Antialiased overdrive~ ?

Feb 19, 2010 at 12:02am

Antialiased overdrive~ ?

Hi,
i’d like to use overdrive to add harmonics to some melodic sounds, but when you test [overdrive~] with a simple cycle~ you get aliasing (see patch below). it, rather logically, sounds a bit like the “ideal rectangle” from the “rect~.maxhelp” patch.

Do you see ways to make an antialiased overdrive~ ?

Thanks in advance.
Alexandre

– Pasted Max Patch, click to expand. –
#48600
Feb 20, 2010 at 12:28pm

no ideas ?
Is the max community really entirely devoted to aliased sounds esthetics ?

Thanks a lot

#174767
Feb 20, 2010 at 9:17pm

Yeah, aliasing sounds cool. What you could try is stick everything inside a poly~ an upsample everything with a factor two or four. It’s all explained in the help file. Use the cross~ object before the out~’s.

_
johan

#174768
Feb 21, 2010 at 6:50pm

thanks, i’m trying this, but why cross~ instead of lores~ or biquad~ ? is it less expensive ? shouldn’t i use also a filter after the [in~] ?

#174769
Feb 21, 2010 at 8:16pm

With cross~ this doesn’t work because the ramp of the filter is too soft…
i used vb.cheby~ instead…
plus i had to filter just after the [in~] because it is not smoothed at all during the upsampling conversion, see patch below (open the poly)…
this works, and sounds nice but, wow, takes a lot of cpu… i did *8 upsampling but maybe *4 could be enough depanding on the sound.

also maybe i could find less cpu expensive than vb.cheby~ ?

I tryed this saturation test also at 96Khz, using 96Khz recordings, (which means upsampling at 8*96=768Khz), this sounds really nice!, it make me remember about my old warm sounding vinyls…

Bonsoir,
Alexandre

#174770
Feb 21, 2010 at 8:17pm

in the last message :

Attachments :
[Denied Mime] upsampled-satu-test.zip (18.5 KB)

???

#174771
Feb 21, 2010 at 8:37pm

let’s try posting each .maxpat separately…

Attachments:
  1. vb.cheby~.mxo.zip
#174772
Feb 21, 2010 at 8:39pm

Attachments
[Denied Mime] vb.cheby~.mxo.zip (11.3 KB)
[Denied Extension] play1.maxpat (21.6 KB)
[Denied Extension] satu-upb.maxpat (11.7 KB)
[Denied Extension] test-satu-upb.maxpat (11.8 KB)

hm..

#174773
Feb 25, 2010 at 9:11pm

finally, attachments working…

#174774

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