DSP Robotics Support

How to adjust delay time without causing artifact (cracks, noises or pitch shifting)

I need to adjust delay time for distance in stage panning in my "3d" panner attempt that cause problem during automatization of position. Any advise would be greatly appreciated .

Hi TrojakEW!

If you alter a delay time dynamically, the contents currently in the delay buffer will be read out at a different rate to which they were entered, so a pitch shift is inevitable while the delay time is changing. This is like the classic Doppler Effect in the real world.

Regarding crackles and noises this could be down to you using a delay which doesn’t use interpolation, meaning you will be requesting non-integer values for the delay clock.

There could be other reasons, like using green prims in the automation without de-zipping for example.

If you care to upload your schematic we can have a look and maybe make recommendations.

Cheers

Spogg

Hey thanks Spogg.

Your answer make me realize what I really want to achieve. Pitch sliding due to delay change is more like feature because it adds "variability" to sound and it is quite handy for fx. For placing/positioning instruments there is no problem since delay will not change dynamically. I will also include option to turn of distance delay.

Really thanks .

In case you didn't want the R2D2 sound when changing the delay time, there is a way to avoid it using two delay lines, one silent and the other active. You change the delay time on the silent one and then crossfade. I think I posted a working schematic some time ago.

martinvicanek wrote:In case you didn't want the R2D2 sound when changing the delay time, there is a way to avoid it using two delay lines, one silent and the other active. You change the delay time on the silent one and then crossfade. I think I posted a working schematic some time ago.

Oooh can I see it please?

I also thought about having a silly amount of fixed delays set to different times and cross-fading between them to alter the delay, but it would probably sound like crap because of cancelling effects in the cross-fade regions. So I never bothered to try it out.
However, it might make an interesting noise, and some people do seem to like interesting noises

Cheers

Spogg

.[/quote]

"....some people do seem to like interesting noises

Cheers

Spogg[/quote]

That would be me....

ROXY

Here you go

@ Martin: Many thanks Martin, I'll check it out soon.

@Roxy: I just love the old stuff! Thanks for the video links.

Spogg