Klipsch Cornwall IV

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

Having owned Cornwall IIs and Bob Crites Cornscalas I will say that the cabinet of the CW IV has very little cabinet coloration that I can discern. The older cornwalls, and from what I've read, even the CW III, all had some form of cabinet resonance. So did Bob's cornscalas, which is the number one reason I sold them even after damping the horns and upgrading the crossovers.

I hear none of that in the Cornwall IV.

Oz

I have my grills on.  I take them off now and then, but honestly, like you say, the speaker sounds great with them on and they look cool and the spousal acceptance factor is very high.  Very retro looking.  Is it a perfect speaker?  Is there a perfect speaker?   They are fun and mine are driven by an entirely tube setup that I built and they see about 64 watts/ch.   The amp really doesn't know they are connected.  Unlimited headroom.   The comment above on the bass is my take as well.  Good and quick until the mid 30's.   I just got a pair of Hsu uls-15 mk2 subs like Oz has and they provide the fill in below 40 Hz.  They hardly come on, but they definitely provide a nice fill.   It is a very good system and really, I don't need more.  Someday I might build an entirely new crossover with the same ODAM caps and the pathaudio resistors I used, but seek out better inductors.  I may rebuild the speaker terminals with something a little more convenient and just internally solder the HF leads so there is only one set of inputs.  I am not into bi-wiring.   Maybe I will get around to this stuff and maybe not.  Sounds great as it is.  I think the imaging grade of B+ was pretty accurate with the stock crossovers.   Putting much better caps in and better resistors brings them into the A range....