Audio Asylum Thread Printer

Mendel

I have had my Acoustat Spectra 22s for over a year now, and it is been two months since I had the interfaces refurbished. These are true hobbyist speakers that provide many opportunities to improve the sound they produce.
While some may argue the point, Acoustat panels are very tough and long lasting. I can't speak to others, but my panels appear to be in great shape with very few wrinkles. Even with high volume Reggae, I have not heard any "panel slap" or other noises indicating that the Mylar has become loose or lost tension. Yes I do get some frame vibration (well get to that) but no panel noise. So I have never given them the hair dryer or heat gun "heat treatment". Some swear by this and do it regularly, other advice that it is the quickest way to ruin your panels. The truth is probably somewhere in between. I bring this up as it is a recognized Acoustat tweak and if you are getting slapping sounds from the panels this and compressed air/vacuuming of the panels can help(if done correctly). Always unplug and de energize your speakers for at least a day before doing any of the above.
If the panels are robust, the interfaces are much less so. Acoustat interfaces are not famous for the quality of the parts (although the transformers in the later versions and especially the Spectra models appear to be of high quality). Nearly every Cap, Diode, Resistor, and wire can be improved upon by modern parts. The older parts go out of spec over time, bias drifts, and the speakers loose a lot of their sound quality. The binding posts are awful. If you have original interfaces, I highly recommend you consider refurbishment. There are some sources that specialize in this service, but pretty much any quality tech with experience with high voltage circuitry should be able to handle it. While your at it, have him make sure the bias voltage is up to snuff, this is critical for ESL operation. Just replacing the parts should bring you up to Acoustat's operating bias voltage of around 4.5KV, most older interfaces are running lower. I had my bias voltage juiced up to just under 6KV, no problems the speakers seem easier to drive (with my tube amp) and more alive and dynamic. Make sure the bias is equal for each speaker or you will have an annoying volume difference between speakers (also a common problem with old Acoustats)
OK now to the tweaks! I must give full credit to tyu who has posted here before and helped me alot and has 30 years experience with Acoustats for many of these tweaks.
1)Take down the potato sack socks.
The fabric is way to thick and just muffles the high end. They sound way better without the fabric. They look crappy no doubt (a couple of giant vertical ice cube trays) but some new stretched Spandex socks can cure that.
2)Loosen the bolts.
Each Acoustat panel has 8 bolts holding the panel to the frame. The conventional wisdom is to keep these tight. This is wrong, as the tighter the panels are coupled to the frames, the more the frames vibrate and sing along. The best sound is with the bolts loose, and some ever removed.
3)Experiment with tilt.
Not sure about other models, but my 22s allow the user to tilt the speakers backward. If strait up panels are 90 degrees, the tilt allows for the panels to go back to about 60 degrees. Experimentation is the key, too much back tilt and you loose too much highs, but with a tilt to between 70 and 80 degrees you will get more focused sound, a lower, more realistic image with a larger sweet spot and less beamy, more realistic highs.
4)Dampen the frames.
If you don't want to go to the work of building new frames, applying some dampening to the frames can help to keep them from singing along with the panels. I used Soundcoat sheets available from Partsconnexion. Just cut them into the appropriate sized strips and stick them on the (back) of the frames. A small but noticeable improvement.
5)Decouple the bases from the floor.
I use Vibropods #5, two in the back and one centered in front. Really helped clean up the bass on loud passages. Have not tried other types like cones or spikes.
Those are the ones I have so far. It also goes (almost) without saying that speaker positioning, toe in and room treatment play big parts in getting the most out of these speakers. But when everything is right, there is something magical about a big Electrostatic that you just don't get from other speakers.
Hope this helps owners get the most out of their Acoustats. Some of these tweaks may be useable with other types of speakers as well.

Planar Speaker Asylum

Planar Speaker Asylum

Acoustat (Spectra 22) Tweeks! (long)

Post a Message!