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I've been pouring over everything SET lately and have come to some conclusions. I'm looking closely at building a kit from Doc.B, probably the Paramount's. In order to maximize their potential I'm trying to decide on a DIY horn loudspeaker that would be most complimentary. I'm leaning toward a 8" Fostex driver. Please offer some suggestions. I'm currently using a pair of Thiel CS 1.6 in a system used mostly for video. I've decided to continue using the Thiel's for the video side of things and to begin developing an SET based system for music only. Any and all suggestions will be closely looked at. Websites and contact information is greatly appreciated.
Follow Ups:
open baffle, then i made some bk-16's, then made some bibs,,,,powered by some p-mours,,,the bibs , overall were the best sounding,,, if you have the tools, and very modest wood working skills / equipment , you should be able to build them in a few hours,,
the open baffles were nice, seemed really fast ,, but i like the overall presentation of the bibs,, also i played all types of music on them , but the little drivers get a little congested on heavy passages, but hell you sometimes can't help to crank it up a bit,,
but watch out for the low xmax, but
this little driver is really good for the price,,
I can second 8in Fostexes. I use a FE204 (obslete) in Voigt pipe, and helped friend of mine build one with FE206E (improved 204). I built mine from pine, and his is spruce. I have heard many different Vp versions, and those who heard these say they are in an entirely different league than other Vps. My wife threatened me that she will kill me if I change them for different speakers. (She has better hearing than any audio freak I know.)
I based mine on Derek Waltons Voigt pipe. That has silghtly different ratios than the standard Lowther-Voigt design (deeper, and larger port size). He also seconds that if you build a Voigt pipe, build it from wood, and avoid mdf at all costs. I have helped another friend of mine to build one with RS driver, that has a small (around 4ft tall) wallnut cabinet, and it has a fabulous tone, with surprisingly strong and precise midbase. That one is built for listening to rock, and it sounds very gutsy on it.
Be prepared that they are extremely tweakable, easy to build, and tolerate many things, even if you mess things up when building the cabinets. In addition, I do not know how they sound, because with different amps / systems they sound like completely different speakers, much more so than any other speakers. Change just a tiny thing in you setup, and you will hear it.Good luck! DIY speakers are the way to go, and any design you choose will be much "better" than just buying a pair of you-don't know what's inside...
Check out the BIB (Bigger is better) thread over at DIYaudio.comIt will take a while to read through in total - just scan through it to get an idea at first, check out the Zilla' site, then search for any specific info within the thread.
Enjoy your journey
Raymond
Ultra-consumers: Spending money they do not have to buy things they do not need to impress people they do not like.
Running Open Baffle with augmented OB bass is excellent. I have been running a small 6sn7 amp, as in the output tube, 6sl7/6sn7-1.5w maybe..BASH plates running the OB bass driver from 80hz up.. Drivers are B200's & sonics are outstanding.Sometimes I highpass the lil amp, but like it better ran fullrange..& sometimes I run ribbons as super tweeters, but not often, the B200's really don't need it IMO. While your waiting for your horns to be built , you really should try OB, & B200's are something to look at also..no whizzer,, great OB driver.
For a while I had an "augmented fullrange driver" system on the market. Used the Fostex FE206E smoothed by a gentle notch filter (otherwise the lower to mid treble region is too hot) and high-pass-filtered at about 140 Hz. Bottom end provided by a low efficiency woofer in its own sub-enclosure within the cabinet, and powered by a built-in plate amp. Since using a powered woofer section is "cheating", I called it the "Cheetah". The Cheetah has been discontinued because a critical part went out of production, and its replacement drove the price up too high in my opinion.I'm not giving away my notch filter values because I may resurrect the design some day, but I think there's a generally similar notch filter posted somewhere on the single driver website. Don't skimp on the quality of the resistor. In my opinion the FE206E is more lively-sounding than anything else near its price range, so it's worth going to a little extra trouble to use it.
Use a pressure-relief subenclosure for the Fostex, as this smooths out the impedance peak at system resonance. Otherwise your low pass filter won't be very effective. Protecting the Fostex from bass excursions improves the midrange clarity on complex passages.
Add a supertweeter if you want a little bit more air and sparkle on top.
The best-sounding fullrange driver I know of is the field-coil Supravox. But it's also a bit pricey.
Duke
In the above post I mistakenly wrote: "Otherwise your low pass filter won't be very effective."That should have been: "Otherwise your high pass filter won't be very effective."
I built these and they macth very well with a 2a3 amp. Best $130 (Drivers) and ($90) wood I ever spent...once you hear a single driver horn speaker you will understand. They will not play complicated music. Blues, rock, jazz, vocal...
Hi!What box did you build? I'm thinking of a simple, small BR box for my FE166E speakers.
having a bit of trouble with "complicated Music" too? I wonder if
ANY loudspeakers you may have tried with your SET have satisfactorily
reproduced such music? If so, please do share which drivers worked.Don't misunderstand my questions, I am a SET enthusiast myself and indeed have NOT yet tried the FE166. I have just seen so many
otherwise well designed SETs fall on their faces (mine don't) when
rock, and other music is played due to LF transients introducing
instability/IMD by virtue of feedback through an inadequately
filtered/regulated power supply chain. I have seen people blame
various high-eff drivers for this as a result of a misdiagnosis of
the malady.Any thoughts?
-T.M.
For what it's worth, I have built and listened to two different FE166 systems. One used ported 1-cubic-foot boxes, like the Fostex recommended ones but a bit larger and tuned a bit lower to allow for the 2 or 3 ohms output impedance of the SET amps. The other used small sealed boxes sitting on top of cheap powered "sub"woofers, making an effective 120Hz crossover. Both systems were driven fullrange; the subs took signal from the speaker cables.Reducing the excursion in this way cleaned up a very large amount of the loud/complex/bass-heavy music problems. The high frequency characteristics remained the same, but were no longer sensitive to bass loudness. My purely subjective impression was that an FE-166 in a ported box is suitable for amps of 2 watts or less; beyond that point the speaker distortion will dominate the amp overload unless you are selective about the music (no rock, no orchestra, no organs!) With the sealed box, you'd probably be OK up to 10-15 watts.
All listening was done with parafeed SET amps using current-source loaded drivers, which provides a great deal of power supply isolation. I don't have a suitable experience base to comment on IM and modulation effects due to power supply limitations in series feed, but I can well believe they could be significant.
Eventally, I sold the ported boxes at cost to a non-audiophile friend who cranks them LOUD and loves them. So does his wife. I told them, repeatedly, about the excursion-related distortion problems but it simply does not bother them.
Hi Paul,I've been pondering your very informative post about ported ( BR ) boxes versus sealed boxes with subwoofers, reduced distortion in the sealed box, etc.
I'm wondering--did you ever try the ported boxes with a high pass filter before a SET driving them, and separately amped subwoofers? If so, did you have the same excursion/distortion problems you mentioned?
It doesn't look like you did, and I'm hoping you didn't (smile), because that might be a way I could have my cake and eat it too--a br system used standalone for small amps and low volumes, and with a highpass and subwoofers for high volumes.
Basically there are two choices:1) A highpass tuned at or near the port tuning. This protects from excessive excursions below the port tuning. In my experiments, I tuned the box to 49Hz, so the main benefit of such a filter would be to reduce inputs below, say, 35Hz. Significant for certain orchestral and organ music, but probably not much effect or rock, jazz, etc.
2) A highpass much higher - say, at 100Hz - so it effectively makes a crossover to a sub. Here the effect would be similar to the sealed box. The ported enclosure cutoff will mess up the phase relation of the crossover if the cutoff frequency is too close to the box frequency. This is one of two main integration problem with subs in general. (The other is that even if the crossover is clean and dual subs are located close to the mains, the room acoustics are a mess in the deep bass!)
Hey Paul,Thanks for your review, I found it very helpful.
I'm considering the sealed system you mention, having seen a similar (or perhaps identical) system recommended on the Bottlehead site (you may be familiar with it*) for the S.E.X. amp.
I see you ran the FE166 full range despite having the subwoofer, and the Bottlehead site recommends the same thing, saying that running it full range makes for a better blend with the sub.
Could you expound on that a bit? It seems that running the FE166 with a highpass filter (at say 120Hz) would unburden the SET quite a bit, reduce IM, etc. So I'm tempted. But do you find that with the bass cut out of the fullrange there is no way to blend the sub and the fullrange well, and that this problem overshadows any gain from unburdening the SET amp?
I'm just curious what your experiences were.
Thanks for your contributions,
George
Haha! Yes, I was referring to the "S.E.X.y Speaker" design which we've posted for anyone to use. We came up with that after we were unhappy with the ported box.I wanted to make this as easy as possible, thinking of customers who might have bought our cheapest amp, so I kept it simple. But I do believe an additional crossover would be an improvement. Here's the deal:
1) The original is a sealed box with fullrange drive; this makes a second order (12dB/octave) rolloff and the small box gives a Q in the range of 0.5 (Linkwitz/Riley) to 0.7 (Butterworth) depending on the amp's damping factor. This matches well with a second order (12dB/octave) powered "sub"woofer, such as the less expensive models from Parts Express. (I put "sub" in quotes because I am using them as woofers, and the smaller/cheaper ones don't go down to 20Hz... :^)
2) With an additional, external line level crossover, 12dB/octave, this same system would produce a fourth order (24dB/octave) acoustic crossover, which I expect to have significant further benefits. I've not been able to prototype this yet, but recent developments make it more practical and I expect to have something to listen to in the next few months. This becomes complicated because of the variety of subwoofers. Some are 12dB/octave and would need an external 12dB/octave filter. Some are actually 24dB/octave and need no additional filter. And some have a fixed 12dB filter (usualy in the 100Hz-200Hz range) plus another, variable 12dB filter. These are sold as "24dB/octave" but it's not easy to determine exactly how best to make them act like 24dB/octave L-R filters at a particular frequency. In some cases it's nearly impossible to determine what the device actually does in this respect. And with a 120Hz crossover, you really need to get it right - just playing with the controls is not likely to get you an optimum.
That's not to even address the idea of a separate sub crossover, used with a "normal" amp. Which I'd love to do - a handy way to use that solid-state boat anchor you gave up on when you discovered SET magic!
Just as I expected--you were gracefully referring to your S.E.X.y speaker. Nice.You're comments are just what I needed. As I chart my course into the SET dimension, I'm balancing SET-nurturing simplicity with my lust to tweak. I find your speaker idea ideal (grin), for it makes some dimensions easy and elegant (e.g. sealed box), while the active crossover allows me to play in what I hope are some relatively benign ways.
For example, my preamp needs coupling caps anyway, so all I have to do is undersize them correctly and, presto!, high pass filter for the SET. And if the sub needs additional slope to its low pass filter, I'm thinking I can add an inductor at it's input without worrying about messing up the mids and highs. (Comments invited.)
Do you think some experimentation with inductor values, checked with a Radio Shack SPL meter and some test tones would allow me to tune the crossover transition reasonably flat?
I'm also pondering the idea of putting a 4'x4' mask around the Fostex box, to eliminate the need for a BSC circuit (no WAF at the moment), but I could just bite the bullet and build the circuit.
Regardless, it seems to me your speaker idea leverages some nice synergies, and is easy and cheap too boot. (Did I mention that I like cheap?) It appears to me that the Fostex FE167E/FE166E have just about the flatest mid/high response of any Fostex speaker, and the sub/sealed-box design unburdens the Fostex, yields ample bass, and sidesteps all the cabinet building/tuning issues (though for some that pursuit is its own reward). Sweet.
than FE166 for BR. Both have better Q-parameters for such usage.
Granted, the FX120 is somewhat max SPL/dynamics limited with it's
modest 89 dB sensitivity and 10W rating, but look at it's response
curve, x-max, etc. Allegedly a sweet little driver. Im about 90%
finished constructing a pair in BR enclosues (will use padded-down
T-90 supertweets) and will give full report when I get a few days
use on them.About the FE167: well, the Q-parameters look much better than
the 166's for BR usage, but still the smallish x-max which,
as I agree with Paul, is surely a major limiting factor in high
SPL play quality. I do notice, however Bob Brines seems be pretty
happy with the FE167 in small BR, and indeed offers such a unit
for sale. I think Paul is right on the money about the FE166 requiring
excursion limiting which a horn or small sealed enclosure affords
to play clean at higher levels, thats for certain. Personally,
I'm not a big fan of whizzer cones, though I understand that
many seem to like the FE166/167. I have a pair of unused FE206's
new in box which I simply don't like, and will probably end up
selling for a pittance --Just care for them. Was tempted to cut
off the whizzers to see if the glare would abate --but frankly lost
interest.
Personally, I would be waiting a couple of days for the release of the Hemp Acoustics drivers... there should be a FR6.5 released. From what I have learned thus far, these should provide a significant alternative (in the way they present music) to Fostex, if a little a more expensive (I am guessing).Importantly for me, the development and manufacturing of the Hemp Acoustics drivers appears not to EXPLOIT that which is euphemistically termed "globalisim".
Not associated w/ Hemp Acoustics in any way.
Kind regards
Raymond
Ultra-consumers: Spending money they do not have to buy things they do not need to impress people they do not like.
I love the Asylum, you can't get away with anything - too many smart people are paying attention!Actually, I think the ported box did use an FE-167E. I agree it's better suited, even with some source impedance (SET damping factor). The cones and voice coil appear to be the same, and they sound extremely similar to me - so the main differences are the Q and efficiency.
Hey Tom,Thanks for the info! I think you know this, but just to clarify, Paul and I were talking about sealed boxes to limit low frequency excursion, so your BR comments wouldn't apply there.
I certainly agree the FX120 has a gorgeous frequency response, perhaps the best I've seen, just a little dip at 20K, nice with your tweeter. Unfortunately the 89dB sensitivity is a deal breaker for me--what are you going to use to drive yours?
I'm no fan of whizzer cones either, and was torn over the FF225K, which has high efficiency, smooth response, and a nice rolloff at 11K that just begs for a tweeter. But I finally decided against it because of the upward tilt to its response.
So I'm leaning towards the FE166E as the best mid-through-high spectral balance in a 94dB (or better) efficient speaker, whizzer be d***ed. And it'll be in a sealed box and used with a sub, so low end is not an issue. Thanks for your insights--and any others.
Yes, the FX120 is obviously dynamics limited unit. I intend to
use mine almost as studio monitors: closer listening distance in
smallish room at modest SPL. I'm hoping they will be nice and
well rounded sonically with good imaging in the little BR boxes.
I'm not looking for/expecting anything under 70hZ or 100dBWm
performance from them. They will be used mostly with a 4 watt
P-P triode conn EL84 amp, and an 8 Watt triode conn KT88 SET.I am also presently in the process of assembling a pair of
Madisound BK-16 horns with the FF165K. I'm hoping for a more
punchy and dynamic presentation with these. naturally I
expect them to be much more colored and to image less well
than the FX120 monitors, but they should provide some more
drama and zing with the 5dB greater SPL and power handling.I will give a full comparison/report here when I get it all
lashed together and a few days of listening. I really don't
expect either set of speakers to do much of anything below
about 70Hz. I may very well end-up not really liking either
much. I have some reservations about what how the aluminum
dust caps may sound. We'll see...Good luck with your FE166's. Sounds like the sealed cabs and
subwoofer augmentation might be a good route.
Hey Tom,You make sense to me. I hope you share your review of your FX120 system--it could be ideal for me as a personal/nearfield system.
I'm pondering on Paul Joppa's insights on acoustic (sealed box) versus electronic (crossover) high pass filters.
I'm going to look into using my FE166E in a BR box, instead of sealed. Then I could use them fullrange sans crossover for low level/power listening, and with an electronic crossover and subs for high level / big bass listening. Might offer the best of both worlds... hmmm...
Thanks, and have fun,
Yes, I heard those speakers and they are very nice. Absolute sound steal at the price mentioned. Probably better than most of the single driver speakers I have around my house costing hundreds more.If you like jazz, you are at the right forum for sound. The small ensemble jazz just sounds super on this stuff.
Also consider a Voight Pipe design, like the Abbys, with perhaps the above driver or another driver. I picked up my Abby's used for around 800 a couple/few years ago.
Also the Sigma 168 is a special driver if you can listen to it in a nearfield setting, and I recently picked up some vintage JBL speakers in large wood cabinets that sound pretty magnificent for jazz too.
*
C34's.They sound really good as far as I can tell.
Check this out.
http://www.lansingheritage.org/images/jbl/plans/c34/page1.jpg
and this,
http://www.lansingheritage.org/images/jbl/catalogs/1957/page6.jpg
Did you use a specific plan or kit to make the cabinets?
Had Home depot do the major cuts, then cut the rest up home, took about 2 hours to cut up all the peices and then it went to gether like a puzel, I used about 8 clamps all sizes...
You might want to take a look at recommended speakers on Welborne's site.
Use the Search function. This question gets asked almost weekly.
You might want to try this forum. They are all about full range speakers that work well with SET. Cheers.
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