On Sun, 2010-11-14 at 12:00 -0500, Mathieu Bouchard wrote:
On Tue, 9 Nov 2010, chris clepper wrote:
By default CoreAudio does a lot of processing on audio when using the built-in outputs. It used to mainly be limiting to keep the shitty speakers from blowing, but it has expanded over time. There is obviously a way to tell CoreAudio to cut that out, but how that is done via PortAudio is a question for the PA developers.
Why does it do that in the application instead of inside some daemon ? I mean, what if you run 3 sound apps at once, does it does the same transformation on three signals (or pairs of signals) before mixing them ?
(I ask because, if that transformation is all linear, it's a waste)
Judging from my ears, the sound coming out of the MBP built-in speakers is dynamically processed. To me it sounds somewhat similar to the kind of processing that is applied to broadcast audio of radio stations before the signal goes on-air. Try turning on and off an [osc~] with a toggle. It sounds crisper than it normally would without processing.
Actually, I don't think that this processing is applied to each source separately. Also, it would make more sense to apply it only to the mixed signal in order to avoid clipping, even if more than one source are set to maximum gain.
Roman