Rat Shack SPL meter: Analog or Digital?

I think the idea behind the analog is that SPLs will vary significantly over time, and with a digital readout it is hard to mentally calculate an average, as it is not simply the mean between the highest and lowest level. There is a time component (i.e., time-weighted average). So with an analog meter, you can "see" an average SPL better.

The analog is much easier to use and read. You can get pressure zone readings much faster with the analog. In my mind there is not question--the analog is much better (and less expensive). Also, you should be aware that the analog meter is not a flat response, but we manufacture a test CD that has calibrated test tones for this meter. You can get it at http://www.rivesaudio.com, go to products and software--or directly to the test CD. There is also a set of instructions that is much better than what is provided with the Radio Shack meter. Be sure to download these--even if you don't get our test CD.

Rives! Where were you 10 years ago when I pulled my hair out trying to calibrate these $30 suckers! And the battery-charge correlated non-linearity error across each scale was no fun either. I remember calibrating the errors across band extremes. Do you have new templates to glue over the existing one that are more accurate at the extremes? Wonder why RS never reprinted more accurate grids....

Rives, is that why your calibration is different than the one at Audio Asylum?
A-A calibration

If I'm not mistaken the one at Audio Asylum is a general C weighted correction. C weighting is not flat, and this curve is published in the Radio Shack manual. However, the Radio Shack does not mimick the C weighting precisely and is a bit worse in terms of linearity. We tested several meters and found they were all very very close. We also tested the meter with Nickel Metal Hydride batteries and regular akaline batteries and found no difference. We did not check Ni-Cad batteries. I believe our results are nearly the same as those published in Sensible Sound (I've been told this, but have yet to see the article--if anyone has a copy I would really like to see it).

Also, we sent our results and a sample disc to Radio Shack. They liked the idea and considered (and even had a meeting on it) marketing our CD. However, the meter is small potatoes to company like Tandy--and our CD--well microscopic would probably sum it up. Too much effort for too little gain for a company like Tandy. But we were happy that they did seriously review it.

Rives,
Can I use your CD with digital meter?

It is not calibrated for the digital meter. We found a fair amount of difference between the digital meter and the analog. The digital is actually closer to linear than the analog, but it was less consistent from various units--it's also harder to use. Our tracks would give you better results than a flat response, but they are not precise for the digital unit. I would recommend getting the analog version.

When I was demoing audio gear, I considered buying one of these to allow me to do a more fair comparison -- apparently it is very hard to set gear to identical volumes, and the louder gear sounds better.

I was told elsewhere, though, that the accuracy of the meters is not good enough to help in this project (I think it's +/-2db?). Is that the opinion here also?

Thanks,

Eric

Eric, the meter is very reproducible, and you would likely be setting levels with a calibrated pink noise, rather than individual test tones. For you what you propose I think the meter would be very well suited, except in the case of comparing an electrostatic with a dynamic speaker. The dispersion patterns of these two are very different and I would question whether or not it's really the same volume. At the moment, I can't really conceive of an alternate method.

The digital version actually has a bar-graph analog display that is just as good as a moving pointer. And the numeric readout sure makes it easier to log results as you vary the speaker setup etc. The digital/analog issue is just about readout convenience...actual performance characteristic of the devices (including any deficiencies) is identical.

Very Interesting: I purchased both the analog and the digital RS sound meters. The analog goes +/- 15 db over
the range 83 Hz to around 8300Hz while the digital stays
around +/- 2 db range; below 83hz it drops like a rock on
both analog and digital and sames goes above 8300Hz both
at exactly where the A or C weighting starts to come in.
I am using both the Rives and the Stereophile test CDs.
I do not quite understand considering I can hear petal
notes down to 25 hz without any apparent loss of sound, maybe 3 or 6 db but 25 DB? At 25Hz, it says I am down 25DB.
At 20khz, I am down 30db. 30DB!!Something is wrong but what??? Yes I followed the instructions,yes I put it on tripod, yes it was steady, yes it was at listening distance and height.

A quick heads up-Radio Shack now has a sale on the analog meter-$29.99 (a big $5 off).