Need help What monoblock power amps for bass?

Hi Atma,

Nice to talk to you again.I know that impendance on each section (speaker is tri-wired) never changes more than +/- 10%.
Also,the whole speaker (if connected to one amp) acts exactly the same.8 ohm stable, +/- 10% maximum.
Seems an easy load for any amp.At least to me.
Alan said that tube amps work great in general (SET designs and Atmasphere OTLs), and also that Pass labs amps are also a great match.
He liked the idea of of 6 monos based on 320 B XLS SET.But i think bass drivers would be better with some other amp than SET.
The problem is that here in Croatia i can not listen to and evaluate a lot of gear.I bought Sinfonia only 3 days after i heard the name "Silverline" for the first time in my life.
And in amps there are many more choices...
So i am learning as much as i can for now.

I would consider Krell. Krell can definitely get a hold of those woofers and control them.

I would recommend the Innesound amps,I have the 1KW Innersound monos driving the bass section of the German Physics Loreleys speakers,4 x12in.woofers for each mono amp,the x-over is at 180 Hz,their impedance is 4 ohms,the the amp puts out 2kw at that impedance.These amps are very fast and the resulting sound in my system is excellent.I have had the Bryston's monos they do not even come close .I also had the Acoustic Reality 1001 monos,they were far superior to the Bryston's but no match to the Innersound KW.I believe there is a pair of Innersound 750 monos listed on audiogon.I never imagined how good the bass was on my speakers till I used these amps,outstanding!!

Hi, Ramy.... I hope you are doing well.

Audiobb, I'd highly recommend auditioning the Nuforce SEV2 mono amps all around (one per speaker should do).

Several years ago the standard Nuforce Ref 9 amps replaced my custom rebuilt amp which was rated at 300 wpc@8 ohm, 600wpc@4ohm and 1200wpc@2ohm and the speakers at the time were rated at a very inefficient 86db into 4 ohm load.

The 100 lbs. custom amp was noted for a number of things especially its fabulously, deep, tight, controlling, and well-defined bass.

The 7 lbs. (each) Nuforce Ref 9 amps were even deeper, tighter, more controlling, and more well-defined, but the Nuforce were also more extended, refined and plain more musical. I sold my custom amp before the Nuforce amps were even fully burned in.

One caveat to the above recommendation, I am a Nuforce dealer. FWIW, I was not a dealer of any sort when I auditioned the Nuforce amps and it was their performance that caused me to toss my hat into the ring.

-IMO

Don't use a pot. I've tried a few in this situation and they just sounded ugly. Constant twiddling and never found the right setting. The really good audio pots are not the right range for this type of fine tuning. A series stereo attenuator in the 0-5k range should work for most combos. However, you could always just add another series resistor to a smaller range attenuator. Of course, this works a lot easier for RCA connections. XLR balanced means doubling up on everything. Series attenuators work well in this situation because they only raise impedance that was already compromised by parallel amps.

This kind of biamping, with different amps only tends to work well when the xover point is low, 150Hz or less.