Direct 'Measurement' of AU-Based Digital XO

[vdB]

Hi all,

(First post here! )

Lately I've been playing around with CrossoverUnit, a set of Audio Units implementing some well known crossover types like Butterworth, Linkwitz-Riley etc. in the digital domain.

To get a better understanding of what I'm doing I'd like to inspect the transfer functions of the various configurations I make in AU Lab. Basically, what I'd like to do is described here, but I was wondering if there is free software around that can do the same trick.

I've tried REW, but it doesn't seem to be able to take specific Soundflower channels as input. I'm not sure if there is a workaround for this?

I've also looked into Audacity, which can generate sweeps and analyse audio data, but for this I need to capture AU Lab's output somehow. Perhaps this could be done with AU Lab's 'record' button, but I'm not sure if this is the best way to do things.

Any ideas?

[boris81]

Look up a free software called HOLMImpulse. I've used it to do what you need but with a different filter platform.
REW should work fine too.
You need to plug a cable to loopback from your soundcard's output to the input.

[vdB]

Thanks boris81. It looks like a great tool. However not for the Mac?

Thanks for the loopback tip too. Unfortunately my 13" MPB has only one audio jack socket. Otherwise REW would probably have been fine indeed.