RS SPl meter

[whitetrash84]

Does anyone know if the correction factors are the same for the newer 33-4050 as they are for the old 33-2050? Guess if I can't find out, I'll just get one of the 33-2050s off of ebay or something.

Thanks

[ThomasW]

It's a fairly complicated thing to create these correction factors. They have to be compared to a known calibrated mic.

Since all these meters generally use the Technics capsule, it's probably safe to use the published factors knowning that they will very from meter to meter..

[derek]

I just checked mine (bought in the 80's) against two new ones. Nothing in common wiht the new ones. Some frequencies were the same and other frequencies were off by 10 db. Not sure if I can get mine calibrated to the standard error or not. I simply don't trust them anymore.

[chrisbee]

derek

Can you tell us where the variations were between the new and old SPL meters? Was it in the deep bass?

I've always wished my meter was flat since all my tests on different subs and floorstanding speakers show rising bass slopes with falling frequency. (after correction) But nicely flat without the correction figures. Fortunately they don't sound bass-heavy.

I suppose my own meter is over 15 years old now. Should I get one of the new 'soft look' models? Or would it just be different, but not necessarily better?

Chrisbee

[ThomasW]

I think all these capsule based meters use a variation of the same Panasonic capsule, so they're all going to be equally 'off' but each in their own unique way. And the so-called accuracy will vary over time, and with changes in temperature, barametric pressure, etc.

Even VERY expensive mics are returned to the factory periodically for recalibration.

So the options are live with what you have, or pay to have it calibrated every year or so. And calibration seems pretty silly for a $40 device.

[shomrighausen]

There are some modifications that you can make to the older RS SPL meters that will 'flatten' the electronics. The panasonic (or whoever makes it) mic capsule is essentially 'flat' down to a couple of Hz... I've modified my 33-2050 using the information found here mysite.verizon.net/tammie_eric/audio/audio.html

I have not done the 'external mic mod'... I have other means for measuring high frequency response, so it didn't interest me. I can tell you that with the electronics 'flat', that the SPL meter measures down to below 10Hz easily...

What is the model number of the current RS SPL meter? If there was enough interest, and I could get my hands on one, I'd be willing to do a comparison between my modified meter and the current production RS meter. It seems that most people are interested in the lower frequencies (especially on this forum ), and I feel that my modified meter is highly accurate in that area.

[ThomasW]

I feel that my modified meter is highly accurate in that area.

How does the modified meter compare to a calibrated mic?