Delay~ in RNBO drifting over time

Jeff Quinn's icon

maybe some one else has started a topic but if i set up a simple delay using

delay~ @maxsize samplerate and a feedback~

then record the output, the repeats are drifting and not lined up to the beat over time.

logic/reaper is set to 120bpm/48k when recording while testing.

MAX plays a short sample into RNBO and i am using the reference patch for delay~ to test.

it looks like all RNBO audio inlets are set to signal and not auto.

audio status is: core audio, 48k, i/o 64, signal 64.

i am on a m4pro mac mini.

if anyone else can confirm this or disprove this i would be grateful, thank you!

Jeff Quinn's icon
DelayDrift.maxpat
Max Patch

Jeff Quinn's icon

i have narrowed it down to the buffer size in Max and in a DAW

if i have low buffer settings like 32 or 64 the drift is minimal. when set to 1024 or 2048 it is significant.

i have tried inserting sig~ before the delay~ and it did not help.

i have also removed the ramp and interpolation in the delay~.
but unfortunately none of those work to fix the drift increasing with buffer settings.

any thoughts?

Roman Thilenius's icon

if the starting time is already incorrect (== other than what you think it is) because one vector is added to the feedbackloop, this little timing error will of course add up with every round. try to deduct once vector of samples from the delay time and see what happens.

sousastep's icon

sounds like you need a subsample-accurate delay, since the number of samples in one beat is generally not a whole number. here's one I made in rnbo using the guitar pedal package's filterdelay, and GSOT's allpass filter:

FilterDelay.rnbopat.zip
zip