My delema

[Al^]

I have a piece of music that I really like, it consists of a Schimmel grand piano and trumpet, I have played a Schimmel grand a few yrs back and never forgot the sound of it, especially the lower registers, I have this track on CD Stello'd amore, when I play it on the Acoustats it's mind boggling real, the lower registers are right and proper, the Diva's have a problem here, more so than the Scintilla's, I have done everything I can think of possible and came down to one conclusion, the xo point needs to be much lower between the mid ribbon and bass panel, on the other hand the Diva's are better sounding then the Acoustats on the upper mid and high freq's, The bass ribbons just don't seem to be able to articulate speed and accurcy of an electrostat, If the Diva mrt section was longer i would just mount it to the Acoustats and have best of both worlds. All this over a piece of music.

[willcycle]

Al, are your Divas biamped? I have a a biamped pair ( Krell KSA 250s rebuilt and super charged along with modded DAX) and find the bass response the most accurate and articulate I have heard - especially with piano.

[EldRick]

Apogee bass panels need a LOT of power to control them accurately. I'm using a Classe Omega (monoamped) with my Duetta Sigs, with a couple of kilowatts output into 4 ohms, and it opened up the bass, added a half octave at the bottom, and gives excellent bass power vs. the Audio Research gear it replaced.

You didn't specify what amp you re using, but it is not possible to get too much power for Apogee bass.

[Al^]

Amp ( Henry Ho's S250), on bass panel, very same amp on the Acoustats, Please don't tell me it's the amp, because I'm quite fond of it. Also I tried others and it's the same including the big Bryston mono blocks. Yes have run them tri and bi amped, Dax and passive, and DBX Driverack. I was ok with the sound of the bottom register TILL I played it on the Acoustats, could be related to the Dax and passive's at this point not sure. Are you using room correction? if so what kind? Thanks
Al

[willcycle]

I am not using any electronic room correction but do have a pair of home made bass traps in the corners of the front wall behind the speakers.

[apogee_admin]

Al, what mid ribbons are you running on your divas?

Jon

[Al^]

Jon, wide narrow wide 3 trace, what is the bass to mid xo point in the Dax? Thanks

[apogee_admin]

No, I meant originals or Graz KLM3/5's as that will make a difference.

The DAX crossover point should be around the same as the passive around 500Hz, they seem to quote the DAX at 330Hz but that could be electrical not acoustic.

[Al^]

I think the MRT is stock, not sure as bass ribbons were done. They sound fine to me, the tweeter I have on lowest output on network box T is 0, mid is 0, bass -30db rake -1 on the dax, now if I use the driverack, do I use the 330 or 550, the mid ribbon don't like the 330 xo point at all. The manuals don't make any sense at all to me. To contradictive in my opinion. Thanks

[willcycle]

The DAX crossover is 330Hz, 6dB/octave gradually increasing to 12dB/octave.

[Al^]

Well I think I solved my problem. I removed the dax and put my Infinity active crossover in place, found 312hz xo point worked excellent, no mid ribbon movement even under high power, may lower to 256hz and see how that works out later. Sounds much better than the Dax. To many dam op amps in that case, Just to make note, I did change the impedances in the dax when I changed amps, one step you can't forget, the other is the SE and XLR switches. Thanks

[Al^]

Well I got the sound I'm looking for, Have the low pass set for 220hz between bass panel and mid ribbon, the mid ribbon was stable to 105 db at 1metre centre of panel C wieghted, way over kill for normal listening levels, Sound is far better than the dax or passives using the Infinity xo, BUT I know the unit and how it functions, The Dax is to confusing for me. Thanks for your imput. now were smiling.