Sidechain click

[davidrichards1983]

Just a quick query about sidechaining (bass ducking) for dance music....

 

I followed the guide below (found it on the web somewhere) - am getting a good sidechain effect, but also getting quite a major click sound when the bass is ducked. Am I right in thinking this is not desirable? Any advice?

 

Many thanks,

 

10 Step Guide

1. Output the kick sample to a bus (e.g. Bus 1). The reason being that Logic can't sidechain directly to an audio instrument, only to audio channels or busses. So this is a workaround.

 

2. Insert a Logic compressor at the very end of the chain on the bass instrument. Remember this is an extra compressor for the sole purpose of sidechain compression. Be sure to use the default settings of the compressor (very importantly: no Autogain, no limiter etc.)

 

3. Set the compressor's external sidechain (the Logic compressor also has an internal sidechain via the expanded options - ignore that in this case) to Bus 1. You set the external sidechain input in the upper right corner.

 

4. Set the attack to 0 ms. You want that bass ducked immediately to gain headroom. The attack of the kick will act as all the punch you need in the mix for that split second when the bass is ducked. This is partly a psycho-acoustical phenomenon.

 

5. Set the knee to hard (0.0). You want the peak of the signal to be the trigger, nothing else.

 

6. Set mode to "Peak". For the same reason above. RMS mode is sometimes used for delay ducking, which is slightly different from kick/bass ducking.

 

7. Set the gain to 0.0 dB. You don't want to change volume otherwise, so set it to unity.

 

8. Set a ratio between 4 and 10. How much depends on how much ducking you want. A ratio of 10 will almost remove any bass attack which might be just what you want.

 

9. Set the release time depending on how fast you want the bass to stop ducking, usually fairly quick, e.g. 20 - 50 ms. Longer times will make it pump more, which could be a desired effect - so experiment. Auto release is optional but primarily recommended when used in combination with more varied rhythms and note lengths than a standard kick/bass pattern.

 

10. Set the threshold according to level and trigger point for the ducking, use your ears and look at the meter. About 3 dB of gain reduction is usually more than enough. Remember that in this scenario you just need the very top of the signal to react, so don't pull that threshold down too far, you'll gain nothing extra.

[Holger Lagerfeldt]

That's my guide above

 

What version of Logic are you using? The click happened with the old compressor but shouldn't happen with the new one in Logic 8.

 

Anyway, try setting the attack to 0.5 or 1 ms and see what happens?

[davidrichards1983]

I'm using 7.2. Will give that a try...

 

Thanks for such a detailed guide - has been a big help......

[Holger Lagerfeldt]

You're welcome.

 

Using 7.2 that explains the click. Usually just going back 0.5 ms on the attack will remove all or most of the audible click.

 

Or just upgrade to Logic 8 The compressor is a lot better in general, one of the better bundled compressors around.