Acoustat Answer Man is here - Page 31 - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

Planars & Exotics ESL's, planars, and alternative technologies

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 8th September 2012, 08:55 AM   #301
diyAudio Member
 
Join Date: Jun 2012
Location: Sweden
Quote:
Originally Posted by MrAcoustat View Post
Because of guy's like Andy & Mike and a few others that i know of, a little flattery is well deserved, those gentleman are not obliged to do what they are doing, for them it's the love of speakers that have been out of business for more than 20 years, BUT there still alive because of guy's like them hats off to all of you Acoustat's proud owners, like i have said many many times before, it may not be the best speaker out there, BUT dollar for dollar they are very very hard to beat.
Amen to that. I think my Spectra 11s sound amazing for the price I paid, I can't even begin to imagine how good the bigger models sound. Unfortunately they are very rare here in Sweden, and shipping them is a pita, so I may never have the fortune of hearing or owning one

The support on this forum is really excellent, thanks guys.
  Reply With Quote
Old 8th September 2012, 02:18 PM   #302
diyAudio Member
 
Join Date: Feb 2009
Quote:
Originally Posted by phazer99 View Post
Amen to that. I think my Spectra 11s sound amazing for the price I paid, I can't even begin to imagine how good the bigger models sound. Unfortunately they are very rare here in Sweden, and shipping them is a pita, so I may never have the fortune of hearing or owning one

The support on this forum is really excellent, thanks guys.
If memory serves, only the 1 center panel (2 if it's a full height model) in the Spectra models has the 5-wire Spectra config, with the outside panels (as in a 33, 6600, etc.) being normal 3-wire panels. I assume this means that if you can get a hold of additional panels you could build new frames to create a larger Spectra model. Just a thought.
  Reply With Quote
Old 8th September 2012, 02:50 PM   #303
diyAudio Member
 
Join Date: Jun 2012
Location: Sweden
Quote:
Originally Posted by hella356 View Post
If memory serves, only the 1 center panel (2 if it's a full height model) in the Spectra models has the 5-wire Spectra config, with the outside panels (as in a 33, 6600, etc.) being normal 3-wire panels. I assume this means that if you can get a hold of additional panels you could build new frames to create a larger Spectra model. Just a thought.
I can get an additional pair of Spectra 11's, but that won't help, right?
  Reply With Quote
Old 8th September 2012, 03:07 PM   #304
diyAudio Member
 
Join Date: Feb 2009
I think you could use 2 of the panels per channel, either in a 1+1 config or side by side like a Model 2. M2 style you would wire 1 panel as a Spectra with the other as a standard panel. I may be mistaken in this, so perhaps someone with more experience with Spectras will chime in. If this can be done, you may be able to do away away with the woofer due to the increase in panel area. AFAIK, only the single panel Acoustats used dynamic woofers, & most people prefer Acoustats run full-range, even with external subs added.
  Reply With Quote
Old 10th September 2012, 03:14 PM   #305
diyAudio Member
 
Join Date: Feb 2009
Quote:
Originally Posted by phazer99 View Post
I can get an additional pair of Spectra 11's, but that won't help, right?
Actually, in order to properly use additional panels and remove the dynamic woofer, I think you might need different transformer interfaces. I'm quite familiar with working with non-Spectra Acoustats, but I think the interfaces on the Spectra 11 might not be proper for doing this.
  Reply With Quote
Old 10th September 2012, 03:43 PM   #306
diyAudio Member
 
Join Date: Jun 2012
Location: Sweden
There's a question about driving two panels with one Spectra 11 interface at Acoustat Spectra 11 electrostatic speaker. It seems to be possible get the panels down to 100 Hz in this configuration. That suit me well as I have subs that can take over at 100 Hz. My knowledge on electronics and electrostats is very limited, so any tips on how to do this modification is much appreciated.
  Reply With Quote
Old 10th September 2012, 05:30 PM   #307
diyAudio Member
 
Join Date: Feb 2009
That question on audiocircuit was answered by none other than AcoustatAnswerMan (Andy Szabo) so hopefully he can add to that. I think two Spectra panels in a 1+1 config or side-by-side + subs could achieve some great results. Would require building new frames, but you can build frames superior to what Acoustat made, considering they had to work to a tight price point.
  Reply With Quote
Old 12th September 2012, 07:59 PM   #308
diyAudio Member
 
AcoustatAnswerMan's Avatar
 
Join Date: Feb 2011
Location: Chandler Arizona
First, let me clear up a few misconceptions presented above…

Acoustat panels with only three wires are quite old, and pre-date the Spectra models by more than a decade. I don’t know for sure when Acoustat switched to the 5-wire panels, but I would guess in the early 80’s. The difference is that 3-wire panels have a connection to only one end of each stator, whereas the 5-wire panels have a connection to both ends of each stator. Although there is a supposed improvement in performance with the 5-wire panels, the 3-wire and 5-wire panels can be used interchangeably.

All Spectra panels have 5 wires, PLUS the stators are split so that each vertical half of the panel can be driven by different signals. All Spectra models use the same panel, regardless of the total number of panels in the speaker. The only difference is how they are driven.

Now on to your specific question…

The audio transformer in the Spectra 11 or 1100 was designed to drive one panel, although they can probably drive two panels. I have no information on how well it might work, as we never tried it at the factory (although I always wanted to!). At the very least, you’ll probably need to change the high-voltage sector resistors to one-half of their original value. This will keep the sector roll-off at the same frequency, despite the transformer driving twice the capacitance.

I would recommend only the stacked configuration, similar to the Model 1+1. Placing two panels side-by-side, like a Spectra 22 or 2200, would not really make sense, since you have only a high's and mid's, and mid’s-only signal from the Spectra 11 interface system. A proper full-range side-by-side has three signals available from the interface: full-range, mid’s and lows, and lows only.

If you want the ESL to go down to 100 Hz, you’ll also need to change the value of the input coupling capacitor, to lower the roll-off frequency. I may not have answered all of the possible questions you have about such a modification, so feel free to ask more questions. And if you do try it, please let me know the results, as I am curious to know how well it works!
  Reply With Quote
Old 12th September 2012, 08:10 PM   #309
diyAudio Member
 
Join Date: Feb 2009
Thanks for the input, Andy. I was concerned I might be giving incorrect advice, so it's good to see someone with real Spectra knowledge clarify this. It looks like a project with excellent possibilities, so good luck if you go forward with this, Scott.

Mike
  Reply With Quote
Old 12th September 2012, 09:50 PM   #310
diyAudio Member
 
Join Date: Jun 2012
Location: Sweden
Thanks for the reply Andy.

With your explanation and the Spectra 11 schematics things are starting to clear up. Let me see if I got it right. There are five wires that connect to the Spectra 11 panel:

- blue and white are connected to one half of the stators, high and mid freqs (> 250 Hz) are sent here
- black and yellow are connected to the other half of the stators, only mid freqs (250 - ? Hz) are sent here
- red is connected to the diaphragm

When you write that one interface can drive two panels you mean that same-colored wires should be connected in parallel to both panels. Placing the two panels stacked vertically will create a more balanced sound image than placing the panels side-by-side.

Did I get everything correct so far?

Now for some questions:

- At what frequency is the high vs mid split in the high-voltage section?

- Wouldn't it be better to connect the mid-only wires to both sections of the extra panel? Wouldn't this make it possible to place the panels side-by-side and still have good high frequency dispersion? Or would this result in an imbalanced frequency response?

- Would it be possible to drive the panels down to (or close to) 100 Hz in a two panel setup?

- When you write that the high-voltage resistors should be replaced, do you mean the two 330K resistors between the stator connectors?

Thanks in advance.

Last edited by phazer99; 12th September 2012 at 09:56 PM.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
No answer Antoni D The Lounge 2 13th February 2011 06:19 AM
need a tech to answer this one pks71 Car Audio 1 19th November 2004 11:50 AM


New To Site? Need Help?

All times are GMT. The time now is 01:13 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2