Altec Valencia shrillness

[Cal Weldon]

One rheostat is connected in series with the loudspeaker and, as the [[Electrical resistance|resistance]] of this rheostat increases, less power is coupled into the loudspeaker and the [[loudness]] of sound produced by the loudspeaker decreases. The second rheostat is connected between the input and ground (earth). As the first rheostat increases in resistance, the second rheostat decreases in resistance, keeping the load impedance (presented at the input of the L pad) constant.

Right so why am I yet to see an Altec L-pad actually wired that way? I only see them being used as a variable resistor ie: two leads connected.

Cheap L-Pads may just be a rheostat

IMHO opinion that is not an L-pad, it is a simple variable resistor which when used as such will change not only the apparent volume but the load seen by that section of the XO which in turn alters the slope and frequency cut off point of the driver as it is rotated (operated).