Hi everyone, I'm relatively new to PD and I've been making a loop pedal/mini daw for a class assignment. My issue is, when I'm overdubbing on the same array, it slowly starts to distort more and more. I was wondering if anyone could help me out with this, I'll attach my patch so you can have a look! (THECHAOSWALL is the main patch)

DP_square_pan.pd THECHAOSWALL.pd

Ignore the messiness of the patch it's still a work in progress

@Blades_Prod Basically, my looper is not working as it should. It does loop round and record the audio, but every layer that I add on is more distorted and riddled with feedback, help would be very much appreciated

@Blades_Prod You have put a [clip~] before your final output, and that will effectively create a "fuzz box" on the output when the audio signal exceeds +/-1.
Pd has a massive internal dynamic range, so it is very unlikely that there is any distortion before that point.
It would be better to simply reduce the final volume with your [*~] and [fader] combo, and remove the [clip~].
You could also put a soft limiter in place of [clip~]..... with a feed forward delay..... using something like [limiter~] and [z~] before your output fader (see the help file for [limiter~]).

The final output must not exceed +/-1 or your sound card will distort.

The feedback will be acoustic probably..... and headphones would help. If you are using a microphone and listening to the loop with speakers then there will be some of the previous loop fed back to the loop with a delay, and it will get very muddy very fast.
The 100% feedback from [tabread4~] to [tabwrite~] shouldn't be producing "feedback" as such.
David.

@whale-av thank you for your reply! I tried using the limiter and reduced the volume using [*~] however, this did not fix the issue. Overdubbing 'Track 1' does not have any distortion, but the rest do even though it's the exact same code in each track's sub patch. I genuinely don't know what else I can try lol.

@Blades_Prod I just copy and pasted one of the loopers into a new patch, it lets me overdub 3 times and then the 4th one is crazy distorted. Could it be an issue with my computer/settings?

A bit of shameless self-plug: I built such a looper for chapter 9 of my book "Digital Electronics for Musicians", where overdubbing both forward and backward is possible, without getting distortion. In the 2nd edition of the book, the project is built with a Bela, as a stomp box. here's the chapter's webpage, in case you are interested https://link.springer.com/chapter/10.1007/979-8-8688-0394-9_9 and here's the source code of the first edition https://github.com/Apress/digital-electronics-for-musicians

@Blades_Prod said:

@whale-av thank you for your reply! I tried using the limiter and reduced the volume using [*~] however, this did not fix the issue. Overdubbing 'Track 1' does not have any distortion, but the rest do even though it's the exact same code in each track's sub patch. I genuinely don't know what else I can try lol.

In the patch you posted you are not overdubbing in Track 1 I think, as there is no feedback from [tabread4~] to [tabwrite~].

You seem to have a large gain on your [adc~] input...... 15 loadbanged to the input.
Maybe that is correct?... but..? 15 is a massive amount of gain and could be the source of your problem.

If you turn your track modules into abstractions then you will be able to see your input meters while you are working..... like this... wall.zip
The disadvantage (maybe) is that they will all be the same.... change one and they will all change.
The $1 within [track] is the argument for the abstraction...... 1 2 3 4 for the track numbers.
I have added an output meter as well, and because they are all the same they now all have feedback from [tabread4~] to [tabwrite~] (overdubbing).
You might be better able to see what is happening on the meters as you work.

The array is overwritten on every pass, so I cannot see why it should be stable for 3 overdubs and then suddenly distort on the 4th.

P.S. I noticed with your original patch that the input gain 15 did not seem to have loadbanged in every track sub-patch. Very strange.

No promotion.... I have just found that I did update to Pd Vanilla a looper that I built for a client back in the days of Pd extended.
It has only one "track" and it uses a delay line instead of an array. It has a visual metronome, and an audio click, and will automatically stop at the end of a pattern when the "Cue seen" button is clicked.
It might have some features that you could use although translating to an array based looper would take some time.
You might not get away with using the visual metronome for a class assignment.
I had found that keeping the [adc~] input low enough was the solution for stopping the patch from climbing to distortion...... PdLoop.zip
David.

@whale-av said:

P.S. I noticed with your original patch that the input gain 15 did not seem to have loadbanged in every track sub-patch. Very strange.

It's because some of the loadbangs are messages, not objects.

@jameslo Well spotted! I am getting old and lazy.....
David.