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Discussion Starter · #1 ·
Last night a well known car audio guy said:

“You do not want to bridge two channels into one mono channel for broadband use, there are multiple phase shifts through the bandwidth. You don’t have this issue when bridging an amp for sub use when your bandwidth is set the less than 100 hz. When using amp amp in bridged (mono) for bandwidths that cover broader ranges you will encounter phase shifts between the two channels at certain frequencies. This tends to destabilize image and stage as the phase changes.

You will be having phase shifts, it happens in ALL 2 channel amps when bridged to mono use over broad frequency ranges. It’s the inter-reaction between the two channels.”

I am neither agreeing nor disagreeing with him because in my +35 years of being an amateur car stereo guy this is the first time that I have ever heard that.

To put this in context the discussion was about using bridged (or monoblock) full range amplifiers on door speakers. So I wanted to see if anyone has anymore information on Phase shifts from using full range bridged amps?
 

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Last night a well known car audio guy said:

“You do not want to bridge two channels into one mono channel for broadband use, there are multiple phase shifts through the bandwidth. You don’t have this issue when bridging an amp for sub use when your bandwidth is set the less than 100 hz. When using amp amp in bridged (mono) for bandwidths that cover broader ranges you will encounter phase shifts between the two channels at certain frequencies. This tends to destabilize image and stage as the phase changes.

You will be having phase shifts, it happens in ALL 2 channel amps when bridged to mono use over broad frequency ranges. It’s the inter-reaction between the two channels.”

I am neither agreeing nor disagreeing with him because in my +35 years of being an amateur car stereo guy this is the first time that I have ever heard that.

To put this in context the discussion was about using bridged (or monoblock) full range amplifiers on door speakers. So I wanted to see if anyone has anymore information on Phase shifts from using full range bridged amps?
Following. My recipe has been to bridge ch down for good mb power.
Perhaps in a 3way it’s not so critical, limited bandwidth


Sent from my iPhone using Tapatalk
 

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I saw that thread too. I also had never heard that specific argument before.

I would be interested in a technical explanation as to why it would happen.

I have moved away from bridging highs based on my own oscilloscope observations of the shape of waveforms on the outputs of bridged amplifiers, but that’s a completely different issue from what ray was describing.
 

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Discussion Starter · #4 · (Edited)
I am using a bridged amplifier on my center channel speaker from 200hz to 20khz.

I am also using two bridged channels (4 channels before bridged) on my two midbass speakers from 80hz to 1khz.

I did it because I needed Class D amps because of space limitations & Class D clip poorly, so I wanted as much headroom as possible.
 

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LOL. That would have to be one really terrible amplifier design. The time through the circuits necessary to create a phase shift even at high frequencies would have to be HUGE (in electrical terms).

This reminds me of the idea that one should use separate amplifiers for left and right to prevent crosstalk between the channels. Also a big LOL. Crosstalk or "chanel separation" of even 60dB is like the left channel making one watt and having a millionth of a watt bleed through to the other channel. Give me a break.
 
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