I was surfing around and found this RTA program for the computer.

http://www.trueaudio.com/rta_abt1.htm

I installed it and just used it to tune eq my spectrum flat (as a starting point for my ears)

it seems only limited by the soundcard you use and the microphone, but then u can calibrate those using the program's internal functions.

I particularly liked the quick sweep function which i used to blast a quick spectrum sweep and then use the SPL display to tune my 701.

What do u fellas think of this lil tuning tool?

I went down this path, got all he bits (probably needed a better sound card) and it certainly works. I ended up doing the car stereo by ear and only playing around with it for the home stereo / speaker projects.

Now I have my own garage I might revisit.

I ended up with a ecm8000 $99 (software comes with a mic curve for this) about $400 to get calibrated otherwise!, some wires $50, 1204FX which came with a soundcard $300 and the software - licensed version is a bit exe. probably cheaper ways but mixers are useful for many jobs.



Othe people seem to be happy. http://www.diysubwoofers.org/talkshop/messages/21626.htm

There are a number of guides on the web if you spend 30 mins in google.

http://www.diymobileaudio.com/forum/showthread.php?t=1

There is a great guide, they also look at mls based rather then typical pink noise RTA, MLS is a lot more accurate, and can help adjust many other things other then just frq response.

swept-sine method is superior to RTA and MLS.

google "angelo farina" for background, and the free Aurora plugin for Adobe Audition.

erm,
so is the quick sweep function of true rta the same thing?

SPL (or amplitude analysis) is the first step to uderstanding the system response.

if you read Farina's article, he shows that with analysis of the received waveform, then phase, amplitude and Harmonic distortion can be found.

As I understand it, the problem with using the sine sweep for SPL/RTA direct measurment is that two thing happen to the measurement at any given frequency:
THD adds to the measured signal amplitude and,
phase errors cancel out the signal amplitude.

these two problems (and other) can be avoided, and even the correct TA (if required) can be determined.