# Calibration Mic discussion



## ehous31900 (Mar 2, 2007)

I am a 2 channel audio guy, 100% PC lossless files. I run out of the PC sound card digital into a Tact 2.0. Here is my thoughts that I need outside sources to second guess. I do not believe the Tact is doing exactly what the Screen says. I have been using TrueRTA to look at changes with an uncalibrated Mic. I have now purchased a Auzentech Forte with a balanced mic input and am in the process of building a 9 volt phantom to use the Tact mic to get the same readings the Tact gets. Obsessed, yes! If you have an opinion or have done this your self, please reply.


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## brucek (Apr 11, 2006)

> use the Tact mic to get the same readings the Tact gets.


But the Tact mic will be compensated for with the internal calibration file in the Tact firmware to render it flat. Do you have this file to use with TrueRTA or REW? Probably not.

A better method would be to get a mic with a calibration file (such as the Behringer ECM8000).

brucek


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## ehous31900 (Mar 2, 2007)

Yes, I have the cal file and assume it will load into Tue rta. I had to have my mother board swapped for the Forte sound card's PCI express. SO this is all theory at this point. Issue with Cal file is I want to keep as much the same as possible. With the Tact only having 9 volt Phantom I figure the mic is fixed? Thanks and keep the thoughts coming,


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## Kal Rubinson (Aug 3, 2006)

ehous31900 said:


> I am a 2 channel audio guy, 100% PC lossless files. I run out of the PC sound card digital into a Tact 2.0. Here is my thoughts that I need outside sources to second guess. I do not believe the Tact is doing exactly what the Screen says. I have been using TrueRTA to look at changes with an uncalibrated Mic. I have now purchased a Auzentech Forte with a balanced mic input and am in the process of building a 9 volt phantom to use the Tact mic to get the same readings the Tact gets. Obsessed, yes! If you have an opinion or have done this your self, please reply.


Rather than TrueRTA, consider RoomEQ Wizard for a better representation of the room response/corrections.


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## Schussor (Jun 8, 2009)

I am also interested in obtaining a .cal file for my USB mic. I got a Nady USB 1C cardioid so that I can make directional measurements of my dipole speakers. Though initial measurements are quite promising as to precision. 
I suspect some FR correction may have been done onboard to deliver a nominally flat response - beyond what is available from an analog version. Otherwise, they would not have quoted a useful response of 20 to 20K while using a 19mm diaphragm rather than a 1"+ as they have in their better undigitized mikes that approach good extension. 

And ehous31900, since you are all digital and have no analog sources from which to lose resolution, why don't you tear out the crossovers from your speakers and biamp or triamp? You can do an order of magnitude better job with a digital crossover than with a speaker level crossover. You get the following benefits:
1. far lower strain on your amps makes them sound way better as they avoid wasting energy on the back emf of the crossover components.
2. You can correct all phase errors like you are correcting room modes and FR abberations.
3. Match speaker drivers better to each other and their crossover slopes.
4. You can have that midrange magic tube amp (or whatever) on your upper drivers, and that bassmaster kilowatt arc welding amp on the bass. With the digtal crossover there is no phase or gain issue with different amps.

If I didn't like analog so much more, that is what I would have done years ago.


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