2. amps-preamps
  3. 1103538881

How to equalize a bi-amplification setup?

Greetings!

Any one experienced in bi-amplification setups with different amplifiers, where output must be equalized?

In my bi-amp setup I use one pre-amplifier connected two different amplifiers, via balanced and unbalanced connection, feeding a pair of 2-ways loudspeakers (Pass Aleph P, Pass Aleph 3 on tweeter and Pass Aleph 0s on woofer).

Problem is the Aleph 0s results in a final higher sound volume (at least +3dB). Theorically I think this should not happen as manual gain of both amplifiers indicate a +20dB gain, altough the Aleph 0s outputs much more current.

How can I "calm down" the bass amp without comprimising the sound quality and without opening the loudspeaker to introduce one attenuation circuit?
sony

Showing 3 responses by sony

sony OP
22 posts
 
Herman, you're right! I've confirmed the "problem" is the pre-amplifier. According to Pass Aleph P manual, Gain: 15dB balanced out; 9dB unbalanced out.

So, we're talking about a 6dB difference!

Cadet1, what's the model/price of the behringer parametric Eq?
sony OP
22 posts
 
Herman, that's right - only the Aleph 0s has balanced inputs.

Drrdiamond, could I extract the signal of the balanced output of the preamplifier and split it into a balanced and unbalanced connection? (one XLR to one XLR and one RCA)

Another reason for doing so is that I will have more power in the end than attenuating the signal to the bass amplifier.

Cadet1, I must say that my bass section is not a sub-bass one (200Hz), since it will be handling frequencies up to 2.5KHz, so there's a lot of midrange there. Couldn't the eq spoil it a bit?
sony OP
22 posts
 
From Nelson Pass I received an excellent tip that applies to this or other setup:

Connecting preamplifier balanced output to the amplifiers unbalanced inputs: pin 3 for Amp1, pin 2 for Amp2; both share pin 1 ground; phase of amp1 inverted at the speaker output.

If Amp1 has more gain than amp2, put pin 3 into a 10K pot.

Voila! Simple and brilliant.
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