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Level Meter [message #86608] Mon, 13 November 2017 21:59 Go to next message
Peter_Johnson is currently offline  Peter_Johnson
Messages: 2
Registered: November 2017
Location: United States
Junior Member
Does anyone have an easy way to use the level meter to measure SPL? I have a 94db/114db calibrator for my reference mic and I would like to use the level meter to measure the SPL in the room.

Thanks
Re: Level Meter [message #86609 is a reply to message #86608] Tue, 14 November 2017 11:19 Go to previous messageGo to next message
jon is currently offline  jon
Messages: 36
Registered: November 2012
Member
While SpectraFoo has no specific tools to calculate SPL, you can arrive at the same measurement by following these instructions.

You will need an external SPL meter to set up the calibration the first time.

Set up the SPL meter in the same position as your measurement mic for Spectrafoo. Set the SPL meter to C weighting with a slow response. Take an SPL reading of the system. Set up a level meter in Spectrafoo using the "SpectraFoo" meter scale.

Make sure that the level calibration is set to "0" in the level calibration dialog. Set the VU settling time to be around 5 seconds using the "meter options" for the level meter. You should probably also check "Draw VU as solid bar" in the level meter options.

Run Pink noise through the system. Take the measurement you get from the SPL meter and write it down. Now take the measurement you get on the 'Foo meter and write it down.


Take the level that you are reading in 'Foo and add its absolute value to the SPL measurement. For example, if you are reading 85 dBSPL on the SPL meter and -20dBFS in 'Foo, add 20 to 85 to get 105. Following this example through, open the level calibration dialog in 'Foo and set it up so 0 dBFS is 105dBu. Now the 'Foo meter should be reading SPL as long as you use the same measurement mic with the same gain.

I hope this information helps you. Please let us know if we can help to clarify anything or if you have any other questions.


Jon Stern
Metric Halo Support
Re: Level Meter [message #86610 is a reply to message #86609] Wed, 15 November 2017 23:51 Go to previous messageGo to next message
Peter_Johnson is currently offline  Peter_Johnson
Messages: 2
Registered: November 2017
Location: United States
Junior Member
Thank you for your response. I did what you said, except I used an SPL calibrator piston that outputs 94db and 114db. I used that to set my "zero" mark. I have yet to try it in the "wild", but look forward to testing it out. Anyone else using Foo to measure SPL?
Re: Level Meter [message #87234 is a reply to message #86610] Fri, 12 July 2019 10:34 Go to previous message
virkovitru is currently offline  virkovitru
Messages: 1
Registered: July 2019
Junior Member
Hi buddy, you can try both the way. But to save money tuning the only instrument will work out.

Regards,
Virko Vitru
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