# REW Volume level for the the measurements



## AlexF (Sep 30, 2012)

I'm a newbie with REW program. Please help me to understand some points.

*1. Volume level*

- *in the "Checking Levels"* help section it is advised to reach *a level of around 75dB* *on SPL meter* (usually *ear height *at your main listening position).

- *during SPL Calibration Procedure* to set the meter range to suit the measurement level *used in the check levels process* (*the 80dB range* is recommended *for the Radio Shack meter*)

- other says *the volume level at the listening position* should be the one I'm feeling comfortable for me \ *usually used for the listening* (music or movies)

*At what volume level should I make the measurements? *

When I set 75 db during level check & SPL Calibration, I cannot make any measurements because the REW tells me that the level is low.

When I set 84-85 db (this is my usually used volume level for the listening, the level is shown as OK and I can make the measurements.

*2. SPL meter pointing*

When setting the SPL meter at my listening position, *where should I direct it*:

*- to the ceiling ???
- to the floor ???
- or to the speakers and at what angle???*

Thank you very much for all your advises in advance.


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## EarlK (Jan 1, 2010)

(i) Test (speaker) Level ?
- Use what ever level ( speaker SPL ) gives you a good level when looking at REWs meters ( in the preferences window ) . Minus 18 to minus 12 is a good area to strive for .

(ii) Mic Orientation ?
- If your test mic has a calibration file for ZERO degrees then point the mic at the speaker .
- If your test mic has a calibration file for 90 degrees then point the mic at the ceiling .
- If your test mic has a calibration file for 45 degrees then point the mic at a 45deg angle towards the ceiling .

- If your test mic doesn't have a calibration file, then I would point it at 45degrees to the speaker ( because a lot of uncalibrated mics have a rising response that then gets attentuated somewhat when using this orientation ) .

:sn:


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## AlexF (Sep 30, 2012)

EarlK, thank you very much for the detailed reply. I have the *RadioShack 33-2055* SPL meter. *For what degree has it a calibration file?*


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## EarlK (Jan 1, 2010)

AlexF said:


> EarlK, thank you very much for the detailed reply. I have the *RadioShack 33-2055* SPL meter. *For what degree has it a calibration file?*


Hi Alex,

All the available generic calibrations ( ie; for RadioShack meters, Behringer ECM-8000 mics, the various Dayton test mics ) are for 0 degree orientation .

:sn:


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## Wayne A. Pflughaupt (Apr 13, 2006)

The SPL meter is not suitable for full-range measurements, since its calibration file is only good up to about 3 kHz. Thus, the meter is typically only used for measuring subwoofers. For that, mic orientation is not relevant. 

Regards,
Wayne


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## AlexF (Sep 30, 2012)

And what should I use for the full-range measurements? I have mic from my AV receiver Denon AVR-1909 Ausissey DM-A409. Is it OK or I have to buy a special mic?


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