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Tap In/Tap Out 1 sample off?

Jun 29 2010 | 12:27 pm

Is this still true for Max 5? I am trying to use it for a fractional-delay filter or would I be better off with an external?

Jun 29 2010 | 8:43 pm

Yes – as far as I’m aware it is true that delay~ and tapin~/tapout~ give an extra sample of delay *WHEN* the delay time is driven with a signal (I’m not 100% on the case of a float/int). You can compensate this of course. Thus in contradiction to raja’s post you *can* set a delay of 0 samples, but you can a delay of one sample, and so on.

The workaround is trivial if tedious….

-- Pasted Max Patch, click to expand. --

(the above will work for any sample rate – the [adstatus] variable could be almost anything that will trigger if audio is restarted…

The reason for the extra sample concerns the method of interpolation and although I reported this a bug c74 do not feel this way – I see their reasoning, although I wouldn’t have made the same choice. The reply I got was that it was not going to change….


Jun 29 2010 | 8:47 pm

Oh – of course – fractional delays of less than one sample are not possible, unless you are prepared / able to delay the rest of your signal path by one sample to end up with the correct relative delay..


Jun 30 2010 | 8:59 am

tapin~/tapout~ introduce one vector size of delay. The extra delay of one sample can be caused by floating point precision.

Jun 30 2010 | 12:40 pm

@ej –

1 – can you confirm with patch that tapin~/tapout~ ALWAYS introduce one vector size of delay? This is not my experience at all…

2 – Yes, of course there may be floating point imprecision converting from milliseconds to samples. However, the sample delay I was talking about is NOT caused by floating point imprecision, but is additional to this. This is easier to see in the case of delay~, where there is no conversion happening.



Jun 30 2010 | 2:33 pm

You’ll find 2 examples which show that there’s always a minimum of one vector size of delay. In the second example you can clearly hear the difference when you change the number of samples of the vector size.

-- Pasted Max Patch, click to expand. --

Jun 30 2010 | 4:01 pm

@ej – ah I see – a minimum of one vector I know about – sorry your post implied one vector plus the required delay….

Thanks for clarification.


Jul 01 2010 | 12:53 pm

Thanks for all your help guys! Much appreciated!

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Forums > MaxMSP