Very old Realistic Sound Level Meter (db) #33-1028 curves or any other information?

[rqkeating]

I am trying to use this very old Radio Shack db meter with REW but have no idea if it has a built in curve or is or is not flat. I don't need extreme accuracy, but if it has an A or C weighting, knowing that, I could take the next step with compensation for that somehow. I only found the model number by looking for images on line. I can't find a model number on the unit, but it does have "No. 1111713" on it.

I've already used this meter with REW and it seems to give the information I would expect, but with so many variables with room acoustics and positioning, I am just not sure.

Thanks in advance. Just trying to use what I have on hand.

20190316_173331

• rqkeating
• Mar 16, 2019

Very Old Radio Shack Sound Level Meter. Possibly model #33-1028

 

[Wayne A. Pflughaupt]

I've already used this meter with REW and it seems to give the information I would expect…

How are you using it with REW? Does it have an audio output?

Regards,
Wayne

 

[rqkeating]

Yes, it has an audio output on the side. It is a single RCA jack. I just used adapters to get it to 1/8" to plug into the sound card.

 

[Wayne A. Pflughaupt]

If all you need to know is if the meter is A or C weighted, simply play a couple of test signals at 1 kHz and 40 Hz. Assuming you have a subwoofer or speakers with deep extension, if 40 Hz measures drastically lower in SPL than 1 kHz, then the meter is A weighted. If the two signals measure close to the same level, then the meter is C weighted.

Regards,
Wayne

 

[rqkeating]

I don't have any speaker I'd trust to reliably go down to 40hz.

Been reading and it seems the cheapest mic I could get for these measurements would be a Behringer ECM8000. I could run that into the Focusrite 2i4 that I already have. No rush. I'll keep reading. Maybe buy used?