SET on JBL Everests - Mouse breeding an elephant?

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

You would be better off unbridging the amps and using one for bass and one for mids and highs.. That would sound better than bridged MC275s believe me.. 50 years with Macs, you don't bridge any of the 225, 240, or 275s without some serious reworks for SQ.. They just don't cut it for me.. or anyone I know.. Loud yes quality no.. Either way vertical or horizontal, The horizontal is better.  The channel load is more equal.

Still better off with SS for bass management.. JBLs use to be wired different to.. because of the JBL driver phase shift.. I like um... one of my all time favorites.. JBLs, Especially the Everest series.

Regards

Impedance phase angles are large at low frequencies, though, so the EPDR (equivalent peak dissipation resistance) drops to a minimum of 2.0ohm at 72Hz, and at the other end of the audible spectrum to 2.1ohm at 18.6kHz. So the DD67000 is far from being a testing amplifier load, but it isn’t a pussy cat.

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You want a serious amp. 2.1 ohm load will heat up an amp in a heart beat.. The question is how much of your music is at either end of the scale. 72 hz or 18.6khz, answer not much.

That MC452 and a single MC275. You’ll like that a WHOLE lot more than the current set up.. Maybe not quite the eye candy, but SQ wise a lot better. Get a good set of Mid/High frequency cables for the MC275, maybe OCC/Silver clad ribbons with PTFE covers. Good heavy OCC or OFC copper with PTFE covers for the bass.. 150-250.00 maybe for both pairs.. 3 meter

You already have a good set of amps..... Xtra cables ..

Invest in some good Telefunken signal valves.. 2-300.00 you're WAY better off SQ wise.. Mac and Telefunken valves go together like milk and cookies..

Enjoy..