# Shure SM58 cal file, anyone ??



## TommyBoy

please, have anyone a cal file to be used with a standard SM58 mic ?
I got a few of those and a pro amplifier I must assume handle any frequency range
for any mic, and I also got one of those hi end sound cards
but no calibrated ref gear, so I can not calibrate my mic,
please help here ???

another noob question:
I have a hard time figuring out what the sound card calibration does ?
does it assume the output and input have SAME level vs frequency ??
what if they dont have this ?
then the output level for example gets way up and down, and same does the input,
but the screen curve is nice straight since it is calibrated, but we dont need to worry about this
since mic curve is known, the difference will simply be the room and speaker,
no matter if the sweep go way up and down when you listen to it, due to SH** sound card,
I tried to add a loop cable on a cheap labtop, and performed a non calibrated sweep,
WOW what a terrible responce that gave me  not rated for hi fi


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## Wayne A. Pflughaupt

You’d have to create your own calibration file, using Shure’s frequency response graph as a reference.  This post tells how to do that. 

The calibration file “tells” REW how much and where the mic deviates from ruler-flat response, so that the program can remove the mic’s response from a measurement

I doubt the SM58 would be suitable for frequency response measurements. Typically measurement mics are omni-directional with small elements, not cardiod. That might matter more for the high frequencies than for subwoofer measurement, but the 58’s low end response falls off so much below 50 Hz that it’s 20 dB or more down at 20 Hz. Basically, all a calibration file would be doing down there is boosting noise.

Regards,
Wayne


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## TommyBoy

thanks alot, you are right that mic is a vocal mic, and for that it is perfect.
it is NOT at all a measuring or ref mic, and specially not for bass,
but it is what I got right now 

well the measurement dynamic range is HUGE,
so boosting 10 and 20 db should not be a problem, as long as the curve I can get from shure is detailed
enought, I was not able to find a very detailed one yet.

I have been looking on ref mics too, but they are in the 100-500 $ range, depending on flatness
and bandwidth, specially in the low end where I want to use it most.


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## TommyBoy

thanks again..
here is the file for SM58 I used

20 -15
50 -7
100 -1
120 0
1000 0
2000 +1
4000 +4
5000 +5
7000 +3
7500 +2
9000 +3
10000 +4
15000 -5
20000 -15









Here is my little sub I use for my PC, before the SM58 was calibrated..









Same sub, with same mic, now calibrated


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## tonyvdb

Do you not have an spl meter and if so what meter are you using? you would get better readings from a radio shack meter then the SM58.


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## TommyBoy

hehe, I forgot, I do have one of those :
http://www.wedgwood-group.com/tenmars_tm-101_professional_sound_level_meter.htm

but the thing say 31Hz to 8kHz
any one know if this one can be calibrated to go lower ?
or anyone got a cal file ?


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## Wayne A. Pflughaupt

TommyBoy said:


> I have been looking on ref mics too, but they are in the 100-500 $ range, depending on flatness
> and bandwidth, specially in the low end where I want to use it most.


Well, that’s the beauty of a program like REW. You don’t need an expensive measurement mic with flat response. You can buy a mic with a _*custom*_ calibration file from our preferred vendor, Cross Spectrum Labs, for as cheap as $70 that will measure (with REW) just as accurately as an expensive mic, and even measure down to 10 Hz. I don’t know if Cross Spectrum can ship internationally – you can check and see – but you should be able to find an affordable calibration service in Europe that could generate a custom file for an affordable mic like the Behringer ECM8000.

Regards,
Wayne


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