tube coupling caps ARE a candidate to change even if they are film and foil because if they fail your going to lose output tubes.

 

RE: Electro-Voice Regal lll, posted on January 12, 2017 at 10:41:57
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Craig

The Kbapps calc is better than the other ones we started with here for the job at hand. While it also warns about avoiding a less than 3 octave spread, you can just enter the numbers and ignore the warning which comes up by just closing it. The concern for avoiding a less than 3 octave spread in the crossover is due to the effect of rising voice coil inductance in the driver as frequencies rise, which will show itself as a rising driver impedance as the frequencies go higher, with the possibility that the low and high inductors will interact with this and/or each other. While rising voice coil inductance could be a concern with the woofer in the Regal (and there are ways to address this), the mid and tweeter are horn loaded where the rules are different, and the acoustic resistance of the horn will dominate the driver impedance.

So punching in a 3500 Hz high pass for the 8 Ohm T35B, the calc gives the familiar 5.68 uF cap. With the 1000 Hz high pass on the 8 Ohm mid it gives an 18.41 cap, which is not far from the math derived 19.89 uF I came up with, but also note that the calc changes the higher frequency to 1080 Hz and the lower one to 3240 Hz. which explains the different results.

So what to do?

I would start by checking the midrange presence L-pad with your DMM to see that it's appropriate for an 8 Ohm driver, with attention to see if there is a series resistor somewhere there which would justify the rather low cap value in the mid. If there is, then this would explain the mystery, but I would junk the original crossover (and L=pad too if inappropriate) and build a new crossover. I originally suggested a 2nd order crossover because EV later used them (likely mainly for driver protection with the encroaching higher powered transistor amps), but I would go with a 1st order crossover like the originals seeing as you are using a tube amp.

From the previous math: C= 159,155/F (Z) we get C1 as 5.68 uF, and this is where F=3500 Hz and Z= 8 Ohms. For C2 we get 19.89 uF for a 1000 Hz high pass with the 8 Ohm mid.

For the inductors (L is the symbol) we use: L=159.155(Z)/F. This is where L= the inductor value in milliHenrys, Z= driver impedance in Ohms, and F= the crossover frequency. So for the low pass with the 4 Ohm woofer we get 0.63 mH which agrees with the calc. With the 3500 Hz low pass for the 8 Ohm mid we get 0.36 mH which is not far from the 0.39 from the calc result.

If you decide to "roll your own" crossovers use only air core inductor coils. and definitely not iron core ones. The original ones are air cores. Also be sure to orient them at a 90 degree angle to each other like the originals, but don't crowd them like the originals, as you'll likely just mount them on a wood board and you will have plenty of room.

Wth a first order crossover you have the option of configuring the drivers as a parallel crossover )like the diagram in the calc), or a series crossover, as the parts values will be the same. See Rod Elliot's excellent study of the parallel vs. series crossovers on his website, and I would go series.

Note that the 159 constant has a comma following in the C version, but a decimal following in the L version.The wrong parts could cost a lot of money.

Keep us posted on the project either way you decide to go

Paul

 

RE: Electro-Voice Regal lll, posted on January 12, 2017 at 16:45:07
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
DaveV,

The Marantz was purchased second hand and I wouldn't doubt it needs work. The RCA was professionally restored about a year ago. I pulled the tube pre/amp/tuner out of an old Magnavox console and have wanted to box it up like a receiver; another project. I'd like to learn how to work on these my self.

Do you know where I can get the cap holders & terminal block like Crites uses?

 

RE: Electro-Voice Regal lll, posted on January 12, 2017 at 17:07:15
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Paul,

This is mostly over my head so pardon my question and my simple way to express it. My understanding is the T35B tweeter is 16 ohms. That's what is printed on the horn. The mid is 8 ohms(?) and the woofer is 4 ohms. Using the calc with 1000Hz, 3500Hz, 16ohm, 8ohm, 4ohm. The C1 tweeter cap is 2.84 and matches what is in the crossover. The C2 mid cap is 18.4 and doesn't match the 5.7uF in the crossover.

It's to bad we can't input the 1000Hz, 3500Hz, 16ohm, 2.84uF & 5.7uF and have it calc the other values.

Do you know where I can get the cap holders & terminal block like Crites use in the Klipsch crossovers?

Craig

 

RE: Electro-Voice Regal lll, posted on January 12, 2017 at 18:51:31
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Craig,

What he uses for the cap holder is really a cable tie with a mount. Some of those mounts are self adhesive and that's ok BUT you want ones with a hole in the center too so you can screw them down to make sure they stay down.
See the link below for great pics of them so you can see what they really are. They sell them too.

Took me a while to find those suckers because I haven't ordered them in years and back in my day everybody knew them as tie wraps.

The connector is a common barrier strip and Mouser Electronics is one likely source. And there's Allied Electronics and tubesandmore.

I checked and Mouser has the ties too but I had to search for "cable tie locking" to come up with the right ones.
They have the mounts too as "cable tie mounts" but I hate their website sometimes and this is one of those times because it's so hard to keep scrolling to find what you want and the way they show them is confusing.

 

RE: Electro-Voice Regal lll, posted on January 12, 2017 at 19:36:20
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Craig

The measurements you posted here on 1/12 listed the T35B you tested at 7.8 Ohms. If the driver actually was a 16 Ohm unit it should measure about 11 to 12 Ohms with a DMM. The diaphragm in that T35B has apparently been replaced with an 8 Ohm one at some point. The replacement diaphrams for the T35/T350 have gone through a spotted history. There were some off-shore copies around with dubious quality. EV sold the original tooling to make them to Great Plains in Oklahoma some time ago, but last I heard they had trouble sourcing the phenolic base the voice coil is wound on, and they were not offering them until they could solve that.. Bob Crites had been offering some 16 Ohm ones he claimed were original old-stock EV, but you need to send the driver to him for a replacement. This begs the question of whether your other T35B also has an 8 Ohm diaphragm. You figure the crossover based on what's actually in the driver, so the crossover specs I supplied for a 4 Om woofer, 8 Ohm mid, and 8 Ohm tweeter should be valid. The power of 1st order crossover design is now in your hands, and you probably have a calculator on your cell phone that can do the arithmetic. Forget the online calculators for this.

You'd have to contact Bob Crites about the cap holders ( a hot glue gun is used by many ; ) and the terminals. You'd have to ask him if he'll do a T35B and what it'll cost. I'd just keep the 8 Ohm ones if they both match.

Paul

 

RE: Electro-Voice Regal lll, posted on January 12, 2017 at 21:43:37
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Paul.

I was searching the Internet trying to find the EV's my friend had with the rather uncommon looking EV midrange horn.
It turned out to be the EV Four but I can't find any EV data on that one.

I did find an E-Bay sale for MR-10 horn mids that look like the ones Craig has and the sellers DCR reading also fall into the 8 ohm range like Craigs reading did.

Just thought you'd like to see these because you were wondering what the midrange horn was.


http://www.ebay.com/itm/Pair-Electrovoice-EV-MR-10-Midrange-Horn-Speakers-/122235831559?hash=item1c75d2c507%3Ag%3AtAIAAOSwcLxYMneN&nma=true&si=%252B%252FQDIrHPr2tU85kgL0c%252FVn2VX9c%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

I think the sellers wording id misleading using "driver". Maybe what they wanted to say is that the diaphragm is the same as a T35 8 ohm because I found a pic of an opened MR-10 an it could be.

Here's another one with the MR-10 and CR-10 Xover.
http://www.canuckaudiomart.com/details/174580-electrovoice_mr10_midrange_driver_and_cr10_crossover_network/images/222051/

Also found a reference to The MR-10 and CR-10 being EV kit MF-1.

All these do sound familiar to me.

 

RE: Electro-Voice Regal lll, posted on January 13, 2017 at 11:07:34
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001



Dave

Thanks for shedding some further light on some of the more obscure EV horns. Attached here is a page from my early/mid 70's How to build and Electro-Voice Component Speaker System catalogue. The MF1 horn/ driver is pictured (viewed from the front) along with the Michigan 1000 Hz crossover and the Wolverine CR35 3500 Hz crossover, all of which are 1st order. The budget tweeter is the TW35. All of the drivers in the catalog are 8 Ohms at this point, even the woofers. Note the budget crossovers are 1st order, which was common at this point as the 1st order type has fewer parts. R.H. Small published his AES paper Constant-Voltage Crossover Network Design in 1969-70 which elevated the 1st order series crossover to the top of the food chain, but the need for driver protection persisted in keeping the higher order crossover networks dominant, until the SET craze started here in the 90's with Sound Practices magazine. One of the ebay ads implies that the T35 diaphragm is used in the MF1 horn, and is still available from eBay suppliers, but I dunno how true this is. Note the black paint on the upper end EV stuff and the grey paint on the budget stuff. EV bought the University speaker company at some point, and products which had been superceeded by newer ones got down graded with a grey paint job and the University badge. Some budget stuff was badged Michigan, and the budget Wolverine stuff seemingly started to disappear at around that time.

Note the smiley face sticker I added to the scan, which transforms the copyrighted material into an artistic collage where fair use doctrine applies.

Paul

 

RE: Electro-Voice Regal lll, posted on January 13, 2017 at 11:38:35
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Paul,

The slow death of another company from the "golden years "
of audio.

Back around 1978 I was in the market for speakers and always admired the EV line BUT they no longer had the good old drivers.
I ended up with the new versions. An SP15 something with a hidden 1 ohm resistor behind one of the basket ribs, 1823M mids that had replaced the T25A, metal 8HD horns, and the T35 tweeters that appeared to be the same except that they were 8 ohm. And I bought all the new xovers to go with the drivers.

I had them all mounted in proper size if not a bit larger cabinets using the EV quide for woofer port.
I did everything I could to make that combo sound good but I ended up selling the drivers and xovers off and buying a pair of EV Regency's with the 15W, T25A, the original fiberglass 8HD horns and T350 tweeters. They were 16 ohm all the way and the xovers had all original caps. What a big difference for the better.

Maybe someday I'll come into some disposable money and go after a pair of the earlier Patricians, the ones without that 30" woofer.

 

RE: Electro-Voice Regal lll, posted on January 13, 2017 at 19:18:21
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Dave

As for stories of golden age companies, EV was acquired by Telex some time ago. If you want to see a dumb stare just ask a young person what a Telex was. If you don't remember, the Telex was an electric typewriter which was hooked up to a phone line, and you composed a type written message on one end, and it would be received and typed at the other end by another Telex machine. Kind of like email the hard way, and it's interesting that the Telex company still exists, and it now owns an audio equipment company like EV. Apparently Telex has invested wisely in other tech companies.

I've never heard an EV Regency, and it's interesting that you would prefer them to the EV SP15, 1823M, T35 rig you built. You must have had the same catalog I had as seen above. I would put my money on the EV rig however, and I would have hammered at them till they worked, but that's just me.. The weak point in that combination was the 8HD mid horn which is shown in the catalog pic mounted correctly with the long dimension in the vertical position. Many people (like me) mounted them with the long dimension horizontal because they fit better into what you had, and they are very beamy that way. If you get them out of the front of the baffle mounting as shown in the catalog, you can then get them in phase with the woofer by moving them physically until they're dialed in, and then do the same with the T35. Well that's a different animal of course, and I'd expect such a rig could run against an Altec 19, and that's really saying something.

Paul

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 10:43:50
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013



Here is my drawing of the wire connections. I don't know how to draw a proper schematic. Maybe someone could convert this into a proper schematic for posterity since one doesn't seem to exist for the Regal III.

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 11:13:52
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013



Here is the actual crossover.

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 11:19:34
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013



Inside the pot.

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 12:05:43
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Actually Craig, that was a good job because it's all understandable even thought it's not a conventional schematic.

But because you didn't enter any color code that may be on the mid and tweeter, like the red and black on the woofer,it doesn't show if all the drivers are wired in phase or not.

It seems pretty straight forward to me otherwise until we get to the 5.7 cap for the mid and why your reading on a tweeter is lower than would be expected for a 16 ohm unit.
Did you measure the other one like Paul Suggested? Measure the other mid driver too.

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 12:21:21
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
The mid & tweeter do not have color codes. I have not measured anything in the other speaker. Because I am a newbie I was going to do one speaker at a time so I always had one as a reference.

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 12:44:46
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Measured the other speaker:

tweeter = 8.4 ohms
mid = 7.4 ohms
woofer = 2.4 ohms

Also measured caps:

2.84 cap = 4.94 and kept dropping
5.7 cap = 8.63 and kept dropping

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 13:01:33
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Does the differant measurements mean I need new voice coils?

Mid 1 = 4.8
Mid 2 = 7.4
Tweeter 1 = 7.3
Tweeter 2 = 8.4

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 13:46:59
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
2.84 settled in around 4.3 4.5
5.7 seletted in around 7.7-7.9

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 14:37:37
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Craig,

I was going to say that all you need to do is pull one wire off of the mid and tweeter to take a DC ohms reading so you can't get the two connections mixed up. But I see you already got the readings.

The cap readings are in UF or microfarads on your meter and not DC ohms?

I'm not sure if I would use "settled in" readings or not. For a film and foil cap I use the number that comes up in the first 10 seconds. For an electrolytic it's not really the same when using a digital meter so I also use an old 1950's cap checker with an eye tube like the tuning eye tube on old console radios to zero in on the value.

Ideally the drivers would read pretty much the same but in the real world they really don't. They aren't that far off and when dealing with that low of a resistance other things come into play like how well the meter probe makes a clean resistance free connection to what your measuring so to me it's a judgement call.

If the voice coil got hot from being over driven, some windings could short together but that's just guessing and I'd think if that happened, the driver would be cooked and not working rather than being an ohm or two different. But that is just my an opinion.

If I were you I'd just replace the 2.84 and the 5.7 and not try to second guess the design or if the drivers are bad or if the diaphragms in the tweeters were replaced. Again, just my opinion.

Because the 3 ohm 12W woofer and that mid weren't items that were used in their previous and larger speakers with a 12db per octave xover at their more conventional xover points, I can only assume that they did what they had to do to get the desired result.

The use of 4,8 and 16 ohm drivers like in the Esquires is already pretty unconventional without any added mysteries or "tricks" they used.

 

RE: Electro-Voice Regal lll, posted on January 15, 2017 at 15:04:06
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Craig

Measuring low resistances becomes tricky, as you can check by shorting the test leads of your DMM together and see what reading you get. When set with a range low enough to read typical speaker impedances even the resistance of the test leads becomes a factor, as well as how clean the speaker terminals are, and how good a connection you have on them. So we're talking Ohms in the above test? It seemed like you switched uF for Ohms in one of the other posts. With the readings you have here it seems that the T35B's (which you previously stated were labeled as 16 Ohms) have both had their diaphragms replaced with 8 Ohm ones. The mids also appear to be 8 Ohm units. It looks like the original crossover is not appropriate anymore, and certainly the tweeter L=pad/treble control will not be either if they are 16 Ohm units, as turning it up or down will actually change the crossover frequency as well as changing the volume of the treble. The terminals on the mid and tweeter should be marked, look for the color of the washers at the base like on the woofer (though they may be faded by now). Some EV drivers are marked T1 (+) and T2 (-), some had push open spring loaded terminals with red or black plastic caps.

A correctly designed crossover and appropriate L-pads will certainly improve the sound of these speakers.

Paul

 

RE: Electro-Voice Regal lll, posted on January 16, 2017 at 13:52:07
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Caps are in uF on meter. Not ohms. Edit/correction made in original post.

 

RE: Electro-Voice Regal lll, posted on January 16, 2017 at 14:42:12
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
I made a mistake and put uF instead of ohms. Made a correction to the original post. Shorting the test leads of the DMM gave me a reading of 0.2 about a second later it read 0.1 and then a second later it read 0.0 I did clean the contacts with sand paper to get a good contact. The washers were painted over. I scraped the paint and there is a red and black washer. In my diagram the red is on the left side of both horns. So mid horn has green wire to red contact and black wire to black contact. Tweeter has yellow wire to red contact and black wires to black contact.

I am confused to say the least. EV literature says the T35, T35B & T350 tweeters are 16 ohms.

http://www.cieri.net/Documenti/Istruzioni/Electrovoice%20-%20Tweeter%20T35,%20T35B,%20T350.pdf

But replacement diaphragms are 8 ohms.

http://www.simplyspeakers.com/ev-replacement-speaker-diaphragm-89486a.html

 

RE: Electro-Voice Regal lll, posted on January 16, 2017 at 14:48:55
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
Craig,

With the red and black markings now known it looks to me like the drivers are wired in electrical phase with each other. All reds go to plus or red input and all blacks go to the minus or black input.

The Tweeters started out as 16 ohm units as did most of the other EV drivers but over the years the tweeters were available in 8 or 16 ohm and they should be marked accordingly.

I know my two 16 ohm T35's measure around 12-13 ohms so your reading of 7-8 ohms is really a mystery if the diaphragms are original.

You have two opinions so far. Mine that was just replace the 2.84 and 5.7 and see what that does and Paul's that said he would replace the pots with pots that were meant to be used with 8 ohm drivers and I take it that would also mean replacing the 2.84 caps with another 5.7 or 5.8 for what looks like the closer to 8 ohm tweeters.

I see where he's coming from about the existing tweeter pots affecting the xover point depending on where they are set but in my view that's going to happen with different pots too, but to a lesser degree because in theory you have a mismatch to start with.

We are both going on the readings you supplied from the drivers and because both sets seem to be not all that far off, it would seem logical that those are the real readings.

To me, the only truly fixed xover is an electronic one like in a bi-amp setup where the xover point won't change with different signal levels or a different driver impedance.

We were both confused about the 5.7 cap for the mids and those would remain in either case unless you changed out the mid drivers and at that point, at least in my opinion, you might as well get different speakers because now you'd also probably have to change the xover parts for the woofer too.

I'm thinking that you like the RCA sound better because it's not as bass or lower mid heavy. In listening to my Esquires I find that somewhat annoying and it does sound like they aren't very open but they are what they are.

 

RE: Electro-Voice Regal lll, posted on January 16, 2017 at 14:53:47
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Did you notice that the two caps are connected (in series?). Is that usual?

 

RE: Electro-Voice Regal lll, posted on January 16, 2017 at 16:33:55
DaveV
Audiophile

Posts: 289
Location: SC
Joined: December 26, 2009
First, I forgot to mention that 8 and 16 ohm diaphragms were once available from EV`for the T35 but as far as I can tell they discontinued the 16 ohm more than 20 years ago.

EV was bought out and so went the 8 ohm diaphragms too. But if Great Plains Audio did get the jig to make them, they are the best bet but they would be 8 ohm as far as I know. You could call to see if they do offer the 16 ohm and when they might have some. Forget e-mail. They aren't good at answering them.

Any new T35 diaphragms you see on line are cheap generics unless they say NOS or new old stock.

The 16 ohm T35 and T35B are a fairly common item on E-bay but unless your lucky I wouldn't expect to see a pair for under $100 and then it's risky unless the seller gives a DCR reading for each or you may end up with another headache.

The T35B is just a less efficient version of the T35 with a smaller magnet and it was used with other drivers that were less efficient than some of their other drivers.
No sense in cutting back a T35 like crazy with a pot when the T35B was already less efficient.

The T350 used the same diaphragm but it was more efficient than the T35 with a bigger yet magnet and it has a larger horn. Some consider it to be one of the best vintage tweeters even if it doesn't go much beyond 15KHZ like modern tweeters. What it does do it does well.

The caps aren't really in series. Yes, one end of each is tied together but that's the plus input to each and not a series connection. A real series connection would the two caps wired like they are BUT without the third connection that feeds both caps.If they were in series the resulting value would be about 1.90uf. And since you need a cap for the mid and a cap for the tweeter that would leave you with only one cap.

I do see that the 2.84 has one wire on one end and two wires on the other end. The two wires are tied together and because the cap is marked 2.84 that can only mean that there are two 1.42 caps in that bundle in parallel that adds the two values. The other end would be a common connection for the two caps.

 

RE: Electro-Voice Regal lll, posted on January 16, 2017 at 20:45:52
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001
Craig

This has been an interesting mystery as many pertinent details have been difficult to arrive at. I have: T35's here (in both 8 and 16 Ohm versions); T35B's (only 8 Ohm versions here); and T350's (only 8 Ohms versions here). The diaphragm is nominally inter-changeable between them (though there have been detail changes and refinements though the years). It's what you have in the driver now that counts and not what a spec sheet says, or even what it says on the driver. Back in the day The Grateful Dead had a sound system with an array of multiple T350's which got blown from too much power, so this is not an unusual problem with these drivers being over driven. From your DMM measurements you have presently: a 4 Ohm woofer; an 8 Ohm mid horn driver; and an 8 Ohm tweeter. Tomorrow I'll post a schematic for a new crossover (based on the data you have supplied) and hopefully this will help. I've never heard the Regals or any of the variants, but Dave has and he can give you his opinion as to how they would stack up against similar vintage speakers. IMHO If they're EV's they are worth fixing, but I grew up listening to EV horns. My main rig now are 6 ft. tall 300 lb. EV monster horns, so I'm coming from a hard core perspective.

Paul

 

RE: Electro-Voice Regal lll, posted on January 17, 2017 at 09:23:24
Paul Eizik
Audiophile

Posts: 1869
Joined: September 15, 2001



Craig

From the info you have provided I would go with a new crossover following this schematic. Note that the part values are just ideals, so use the next nearest standard value available. Also note the L-pad which is pictured with the shaft pointing away from you, and with the solder lugs pointing down. The L-Pads would be inserted at the X in the schematic, and I left this separate from the schematic for simplicity.

Paul

 

RE: Electro-Voice Regal lll, posted on January 19, 2017 at 17:09:43
CraigI
Audiophile

Posts: 38
Location: Minnesota
Joined: February 26, 2013
Paul,
Thanks for the schematic! Just curious, what did you use for the low and high crossover frequencies?

I was hoping I could keep the speakers original in design but update it with new caps. That's not turning out to be the case. I checked with Bob Crites. He says he has NOS 16 ohm T35 diaphragms but wants $100 each installed. Through my research I have come to believe the MR-10 horns were 16 ohms in the Regal III. That would make the 5.7uF mid cap a little closer to what is expected. Since I'm not willing to drop $200-$400 on new 16 ohm diaphragms and since mine measure 8 ohms and new 8 ohm ones are readily available it makes sense to change the crossover & L-Pads to work with what I have.

What is the reason for the 16 ohm and why did 8 ohm become common? The following are the parts I'm considering. The L-Pads have me a little confused. There are different wattages & mono vs stereo.

https://www.parts-express.com/dayton-audio-dmpc-56-56uf-250v-polypropylene-capacitor--027-425#!

https://www.parts-express.com/dayton-audio-dmpc-20-20uf-250v-polypropylene-capacitor--027-436

https://www.parts-express.com/jantzen-audio-037mh-18-awg-air-core-inductor-crossover-coil--255-222

https://www.parts-express.com/jantzen-audio-065mh-18-awg-air-core-inductor-crossover-coil--255-236

https://www.parts-express.com/speaker-l-pad-attenuator-15w-mono-1-shaft-8-ohm--260-250

Craig

 

Page processed in 0.038 seconds.