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Pros an cons regarding bridging amplifiers

sergeauckland

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#21
If you can bi amp your speakers then use an amp running in stereo for each speaker. One channel for the highs & the other for the lows.
Increased power and you don't need to bridge.
If by biamping you mean retaining the passive crossover, it will make zero difference. This is because the voltage available across each section remains the same, so no increase in power. Furthermore, unless the amplifier is unstable and of marginal performance, the superposition principle ensures no benefit.

If by biamping you means removing the passive crossover and using an active crossover, then yes, that can bring many benefits, not least of which is more volts across each section before clipping.

S.
 

DonH56

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#22
A big consideration is residual noise when you bridge. It basically doubles. With big power amplifiers and sensitive speakers, it becomes an issue.
Technically, someplace between sqrt(2) and doubling... The SNR gain should be 3 dB as voltage doubles linearly (+6 dB) whilst noise from two uncorrelated sources should RSS and thus increase 1.414... times (3 dB). So bridging should provide a 3 dB boost in SNR. The catch is, as John says, the noise floor is fundamentally higher, so folk bridging amps may have hiss they did not have before.

The other issue is that some noise, like power supply noise, is correlated. If the amps are perfectly out of phase they could cancel the 50/60 Hz (or whatever) power supply noise, but if they are completely in-phase they could double. Real-world is probably someplace in between.

Stability is another consideration. If your speaker dips to 2-3 ohms with a high phase angle, not all that uncommon, then your bridged amp must be stable into a 1-1.5 ohm load.
 

Wusbag

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#23
If by biamping you mean retaining the passive crossover, it will make zero difference. This is because the voltage available across each section remains the same, so no increase in power. Furthermore, unless the amplifier is unstable and of marginal performance, the superposition principle ensures no benefit.

If by biamping you means removing the passive crossover and using an active crossover, then yes, that can bring many benefits, not least of which is more volts across each section before clipping.

S.
Thanks for the info.
I will admit that I don't know the science behind it.
I just know that when I set up this way I was able to get improved non distorted volume.
When I bridged the amps would shut down at high volume.
 
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