Archived from groups: rec.audio.pro (
More info?)
The IAS sub only used two drivers, plus a lot of DSP. The idea isn't
to "aim" the sound, per se, since that would require a much larger
array. The idea is to alter the directivity index as a function of
frequency, to compensate for energy storage in the room.
The approach also gives you a fighting chance at matching the
directivity of the sub to the sats at the crossover point. (This is
often a problem with the sound of most sub/sat systems, in my
opinion.) For example, in one of our demo rooms, we mated the subs to
a pair of Quads. The subs were fully monopolar at the lowest
frequencies, and gradually transitioned to dipolar operation at the 80
Hz crossover point. The goal was to try and get the a fairly seamless
integration, while preserving the really deep bass.
-k
mrivers@d-and-d.com (Mike Rivers) wrote in message news:<znr1101230282k@trad>...
> In article <cnvkhv$aco$1@panix2.panix.com> kludge@panix.com writes:
>
> > >Ken Kantor's company after NHT Pro (before his present one) had an
> > >instantantaneously steerable subwoofer
>
> > How many individual drivers did it have?
>
> I can't recall for sure but my impression is that it had two
> back-to-back and maybe a third one. Kind of worked like an MS
> microphone in reverse (or an ILS). Lotsa DSP