New (but guided) REW session queries

[jont-uk]

Hi - new(ish) REW user/lurker and decided to give my system a calibrate last weekend to better integrate my 3xGallo MPS150 subs, 4 Gallo micro surrounds, B&W805 and HTM2 together. I was on a call/TeamViewer session with a UK AVForum/REW expert and we walked through the REW sweeps/timing/crossover/etc and then ran the DIRAC for my Arcam AVR550 to take control of the room EQ and then a final REW review to tidy up any sub issues.

Overall the process steps worked out but we had some issues that meant we couldn't complete the calibration successfully and are trying to work out what the issue is.

I am running the latest Mac version of REW on my M1 MacBook Pro running Monterrey 12.5 with a Umik-1. Connected to the Arcam by HDMI and 8.1 16 bit/48Hz setup selected in Audio MIDI panel.

First inconsistency was the level of the tones generated by the Audio Midi setup on the Mac in relation to the REW tones (which were 10db louder) and the inbuilt tones from the Arcam which measured the same as the Mac tones (no gain applied in the Arcam) ?

Second was after swapping the C and LFE channel mapping in REW (which I understand is a HDMI connection bug/issue) and running the sweeps to get everything set, when we ran DIRAC the filter applied -10db to the LFE which made it broadly inaudible, added 5db to the L/R and 4DB to the C yet in the REW SPL it measured a 10db difference between the L and the C (hot) and the sub was also 10db too hot ?

In addition the Umik-1 kept dropping out and not reading some of the sweeps so we swapped the Umik-1 out for the XTZ calibration mic and got similar results (ruling out mic issue ?) ... Also the timing reference stopped working halfway through which wasn't ideal ... is there any known issues with last weeks Monterrey 12.5 update and REW ?

Happy to post any sweeps or the data files if anyone wants to have a tinker/look at what happened but scratching our heads at the moment as to whether the combination of Mac/REW and DIRAC is a problem at the moment ?

Thanks if anyone wants to chime in or if John D has any OSX bug/issue insights ?

 

[sam_adams]

Hi - new(ish) REW user/lurker and decided to give my system a calibrate last weekend to better integrate my 3xGallo MPS150 subs, 4 Gallo micro surrounds, B&W805 and HTM2 together. I was on a call/TeamViewer session with a UK AVForum/REW expert and we walked through the REW sweeps/timing/crossover/etc and then ran the DIRAC for my Arcam AVR550 to take control of the room EQ and then a final REW review to tidy up any sub issues.

Overall the process steps worked out but we had some issues that meant we couldn't complete the calibration successfully and are trying to work out what the issue is.

I am running the latest Mac version of REW on my M1 MacBook Pro running Monterrey 12.5 with a Umik-1. Connected to the Arcam by HDMI and 8.1 16 bit/48Hz setup selected in Audio MIDI panel.

Make sure that your bitrates and sample rates match on inputs and outputs. UMIK-1 is 24 bit / 48 KHz. Your output settings must match.

First inconsistency was the level of the tones generated by the Audio Midi setup on the Mac in relation to the REW tones (which were 10db louder) and the inbuilt tones from the Arcam which measured the same as the Mac tones (no gain applied in the Arcam) ?

The 'tones' generated from Audio MIDI Setup.app are not calibration tones. They are only useful for channel ID, nothing more. The level of the tones can be changed in the preferences.

Second was after swapping the C and LFE channel mapping in REW (which I understand is a HDMI connection bug/issue) and running the sweeps to get everything set, when we ran DIRAC the filter applied -10db to the LFE which made it broadly inaudible, added 5db to the L/R and 4DB to the C yet in the REW SPL it measured a 10db difference between the L and the C (hot) and the sub was also 10db too hot ?

The LFE channel, by design, has a signal level that is +10 dB higher than the other channels. When testing that channel alone for level one must reduce the input level accordingly to produce meaningful results to compare against the other channels.

In addition the Umik-1 kept dropping out and not reading some of the sweeps so we swapped the Umik-1 out for the XTZ calibration mic and got similar results (ruling out mic issue ?) ... Also the timing reference stopped working halfway through which wasn't ideal ... is there any known issues with last weeks Monterrey 12.5 update and REW ?

Which version of the UMIK-1 are you using? The older model had a USB-A to mini USB-A cable. The newer version has a USB-C connector on the mic. If you are using the older version of the UMIK-1, what adapter/cable are you using to go from the Mac's USB-C connector to the USB-A connector on the UMIK-1? The Apple adapters should be considered the reference and third party adapters should be checked out thoroughly to ensure compatibility. Removing login items, turning off networking, and quitting open apps other than REW may resolve the dropout issue.

 

[jont-uk]

Thanks Sam - rather than re-quote I'll just put answers on separate lines ...

My mistake - we did set it to 8.1 24-bit/48Hz ...

Useful to know - thanks

Ah - LFE being +10db might be the reason the C was 10db hotter then if we had to swap assignment in REW due to HDMI connection ?

It's a brand new Umik-1 with usb-c and a single cable length from mic to Mac - the XTZ is XLR>usb-a and I have an Apple A>C adaptor I used for that when we swapped ...

I'll attach the REW files for anyone else's interest ...

 

[jont-uk]

Main file after Dirac is too large to upload (32Mb) ... was going to create a dropbox share here but can't as haven't got enough posts ... DM me if you want the main file link ... thanks

 

[sam_adams]

There's a broad response drop between 40 Hz and 70 Hz that may be indicative of a modal issue in the response. You may have to experiment with subwoofer placement in the room to alleviate that. You also did not use a timing reference when the measurements were made so that makes it difficult to evaluate the sub response in relation to the main speaker's response.

 

[jont-uk]

Think the timing references were in the main file which I can't upload but DM me and I'll send you a dropbox link ... not many options in the room for placement unfortunately - 2 are at the front on the L/C/R axis and the third is centred behind the MLP in the bay of the window - planning on using a miniDSP-HD to manage the subs and seems a 12ms delay sorted that out - but trace might be in the main file ...

 

[skid00]

I just bought a 15 foot usb-c to usb-c cable for my UMIK-1.

I had loss of signal half way thru sweeps. Sometimes the timing chirp wouldn't.

A 12 foot cable fixed all that.