Home Propeller Head Plaza

Technical and scientific discussion of amps, cables and other topics.

[ Follow Ups ] Thread: [ Display  All  Email ] [ Propeller Head Plaza ]
[ Alert Moderator ]

I've been working with this idea for 17 years

My first experiments with it began around 1989 after seeing some of the most highly regarded speakers around used them including those I liked and admired. Snell AIIIi for one and later seeing Vandersteen 5, Wilson's best speaker, recently Opera Tibaldi, and quite a few others. It took me several years to understand how and why this works. BTW, you don't just add a tweeter to get optimal results. Those who did haven't gone nearly far enough. The rear firing tweeters result in HF energy arriving at the listener from a large number of directions shortly after the sound from the front firing tweeter. This is what invariably happens with midrange and LF sound but becuse NO tweeter has the kind of dispersion midrange and woofers have in their range, this does not occur with HF with front firing only speaker systems. To optimize the effect, the output of the front tweeter has to be reduced and the entire spectral balance of the speaker system has to be readjusted. When the treble is right, anything is possible. When it's wrong, nothing else seems to matter, the speaker's overall sound will always appear dull or shrill and always like it emerges from a box. What is the resulting sound like in comparison? It is clear, open, the high end is all there, but it isn't shrill and the stereophonic effect is apparant over a much larger listening area. High frequencies have a lot to do with the perception of direction. It also allows the low end to be extended to provide lifelike bass levels if the speaker is capable of it without sounding bottom heavy or out of balance. I have successfully reconfigured AR9, AR2a, KLH6, McIntosh ML-1C, original Bose 901, and now Empire 9000M in this way with very satisfactory results. Crossover frequencies ranged from 6khz to 9khz with a simple 6db per octave slope. In the case of 901, the most drastic case, a front firing tweeter had to be added as well and its spectral balance made somewhat different from the rear tweeters. The tweeters also had to be handled by a separate amplifier through which the Bose equalizer signal didn't pass to avoid damage to the tweeters from excessive bass. In all cases, in relatively live rooms, the optimal balance was about 12 times as much energy from the rear tweeters as the front tweeter. No single front firing tweeter regardless of cost or design can equal a direct/indirect array in these critical areas. This is the best approach IMO to achieve the same goals sought through different means but at far greater sacrifice. These techniques include bipolar panel and other bipolar arrangements, pulling speakers away from walls to reduce reflections in the midrange and bass region, and building dead end live end rooms to achieve the same goal. BTW, this type of radiating pattern is a lot closer to the way most real musical instruments propagate sound than what comes out of most high fidelity loudspeaker systems. I've got several other systems to experiment with including AR2ax and Advent/2 and I expect similar results. I encourage anyone interested in really improving their audio systems to experiment but I'll say up front, it requires a great deal of time and patience to get it right.

This post is made possible by the generous support of people like you and our sponsors:
  Schiit Audio  

Follow Ups Full Thread
Follow Ups
You can not post to an archived thread.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]