Acoustic timing reference not triggering?

[markr5485]

Hello, very new to REW so please bear with me. I tried searching but couldn't find anything to fix the issue.

When trying to run a measurement with acoustic timing reference, REW doesn't pick up the starting timing reference. It does pick up the final timing reference, but it treats it as the initial timing reference and doesn't measure the sweep. Hope that makes sense...here's an example:

1. Press run sweep.
2. Initial timing reference plays. REW shows "capturing noise floor" while the initial timing reference plays.
3. Sweep plays. REW shows "waiting for timing reference"
4. Ending timing reference plays and REW recognizes this as the initial. "Remaining sweeps: 1".
5. Once the time runs out, an error comes up saying "Timing reference not recognized"

Here's what I'm using:
Macbook Pro M1 with latest version of REW
Denon s760h connected via HDMI
miniDSP
UMIK-1 connected via a USB hub (only USB C ports on the Macbook)

Any tips on getting this fixed? Without the timing reference selected the graphs look normal, but I'm trying to time align the subs and need the acoustic timing reference from what I understand.

Thank you!

 

[John Mulcahy]

The AVR may be taking a while to detect and start playing the signal and not actually put anything out until after the first timing reference has already happened. REW puts out a burst of very low level dither before the sweep to try and get around that, but it might not be enough. On the Measure dialog for the V5.20.14 early access builds there is an option to "Fill silence with dither" which does even more filling in to try and get devices to lock onto the signal and stay locked on, worth trying that.

 

[markr5485]

The AVR may be taking a while to detect and start playing the signal and not actually put anything out until after the first timing reference has already happened. REW puts out a burst of very low level dither before the sweep to try and get around that, but it might not be enough. On the Measure dialog for the V5.20.14 early access builds there is an option to "Fill silence with dither" which does even more filling in to try and get devices to lock onto the signal and stay locked on, worth trying that.

Appreciate the quick reply!

I'm on V5.20.14 and just tried "Fill silence with dither" but the same problem occurs.

Any other suggestions?

 

[John Mulcahy]

You could try doing a check levels immediately before starting the measurement.

 

[John Mulcahy]

I have doubled the time REW spends putting out a dither signal when "Fill silence with dither" is selected to see if that helps, change is in the latest 5.20.14 build.

 

[jean38]

Jai eu un problème identique sur la deuxième référence ( la première fonctionnait , mais pas la deuxième) . J'avais bien désactivé le microphone du pc et les haut-parleurs dans le panneau de contrôle de Asio4all. Après avoir avoir installé la version 5.20.14 , toujours le même souci.
Bref, en retournant sur le panneau de configuration des sorties sous windows , j'ai désactivé le microphone du PC , et là la deuxième référence a fonctionné .