Sound Level Meter

[peaceh]

Hi!
Im looking for a Sound Level Meter to calibrate my monitors.
Everywhere I read they use the Radio Shack Sound Level Meter.
Unfortunately it doesnt seem to be available in Sweden.

Any Swedes here that can recommend one that they have tried and is available in Sweden?

Or have one for sale or lend?

/mattias

[RecRoom]

The iphone has a decent one.... from what I hear it was even reccommended by Mr THX himself, Tomlinson Holman. Called SPL.

[Postman]

iPhone? How far we have fallen.

[Craig F]

what Tomlinson doesn't say is that he calibrates his iPhone with a B&K SPL meter

[tamasdragon]

The Radio Shack and probably the iPhone is fine for quick and dirty calibration, to get into the ballpark. But real serious things requires much more precise equipments.

[MIKEROPHONICS]

You will be surprised by how accurate the iPhone is. When I was sweeping my room with an acoustic consultant we were impressed!

[peaceh]

But as I understand it the iphone apps arent very accurate in the low ends due to the built in microphone?

[Reckless Erik]

Band limit your pink noise.

[MIKEROPHONICS]

just what are you trying to achieve?

to put you within a needles width of a dB or less of film monitoring (but small room levels) and to even spl on your various speakers for your premixes in a small room it is fine. To line up anything more serious - no.
But we are in an industry where emperor's new clothes prove a popular wear....

[Postman]

You will be surprised by how accurate the iPhone is.

Maybe yours is, maybe you're just lucky that way, but how does anyone else know about theirs? Unless they compare it side by side to a calibrated device how can they? It all comes down to that little microphone in each iPhone. Tiny omni mics usually have reasonably flat response (within a couple db typically) but the output level from them can vary quite a bit.

For instance, the little Panasonic mics I use in Syncheck are supposed to be very flat from low to high, with an output level variation of +- 4db. That's an 8 db spread! For a run of a few hundred I will find only a couple dozen that have unacceptable response curves (yes, I measure each and every one), but the output level from one to the next is all over the map! This inconsistency has been consistent for years, from batch to batch to batch, I think it is just the tolerance of manufacture. If the iPhone's mics behave similarly (as I expect they do) the only way to compensate for variation is to adjust the mic preamp gain of each and every iPhone. I would be shocked to find the Apple factory doing that. I could be wrong, so let's assume I am wrong and they actually do adjust each one. What happens when those little mics age? Or when they get warmer or colder? They change.

I'm not defending RS meters as being good, but at least the factory has adjusted each one to some kind of standard, which is presumably one step closer to a standard than iPhone. Also, their microphone bodies come in a standard size that plugs into an acoustic calibrator so you can adjust them yourself. How do you calibrate an iPhone? The only way to do it is to compare it side by side with another meter which is calibrated.

iPhone is ubiquitous but that doesn't make it particularly trustworthy for SPL measurement. Mike, you're just a lucky dude.