Re: Audio Delay Circuit

From: Mac (foo_at_bar.net)
Date: 10/27/04 

Date: Wed, 27 Oct 2004 05:46:58 GMT

On Wed, 27 Oct 2004 04:58:08 +0000, George W wrote:

> I have a need to measure the relative delay between two audio signals
> arriving at a receiver via different paths. The audio signals are standard
> 3 kHz audio bandwidths containing voice or music. One could arrive as much
> as 1 msec before or after the other. I'd like to be able to measure the
> difference in time of arrival between the two signals down to 1 usec if
> that's possible.
>
> Any suggestions? I'm thinking of using a 180 degree phase shifter and
> adjusting a variable delay line for a null when the signals are summed.
>
> Thanks.
>
> George

Nowadays it might be cheap enough to do a DSP based solution. You might
not need an actual DSP. You might be able to just use programmable
logic, but the idea is to correlate the two signals and find out where
the maximum is of the correlation function.

Or something like that. I'd have to look into the details. ;-)

--Mac

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