SET on JBL Everests - Mouse breeding an elephant?

The real treat it seems would be running the DD67000’s actively - have you considered that?

https://positive-feedback.com/interviews/greg-timbers-jbl/

Wow the active system sure looks complex. I wonder why TWO bass amps.. and 4 amps per speaker.

A pair would be fine.

Mac 275s aren't at their best when stacked like that. Series or Paralleled, the SQ suffers.

I'd use one Mac 275 get a couple of good NOS Telefunken signal valves and a pair of good SS bass amps. 

Honestly for 1000.00 USD I could tear the pants off the set up you currently have. No SET involved. Those 275 sound a LOT better unbridged. You could use one for the mids and one for the highs or one for both.

THEN serious high watt cool running class d amps for the bass. Me I'm not into looks when it comes to BASS amps.. I'm looking for reliability, sound quality, big clean power supplies and enough dampening.. period!! I like circuit breakers in my bass amps too..

I use 12k Behringers on everything now.. 1000hz down nothing better..
and good to 1 ohm. ONE would bounce those JBLs all over in the BASS section, TWO one per side and 2 MC275s.. for the lows and highs..

You'll think 22 X 40 with vaulted ceilings.. You'll think Amphitheater!!

BTW they are 3-500.00 each.. I do a little fan mod and they are completely silent.. 3500 + watts per channel at 2 ohms 1750 @ 8 ohms

MC275 bridged.. ?? I remember VERY well. I did MC240 twice, bridged, it took a lot of work to make them sound right.. 275s were just LOUD..

VOT speakers.. 80s... They were used for square dancing 150 x 150.

I loved that job... Russco record players too..

Regards

+1 phusis - Always bi-amp at least. They will sound so much better even at low volumes and with all types of music.

I have to apologize for posting such a confusing question.  Let me start over.  I am using one bridged 275 to power the left speaker and a second bridged 275 to power the other speaker.  No biamping.  I’m using the internal crossovers.  A buddy has built an Elekit TU 8600s SET for his Valencias and the result is VERY impressive.  I have been wondering how it would sound on my Everests.  I know it could never handle four 15”s when playing music with any significant bass signal, but what about music that has an almost exclusively mid/tweeter signal - jazz ensembles, classical or jazz piano, acoustic guitar and such?  Perhaps the Elekit could work then?
 I’d have to put some sort of switching system into the mix to go from one amplification system (the 2 bridged 275s) to the other amplification system (the SET), depending on the type of music.  Complicated, yes, but man o man, the thing is really magic on my friend’s Valencias.  And my Everests are almost as efficient.  
Probably too much trouble to fool with.  I’m already tired of it, just trying to explain what I was thinking….

   ''Always bi-amp at least.''
I agree, my JBL 4435 monitors sound better active then passive.