I would really appreciate some timely feedback to risk proceeding with my little ESL fantasy, albeit via the back door.
As I have insufficient knowledge (and especially the time) to do much DIYing, Jim Salk
http://www.salksound.com/ is cloning Gary Dahl’s BTA speakers for me (minus the RAAL ribbons, which Gary no longer uses since he switched from his Lundahl transformer coupled 300B p-p amps to Gary Pimm’s vastly upgraded Tabor solid-state amp)
http://www.diyaudio.com/forums/multi-way/100392-beyond-ariel-1295.htmlJim should have them finished around February. But before he ships them I thought about how the ER Audio 505 panels would work above each GPA Altec 416-8B midwoofer.
http://www.eraudio.com.au/Mini_Panels/mini_panels.htmlhttp://www.greatplainsaudio.com/downloads/416-8B%20Spec%20Sheet.pdf I’m certainly no expert, but by using two or three 505 panels above each 416 midwoofer, would not soundstage for the highs and upper mids greatly improve in all three dimensions?
As for the critical midrange, Gary passively crosses the (equalized) Azurahorn/Radian driver combo with the Altecs to have the latter begin playing at 700Hz.
The GPA Altec 416’s under hung voice coil keeps distortion low. And Gary has each midwoofer in sealed low diffraction cabinets, where the response goes down to only 70Hz, further minimizing distortion. A pair of Jim’s version of the Rythmik 12" sealed servo subs take over below this.
Whether I use Rob’s passive crossover or bi-amp the system with something like this
http://www.firstwatt.com/pdf/prod_b4_man.pdf , would you expect the results to be comparable to those here?
https://drive.google.com/file/d/0B1XTT_kQmJ_QNE1wbnVFdUsyLWs/view Note, however, the “milliwatt” typo in the specs.
http://www.jblpro.com/pub/obsolete/4331a_4333a.pdfAt least some things have changed for the better. I am no longer limited to using the First Watt F4 amp, at least not alone. My room size will be either 12 ft x 15 or 14 ft x19, where, due to heat and clutter issues, I would either passively or actively cross the speakers, respectively.
As for bi-amping, I would drive the ~ 97db Altecs with either the F4 or my First Watt J2 (also 25 wpc/ 8 ohms), or sell off one for a really superb sounding Class AB amp.
But if bi-amping, and to drive the ESLs alone, how well would 300B SET monos work?
While they are noted for an awesome 3D soundstage and a magical midrange, don’t their highs roll off soon after 10kHz?
And as they are typically 9 wpc, how much output will they do at 10kHz, when each 505 panel’s impedance drops to 4 ohms? And down to 2 ohms at 20kHz, according to the curve here?
http://www.eraudio.com.au/Mini_Panels/mini_panels.html However, in terms of wpc vs. required SPLs, since my average listening levels would be ~ 60db at 1kHz, in a 14 ft x 19 room, at 200Hz they would be only ~73db, as per the 2003 curve
https://en.wikipedia.org/wiki/Equal-loudness_contourOn the other hand, as caps in parallel are additive, wouldn’t impedance below 10kHz be approaching zero if I use 3 panels per side? How would the 300B’s output transformers handle that kind of load?
Otherwise, I’d hate giving up on 300B SET magic, but would an OLT tube amp be a much better choice to drive three of those 505 panels? Maybe something like this?
http://www.lineartubeaudio.com/zotl-10/Ultimately, however, as you are the guys with the heavy ESL design, building and in-use experience, please evaluate the feasibility of this particular hybrid speaker + subwoofers concept. If the consensus here does not total 80% or better likelihood for a really awesome sounding build, then there’s no point to risk spending the 505 mini panels, since I don’t think that ER Audio does refunds.
I’d probably go for a passively or actively crossed OB speaker project.
Looking forward to your replies.
