CODEWITHSUNDEEP
audiomicrophone
Tedd Hansen
Tedd Hansen

Reputation: 12314

Frequency differences from MP3 to mic

I'm trying to compare sound clips based on microphone recording. Simply put I play an MP3 file while recording from the speakers, then attempt to match the two files. I have the algorithms in place that works, but I'm seeing a slight difference I'd like to sort out to get better accuracy.

The microphone seem to favor some frequencies (add amplitude), and be slightly off on others (peaks are wider on the mic).

I'm wondering what the cause of this difference is, and how to compensate for it.

Background:
Because of speed issues in how I'm doing comparison I select certain frequencies with certain characteristics. The problem is that a high percentage of these (depending on how many I choose) don't match between MP3 and mic.

Upvotes: 1

Views: 104

Answers (2)

vines
vines

Reputation: 5225

If you can measure the actual microphone frequency response by some method (which generally requires having some etalon acoustic system and an anechoic chamber), you can compensate for it by applying an equaliser tuned to exactly inverse characteristic, like discussed here. But in practice, as Kilian says, it's much simpler to get a more precise microphone. I'd recommend a condenser or an electrostatic one.

Upvotes: 0

Kilian Foth
Kilian Foth

Reputation: 14346

It's called the response characteristic of the microphone. Unfortunately, you can't easily get around it without buying a different, presumably more expensive, microphone.

Upvotes: 1

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