Cheapest way to decent RTA? (preferably portable) (1 Viewer)

[Mike Dr]

Software is expensive, standalone RTA's are even more .. I dont mind DIY work, I dont mind soldering .. and if there's a design out there that works well enough I might even come up with a kit for others to buy (i can prototype PC Boards).. so the question is.. what is the most cost-effective RTA out there...

standalone would be great, but probably not feasable .. something with software is probably the answer, but software has to be able to calibrate well and deal with crappy (i.e. laptop) sound cards

thanks

 

[Ellen]

Don't know about hardware solutions but True Audio's TrueRTA might be a good solution. Comes in several different levels. Pay for only the level you need. I believe that the next version of the program will accept mic calibration files.
In addition, the demo version of the loudspeaker and audio measurement software Praxis from Liberty Instruments includes an RTA.

 

[ThomasW]

Ellen's correct, the TrueAudio, TrueRTA is a VERY good little program. If you have the bucks, pop for the 1/24 octave version, it gives a lot more info.

 

[Mike Dr]

Ok, trueRTA does sound like a pretty inexpensive program.. no what about mics? How does it calibrate for different mics?

 

[Mike Dr]

Ok I just looked at the list of recommended mic's and preamps on trurta's site and all the pre-amps are stationary. I want something I'd be able to use in the car with a laptop as well - any recommendations?

 

[ThomasW]

Mike

Check the FAQ page on the TrueAudio site. He's got some fairly low buck recommendations as well

 

[Mike Dr]

Thomas, check my reply just above your comment

 

[ThomasW]

trurta

Didn't realize that the above was supposed to be 'TrueRTA'.

Anyway, we have a pair of the Behringer ECM8000 mics on order. Am planning on comparing them against our calibrated B&K 4133, and possibly creating a calibration curve that can be used with True RTA and ETF 5.0.

If you wnat a battery powered mic pre-amp go with one of the little Panasonic electrets mic/pre-amp combo's

I too use a laptop, but can always seem to find an outlet to power the pre-amp

 

[Mike Dr]

The problem for me is that I would want to use this for my car as well

 

[Marv]

Has anyone tried to use the Radio Shack SPL meter as the mic? It's portable although probably not flat enough for full range testing.

-Marv

P.S. Thomas I'm still working on getting a digicam for my IB picts.

 

[Mike Dr]

yeah that's what I've been using since correction curves are widely available. I still dont know exactly what to set it to to get proper reading.. i've been setting it to 100db, C weighted ..

 

[ThomasW]

Mike
There are a couple of ways to go if you need battery power. The easiest is getting an AudioControl MP-200 Battery powered 9 volt operation only $349+ shipping
The other is getting one of the DIY mics that use the panasonic cart. And building a battery operated pre-amp.
BTW the MP-200 (I have one) has no better mic than the $30 Behringer ECM8000. The down side to the ECM8000 is the need for 48+ volts phantom power. Battery powered mic pre-amps with phantom power are $300+
Of course if you can run and extension cord out the window or are willing to use a battery powered inverter. You can get the Behringer DSP110 for $70. combine that with the ECM8000 $30, and you'd have a pretty nice measurement system for cheap.