Measurement Microphones - Would this work?

[Myriad_Rocker]

My Yamaha home theater amp came with a microphone that was used to calibrate it. I put it on a camera tripod and put it at the main listening position and let it do its thing. So...my question is, would this microphone be adequate for using it to test my mix room? If not, I'm going to buy one of those ECM8000 mics that a lot of people seem to use.

Also, would it be adequate to plug said mic into my laptop via the built in sound card to take the measurements of the room? I'm still working on treatment and I don't have all my equipment yet.

[gullfo]

depends on the range of the mic and it is omnidirectional. it might suffice. the PC mic typically will not work because its range is limited and its also enclosed which is going to skew the results.

[Myriad_Rocker]

depends on the range of the mic and it is omnidirectional. it might suffice. the PC mic typically will not work because its range is limited and its also enclosed which is going to skew the results.

It has to be omnidirectional, right? It's kind of a little cone shape with the mic pointing upward. I put it on a camera tripod between the L and R surround speakers and directly in front of the center channel, probably 8 feet away. I'll look in the manual and see if I can see anything about the range of the mic.

[Ethan Winer]

depends on the range of the mic and it is omnidirectional. it might suffice. the PC mic typically will not work because its range is limited and its also enclosed which is going to skew the results.

Agreed. Also, some "bundled" microphones might have a known error that is compensated for in the measuring software.

--Ethan

[gullfo]

Ethan - did you mean "not compensated" for?

[rod gervais]

Ethan - did you mean "not compensated" for?

Glenn,

I am not Ethan, but will reply none the less..........

Any decent room testing software (meant for general use by multiple users) will provide the ability to input calibration data for the specific mic being used for testing.

Even the "the best" microphones (made for sound testing) have differences between any 2 mics just picked up off the assembly line.

This is why (good) mics (specifically made for sound tests) are provided with calibration data, which is then input into the testing software. So that they (meaning the users) might be able to compensate for unknown (by the software developer) differences between microphones.

However - this is not software for the purpose of general use by multiple users - this software is proprietary - specific to the gear being tested.... it is bundled with a certain microphone - and it is quite possible that the calibration data (for that specific mic) is nestled in the program itself - - thus the software would be compensating for "known errors" that exist in the mic.

The way he said it make sense to me.

Rod Gervais
Director of Education
GIK Acoustics
http://www.gikacoustics.com (USA)
http://www.gikacoustics.co.uk (Europe)
Tel.(US)1.888.986.2789
Tel.(UK)+44(0)20.7558.8976

[Ethan Winer]

Ethan - did you mean "not compensated" for?

No. As an example, if the measuring microphone has a gradual 6 dB per octave roll-off above 10 KHz, the software can include compensation to display a flat response. But the microphone itself is not flat, so when used with REW or an SPL meter with test tones etc, you won't know at what frequencies to apply correction manually, or even that the microphone needs such correction.

--Ethan

[rod gervais]

Ethan - did you mean "not compensated" for?

No. As an example, if the measuring microphone has a gradual 6 dB per octave roll-off above 10 KHz, the software can include compensation to display a flat response. But the microphone itself is not flat, so when used with REW or an SPL meter with test tones etc, you won't know at what frequencies to apply correction manually, or even that the microphone needs such correction.

He just said what I said, except he said it better...........

Rod Gervais
Director of Education
GIK Acoustics
http://www.gikacoustics.com (USA)
http://www.gikacoustics.co.uk (Europe)
Tel.(US)1.888.986.2789
Tel.(UK)+44(0)20.7558.8976

[gullfo]

agreed - if you can manually compensate (for any mic) then yes, i agree its feasible to use... however my general concern (also agreement with Rod) is the differences in manufacture of the laptop mics is probably an order of magnitude more variation than a "crafted" one (we hope ) so as a(nother) general rule - a decent outboard omni-directional mic (like an ECM8000) will be more reliable than the one in your laptop.