Change to Horns or stay Dynamic

Exlibris-

None of the amps you've tried or mention can generate the
2.2kW peaks your speakers are capable of handling.

The Spectron Musician III SE Mk. 2 monos can deliver 7000 watts (and hold it for 500 msec).

But like you say, "the problem isn't amplification, it’s the drivers."

It must be very disappointing to spend over $40K on speakers and find out their drivers come up short of the volume levels you want.

Good luck with your search for new speakers.

Dgad-

Check out:
http://www.stereotimes.com/speak010708.shtml

PS- Amazing how Dcstep can tell your system isn't properly set up without ever hearing it.

"The -only- reservation I have about my MBL 101Es is that they too get congested at loud volumes during complex passages. They lose detail and smear and the soundstage becomes confused."

I'll bet any speakers with a sensitivity of 81dB/2.83V/m powered by 40watt tube amps(no offence to current owners intended), will sound congested if you try and push them past 93db in a big room.

Solution: Spectron Musician III SE Mk. 2 monoblock amplifiers.

"The Jazz module is similar in design to the Summa. It has recently received a golden ear award from TAS"

The TAS GEA was given to Duke's Dream Maker.

Duke-

Congrats on the TAS GEA!

Seems like you're saying the radiation pattern of horn speakers are just as important as their increased dynamic contrast. Less negative room interaction = better
spectral balance.

I note that you're a Gradient dealer. Their new Helsinki 1.5, which are designed to reduce room interactions, seems like the ticket to a more natural-sounding spectral balance.