On 2014-03-28, Charles Z Henry wrote:
Probably everybody knows that you lose something when you mic a bass drum and send the output to a vented box subwoofer. It lags a little bit behind and the tone gets smeared out in time by the resonance. A successful loudspeaker like this would be able to reproduce impulses (drum hits, canons, etc...) with greater clarity.
That's an excellent point, and the reasoning is similar to why I for one as a techno freak have always preferred closed speaker designs to reflex ones. A well constructed speaker behaves approximately as a minimum phase system wrt the listener, so the gentler the amplitude variation, the gentler the envelope smear caused by group delay variation as well. That's a particular problem at the low end, and you really, *really* can hear the difference even between a critically tuned reflex and a closed box.
If you want to get a hold of what it sounds like and don't want to do real filter design, try an allpass with severe phase nonlinearity at the bass frequencies (a comb allpass section with near unity gain and long delay will do). It's by definition not minimum phase so you can't do anything quantitative done, but it'll get the job one as far as phase goes. A sharp acoustic kick or practically any one of the snappier standard ways of synthesizing tech bass drums will do. They turn from kick to a distinctive slurp, and lose a good amount of their subjective power. Once you get the taste of it, you'll learn to absolutely hate the effect. Of course that'll then try your sanity, since nowadays pretty much every home theatre comes with a subwoofer that is sluggish in that way, not to mention what your typical poorly damped room modes contribute besides. With orchestral music it's not such a problem because the aesthetics favour lively halls and steady state content, but anything electronic or percussive, with lots of sharp transients and a wide bass extension simply turns to mush.
-- Sampo Syreeni, aka decoy - de...@iki.fi, http://decoy.iki.fi/front +358-40-3255353, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2 -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
