Real time audio analyzer for Mac

[JacobAppleGeek]

Hi!

Does anybody know of a real time audio analyzer that can measure all the frequencies coming from a mic along with db etc...

This is the PC equivalent... http://www.virtins.com/VTRTA168.shtml

We would prefer a solution that included a precalibrated mic like the PC option... we just need a mac option.

Thanks!

[cmchamp]

http://www.faberacoustical.com/

This is what I use - well, a previous release. I haven't upgraded yet.

[JacobAppleGeek]

Do you use a certain mic with this software? If so, how accurate are your db readings?

Thanks!

[cmchamp]

I don't use it for dB readings, but for voicing loud-speakers and analysis of recorded sounds for acoustical analysis of worship spaces.
For dB readings, we just use a 30 year old Radio Shack dB meter.
C.

[Brad Weber]

What is the purpose of this effort? I ask for a couple of reasons. One is that with computer based systems any absolute values are dependent on the devices and settings. That is where whether a calibrated mic or at least one with a known sensitivity is required. Basically, a sound pressure level hitting the mic generates a voltage that the computer sees as representing some SPL level. However, the relation of the source SPL to the voltage and/or of that to the SPL represented will change as the microphone and signal path settings change. If the goal is to be able to know that with the same mic the signal today is the same as yesterday or to look at frequency response then that may not be an issue as you are working with relative levels. However, if the goal is to say that the level is XdBSPL, an absolute level, then you will need some way of defining that what displays a XdB is actually XdB.

But even that is no guarantee of accuracy. If you are doing legal or critical work then you might need a Type 2, 1 or even 0 rated microphone and a pistonphone or calibrator. And an analyzer that meets all applicable ANSI, ISO and IEC standards.

The pricing on the system referenced is interesting as the RTA-168A version with a Superlux ECM999 mic is shown to be $50 less than the RTA-168B version with a Dayton Audio EMM-6 mic yet the EMM-6 is a less expensive microphone, the pricing I could find for it ($48.26) was $40 less than the pricing I could find for an ECM999 ($8. FWIW, Ray Rayburn quit selling the ECM999 microphone a couple of years ago as he apparently felt the quality had declined in the more recent versions.

[JacobAppleGeek]

Great! Thanks for the input, guys!

[cmchamp]

fwiw: we don't use an SPL meter for any "legal," just for reference

[Brad Weber]

Originally Posted by cmchamp

fwiw: we don't use an SPL meter for any "legal," just for reference

There are many reasons to avoid getting into measurements that have to stand up in court or that you know will be attacked by other experts (whether they really are or not). Don't do it to all of the applicable standards and you'll get attacked for that. Do it to right and some self proclaimed 'expert' with impressive sounding credentials to a public who knows no better will testify that they disagree with the findings.

The latter was related to me by a colleague. A local vendor had installed a sound system in a facility and told the Owner at the time that for it to perform properly they would have to address the acoustics of the venue. The Owner did not do anything about the acoustics and then refused to pay for the audio system on the basis that it was performing properly. It was going to go to court so the vendor had measurements performed using appropriate equipment and methods which supported that the problem was that the acoustics did not meet the criteria that had been identified and introduced this as evidence. The Owner hired a "Professor of Physics" with all sorts of letters after his name but who may have had no background in acoustics who walked into the venue, had a student stand across the room and clap their hands and then walked out. This person apparently then testified in court that the acoustics were fine including stating a specific RT60 time derived from their listening to the student clap their hands. Guess which, the formal measurements or the 'professor', the court believed?