Acoustat Answer Man is here

I agree. I watched that movie on my system and recall that it had very prominent LF content. Even my Spectra 4400's complained a little bit, despite being crossed-over to a subwoofer below 80 Hz. I like movies with lots of LF content, but I think some of them overdo it, leaving only a few very fine systems capable of properly reproducing it. Of course, the average sound system probably doesn't even try, so lots of folks never realize what they're missing.

Hi Andy Jocelyn's DIY Spectra 8800s measured 24hz without subs and 14hz with the two JLs F-112 in the system i have yet to hear such clean bass from any other speaker panels or boxes just SCARY bass realy to much for me BUT it's not my system.:):):)
 
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I agree. I watched that movie on my system and recall that it had very prominent LF content. Even my Spectra 4400's complained a little bit, despite being crossed-over to a subwoofer below 80 Hz. I like movies with lots of LF content, but I think some of them overdo it, leaving only a few very fine systems capable of properly reproducing it. Of course, the average sound system probably doesn't even try, so lots of folks never realize what they're missing.

This one also as very prominent LF content , the Leonardo speakers could not handle the LF in track #2 ( Dadawa ) in Munich this year but the big Acoustat's no problem at extreme volume.

Dadawa - - - Sister Drum xrcd
An externally hosted image should be here but it was not working when we last tested it.
 
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Is there a database where you located this?
There is much Acoustat info floating around the web(much of which originated from the Audiocircuit) but no database that I am aware of.

Attached is Zdata for the other Spectra models, and a crude overlay I made some time ago.
The 3300 impedance looks to be quite a bit "friendlier" than the 2200 in the midrange but no differenct at the LF/HF extremes. This is not particularly surprising since the 2200 & 3300 use the same interface(MK-2123) and only differ in the transformer secondary tap feeding to the midrange mixer resistor.

I would expect the 4400 & 6600 to have similar impedances as well since they both use the MK-2146 interface. I'm not sure why the 6600 show significantly higher impedance an LF than the 4400. My guess would be the 6600 impedance measurement was taken with a higher signal level increasing the core permiability and thus primary inductance. Impedance of transformer driven ESL is a moving target...
 

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There is much Acoustat info floating around the web(much of which originated from the Audiocircuit) but no database that I am aware of...

...My guess would be the 6600 impedance measurement was taken with a higher signal level increasing the core permiability and thus primary inductance. Impedance of transformer driven ESL is a moving target...

First point: most of the technical data on the Audiocircuit was provided by yours truly from my old Acoustat files. So in that respect, the Audiocircuit website is THE place to get Acoustat manuals and other technical information on Acoustat. They also have a Q&A forum in which I participate.

Second point: I created all of the original Spectra impedance/phase plots, but I remember very little of the method used. Furthermore, since they were done at different times, it is entirely possible that slightly different methods and/or drive levels may have been used. So the graphs are probably useful only for studying the relative variation of impedance/phase vs. frequency for a given model, not the absolute values. Therefore, the graphs are probably less useful for looking at the differences between models.
 
First point: most of the technical data on the Audiocircuit was provided by yours truly from my old Acoustat files. So in that respect, the Audiocircuit website is THE place to get Acoustat manuals and other technical information on Acoustat. They also have a Q&A forum in which I participate.

Second point: I created all of the original Spectra impedance/phase plots, but I remember very little of the method used. Furthermore, since they were done at different times, it is entirely possible that slightly different methods and/or drive levels may have been used. So the graphs are probably useful only for studying the relative variation of impedance/phase vs. frequency for a given model, not the absolute values. Therefore, the graphs are probably less useful for looking at the differences between models.

Thank's again Andy for all the FREE help you give on the great Acoustat speakers, no matter wich model they are very hard to beat, i was at Jocelyn's place tuesday with a few friends they said that they had never heard the Sister Drum track from the Dadawa album played so loud and clean before in their lives and yes it's true it was scary loud BUT clean the - DIY Spectra 8800s - AWESOME.

An externally hosted image should be here but it was not working when we last tested it.
 
Thank's again Andy for all the FREE help you give on the great Acoustat speakers

Indeed. :up:

The DIY community is blessed that Andy took it upon himself to create all this nice Acoustat documentation during his employment, and share it freely long afterwards. There are many other audio related companies for which it would be nice to have access to similar documentation and support.
 
Indeed. :up:

The DIY community is blessed that Andy took it upon himself to create all this nice Acoustat documentation during his employment, and share it freely long afterwards. There are many other audio related companies for which it would be nice to have access to similar documentation and support.

True BUT do you know many products like Acoustat's that even after 20 years of being shut down because for me when they left the USA they where no longer OUR BELOVED ACOUSTAT still have a folowing like this, i have owned them since 1984 and i'm sorry that i did not know them sooner i lost a few years with BOXES but i have been out of the BOX for 30 years now and that's the way i am going to leave this world, Life without Acoustat's is possible but senseless
 
Is there a limit to the number of panels that can be hooked up to one MK-121 C
(From a 2+2)
In other words, could I make a 3+3 (66/6600) ?
Thanks,
Paul

I am far from being tech savy but i phoned my friend Jocelyn and on the MK-121 C the limit is 4 BUT with the MK-2146 you can use 2 - 4 - 6 - 8 - 10 - panels on one interface if you want more info please send me a PM and i will send you Jocelyn's email address. André
 
Is there a limit to the number of panels that can be hooked up to one MK-121 C
(From a 2+2)
In other words, could I make a 3+3 (66/6600) ?
Thanks,
Paul

The MK-121 series interface was designed for a maximum of 4 panels. This upper limit is due to the number of taps on the low frequency transformer, which are used to adjust the bass equalization according to the number of panels connected.

That being said, you can drive more than four panels with the MK-121 interface, but you will probably find that you have too much bass. That is why the Model 6 (six panels) and Model 8 (eight panels) used a special version of the MK-121, which used a different LF transformer with bass-equalization tailored for the larger panel area. The Models 6 & 8 also used two interfaces per speaker, each driving three or four panels.

The MK-2146 interface mentioned by Mr Acoustat is for Spectra models only, and can only be used to drive segmented Spectra panels. So unless you have Spectra panels, or want to modify your existing panels into Spectra panels, the MK-2146 is not an option.
 
The MK-121 series interface was designed for a maximum of 4 panels. This upper limit is due to the number of taps on the low frequency transformer, which are used to adjust the bass equalization according to the number of panels connected.

That being said, you can drive more than four panels with the MK-121 interface, but you will probably find that you have too much bass. That is why the Model 6 (six panels) and Model 8 (eight panels) used a special version of the MK-121, which used a different LF transformer with bass-equalization tailored for the larger panel area. The Models 6 & 8 also used two interfaces per speaker, each driving three or four panels.

The MK-2146 interface mentioned by Mr Acoustat is for Spectra models only, and can only be used to drive segmented Spectra panels. So unless you have Spectra panels, or want to modify your existing panels into Spectra panels, the MK-2146 is not an option.


Thank you for your detailed info this is the reason that i always tell members to get in contact with my friend Jocelyn he did explain some of this info but like i have said MANY times i am not tech savy all i can do is give members info on someone that CAN help them.and having you here is a very big help.
 
Today for the first time I listened to the Telarc 1812 overture on my 2+2's in a 2400sq ft room, They handled the muskets at 100db with no problem at all, better Than my Apogee Diva's in a small room, I could feel the shots on my chest at 60ft, I also find with pipe organs the also seem to go deeper without any boominess , These speakers truly need a big enviroment to breathe in, I use a H2O-S250 that plays with my 1ohm Scintilla's on them, the amp just idles on the 2+2's, better sound than the VTL 100 tube mono blocks :) , I bought these new in 83, and never enjoyed them for many yrs and most time stuck in a room never used, funny how a room can change a speaker from confined to totally open and full frequency reproduction with no stress.
Al
 
Today for the first time I listened to the Telarc 1812 overture on my 2+2's in a 2400sq ft room, They handled the muskets at 100db with no problem at all, better Than my Apogee Diva's in a small room, I could feel the shots on my chest at 60ft, I also find with pipe organs the also seem to go deeper without any boominess , These speakers truly need a big enviroment to breathe in, I use a H2O-S250 that plays with my 1ohm Scintilla's on them, the amp just idles on the 2+2's, better sound than the VTL 100 tube mono blocks :) , I bought these new in 83, and never enjoyed them for many yrs and most time stuck in a room never used, funny how a room can change a speaker from confined to totally open and full frequency reproduction with no stress.
Al

Yes the room they do need space to breathe, when i bought my condo i owned 2+2s and with a 13x20 living room i knew they had to go so one more time in came the 1+1s and even those would be better with a few extra feet wide but i will not live without Acoustat's in my life i have always told my wife that the speakers could leave ONCE i am no longer there.
 
There's one thing I'd like to do, I like flat eq'd sound, but can't figure out a way to do with that distance, to long for rca cables, maybe a comp and software? any advice here welcomed . Like to see how far they are off in freq response. Thanks
Just buy an UMIK-1 and hook up to a laptop running the REW application. It's very accurate and pretty simple to use.