High Efficiency Speaker Asylum

Posted by freddyi on May 19, 2001 at 14:26:00

by using a straight ~1/4 size 100Hz tractrix, exponential -> hyperbolic horn and lively 15" you can get ~108-110dB ~110Hz ->500 or higher and use an Altec 511 or if handy a homemade tractrix HF horn - passive xover.

augmentation < 110Hz can be done simple using direct radiators with active xover and decent amp.

with the 100Hz horn running pretty much full-out I'm not sure how much excess is left for 511 to be lightly contoured - might not matter - suspect it will sound pretty good without any EQ.

(btw - my homemade parallel 2A3 amp is pretty cool but I sure wouldn't rule out push-pull triodes without any loop nfb! - might be better in some aspects than SE - usually better damping - my mod class AB1 Eico ST-70 using ppp 6BX7 @300vdc vak is very good - hard to beat those xformers)

if you've only 3 watts then something like this mess might be a consideration - you've got ~112dB up close.

Freddy