# Help: Home theater measurement software



## Anechoic (Jan 16, 2009)

Hi all,

The calibrated mics I sell come with a CD with the calibration data files in .FRD format. The .FRD format is a basic text format, and that text format is supported by most audio/acoustics software that folks like us use. The problem is that everyone uses a different file extension to represent the format - some use .cal, some use .mic, etc etc.

I supply my files using .FRD extensions because it's a definite file format, but I'm constantly answering support emails from people who are confused over the data formats because of the different file extensions (even after including a "Read Me" file on the CD to try to clarify things). So I decided I'm going to try another approach. I'm going to contact as many program authors as I can and see if we can try to find a common file extension to help reduce confusion. This attempt may be in vain, but my only other approach is to generate the same file using a bunch of different extensions and I'd rather not go down that road since that puts the onus on my to find and support every extensions out there.

What I need from HTS readers is to know what programs do you guys use for measurements that take mic calibration files?

I know about the following:

TrueRTA
ARTA
REW
Fuzz Measure
WinMLS
Aurora

AFAIK, Sound Easy and Speaker Workshop already support FRD. SMAART uses a binary format so I'm not going to bother. Is there anything that I've missed?


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## gutz (Jan 29, 2009)

HOLMImpulse - I think it also support frd but worth a check


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## JohnM (Apr 11, 2006)

REW V5 by default looks for .FRD files as well as .CAL files, and will try and parse any file extension if the file dialog filter is set to "all files".


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## Dennis H (Apr 2, 2007)

Liberty Instruments Praxis uses FRD files with a .dat extension. Comments start with a " character. If you want it to use mic sensitivity, it goes as a comment in the first line. The line has to end with MV/PA for mics or MV/g for accelerometers. Include NINV if the mic is non-inverting; otherwise it assumes it's inverting.

" Example Mic correction data: NINV Ref Sensitivity = 8 MV/PA
10 0 0


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## Anechoic (Jan 16, 2009)

Thanks for the updates guys. Any more?


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## Anechoic (Jan 16, 2009)

Just as a follow-up, real life intruded and I wound up putting this on the back-burner but I finally got around to sending this email to the website contacts of these packages (I didn't include REW since John indicated that he already looks for .FRD).

So far I've gotten no responses. I'll wait a while longer to see what happens.


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## Anechoic (Jan 16, 2009)

Good news! I heard back from John (TruRTA) and Ivo (ARTA) who both will start supported .FRD in their next releases.


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## Anechoic (Jan 16, 2009)

Just to follow up on this ancient thread, I ran into David Josephson (of Josephson microphone fame) over the summer. He is the chair of several Audio Engineering Society (AES) committees (including one on microphone measurements) so he is familiar with developing standards. I discussed the issue of the FRD format with him and he suggested that it might be appropriate to formally incorportate FRD into an AES standard.

I just saw the meeting minutes from the AES SC-04-04 (microphone standards committee) meeting from the October AES meeting and it looks like a working group will be formed to develop an AES standard for the FRD format.

Progress!


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