[RFI] NOISE GADGETS

[Jim Brown]

On Wed, 10 Nov 2004 09:32:08 -0600, EDWARDS, EDDIE J wrote:

>So my question is:
>How does the change in DC resistance due to beefier cables affect the
>bass frequencies?
>
>First your saying there's no transmission line behavior due to the low
>frequencies used, then you're talking about damping factor which implies
>an impedance characteristic is in play.
>
>I always thought that as long as you had a large enough conductor to
>handle the power levels (with some safety margin) you were OK (thus the
>Monster Cable guys are full of it).  But you're saying there is some
>sort of impact to low frequency response based on the DC resistance?  
>
>Again, I'm no audio guy, but I'm having trouble putting this altogether
>in my head.  Thanks.

Read the parts of my original post about the woofer "flopping around" if there is too 
much resistance between it and the power amp. It is NOT transmission line behavior at 
all, but it IS a simple, lumped parameter, analog circuit excited by a (very) complex 
waveform.  The power amplifier can be thought of as a constant voltage source having a 
VERY low output impedance (a tenth of an ohm is typical). And the woofer has rather 
complex electrical equivalent circuit that relates to its mechanical properties and 
includes L's, C's, and R's both in series and parallel. It can be analyzed as a simple 
transient problem -- you excite the woofer with an impulse through the resistance of that 
wire. If the resistance is large, it will ring (flop around), but if it small it won't, because the 
low source resistance will damp it.  

There are many excellent engineering texts on loudspeakers if you want to learn more.

Jim