[PD] Playing and recording simultaneously

[IOhannes m zmoelnig]

On 2010-07-04 22:12, Mathieu Bouchard wrote:
> The total delay is the sum of the logical delay as written in the audio
> settings dialogue of Pd

i wouldn't give a groschen for what is written in the audio settings
dialogue of Pd.
i dare say that the value you see in the dialog jhas a direct
relationship [1] to the actual delay you are experiencing.

mfgasdr
IOhannes

[1] http://en.wikipedia.org/wiki/Direct_relationship

> , plus the digital in-delay and out-delay of the
> soundcard and/or driver, plus any analogue delay introduced by the
> soundcard due to filtering, plus the microphone's delay, plus the
> speaker's delay, plus the room's delay (relative to position and
> orientation of both speaker and microphone).
> 
> In the end, any digital delay can be counted by easy addition, whereas
> the analogue delays are frequency-dependent and thus have to be counted
> as filters. So, to measure a room's response, you'd first just subtract
> the digital delay, but after that, for the analogue effects, you'd need
> to deconvolve instead (but I suppose that you already know that).
> 
> It may be tricky to know the digital delay beforehand... but if you put
> the microphone and speaker really next (in)to each other, then just look
> in your recording for the point when the response begins, then it might
> be quite close to a digital delay, IF your impulsion contains enough
> high-frequencies. But I don't know how close it is, as I haven't tried it.
> 
> The total digital delay is soundcard-dependent, driver-dependent, and
> OS-dependent, on top of being dependent on a setting in pd.
> 
>  _ _ __ ___ _____ ________ _____________ _____________________ ...
> | Mathieu Bouchard, Montréal, Québec. téléphone: +1.514.383.3801
> 
> 
> 
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