We have been reviewing the CARA program to determine whether it's something worth using in our day-to-day modeling needs. We came across a "feature" that is sure to interest some of you...
Good news: You can manually input your own absorption coefficients for room treatments.
Bad news: The input fields for the data are in 1/9-octave bands. (Those crazy Germans!
) There is a feature that allows for an average of the numbers between 100 and 300 Hz, but, well, that's just not how we do things 'round here.So, since most data (in the US, anyway) is published in octave or 1/3-octave bands, this presents somewhat of a challenge. You can interpolate the values between, but it's a little tricky. For anyone who might need it, we're working on a spreadsheet that will help convert octave or 1/3-octave values to CARA values. (They are also requested by CARA as absorption coefficients multiplied by 100.)
NOTE: This will not be a true representation of the data were you to actually measure them in 1/9-octaves. But it will be a fairly reasonable facsimile. "Close enough for gov'ment work," as they say.
(Besides, what do you expect for US$60?)Anyway, more soon. And please - should any of you have comments pertaining to this, or if you know "another way" to input data into CARA, please feel free!
A very special THANK YOU!!! to Eric D. for assisting me with this.
Best regards,
Jeff D. Szymanski
Chief Acoustical Engineer
Auralex Acoustics, Inc.