Cheap dB meter?

Anyone know where I can find a cheap dB meter to measure my case noise?

Radioshack sells them- im not sure how much- try ebay too.

radio shacks are about $40 us for the analog and around $55 for the digital one and they are farelly accurate and can take quite the spl beating

you can use your microphone that usually comes with your pc's soundcard and such as a decibel meter. That's about as cheap as you're gonna get.

safemode said:

you can use your microphone that usually comes with your pc's soundcard and such as a decibel meter. That's about as cheap as you're gonna get.

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Definetly cheap, but waaaay inaccurate. Theres no way to calibrate a microphone input for use as a db meter without a real db meter.

If you raise the input level of your microphone, you've raised the db level thats going to show up in any program that lets you monitor the mic input. Not only that, but not all mics are the same. Some pick up any and all sounds from every direction, and others are very directional.

But the real difficulty is in taking the measurement, even if the meter is calibrated. The ony way you can get accurate readings would be to have the fan and the meter located precisely in a controlled environment. Move the meter just a touch, the reading changes. Distance from the sound source is just as critical. And when you are done the readings are only comparable to whatever other readings you've taken with your meter in your test jig in your controlled environment. This is why every manufacturer's db specification must be viewed with a grain of salt. No two manufacturers test in exactly the same way, and most are eager to fudge the numbers in an attempt to make the fan more marketable anyway.