Sound Pressure Levels on guitar amps

[0xeneye]

I am looking for an accurate way to measure Sound Pressure levels on guitar and bass amps. Besides buying a $30 gadget I would use for 15 minutes a year, I was wondering if anyone here had better ideas.

If you just want to measure, say, db levels at 6 feet from an amp, what would you use? (And something you could take live, not in a studio) A friend wants to calibrate the level controls on his pedals so that he more consistently jumps 9 db above normal for lead tones live.

I was think there may be a freeware app or something that does this more accurately than the VU meters on a mixer. Thanks.

[vxboogie]

There are quite a few smartphone apps for SPL levels. They might get you in the ballpark for relative levels between patches and you wouldn't need a calibrated mic/app for relative levels. I would set it to C-weighting and slow.

The bigger issue is that many factors such as tonality, compression and distortion are a large part of how loud it sounds, and especially how it sounds in a mix, to the human ear.

[vvv]

FWIW, I have a US$30 Rat Shack spl meter, and the thing gets used a bit more that I would have predicted, from setting monitor levels to setting amp levels to checking outside the house to head off noise complaints.

"What? See here, officer, my meter shows 65db, well below the ordinance violation level."

[Scodiddly]

FWIW, I have a US$30 Rat Shack spl meter, and the thing gets used a bit more that I would have predicted, from setting monitor levels to setting amp levels to checking outside the house to head off noise complaints.

"What? See here, officer, my meter shows 65db, well below the ordinance violation level."

The RatShack SPL meter is worth ten of yours. Very handy in a variety of circumstances.

I wouldn't trust an iPhone app, or rather the mic in an iPhone, to have any real accuracy above 90-100dB.

[dfuruta]

another vote for the rs spl meter - not something i use every day, but it comes in handy now and then. they go for nothing on ebay, too.