Acoustat Answer Man is here - Page 34 - 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 1st October 2012, 10:57 PM   #331
diyAudio Member
 
AcoustatAnswerMan's Avatar
 
Join Date: Feb 2011
Location: Chandler Arizona
Quote:
Originally Posted by phazer99 View Post
I've gotten hold of a second pair of Spectra 11's (even cheaper than the first pair ) and did some measurements today. I bypassed the high pass filter, disconnected the Spectra woofer and set the crossover for the subs at 100 Hz. The panel drops quite steeply below 250 Hz so there was a quite big "valley" in the frequency response before the subs took over. However, the sound was very crisp and clear with better highs, but I also heard some pops/cracks (panel discharges?), which made me a bit worried.

Connecting a second panel in parallell to the same interface made the frequency valley a bit less deep, but it would require some kind of digital EQ compensation to run the panels flat down to 100 Hz. Maybe the easiest option is to get hold of a pair of Spectra 22/2200 interfaces or transformers (if anyone has some for sale I'm interested ). Meanwhile I think I'll just replace the high pass caps with better ones.
I am not at all surprised by your results. Neither the 11/1100 transformer or a single panel will have much response below 200 Hz. Adding more panel area will help some, but you are still limited by the LF response of the transformer. LF performance is what makes a transformer expensive, and it's no wonder that the full range Spectra's have about eight times more 'iron' in the transformers.

I am also not surprised at the increase in crackling of the panel. You are probably running into some saturation of the transformer, plus a single panel can act that way when you are trying to run it full range. However, it is highly unlikely you have caused any damage to the panel. This is why all of Acoustat's single-panel models are hybrids.

I guess the moral of the story is that you can't make a silk purse out of a sow's ear (not that I would suggest that the Spectra 11 is a sow's ear).
  Reply With Quote
Old 2nd October 2012, 07:44 AM   #332
diyAudio Member
 
Join Date: Jun 2012
Location: Sweden
Quote:
Originally Posted by AcoustatAnswerMan View Post
I am not at all surprised by your results. Neither the 11/1100 transformer or a single panel will have much response below 200 Hz. Adding more panel area will help some, but you are still limited by the LF response of the transformer. LF performance is what makes a transformer expensive, and it's no wonder that the full range Spectra's have about eight times more 'iron' in the transformers.
Do you know the specs/model of the Spectra 2200/3300 transformers? Is it something you can buy off the shelf?
  Reply With Quote
Old 2nd October 2012, 12:54 PM   #333
diyAudio Member
 
MrAcoustat's Avatar
 
Join Date: Jun 2010
Location: St-Catherine Quebec
Quote:
Originally Posted by phazer99 View Post
Do you know the specs/model of the Spectra 2200/3300 transformers? Is it something you can buy off the shelf?
Andy Szabo2007-10-07 23:24

The MK-2123 interface was common to Acoustat Models Spectra 22/2200, and 33/3300. An internal wiring difference changed the bass equalization for either the two-panel 22/2200, or the three-panel 33/3300. There should be a rubber-stamped number on the interface label indicating whether the interface is set-up for a 22/2200 or 33/3300. If for some reason that stamp is not visible, the speaker can be identified by its width: the cloth-covered portion of the 22/2200 frame will measure 21.5" wide, and the 33/3300 will measure 31.75" wide. The only difference between the 22/33 and the later 2200/3300 is the cosmetic wood and brass strips along the sides of the panel. The panels and interface electronics are identical.



You can find most of your answers here this is the Acoustat bible.


Acoustat
__________________
Chord CPM-2600 amplifier - Chord One cd player - Acoustat 1+1 speakers -
Life without Acoustat is possible BUT senseless.
  Reply With Quote
Old 2nd October 2012, 07:46 PM   #334
diyAudio Member
 
AcoustatAnswerMan's Avatar
 
Join Date: Feb 2011
Location: Chandler Arizona
Quote:
Originally Posted by phazer99 View Post
Do you know the specs/model of the Spectra 2200/3300 transformers? Is it something you can buy off the shelf?
All Acoustat transformers were custom-made, so are not available 'off the shelf'. However, there may be some NOS or used parts that you may be able to find. Keep in mind that each full-range Spectra uses two identical audio transformers, one for each phase. So you need four for a stereo pair. Also keep in mind that the full-range Spectras use a more complicated high-voltage combining and sector-dividing network, so that must be created as well if you intend to build a full-range (or at least down to 100-Hz) speaker. There are also complete, used speakers available, so that might be an easier route.
  Reply With Quote
Old 4th October 2012, 02:44 AM   #335
Atom666 is offline Atom666  Canada
diyAudio Member
 
Atom666's Avatar
 
Join Date: Oct 2005
Location: Toronto, Canada
Hi Andy
Here is my attempt at a Monitor 4/ Spectra 44. There are 4 x 9" panels at a 6 degree angle. 2 panels are 3 wire and 2 panels are 5 wire .I am going to drive them with a MK121C interface initally. I also have a Spectra MK2123 interface .My question is can I drive the 4 panels with the Spectra 33 tap ,or will there be too much bass?
Thanks
Andrew
Attached Images
File Type: jpg 012 acoustat resize.jpg (144.3 KB, 144 views)
File Type: jpg 013 Acoustat Resize.jpg (127.4 KB, 136 views)
File Type: jpg 014 Acoustat Resize.jpg (114.2 KB, 138 views)
  Reply With Quote
Old 4th October 2012, 03:43 AM   #336
diyAudio Member
 
MrAcoustat's Avatar
 
Join Date: Jun 2010
Location: St-Catherine Quebec
Quote:
Originally Posted by Atom666 View Post
Hi Andy
Here is my attempt at a Monitor 4/ Spectra 44. There are 4 x 9" panels at a 6 degree angle. 2 panels are 3 wire and 2 panels are 5 wire .I am going to drive them with a MK121C interface initally. I also have a Spectra MK2123 interface .My question is can I drive the 4 panels with the Spectra 33 tap ,or will there be too much bass?
Thanks
Andrew
Sorry Andrew very nice model 4s but NOT 44s or 4400s because those need to be 22 inches wide by 94 inches high like these next to a pair of model 3s models -2 - 3 - 4 - are all about 66 inches high. André

Click the image to open in full size.

Click the image to open in full size.
__________________
Chord CPM-2600 amplifier - Chord One cd player - Acoustat 1+1 speakers -
Life without Acoustat is possible BUT senseless.
  Reply With Quote
Old 4th October 2012, 02:12 PM   #337
Atom666 is offline Atom666  Canada
diyAudio Member
 
Atom666's Avatar
 
Join Date: Oct 2005
Location: Toronto, Canada
Sorry Andre
You obviously don't get it, see post #38
See here Acoustat Answer Man is here

Andrew
  Reply With Quote
Old 4th October 2012, 02:25 PM   #338
diyAudio Member
 
MrAcoustat's Avatar
 
Join Date: Jun 2010
Location: St-Catherine Quebec
Quote:
Originally Posted by Atom666 View Post
Sorry Andre
You obviously don't get it, see post #38
See here Acoustat Answer Man is here

Andrew
Ok Andrew did not notice that particular post but one thing i can tell you is that i had a friend like you that could not fit his Acoustat's 2+2s in his basement for the same reason ( height ) he did what you did 4 panels side by side they realy sounded good BUT did not sound like normal 2+2s BUT better than any boxed speaker at the same price

PS: They do look very nice ENJOY
__________________
Chord CPM-2600 amplifier - Chord One cd player - Acoustat 1+1 speakers -
Life without Acoustat is possible BUT senseless.
  Reply With Quote
Old 4th October 2012, 02:38 PM   #339
diyAudio Member
 
MrAcoustat's Avatar
 
Join Date: Jun 2010
Location: St-Catherine Quebec
Quote:
Originally Posted by david yost View Post
I agree with you, MrAcoustat, the 1+1s are a wonderful speaker. My next project will be to "Spectra" mine -- to improve horizontal dispersion a little -- and add either a single plane bass array or a double bass array; then I am done! I promise!
QUOTE: Then I am done, I and my wife have heard that statement before
__________________
Chord CPM-2600 amplifier - Chord One cd player - Acoustat 1+1 speakers -
Life without Acoustat is possible BUT senseless.
  Reply With Quote
Old 4th October 2012, 04:35 PM   #340
diyAudio Member
 
Join Date: Feb 2009
Nice job, Andy. You're going to end up with a totally unique Acoustat. I'm very curious to hear about how combining the standard and Spectra interfaces turns out. Hopefully after zeroing in on the interface config you WILL be done, but no one here will hold you to your promise.
  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 07:19 AM
need a tech to answer this one pks71 Car Audio 1 19th November 2004 12:50 PM


New To Site? Need Help?

All times are GMT. The time now is 10:49 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