Legacy Whisper bass?

[studiotech]

Does anyone out there know what Bill Dudleston is doing with the bass alignment of the Whisper? It is a dipole, but what is he achieving with the second woofer behing the first?

Also, his woofers look more like the pro sound type without much excursion capability, but I keep reading on here that one must have high excursion to successfully have an open baffle. I have heard the Wisher twice and really liked the sound in the bass region.

Greg

[JonMarsh]

Been there, done that.



The Legacy Whispers use an outboard EQ box which controls the bass alignment (boost) and gives some flexibility over the in room response.

The compound woofers acts a bit like an ISO Barik configuration.

This set here was built with some pioneer woofers, sourced for a QTS of 0.6; not all that long a throw, but lots of cone area.

It's swept volume that counts... like a big V8.

~Jon

[Bill F.]

It is a dipole, but what is he achieving with the second woofer behing the first?

I've wondered this same thing. The Whisper write-ups I've read are quite coy on this point, saying only something about how they help further narrow bass dispersion.

On relatively narrow baffles like the Whisper's, two in-phase cones would serve to lengthen the the effective front-to-back path length without bringing Fp down into the passband.

I believe their close spacing also serves to raise their Qts, since half the airload damping is effectively removed from each cone.

Just guesses--I'd love to hear Bill D's answer.

The compound woofers acts a bit like an ISO Barik configuration.

But the purpose of that alignment is to lower Vas for small boxes--the opposite of what's normally considered ideal for OBs, where the best drivers have the largest Vas.