Build or buy, speaker options

I have a pair of Triangle Volante 260 speakers which I love dearly most of the time. The times that don’t love them dearly are the Fridays when I get home from work and want to shed the stress of the week with a little high energy wall of sound type tunes. As mentioned before in this forum, the midrange and high end quickly fade out after a short while at high volume, then fade back in when I turn the volume down. Georgehifi posited that it could be iron core inductors in the crossovers getting saturated, and that sounded feasible. But, in an email conversation with Madisound, their tech indicated that he’d never experienced such a behavior, and that saturated inductors were more likely to exhibit distortion. The tech ask for some photos of the crossover, but I wasn’t able to get a clear shot of one of them, and trying to remove one from the cabinet proved much more involved than I thought it would. No good photos, but I did see iron core inductors, for sure. The Madisound tech thought “Maybe they are using poly switches that close when the power is too high, putting the speakers through a resistor”.  This is something I’ve never heard of, so I’m totally unfamiliar with poly switches or what they might look like.  It’s looking like I may not be able to solve this problem. 

The options I’m considering are selling the Triangles, and purchasing used market speakers, or building my dream speakers.  

If purchasing used, the qualities I like in a speaker are: detail, frequency balanced but leaning slightly toward warmth, tight punchy bass with authority, and higher frequencies that are truthful and never screeching. They would also need to handle a fair amount of SPL without strain. Amplifiers are Parasound JC 1’s.

If making my own, I’d be shooting for the same qualities. With that in mind, I’m considering a sealed cabinet design for two 8” woofers.  Separate cabinets for midrange and tweeters, also sealed. I think I’ve decided on the drivers for the bass cabinets, the Morel CAW938 9" Woofer, which is an excellent driver for sealed design. The midrange, I’m considering either one or two drivers per cabinet, the reason for two would be power handling, although I’m also thinking that this may be overkill, and that one driver per, with good power handling may be the ticket. Manufacturers I’m considering for midrange are Morel, Seas, and ScanSpeak. Tweeters are yet another big question, but the more I research the topic, the more I lean toward soft domes, same manufacturers as the midrange. 

Crossovers are yet another War and Peace length set of considerations,  but I am thinking about active crossover between the bass cabinets and the mid/tweeter cabinets, a passive crossover between the mids/tweeters. Amps for the bass cabinets would be newly acquired D class, possibly in the 500 wpc range. I’d use the JC’s for the mid/tweeters cabinets. 

I’d be interested in any advice, comments, experiences of others, as long as they aren’t overtly rude.  Budget for either purchased or built would be in the $4000-$6000 range.  

And, I’ve been following with interest a thread on this forum regarding the merits/drawbacks of sealed and ported systems. Some interesting observations and opinions.