Great bass amp SS for 15" 8 ohm woof 800hz max

I'm looking into biamping a speaker system. Using a 2A3amp on the top (800 Hz up on a horn) 2a3 has volume pots. Looking for recommendations for a great solid state amp to handle the the lower 800hz. It must match up with the 2A3 rich midrange. The woofer is 15" and is 98DB efficent.

Depending on your budget, some options might include the Bryston 4B-ST, or Krell KSA 150 or 250. The Krells are powerful, controlled, and tuneful. Others may disagree, but I am less of a fan of the later Krells in this application.

I have never heard it above a crossover point of 50Hz, but I am using a Crown Ref.1. It is 800 wpc and has a damping factor of over 20k. I am using it to drive 18 inch drivers from 35 Hz on down. In that application, it is wonderful and extremely controlled, but I haven't a clue how it would perform in upper bass to mid range area. For all I know, it might peel paint beyond 100Hz. I'm sure you will get other opinions.

If you really want to go nuts, get a pair of Levinson 33s (240v). The 33h is also wonderful, but, to my ears, sonically not as good in any area (power demands aside).
Hello Hicourt -

I would like to gently suggest that you may be headed in the wrong direction by trying to match a solid-state amp with your existing tube unit. This can sometimes be done successfully when the crossover frequency is low - around 100Hz or lower (the lower the better). In your case, the crossover point is well into the upper midrange, and I believe you will find it difficult (or impossible) to create a coherent blend given that there are few, if any, SS amps that match the voicing of your 2A3 tube unit. In fact, because the crossover point is so high, you may have some trouble doing this with other types of tube amps. System coherence is a critical issue, and a very tricky problem when crossing over in the midrange. I suspect that you would get the best coherence by using another 2A3 amp, but if this doesn't deliver the bass performance you are looking for, then another tube amp that is at least similar in design (with more power, perhaps) should do the trick.

Have fun!

Best regards,

Steve McCormack
Hello Hicourt,

Apart from subwoofer applications, it really is important to match up the amplifiers as close as possible in a bi-amplified system. I have several customers who have tried solid state on bass, tubes on mids & highs in their systems, with mixed results. Most have gone back to using a single amplifier or biamplifying with identical amplifiers. It's hard enough to get two different drivers to blend seamlessly without driving them with differently-voiced amplifiers.

I can't think of very many solid state amps that might (just might) be a reasonably good match for a 2A3 SET amp. You might try Pass Alephs or the Accuphase A50, but I think you'd be better served by perhaps something like a 211 or 845 SET if you want more power in the bottom octaves. Then at least you could roll tubes to more closely approximate the voicing of the 2A3. You might ask the advice of your 2A3 manufacturer on this.

On the other hand, using a single high-quality large SET amp full-range and forgoing the 2A3 altogether would probably give you a more coherent presentation, and might (or might not) be better overall. Then you could switch back to the 2A3 for low volume listening (or sell it to finance the larger amp purchase).

Just curious, if you don't mind sharing - what driver & horn are you using on top, and what woofer for the bottom?

Best of luck to you,

Hi again Hicourt,

Althoug I answered you question quite literally, I agree with the following posts. I can't imagine how two different amps of any sort would blend well at 800Hz. I do believe you would just be playing with a low probability game of trial and error. I believe that Steve and Duke are correct and would suggest that you consider another road.

I too amd curious about your speaker application. I keep thinking that it sounds like an old Altec horn system based on your crossover frequency and woofer size, although I imagine that there are many possibilities.

Let us know what you decide,