A cursory poll of current subwoofer designs competing for the lowest, loudest, baddest bass? It shows them all almost exclusively devoted to first driving down transducer resonances for the lowest possible reach. Remember, unlike midrange and treble units -- always crossed out well before approaching critical cone resonance threshold -- bass drivers, by definition, run without electronic low-pass filters. Downwards, they operate wide open to attain their low frequency extension. Why would you stop 'em short? Because they'll go out of control once hitting self-resonance? This lousy check-in with reality sets off self-fulfilling prophecies. Large driver diameters. High mass. Long strokes. Steep associated power requirements. Accelerometer feedback loops. Error correction circuits. And surrounding it all, the gleefully adolescent fascination with size and SPLs. Quite a kettle of (rotten?) fish, this. |
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Therein does lie the real rub, true. This brute force approach of woofers-on-steroids [see left for an example] gave rise to the concomitant observation of slow bass in the first place. Did the speed of sound constant momentarily -- and very unscientifically -- forget to operate in customary fashion at lower frequencies? Not at all. It's simply that a high-excursion driver takes more time to complete a single cycle of rarefaction and compression than, say a horn-loaded driver whose output is acoustically amplified to require a far shorter and thus faster excursion cycle for the same output level. By transitioning to larger and larger woofers with more grotesque strokes, another common victim in the races for high output/low frequency records became the now unavoidable time delay between the fundamentals and their upper harmonics. Astute listeners noticed that the bass lagged behind the remainder of the spectrum. It also didn't blend, fundamentals and harmonics arriving out of sync, clearly not part of the main speaker system. Far smaller drivers would be the ticket to gain speed and coherence - if they could go low enough loud enough, be liberated from asymmetrical pressure buildup, retain low driver mass and cone travel requirements and be guaranteed immunity from room reflections. What a wish list. |
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As I reported briefly in my CES 2003 report, VBT does approach low bass radically differently. My stunned exposure to their patent-pending solution in that hotel room had already regressed me. I'd slipped from the "common knowledge" of that's impossible to the head-scratching ignorance of hot damn, it works exactly as claimed. How to regain one's primate intellectual self-confidence in the face of such impertinence? Secure at least a rough appreciation for the underlying concept so you can think to yourself: Of course, that's - so obvious. Can't imagine how anyone wouldn't see that. Yeah, right.
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