Sound Card Cal Issue

[krsstyles]

Hi guys, I'm trying to create a sound card file (avid hd native and a omni) when I try and do this at 44.1k sample rate I get a weird freq response. I have tried all the avid mixer settings for over week now. The only way I can get a decent file is if the sample rate is at 96k. I have attached the file below if some one could have a look.

Kind regards,
Kunal

 

[John Mulcahy]

Quite an old build, currently on beta 50, but that probably isn't a factor. When you change sample rate in REW you need to also change the rate the card is configured for in Audio Midi setup, that may help. It looks like the problem might be a large latency somewhere though, causing the end of the sweep to be missed, which is difficult for the soundcard cal to deal with. On the plus side there is no sign of monitoring feedback, picking that up is one of the main reasons to do the cal, so you will be fine carrying on without a cal file. When measuring if you use the acoustic timing reference option any latency issues will be dealt with automatically.

 

[krsstyles]

Thanks John, for the quick reply!

I have updated the build to 49. My sample rate was set the same on the soundcard and your app but I realised after reading your message I had to set the buffers the same on both apps too. Any buffer size over 64k on avid hd native would cause latency and I could see from the live graph reading when doing the measurement the latency did allow the measurement to finishes as you said.

Happy this is sorted but for measurements I have my Omni L+R going in the sub and then sub outs into monitors is this the best way to take measurements or should all the monitors go to separate channels on my soundcard and sound card out 3 in to sub LFE or sub L or R?

Thanks for all the help!
Kunal

 

[John Mulcahy]

If you are interested in the sub to mains integration then as you have them connected sounds fine.