2. amps-preamps
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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
cadet1
50 posts
 
I BI-Amp the lows with a different amp and use a behringer parametric Eq to adjust the input sensitivity and equalize two room resonances. I realize I am putting another device between the preamp and bass amp, however the ability to have relatively flat in room bass responce far outways the negatives. (At least for me)Pipe organ is a joy without that 40Hz room resonance I used to have and I don't have to mess with the mids and treble.
sogood51
2,157 posts
 
I don't remember your gear...it's been a while. Can you switch inputs on the amps so that the extra gain from using balanced is on the upper freq's and not the bass. 3db is not a lot and may be able to be smoothed out a little from speaker placement with a pick-up of 1-2db in the bass freq's through room gain.

I usually don't post on gear I'm no longer up on but did use this type of approach at one time in a past setup...sounded much more in step so if no use with your problem...may help someone else latter.

Dave

Dave
sogood51
2,157 posts
 
I don't remember your gear...it's been a while. Can you switch inputs on the amps so that the extra gain from using balanced is on the upper freq's and not the bass. 3db is not a lot and may be able to be smoothed out a little from speaker placement with a pick-up of 1-2db in the bass freq's through room gain.

I usually don't post on gear I'm no longer up on but did use this type of approach at one time in a past setup...sounded much more in step so if no use with your problem...may help someone else latter.

Dave
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?
cadet1
50 posts
 
Behringer PEQ 2200 Ultra-Q 5 band parametric. On sale at parts express for $69.99. These are mono so you would need 2. very good for the money. In case you are wondering, my syster is proceed electronics and revel M-20 speakers with DIY subs which are equalized. I hope to soon get revel studio's and passively bi-amp and eq the woofer section below 200 Hz. Parts express has a return policy so you can't go wrong.
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