Issue #4 - DIRECT DRIVE
Direct Drive means that each amplifier is directly
connected by nothing but a short wire to its driver.
No intervening components.
This means getting rid of the old passive filters aka
‘crossovers’ by doing their work in the processor.
During 30 some years of designing passive filter
circuits I was constantly aware of their
shortcomings. The unavoidable cost was
degradation of the signal.
Back in the 90s we demonstrated this quite starkly
with our HOTROD series. By merely upgrading the
quality of the filter components in our standard
models we achieved obviously superior results.
But the underlying problems with those circuits
remained - they are by definition resonant circuits
that add ringing and delay.
Worse: they decouple the driver from the amplifier.
When the amp is stiffly coupled to the driver it
controls the driver's position moment by moment;
when that coupling is degraded by intervening
components the amp loses its grip and driver’s
position begins to be dominated by its own moving
mass and resonant system. So it fails to track the
This is especially noticeable in the bass. A well
coupled woofer goes "WHACK WHACK WHACK!"
Poorly coupled goes "BLUB, BLUB BLUB..."
Blunt, again: this single advantage is, by itself,
reason enough to ditch the old passive filters in
favor of Direct Drive. Just compare the two
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