RE: Having issues with REW

[B4DG3R]

Hi All.

I am having some issues using REW to analyse my bedroom studio. I am using:

• A Pioneer DJM 800 Mixer which is connected via RCA to:
• A RANE SL3 Serato box. Not an ideal interface for this application but it works.
• A Zoom H4N as my microphone - plugged in via USB
• iMac osx Mojave.

I have everything detecting within REW, but I am unsure of a couple of things:

1. I don't think its possible to create a loopback connection on my SL3, as the aux RCA input is being used to carry the signal from DJM 800>through SL3>toREW

2. I keep getting an error message within REW after performing the test, (3rd image below) about the dB level between 20Hz and 20kHz varies by (e.g 84db) and is much higher than it should be. I have tried adjusting the sweep level output, volume on the mixer and record volume on the Zoom H4N. The result changed by about 5dB I would move further away, i.e centre of the room (like the tutorial says to do), but I am restricted by having a short USB cable. could this be the issue perhaps? I need to be further away from the sound source. 5th image is a Screenshot of my sound cards settings page

Below is a screen shot the reading REW spat out, I don't think this is a decent representation of the rooms true acoustics, due to these tech problems I am having.

Below that screenshot of my "interface" inputs/outputs.

Hopefully all I've wrote here is somewhat understandable and any help regarding this would be appreciated.

REW

 

[John Mulcahy]

You are making sound card calibration measurements but using a room measurement setup, REW is warning you the result looks nothing like a soundcard cal - because it isn't.

Soundcard calibration isn't applicable for your setup as you are using a USB mic. Just make sure there is no monitoring (none of the input can get back to the output or the measurement won't be valid) and use the Measure button to make your measurements.

 

[B4DG3R]

Hello John,

Thanks for your quick reply. So how exactly would i set that up in preferences? Still keep my SL3 as the output and H4N as the input? Would you advise on a long USB cable to ensure 1m away from sound source? I am doing this for a school project and I am wanting to nail it!

 

[John Mulcahy]

Preferences are OK as they are. Put the mic where your head normally is and use your usual speakers as the output, but only play one channel at a time - Measure with the L speaker as output then the R. Keep well away from the mic when measuring.

 

[B4DG3R]

Hi John,

Great thanks. I have gone ahead and followed the above instructions. Success! (i think!?) have attached the mdat. file if you're interested.

 

[John Mulcahy]

Those are unusual impulse responses. Are you sure monitoring is off? Tapping on the mic doesn't product anything at all from the speakers? How big is the room you are measuring in?

 

[John Mulcahy]

It looks like the input side may be running at 48k and the output at 44k or vice versa. Check in Audio Midi Setup to make sure all your interfaces are configured to run at the same sample rate and use that rate in REW.

 

[B4DG3R]

Using the zoom attached via USB in I/F mode, it captures sound (can see on the meter moving), but doesn't produce any sound through speakers. I'll double check those settings you mentioned, the SL3 has 48k studio grade pre-amps, would that be causing the variance or is it just a setting i need to change?. The room in meters W x L x H = 3.6 x 2.89 x 2.71.


My desk is not in an ideal listening position either, due to small size of the room and also being my bedroom, the bad takes up most of the room.

 

[John Mulcahy]

Try selecting 48k in REW. The Audio Midi Setup app in Applications/Utilities will let you see the sample rate the various interfaces are configured to run at.

 

[B4DG3R]

Okay. Should i set on the zoom to 48k as well?

 

[B4DG3R]

Looks very different this time around John,

Changed to 48k in REW, in the midi wizard changed SL3 to 48k and also on the zoom. mdat file attached.

 

[John Mulcahy]

That's more like it! Looking good now.