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Belated THANKS to Uncle Stu, R.I.P.

71.50.25.128

Posted on December 29, 2016 at 10:13:09
drlowmu
Manufacturer

Posts: 9706
Location: East of Kansas City
Joined: January 10, 2005






Hello High Efficiency Audio Fans :

I did this mod, "my way", a couple days ago, and it helped my VOTT A7-800 set up. Uncle Stu posted this a year or so ago, and he passed away, but he needs to be given credit for unselfishly sharing this.

Can you think out of the box? Are you willing to TRY new things?

The fourth and top most box I added was very audible. Got a moving and storage business near you? It will cost under $20 for four new boxes to do your whole system.

My boxes were about 16 by 17 by 21 1/2 inches. So, I have a minimum of 16 inches baffle width at 45 degrees, and an 86 inch height. Rather than one large baffle, my pictured implementation allows one to position, box-by-box, by ear, on complex music, to a 1/16th of an inch, in each range the box influences.

If you have a decently-resolving horn system, this will improve it.

I can now better understand the words, diction improved, and other things as well. The Poinsettias are a big improvement also, adjust pot position near field, by ear, on complex music. A must-do.

The easy "click on it" - URL below, is Uncle Stu's original post. Please scroll down and read the entire Post, and see comments , photos, from Uncle Stu, and user's photographed implementations.

Consider this my Christmas present, a few days late.

Have fun, I certainly am !!

Jeff Medwin

 

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Hmmm..., posted on December 29, 2016 at 11:01:42
Lee M
Audiophile

Posts: 457
Location: Wisconsin
Joined: March 24, 2001
Contributor
  Since:
July 11, 2014
Are you married? ;-)

 

RE: Belated THANKS to Uncle Stu, R.I.P., posted on December 29, 2016 at 13:32:56
Coner
Audiophile

Posts: 1882
Location: S.W. Washington state, USA
Joined: November 17, 2001
Are you using OEM porting?. I thought that the first tweak is to
reduce the port size for optimum bass, but maybe you did behind the
grille. I forgot, but if anyone can tell me what the size should be
for 416/515?.

 

:-) /n, posted on December 29, 2016 at 14:24:12
Ivan303
Audiophile

Posts: 35567
Location: Cadiere d'azur FRANCE - San Francisco
Joined: February 26, 2001
n



 

RE: Hmmm..., posted on December 29, 2016 at 19:01:24
kitch29
Audiophile

Posts: 747
Joined: May 1, 2015
Why. The ads here don't do it for you?





 

RE: Hmmm..., posted on December 29, 2016 at 19:40:55
Inmate51
Audiophile

Posts: 9195
Joined: July 6, 2005
Hahahahahahaha!

My guess is "no". I'm pretty sure that neither my wife nor yours would tolerate such a scene in a family part of the house.

:)

 

RE: Hmmm..., posted on December 29, 2016 at 20:34:37
Rod M
Web Geek

Posts: 10828
Location: So. California
Joined: March 1, 1999
Contributor
  Since:
March 1, 1999
That thought did strike me, but then I wondered about the speaker wire tweak. Is it a diffuser? But why only on one side?


-Rod

 

RE: Belated THANKS to Uncle Stu, R.I.P., posted on December 30, 2016 at 15:08:47
drlowmu
Manufacturer

Posts: 9706
Location: East of Kansas City
Joined: January 10, 2005



The thing I want to avoid is to change the box from stock. Everyone changes them, butchers a stock box, but not me. I added no braces inside either. I did mass-load the boxes, by ear, and stopped around 290 pounds per side. That easily improved the stock box, was very inexpensive, and guess what, it is totally reversible back to stock.

If you change the port, you determine that port size by ear, AFTER all else is set-up, and I would do it last. When you change the port size, you also change other parameters me thinks, perhaps efficiency, etc.

So, with the help of Dennis Fraker, who used to typically put eight A7-800s in each of the movie theaters he owned, or for theaters he bought and renovated for resale, I did my changes in a different pecking-order than what others typically do. ie:

a) I sent my 802s off to GPA for re-magnetizing and new stock diaphragms.

b) I carefully cleaned the surrounds on my 515Bs.

c) I extensively rewired the speaker internally, from the crossover to the drivers. I use Mil Spec wire, ran doubled-up 12 AWG ( equals 9 AWG ) to each woofer polarity, at Bob Fulton lengths ( 57 1/8th inches ). I ran 14 AWG Mil Spec from the crossover to the 802, not doubled up, however, 57 1/8th inches in length.

d) I rebuilt the 800 HZ / 12 dB crossover with much better parts, better Mil Spec wiring, and changed the adjustment pot from 20 Ohms to a 6 Ohm Ohmite 25 Watter, so I can get fine driver adjustmemts easier. " Human engineering " versus 20 Ohms . I used DIY golf balls to isolate the external crossover with mass loading. And my cap choice is to die for.

e) On the ALTEC 515B and 802D drivers, I eliminated the stock ALTEC " press to fit " terminals, stock, and Wonder soldered the Mil Spec wire carefully, properly, directly to the terminals that feed the voice coil wires. A big permanent improvement.

f) I made up DIY speaker cables, Fulton length multiples, Mil Spec and used three 12 AWG Mil Spec wires in parallel, lightly twisted, for each polarity.

g) I decided that the NOS 45 tubes I had been using, were not linear in the mid range, had a broad shallow depression, and just one listen to a JJ 2A3-40, in my 45 amp, convinced me to build a new DC amp using JJ 2A3-40s for the VOTTS, done 12-1-16, still breaking-in and needing final bypass work on all the film caps. Excellent change BTW !!

Comer, everything I did above, I would do again and suggest to others in the order shown, and the "port size" will be something I may be ready to visit dead last, late 2017, but only after I get all the most important things done in " my " pecking order, which I have thought-out carefully and conservatively. When the speakers are "flying" I will attend to port size.

I am simply conservatively taking my time, spent all of 2016 on this, expect to keep these speakers, need to just optimize them as I see fit.

Have fun, I am !

Jeff Medwin

 

RE: Hmmm..., posted on December 30, 2016 at 15:25:12
drlowmu
Manufacturer

Posts: 9706
Location: East of Kansas City
Joined: January 10, 2005
Hi,

I am not sure what you mean about a wire tweak.

If by diffuser, you are referring to the four stacked and staggered boxes, you have an 'optical seclusion', they are centered between the two VOTTS equal distance - wise, and the front corner points at two 45 degree angles to the listener's center seat.

All you need to do is read the entire thread carefully from the URL I provided, starting with Uncle Stu's original post.

Tell the guys I am single. Married to 10,000 plus LPs.

Jeff Medwin

 

RE: Belated THANKS to Uncle Stu, R.I.P., posted on December 30, 2016 at 16:20:40
Coner
Audiophile

Posts: 1882
Location: S.W. Washington state, USA
Joined: November 17, 2001
Thanks Jeff, very thorough reply!. You definitely know what you're doing,
and yes, I'll experiment at porting (using RTA) with a panel behind the OEM panel, so it will look the same, and won't be cutting on the OEM panels.

 

RE: Belated THANKS to Uncle Stu, R.I.P., posted on December 30, 2016 at 16:30:08
drlowmu
Manufacturer

Posts: 9706
Location: East of Kansas City
Joined: January 10, 2005
Thats a good idea, from behind, and removeable. Usually its around 100 inches, but, as I said, its dead last on my list. The amp is where its at. Every little change is heard through the ALTEC drivers.

BTW, DynamiCap E 4.0s are fabulous sounding on the speaker crossover, see em with modded leads?

( 14 and 12 AWG m22759/11 )


Jeff

 

RE: Hmmm..., posted on December 30, 2016 at 18:13:49
elblanco
Audiophile

Posts: 2324
Joined: August 20, 2004
the wire draped in front of the right speaker is lo-fi. draping must be done equally.

BTW, the second box is out of alignment.

 

Two better photos to explain it......, posted on December 31, 2016 at 13:15:51
drlowmu
Manufacturer

Posts: 9706
Location: East of Kansas City
Joined: January 10, 2005






Shows newly-added baffles' interaction / relationship / positioning between the two VOTTs better. Position it by ear, centered between speakers.

Let me know how your listening turns out please !! Email address is above. Do not forget the plants' positioning also.

Jeff

 

I would do things a bit different..., posted on January 4, 2017 at 06:18:34
noway
Audiophile

Posts: 338
Location: Canada
Joined: August 28, 2007
...If they were mine: First I would make sure I have a big room and put the speakers symmetrically in the room. Exactly symetrically...so that the distances from back and sides of each speaker to its adjacent walls are identical. I would also remove all those cardboard boxes and bricks and the plants (what if water dripped down!)and everything green, like the wires and that green pillow thing in the upper corner. Of course you would need to make up something to lift those drivers, other than bricks. Maybe some brackets instead. After the speaker position is optimized, put some short riser bases with spikes under them. I would use monoblock amplifiers and keep them on the floor on amp stands, close to the speakers using short speaker cables. Keep the cables behind the speakers not draping over the front like Halloween cobwebs. I would also try to touch up the white VOTT logos on the sides. I would decorate the room normally with wall hangings, bookcases, some soft furniture, a variety of textures,etc. and try to make it look like a relaxing, inviting place to be, after checking out some interior design books. Not saying it would all sound as good as what you have now but at least my marriage would be safe.

 

RE: I would do things a bit different..., posted on January 4, 2017 at 21:54:42
drlowmu
Manufacturer

Posts: 9706
Location: East of Kansas City
Joined: January 10, 2005
IMHO, almost very bit of your advice, except symmetry, fails to make the audio better, only worse !! You have to live with your wife, not I, I am single !! And my room is 14 by 18 feet.

Try a flower pot on TOP, around the middle of your ALTEC, see the original post's photo of that again, and set the exact plant position BY EAR, standing near field, while playing fairly loud and, complex music. The results will astound you.

Then you will discover WHY those flowers are there. Enjoy !!


Jeff Medwin

 

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