Meters for room calibration

[idris]

Is this meter up to the job for room calibration (for a basic sound editing suite, as opposed to a full dubbing theatre)?
http://www.maplin.co.uk/Module.aspx?ModuleNo=226470
The spec looks almost the same as those twice the price, but I don't know if the "almost" is what makes the difference.

[Postman]

A big limitation is the meter's integration time, they call it "time weighting". It is spec'd as FAST. SLOW allows a much more steady reading when using fullband pink noise. Fast will probably be okay with limited bandwidth pink noise.

The unit's frequency response is not particularly wide. Once again, limited bandwidth pink would get around the limitation. The frequency response is not particularly flat, either, which is another downside. You don't really know where the problems are.

Finally, a sound meter should be of the "true RMS" type. Not all are. A true RMS meter will respond to something called "crest factor" in a different way than a cheaper averaging type of meter. The higher the crest factor, the more the error can be. Crest factor is higher with fullband pink noise than with limited band pink. (Crest factor is like a ratio between instantaneous peak levels and average levels.) The specs don't say which type this is, based on its cost I'd guess it is an averaging type of meter. The difference is hopefully small with limited band pink noise but a good quality pink noise could reveal up to 1 db of error.

In my mind the errors can all add up to a big problem, or they could all cancel each other out. I don't know, no way to really know! It is certainly better than no meter at all but there is a point where something that is cheap is just TOO cheap. When you add up all the possible errors, it seems likely this is not going to be very accurate. You could easily make a measurement that is several db different than a good meter would show you.

[Craig F]

I would get one of these http://www.bksv.com/Products/SoundLe...2250Light.aspx

[mikevarela]

Food for thought...

Grab a SyncCheck and use it's onboard SPL meter. Save some cash and get the video offset functionality as well