Klipsch Cornwall IV

Yes, thanks Don. I was puzzling over this myself.

According to their site it is basically a shielded resistor.  I have no idea why that would be necessary, but anyway there is no hum of any sort, the speaker sounds great, I didn't change the values of any parts so the crossover functions as it always has, just sounds better.

I have now damped the tweeter, midhorn, and the three bass ports.  Very easy modification. 

The crossovers are next.  I have to sell something to fund the upgrade. I'd rather go in there once and do it the right way.  So, I'm going to need ~$900.  

Donsachs, do you have any opinion on adding damping to the inside of the cabinet?  It seems to be calling for it.  My concern would be that in lowering the resonance (a good thing) it might create a reflective surface for sounds to bounce around too much and change the voicing. 

jb,
Years ago in my Klipsch Epics i attached sheets of Blackhole, a multi layer anti-resonance sheet for speaker cabinets, and it improved the silence of the cabinet dramatically. I do remember reading in a couple of places that you should not put damping material on the back of the baffle. I don't know why that would be wrong, but I took the advice.

I don't know about damping the cabinets.  They may be as lively as Klipsch wanted to work with the woofer to get the sound they want.  Or not....  The easiest thing is to make whatever you are doing removeable so you can put it back to stock if you don't like the change