Rat Shack SPL meter calaibration

I understand that the Radio Shack SPL meters are not real accurate. I have the $60 digital readout unit. I have been playing around with it to try to work out a hump in the bass from my system using bass warble tones. Can anyone tell me where the problem areas are with these meters and what sort of compensation you need to do to interpret the info it gives you?
Do a search in the forums, Sean posted a complete list of them a while back.
search the forum archives: Sean has posted on this topic several times so it should be in there somewhere
I am pretty sure that the RS adjustments are archived in the FAQ section @ Audioasylum.com
I believe Sean's correction table was for the Radio Shack (Realistic) analog SPL meter, ie not a digital version. Cheers. Craig
I did a search a few days ago and didn't find what you guys are refering to. I guess I will try again.
You need the RS Analog Meter.Its what all test discs/reviewers reccomend/{Avia etc].
No you want the analog version, and it costs less than the digital one. I suggest you exchange it. The consesus is the analog one is the 'better' use use of the two. And Dekay is right, callibration of the analog version is in the FAQ section at http://www.audioasylum.com


Thanks for the links Aroc. I read what was there and they are saying the digital and the analog are the same, other than the read out. The calibration chart will help out. The thing seems to be within reason except for the extreams. I sure as hell won,t worry about 1/2db. If your in room response is anywhere close to +or- 3db you are doing better than I think you should Realistc-ly(sorry)expect in most rooms.
I just looked at the audioasylum chart and it is wrong
wrong wrong. How do I know? I did a test of 12 of these
meters. 6 analog 6 digital. Using LEAP and Melissa to calibrate. First, the analog meters were more accurate
and consistent, although they varied by 1-2 db. As far
as the low freq. it is quite accurate down to 30hz but
reads low at 25 and 20. It is also very accurate from
200-2k. Above 2k is where it goes astray and where the
audioasylum chart is way way off. You absolutely do not
want to add to these readings as they are already too
high. Here is a list of the average of the six analog
meters corections from 2khz. You SUBTRACT these from
the meter reading. 2k -1db, 2.5k -4db, 3.15k -4db,
4k -4db, 5k -5db, 6.3k -5db, 8k -4db, 10k -3db, 12.5k 0db.
you ADD to the next two. 16k +2db, 20k +5db. If you use
these corrections you can get a surprisingly accurate
in room speaker response curve.
Using a consumer-grade SPL meter to do an in-room response curve is tricky. If you're careful, it will allow you to identify a few gross anomalies, but it just isn't accurate enough (or, as some of these posts suggest, consistent enough) for more than that. Frankly, I think your ears may be a better tool.