Re: Monster Cables

"Chris Hornbeck" <chrishornbeckremovethis@xxxxxxx> wrote in
message news:94pom3t2c8vjld76nihcjtui8ck0ronktj@xxxxxxx
On Fri, 21 Dec 2007 21:22:35 +0100, Chel van Gennip
<chel-news@xxxxxxxxxxxx> wrote:

The model of damping, or forcing exact movements of the
voice coil, is that the voltage induced by the coil
moving through the magnetic field equals the output
voltage of the amplifier. This works best if any
difference between these voltages result in a high
current (and so a big force from the coil in the
magnetic field). This will work best if the total
resistance in the loop is about zero, or as the
(resistive) output impedance of the amplifier is about
the same as the resistance of the voice coil, but
negative.

Tests show indeed an improvement, especially at low
frequencies, when you use an amplifier with a negative
output impedance.

Depends on how you define "improvement".

Damping is improved indefinitely with lower total (wire
plus voice coil) resistive losses.

Yes, but cutting voice coil resistance beyond a certain point isn't easy.

Magnitude response is a judgement call; many would prefer
a Butterworth or some other particular response which
would call for a particular total (wire plus voice coil)
series resistance.

Which magnitude is that? Most listeners judge speakers about acoustic
performance in a real-world listening room. The transfer function from the
speaker to the ear is usually such that the speaker response is only
peripherally responsible for the final result. IOW, if you put different
speakers in the same room, you get results that are far more similar than
the same speaker in different rooms.

But it is possible, with sufficiently large sealed boxes
and sufficiently large motors, to overdamp a resonant
system for someone's definition of "overdamping". So
"improvement" is specific. Just to kibbitz...

There's a current school of thought for building woofers that says that you
build a horrifically overdamped speaker, because that's what you get with a
speaker with a good sized magnet in a tiny box. You want the good magnet
for modest efficiency. Then equalize it for the desired response. The
equalizer obviously trashes the damping in the bass because its a big
resonant bass boost network. But, you get the desired bass response.


.

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