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A few questions on compressors
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| G-Con |
Hello everyone.
I'm finishing off a tune i've been working on (finally!!) and have come across a few problems with compression.
1) I've created a sub bass and am sidechaining it to my kick. When doing this, a nasty clicking sound occurs as the bass gets compressed on eack kick. When the attack is at its fastest, the clicking is at its worst. As i lengthen the attack, the clicking gets quieter and eventually goes away (around 150ms). Surely for sidecahing i need a fast attack though otherwise the bass and kick will conflict. Can anybody tell me why this clicking is occuring and what i'm doing wrong?
2) As I'm at the final stages, I have stuck a compressor on the master channel with a low ratio (2:1) and low threshold (-7db). The gain reduction as a result is around -6 to -7db. This makles the tune quieter than before so I've increased the make-up gain. I cant really tell much difference from now to before. But my main lead is making a weird trembling effect, sort of going up and down. If I turn the compressor off, the trembling effect goes away. Would this be that pumping effect that people talk about and would it be a sign that I am over compressing? My tune only clips a couple of times briefly throughout so I only wanted a compressor to stop this happening and maybe give a more pumping feel (but not so its noticeably changing my lead sound which it is) Can anyone tell me what sort of gain reduction i should be going for on the master channel. I think I've mixed it okay so I want the compressor on the master just to enhance the track a litlle, not fix any mistakes in the mixing.
3) Finally my computer usage is currently hitting 98%, slowing playback right down, stuttering loads. So ideally I would record it all to audio so I can then play around with compression on the master channel and be able to listen properly to the outcome. Is there anything wrong with recording my tune even though there are a couple of occassions when clipping occurs, so I can then attempt to sort stuff out on the master channel, or must i remove the clipping first BEFORE recording it? (when i say clipping, all i mean is the master meter goes into the red. I dont actually hear anything occur.
If you have read this far, then i am already impressed and very grateful. If you can answer these questions, then I'll be eternally in your debt.
Cheers |
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| Fatboy |
1) That sounds like a combination of too fast attack and too much gain reduction. Try to raise the threshold of the compressor at the same time as you lower the attack time.
2) Gain reduction of 6-7dB on average throughout the track is usually way too much. 2-3dB, sometimes 4dB, is more common. With that said, I wouldn't use a compressor who's only task is to remove clipping, a brickwall limiter with the threshold set at 0dB would do that job perfectly fine. Either that, or simply lower the gain of the master channel.
3) What you're describing here is usually what's going on before mastering. I would simply lower the master fader until the track stops clipping and bounce it like that. Watch out that you bounce it in the right bit depth. 24 bit is fine, while a truncated 16 bit file might have audible artifacts depending on the source material.
Hope that was somewhat useful:) |
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| mysticalninja |
sometimes u just dont need a compressor on the master out.. try a multiband compressor maybe tho? so u can just get the low end some compression or something.
about the click on the sidechain, and you using a send of the original kick as the signal for the sidechain? dont do this, use a seperate track with the same kick, and put sidechain signal kick just A MILLIINCH infront of the other kick. i almost always use as low as an attack as the sidechain comp can get. i think its more about release. |
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| 3rd Signal |
I agree with the answers given but decided to answer it myself aswell.
1) well, Fatboy said everything. same effect as JP80X0 got (only they say it's on purpose). the envlope ain't supposed to open that fast, and when you do that it results in a clip. IE take a wave sample and cut it where it gets to the highest point (to the peak), once played you'll get the same "clip" effect.
that issue can basicly be handled with slowing the envlope's slides from top to bottom and the opposite.
2) if you don't know compression well then it's better not to use it on a master, it can close up the mix badly in a non fixable way.
I advice (that's what I do) to leave mastering for the pro's and basicly just put a Maximizer on the stereo out to gain the few DB's you can.
the effect your experiencing is caused due to bad compression, you over compress it in certion points of the track where the track as a piece as louder then usuaull and then the compressor reduces the volume.
I hope I said it correct, cause that's the explaination I got (just in hebrew so I had to translate it).
3) about finishing touches, I don't think it will do any harm, unless the peak is very high. and it will distort.
I usually work where the top peak of the track is -4DB at most and gain it later when I finish the track, on each export I import it back into cubase in a new project and put a limiter to feel it a bit louder but the last touch is always left for the company which will label the part.
anyhow good luck bro and would love to hear a demo.
Barak. |
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| G-Con |
Ok. Cheers for all the replies. So as far as I understand it you are saying that the fast attack is the problem for sidechaining. Problem is
I need a fast attack other wise the bass will duck after the kick instead of during the kick. I will try what you said mystical ninja. Sounds like a neat trick.
For the second one, you are telling me to use a limiter, NOT a compressor to get rid of the few areas of clipping.
For the third one I should perhaps just lower the master volume slightly to get rid of clipping. Then bounce to audio. Then maybe put a limiter on it to squeeze a few more decibals. One question with this one. Where should my master volume be set at once I'ver bounced to audio. Bang on Odb and then use my limiter to judge the loudness or should the master be set lower.
I only ask this beacuse last night, i bounced to audio without anything on the master (leaving the clipping in) but when I imported back into ableton, it was no longer clipping on the master and also seemed quieter. This has got me really confused. If it was clipping before I bounced it and sounded quite loud, then surely, it should still clip after i've bounced it and sound just as loud?? |
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| mysticalninja |
| try looking at it in abletons wav editor, you can probably see it clipping. |
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| Fatboy |
Yeah, try out mysticalninja's trick. Haven't tried it myself, but it makes sense. With the limiter, I meant that if the compressors's sole role on the track is to remove a few peaks, then a limiter makes more sense, unless you like the sonic result of what the compressor is doing to the rest of it. Btw, a limiter is basically a compressor with a really high ratio, so that would give you the same result.
I always keep the masterfader at 0dB when doing mastering. It gives a simple overview of how much level your processors are outputting, and how much you need to adjust them.
About the clipping after bounce, it depends on the software involved. Some have some sort of softclip algorithm applied after bounce, while most just bounce the distorted file as is. The thing is that it's not possible to bounce files that exceeds 0dBfs, which means that programs will not identify the clipping in the same way than for example two tracks being summed together to the master bus. A proper digital meter will be able to see this, but not all. The usual rule is that 3-7 consecutive samples at 0dBfs makes the meter indicate that it's clipped. I use Live from time to time, but don't know how it's meters works, but I would still make it a general rule not to bounce before adjusting the master so that all clipping is removed. |
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