How to use REW to analyze the acoustics of your room...

How to use REW, What is a Bass Trap, a diffuser, the speed of sound, etc.

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Gregwor
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Re: How to use REW to analyze the acoustics of your room...

Post by Gregwor »

I'm still not clear about how I should set the volume on my subwoofer when doing the testing.
I would just use my ears to get a balanced sound between your mains and your sub. After that, do some measurements with REW and check the SPL. It'll be pretty clear on the graph if your sub is too loud or too quiet.

Greg
It appears that you've made the mistake most people do. You started building without consulting this forum.
Soj
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Re: How to use REW to analyze the acoustics of your room...

Post by Soj »

Hello, 1st post here and wanted to thank you for the elaborate guide,
I am a studio owner.musician who knows the bare basics of acoustics and build some bass traps/ER traps in the past.
I have some free time now and i thought i'll take the plunge into the measurements world (i have always hired some one in the past for that and now i wish to expand my knowledge in the subject of REW).

So i started by not getting the behringer ecm 8000 because of your thread and so i went and got the presonus you recommended.

I would appreciate it if you could elaborate on why an app like decibel x for the iphone wont be as efficient as a db meter?

I would also appreciate it if you could explain whether the presonus will need calibration and if so how do i calibrate it.

Thanks!
DanDan
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Re: How to use REW to analyze the acoustics of your room...

Post by DanDan »

Welcome. We have not heard from Stuart in some time, so I guess I could help you here.
dB or Sound Level Meters come in a very wide range of price and quality. Indeed you may still see mention of the original Radio Shack one, which was a truly awful POS. Over time things change. Now iPhones can become really decent fully featured SLM. The free and cheap ones are fine, I have tried most, but I do appreciate the more Pro nature of Faber SoundMeter and this also this company https://studiosixdigital.com/audio-hard ... phone.html
I use my iPhone all the time when doing safety surveys in clubs and venues. One wouldn't want to wander about on a busy saturday night with a Bruel and Kjaer or other big conspicuous mega buck meter.

If your Mic has a Cal file, then REW should be able to read it and become a 'free' SLM. The accuracy will be equal to that of the Cal file.
I have found the UMIK-1 to be 1.8dB off in two samples from different years. I have found iOS apps to be closer than that.
Comparative Calibration is very simple. REW, SoundMeter etc. can be calibrated against a trusted exterior SLM, or a dedicated Calibrator Device if using an external 1/2" Mic

You just play a steady Pink Noise, adjust the level to some convenient number on your borrowed, ideally Calibrated, but in any case trusted SLM. Say 75dB. Then use the Cal trimmer in your app to get it to read the same.
Soj
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Re: How to use REW to analyze the acoustics of your room...

Post by Soj »

DanDan wrote:Welcome. We have not heard from Stuart in some time, so I guess I could help you here.
dB or Sound Level Meters come in a very wide range of price and quality. Indeed you may still see mention of the original Radio Shack one, which was a truly awful POS. Over time things change. Now iPhones can become really decent fully featured SLM. The free and cheap ones are fine, I have tried most, but I do appreciate the more Pro nature of Faber SoundMeter and this also this company https://studiosixdigital.com/audio-hard ... phone.html
I use my iPhone all the time when doing safety surveys in clubs and venues. One wouldn't want to wander about on a busy saturday night with a Bruel and Kjaer or other big conspicuous mega buck meter.

If your Mic has a Cal file, then REW should be able to read it and become a 'free' SLM. The accuracy will be equal to that of the Cal file.
I have found the UMIK-1 to be 1.8dB off in two samples from different years. I have found iOS apps to be closer than that.
Comparative Calibration is very simple. REW, SoundMeter etc. can be calibrated against a trusted exterior SLM, or a dedicated Calibrator Device if using an external 1/2" Mic

You just play a steady Pink Noise, adjust the level to some convenient number on your borrowed, ideally Calibrated, but in any case trusted SLM. Say 75dB. Then use the Cal trimmer in your app to get it to read the same.

Thanks for the replay, i guess ill stick with the iphone then.
Unfortunately the presonus calibration mic does not have a calibration file, neither can i find one online, maybe it does not need one?
davidames
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Re: How to use REW to analyze the acoustics of your room...

Post by davidames »

Hello everybody! Thank you Stuart for the extremly useful information.

Im about to start with my measurements. I would like to know if you are still available to receive my data and give some kind of feedback. If not, does anybody know any member with the expertise and the kindness to help me analyse my data?

Regards!

D.
davidames
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Joined: Wed Jun 17, 2020 7:00 am

Re: Meassurement results analysis.

Post by davidames »

Hello everybody! Thank you Stuart for the extremly useful information.

Im about to start with my measurements. I would like to know if you are still available to receive my data and give some kind of feedback. If not, does anybody know any member with the expertise and the kindness to help me analyse my data?

Regards!

D.
JamesJones
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Re: How to use REW to analyze the acoustics of your room...

Post by JamesJones »

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