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I have had the Acoustst Spectra 22 speakers in my 11 X 14 room for about a week now. They replaced Totem Hawks in this room. Amplification is Rogue Audio Stereo 90 (modified) and Audio Research SP14 (modified). Source is J.A. Micheel Orbe turntable, tecnoarm and Lyra Delos cartridge. Interconnects are Kimber Select cooper, speaker cable is Kimber 8TC (older blue/black variety). The front wall has a 60 inch plasma between the speakers, and 4 inch thick 2X4 foot Roxul panels on either side of the TV. After doing much experimentation, the speakers are currently about 38 inches out from the absorption panels, 5 feet between inner edges of the panels, 15 inches from side wall on right side, open area beyond the left speaker.
I have yet to get amazing imaging from these speakers. I think the Totems imaged better. As everyone knows, the Acoustats are very directional and only image at all in the one central sweet spot on my three seat couch. The other two seats sound OK but the image suffers. The couch on the other side near the right speaker is crappy.
So far I like them best for jazz or smaller uncomplicated music. If the music becomes very busy, with lots of different instruments playing (like most rock and roll) the speakers can sound strained and lose there composure. This happens at what I believe are relatively moderate sound pressure levels (I have no way of measuring) and levels which the Hawks (and their 5 3/4 inch woofers) handle with ease. I find the Spectras go down lower in the bass than the Hawks, but the bass is looser.
I read on the net that a guy with Spectra 22 in a small room found them sounding thin and tried to tilt them slightly downward towards his listening position. I tried this with small felt pads at the back of the wooden bases and the sound did get fuller but not sure if it was an improvement.
I am interested in any suggestions to help me get the most out of these speakers. I know they are 28 years old and they appear to be stock, judging from the bazillion staples at the top of the panels. Not sure if the interfaces have been touched.
Now for some nubie questions!
1) There is a switch on the interface to go from full range operation to a 100 hz crossover to sub out binding posts. Can you try this even if you don't have a sub hooked up? Interested to hear the panels with the bass taken off them. My understanding is that most people who use a subwoofer use the crossover in the subwoofer set at a lower crossover point (maybe 50 or 60 hz) I am not interested in more bass, but the sound of the panels with the bass removed.
2) It seems to me that the right speaker is ever so slightly playing lower or less dynamic than the left. I understand that the lower power supply bias can lead to one speaker playing lower than the other. TYU has mentioned many times that bias is one of the keys to the sound of electrostatic speakers. My Spectras are the older version with the captive power cord and no wall wart transformer. Is it possible to adjust bias for this version? How do you measure the bias for these speakers? Can the ultra sonic bias control of latter versions be added?
3) Been thinking of taking down the socks to hear them nude. Too many staples to remove will probably just cut them free. This may make the socks unusable. Do they sound cleaner and image better without the socks?
4) Should I ditch the absorption panels behind the speakers. I tried it briefly and found the sound got more "splashy". I guess I can do more experimentation.
5) I have heard pros and cons about using tube amplification with these speakers. I have a Quad 606 power amp (180 watts into 4 ohms I believe) that I might try out this weekend. On the Hawks, the Rogue amp sounds much better.
6) I will eventually have the interfaces looked at by a technician in my area. Too difficult and time consuming to send them down to Florida. What work should be down as basic maintenance on the interfaces and are there any relatively simple mods that should be done. I would like to insure that all caps and key resistors and diodes are up to date and that bias is correct and the same for each speaker.
That's it for now. I knew this was going to be a journey and there have been some flashes of brilliance so far, but not as many as hoped for. The sonic potential of these speakers is obviously higher than the Hawks. The question is how to get there on a consistent basis. Appreciate any help.
Mendel
Follow Ups:
If you have not already seen my posting about my Spectra 11's, it might help. I took the socks off my 11's right away and it was a big change! The photo shows them with their new Tule (tool)covers. You really can not see that covering until you stand right in front of them and feel. Good Luck, bobwire
Are you able to use the 14'wall? I had a set in a room like that,and had them pulled half way in the room, more holografic but sounded better.jmho
Could not use the 14 wall as one end empties out into another area and I need the 14 feet depth to get them out into the room. They are now almost 4 feet from the front wall, 8 feet from my couch back which is less than a foot from the back wall. A tight squeeze but they seem the perfect size to energize this listening space.
I am getting very good sound out of them now. But it has been a lot of work. These are definitely hobbiest speakers, not for those looking for a speaker that sounds good anywhere. The main issue for me has been the directivity. The smallest changes in distances, tow in angle and even tilt of the panel array result in easily heard changes in the sound. For example, my basement floor is not level, turns out that even though both arrays are in the fully upright position, the left speaker in beyond level and the right array is tilted up. The sound favours the left side, adjust the tilt with a level and image snaps into place.
Every tube roll has never been more obvious. Bad recordings are exposed but good ones sound amazing. My Rogue with EI KT 90 seems to have the power and the transformers to get the job done. And I know the is still more upside hiding in these beasts.
"38 inches out from the absorption panels, 5 feet between inner edges of the panels, 15 inches from side wall on right side, open area beyond the left speaker.
"
Step 1, get rid of the absorption panels behind the speakers. You are killing a large percentage of the speakers designed radiation this way. This will go a long way towards improving both soundstaging and dynamics.
I ran my Acoustat Spectra 2200s in a totally untreated room and it worked brilliantly. They are already balanced a bit tilted down in response so to damp them will only overdo it.
Step 2, the "tweeter" part of the speakers should be on the inside if they are not already (it is not clear from your post) then toe-in the speakers around 10-15 degrees. This will improve the image focus.
Step 3. Measure the bass in the room. There is likely a resonance that is getting excited in the 60-70Hz range that will perhaps muddy things up. I took care of it with a digital equalizer at 62Hz. It also improved the dynamic range of the speaker because it is also related to the panel resonance. You can use an analog equalizer but it won't work as well. If you are only using digital it can be done entirely in the digital domain (i.e. no need to use the shitty DAC built into most digital eqs).
Step 4, measure/adjust the bias on the panels. Mine had the wall warts and the ultra sonic bias control so since yours are different I can't really help you there.
I got a big improvement in taking off the Socks for my Acoustat 1+1 but I never felt the need to take off the socks on my Spectra 2200s because they really sounded fine as they were and the sock was MUCH thinner than the ones on the 1+1. I don't know if the Spectra 22 used the same sock material as the 2200 or more similar to the 1+1.
I found tube amps worked best but only a really top notch one (I had KR Audio). Otherwise I found a good hybrid amp worked very well (I had a Sphinx Project 14 and reviewed an AcousticPlan Santor...both did very well). A good sounding SS amp on them was the BAT VK200, which my friend, who owns them now, is using. It is also now quite affordable.
A push/pull tube amp like the Rogue might have issues in exaggerating the bass panel resonance and this will limit dynamics. The reason is that a lot of push/pull tube amps have too small output transformers, saturate and make a somewhat soft "tubey" bass. In this aspect you will find an SS amp will control the bass from the speaker better. Also, you have to be aware that the Spectra 22/2200 drops to 2 ohms in the bass and goes to about 12 ohms in the mids before dropping to 2 ohms again by 20Khz. Did you try the 4 ohm tap on the Rogues?
Good sounding amps that I have tried on my Spectras:
KR Audio VA350i
KR Audio Kronzilla monos
Sphinx Project 14 MkIII
Sphinx Project 16
Classe DR3 bridged for mono
BAT VK200
Silvaweld OTL reference monos
AcousticPLan Santor
Conrad Johnson Evolution 2000
What should also work well:
BAT VK500
Pathos InPower monos
Atmasphere MA-1
VAC 30/30 and 70/70
Other big SET amps
Einstein OTLs
The problem is that the speaker, while now very inexpensive is capable of really revealing the qualities of top gear. It will continue to improve as you improve your gear.
Thank you very much Morricab for your detailed and informative post. I have already tried removing the absorption panels twice and both times found the sound got to "splashy" and I'll defined so they never stayed down long and I never tried to optimize them that way. I will definitely try again and leave them down for awhile to experiment.
The tweeters are definitely aligned the proper way the guy I bought them from had marked them (correctly). They are towed in maybe 15 or 20 degrees but I am constantly varying this as I experiment.
The bass seems ok in the room (with the panels) but I have no way currently to measure it. My Spectras are the older version with captive power cord and no wall wart. The socks seem very thick and heavy . I intend to take the down when I get back to town.
There is no doubt the bias must be checked bias drift must have been a problem with these early Spectras that is why they added the ultrasonic bias. Nobody has yet been able to explain how to check or bias these non ultrasonic Spectras.
I use the 4 ohm tap on the Rogues. I seem to be able to get plenty of clean volume, but the sound has just not jelled yet. Imaging is not great yet, and I have yet to hear the great speed and detail that electrostats are known for. Honestly I think the Totem Hawks sound faster and more detailed in my room.
Hi Mendel
Sorry to hear that things have not locked into place image and speed wise.
Be sure that they will!!
You just have to keep working at it.
I suspect that this is one of the rarely talked about shortcomings of this speaker.
One time, in my old much bigger (shared) listening room I had to paint it.
So I carefully measured everything (because they were working a treat) before removing the speakers from the room.
After the painting was finished, I put the speakers back in their "same" measured spots, …
And, …
They sounded terrible!
I spent weeks working on them, …
Grrr!
Try, move, back to the original spots, then try, move again!
But then I got it right and wow!!
So good!
You really do need to keep working on it.
Don't get frustrated.
I will all come together and you will be so pleased.
Hope this helps.
Bruce
Mendel,
As I mentioned in your original post, I have experience with Acoustats, but zero with Spectras. So take my comments with appropriate measure of salt. Acoustat servos have a time delay which slows the response of the rear stator a few milliseconds to prevent wave cancellation and "tuned" so that 3' or so from the front wall delivers the desired effect. I suspect that the Spectras have similar delay. Wondering how all that would play with heavy damping on the front wall behind the speaker. Trial and error experimentation is likely the only way to know. I also wonder if amp power is optimum for the interfaces. Most folks I've read about with Spectras run them with 200 to 300 watts per side. The Rogue is a great amp, but may not be the right match to this task.
Hi
I have spectra 22s driven by a quad 606 in a small room (12.5 feet by 10.5 feet by 7.75 feet).
I use them right near the back wall which has a heavy curtain from one side to the other behind the speakers.
I have the wall wart version.
When I first got them I took out everything easily removable and got it gold plated together with the wall warts.
I have used them with and without subs.
Let me give you some of my observations.
The sweet spot/optimum imaging position is extremely difficult to obtain, it seems that less than a quarter of an inch of speaker positioning can make a world of difference!!!
Let me give a little comparison on the sweet spot.
I recently auditioned sanders model 11 speakers.
The sanders have a reputation of having a very small sweet spot.
Well, with the sanders, no matter where I moved in the single seat listening chair I could hear no difference!!
By the way I that the sanders sounded significantly better!
I started to notice a difference between the left and right panels maybe fifteen years ago!
Guess this was a result of drift in some of the components.
The answer is to send off the interfaces and get them worked over and any out of spec components replaced and the panel voltages set back to factory spec.
I have the speakers right back against the wall with the speakers angled directly toward me and many hours of adjustment to get the positioning right.
I purchased the subs, martin logan dynamos (sealed units which are reputed to be the fastest) maybe eight years ago.
I got them for two reasons, partly to get more loudness from the panels and partly to get better base and maybe a bit of slam.
I use the spectra 22 crossovers.
I felt that I do have better base, maybe I do have some increased loudness.
As regards tilting I did exactly what the manufacture's instructions said, tilting slightly back.
If you want to get more out of your spectra 22s you really will need to get the interface units checked out.
I am sure my spectra 2 would sound better if I did.
It is up to you whether you get subs but do bear in mind that these speakers were designed to be used with subs (I declined to buy them at the time and I am glad because I think that the acoustat subs were pretty ordinary).
No one seems to talk about this very much.
Hey, if you did not own the spectra 22s you might not even now about the switch and extra terminals on the back!!!
If you are getting them checked over a bit of hair dryer diaphragm tightening might help, I have not done this myself because the risk of catastrophic damage was too great!!
I find all types of music sound great but things like female vocal do sound especially good and I think this is because most non electrostats struggle in this area.
Here is where I think it all comes together.
The spectra 22s are not very expensive these days.
It is not that expensive to get them professionally checked and optimised.
You could not get any new elsctrostats for anything like this price!
And,… even these 30 year old speakers sound better than most new speakers you could buy!
As an aside, a while back I had a demo of some big name expensive speakers, and at the end I exclaimed that my own speakers sound massively better.
The demo dealer was taken back but that was how it was.
To sum it up you have have got yourself a great speaker for a great price and with a little effort you can have a super great speaker for a super great price!
If you have any further questions feel free to ask, meanwhile enjoy!
Regards
Bruce
Cleaned all contacts between the panels and the interfaces with alcohol (the cutips came away black) and removed the countless staples and rolled the socks down. Big improvement. The socks were definitely muddying the sound. Panels look pretty good a few very small ripples at the corners but they definitely look dirty. I will try some compressed air and vacuum in the coming days. They definitely look like they could use a bath but I don't think I have the stones to try it! Lots of fun.
Thanks a lot for the post Bruce! Good information there. Yes, for $1k I got a very good speaker that has the potential to be great I think. That will not buy you much in today's electrostats haha. I agree that they are extremely sensitive to positioning, upstream electronics and recorded material.
For example, tonight I discovered that they much prefer triode output on my power amp, despite the fact it is only about 55 watts compared to 90 in Ultralinear. I always ran my Hawks in triode but figured I needed the extra power to deal with the Spectras. Wrong. They actually play loader without falling apart in triode and image better. Obviously the Rogue sounds much better in triode mode. And the Spectras demand quality watts above sheer quantity.
I will do the interfaces and post my impressions.
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