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[Mitchco]

For some folks taking acoustic measurements, it is easier to "play" the sweep file in JRiver and have a USB mic connected to a separate laptop to capture the sweep from the loudspeakers.

REW takes care of any clock drift by using start and stop "chirps" in the sweep file being played. Attached is a screen shot to show what I mean.

However, when the sweep file is played by JRiver, it does not play the last chirp and REW throws an error message saying it did not detect the the ending timing signal and I can't hear it coming out of the speaker.

Any thoughts as to why this might be?

Kind regards,
Mitch

[Mitchco]

Ooops should have attached the file to try...

[mattkhan]

plays fine here with no DSP involved but it cuts off at the end when the convolver is on (with a typical acourate sized filter, i.e. quite long)

if I add about 350ms of silence to the end of the sweep then it plays ok, this means the total amount of silence at the end of the track is approximately equal to the delay added by the convolver

i.e. the behaviour is consistent with the playback timing (i.e. when to stop output) being blind to the DSP delay

this could be verified by using convolution filters with different delays, if true then shorter filters will be less prone to the problem.

seems like a bug to me if correct

[Mitchco]

Thanks Matt, for taking a look and catch!

I downloaded JRiver MC 26 as a fresh install on a different computer and played the file with only the Output Format enabled and the chirp at the end of the file still does not play. So I don't know what is different between your config and JRriver's default setup.

It may be cross fade or don't play silences, or prebuffering or... I am going to play with some settings today and see if I can track it down.

Again, good catch on the convolution.

Kind regards,
Mitch

[mattkhan]

I added 2s leading silence to the convolution filter and this proves that playback control is ignoring this delay (as now it cuts it off mid sweep)

I did try a few of those options (prebuffering, don't play silence) and it made no difference. I was testing on a pretty vanilla installation too (a laptop I don't use for music playback) so I don't know why it still doesn't work on yours even without the convolver active. Odd.