Do the speakers sound good in stereo set to full range? If so you’ve obviously got no issue and it’s all in the crossover. Also, when income allows don’t get an amp — get a stereo integrated amp. Getting the Denon’s preamp outta the picture for stereo listening is at least as important as upgrading the amp if not more. The preamp section of your AVR sucks — they pretty much all do — and the preamp is crucial to get the best performance out of a system. Just my $0.02 FWIW.
Electrostatic Speakers Vs. Horn/component Tweeter
I’m curious… when a horn or tweeter goes bad, it’s clearly obvious. The driver is shot and the audio sounds clipped and distorted. Electrostatic however, have massive surface areas and use static electricity to vibrate the material…. So when an electrostatic speaker goes bad, what actually happens to cause it to go bad, and does it go bad like a tweeter, where it goes from sounding fine to sounding like crap in a split second? Or will an electrostatic speaker slowly decay over time, so you don’t notice it initially, and then one day, it just doesn’t sound as good as you remember it sounding? If an electrostatic speaker goes bad, what causes it? Is it torn material? Is it something where you can replace a single small part? Or do you typically have to replace the entire panel?
I’ve come across plenty of blown regular speakers in my life, but never a blown (if that’s even possible) electrostatic speaker.