2. amps-preamps
  3. 1131913685

Bi-Amping

Hi everyone,

Well I steped up to dual power amps and bi-amping my custom made (self built) speaker system that I have finally finished- Cerwin Vega 15 inch subs, Vifa 8" bass and 6.5 Mid bass, dual Vifa 3 inch SoftDome mids, with a Morel 30's for the tweeter. The subs are @ 80Hz (via the B&K), the speakers are crossed @ 300Hz, 500Hz, 700Hz, and 3200Hz- 2nd order for the lows and 3rd order for the highs. One amp runs the subs and the other the speakers.

I am using two (2) Proton D-1200's, a B&K PT5 preamp, with an Audio refinement CD player. I am running Monster MCX 2s wire (4- 15' foot runs), Audio Quest power cables, and Monster M850i Interconnects, this is connected to a dedicated 20A wall outlet.

My room size is 28x14, shot gun style, painted dry wall, and half carpeted/harwood flooring, 8' room height.

My question is: I was expecting a more powerful sound then what I have presently. While everything did open up, it seems the DB output did not increase substantially, as a matter of fact, it seems I must now nearly max the volume control on the B&K to achive similar output when I was using a single amplifer. All be it, the sound is more refined and much tighter, the DB output did not increase. And I am concerned that the B&K is having trouble outputing enough voltage to run two amplifiers.

Is this the norm? Am I not suppling enough "juice" to the amplifiers via the wall outlet? Or, do I have to large a "hole" between the subs and the Speakers?

While this does sound very impressive, I am not as "jazzed" as I thought I would be.

Any ideas, comments, help?
alpha_03

Showing 3 responses by whoaru99

whoaru99
98 posts
 
It's going pretty much as it should.

I think those amps are 100 w/ch each, yes?

Even if both amps were fully additive in the bi-amped configuration and equal to 200 w/ch, it would be only a 3dB increase in volume. 3dB is generally the point at which people just start to notice a difference in the loudness. This is the best case scenario.

If much louder is what you want, you'll have to come up with much more powerful amps. It will take roughly 10 times the power you have now to make the system sound twice as loud.
whoaru99
98 posts
 
Even with active x-overs etc. going from 100 watts to 200 watts is at best only 3dB increase. This is just past the verge of an audible increase in SPL.
whoaru99
98 posts
 
Nobody is questioning the Proton amps - I'm sure they are very nice.

Pretty much the bottom line is that the very best case only provides 3dB more volume doing what you are doing and the average case, less than 3dB. So, it is no surprise to some and no indication of a problem that you hear little difference; it is what it is and the principles of physics/acoustics/electronics are what they are.

If you want significantly louder you will need to drive the speakers with much more powerful amplification.
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