Impulse Graph Question

boxerfan88

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Preamp, Processor or Receiver
Yamaha RX-A3030
Main Amp
DA&T A38 Integrated
Front Speakers
Usher Mini Dancer 2
Center Channel Speaker
Usher
Surround Speakers
Bose
Subwoofers
Orisun DD12
Video Display Device
Samsung Plasma TV
Hello there,

I am trying to make sense about the double spike in the L+R stereo sweep, and understand what it means. Maybe someone out here can help educate me.


Stereo sweep shows a double impulse about 120uS apart...I wonder why? Is it because the L and R speakers are time offset by that amount?

Impulse-LR (stereo).png



The impulse overlay graph (L-pink; R-red; L+R_green):

Impulse Overlay.png




The individual speaker sweeps shows only a single impulse (as expected).

Impulse-L.png
Impulse-R.png



Thank you in advance for any feedback about the double impulse.
 

boxerfan88

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Aug 18, 2019
Messages
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Preamp, Processor or Receiver
Yamaha RX-A3030
Main Amp
DA&T A38 Integrated
Front Speakers
Usher Mini Dancer 2
Center Channel Speaker
Usher
Surround Speakers
Bose
Subwoofers
Orisun DD12
Video Display Device
Samsung Plasma TV
Thank you very much. Now I understand.

Am I right to assume that 120 uS delay is not a problem?
What's the threshold that one should get worried about?


Researching the web seems to suggest 10ms-20ms (10000uS - 20000uS)...
 

sm52

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Mar 14, 2019
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Am I right to assume that 120 uS delay is not a problem?
If there is a delay between the left and right channels relative to the position of the microphone, then this is not a delay, but a different distance from the microphone to the left channel and from the microphone to the right channel. It is not necessary to measure both channels at once.
 

boxerfan88

Registered
Thread Starter
Joined
Aug 18, 2019
Messages
24
More  
Preamp, Processor or Receiver
Yamaha RX-A3030
Main Amp
DA&T A38 Integrated
Front Speakers
Usher Mini Dancer 2
Center Channel Speaker
Usher
Surround Speakers
Bose
Subwoofers
Orisun DD12
Video Display Device
Samsung Plasma TV
I see. Thank you.
 
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