Axiom Home Page Forums General Discussion The Water Cooler Anyone with a SPL meter and an iPhone/Touch?

There's a free Ultimate Ears SPL meter on the app store. I'm curious how accurate the iPhone's SPL meter is to an actual one.

If it is close, not a bad use of an iPhone.

I've used it, seems to work ok, there is also free real time frequency analyzers that use the mic in the ear buds...not sure how accurate the SPL meter is compared to The Shacks version...

Hunh. I have to give that a shot. Not sure when I'll be able to do it, though.

I will try tonight...

I downloaded the app at lunch and ran the SPL meter in my car on the way back to the office (about 40 mph driving, no radio, windows up). On the default "A" setting it showed about 70db. When I switched it to the "C" setting it jumped up to about 95 db. I don't remember there ever being that much of a difference between the A and C setting on the RS SPL meter. Also, I thought that the C setting was the one suggested for HT calibration... I know what 95 DB sounds like on my RS SPL meter with the c setting and my car is no where near that loud. I will compare the two together if I get a chance tonight, otherwise I might not have time 'till tomorrow.

Cool, a sample of 3.

Yes Dave, the C weighting includes the lower frequencies, in addition to the higher range, so a higher dB would be expected...

It's saying my office averages 45dB. I'll try it at home with some test tones against my Radio Shack meter to see how it compares.

I can't imagine that the mic on the iPhone/iPod Touch can be good enough to capture all the necessary frequencies. Could be wrong, though.

Seems reasonable. I'd believe I'm listening to the ABs at around 70dB right now.

I agree. I'm sure it's optimized for voice frequencies.

that is what I thought, the app desciption says it is very accurate, not.

48mb hmmm

Well, shoving it up against the AB tweets, mids, and EP0 show generally the same dB level, so maybe it is fairly accurate across the range.

I forgot to follow up on this...

I pulled out my RS SPL meter and my iphone and did a quick comparison. I ran the test tones built in with my denon through my m80's vp150, QS8's and EP500 while holding the iphone in one hand and the SPL meter in the other.

Suprisingly, both were reading the same within 1 db or so.

I did not run a frequency sweep or anything sophisticated.