how important is compression

Discussions on sound production outside the synthesizer such as mixing, processing, recording, editing and mastering.
intrancewetrust
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Re: how important is compression

Post by intrancewetrust » Sat Aug 11, 2012 12:03 pm

tl;dr...

but in respect to electronic music, once people started using compression it helped create some massive yet 'clean' sounds. going back in time you can really hear how muddy things can get when people tried to create a 'big' sound. sidetrain compression is especially delicious in fast bass heavy music, like psytrance, really makes the music breathe and pulse

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Re: how important is compression

Post by bouzoukijoe1 » Sun Sep 23, 2012 9:10 pm

just stumbled across this thread... I'm actually having problems right now recording with a specific mix where some of the frequencies peak too high relative to the rest of the track. now, when I record into my digital multitrack, I have to stay withing the peak indicator to avoid clipping and distortion (otherwise it sounds like c**p if I raise the input level higher). however, it hits the peak indicator way before the volume can reach normal loudness levels, so the peaks are keeping me from reaching normal loudness, making the overall mix very quiet.

so according to my research so far, people confirm that a limiter/compressor is the way to deal with it. it should dial down the peaks enough so that I can raise the overall input level and thus allowing me to make the mix louder overall. or at least, this is what I understand in theory.

I think the reasons for why compression came about are probably because of problems like this. this explains why people use it on vocals and drum recordings a lot, because there is natural inconsistency in singing and drum hits across an entire recording. sometimes I think the human voice and drum hits get really loud in some parts of the track, enough to peak too high and possibly cause clipping. this is the main reason -- I believe -- why one should use compression in a functional way (vs. a stylistic or "colouring" way).

so to Zamise's point, compression (as I understand it) is not a garnish on your music. it should be a necessary tool to make your track more consistent across the entire song within a given frequency range. someone correct me if I'm wrong.

the reason it is bad to use if you don't need it is because you are restricting the natural frequencies in your mix and compressing them, therefore losing some frequencies. if your mix sounds great out of the gate (no pun intended), then it doesn't seem to make sense to "remove" dynamics(?) unless you have a good stylistic reason to do so.

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Re: how important is compression

Post by Stab Frenzy » Mon Sep 24, 2012 6:24 am

Don't try to slam your tracks through a compressor to get them as loud as commercially released tracks when you don't really know what you're doing, you'll just ruin your music. Mix at a good safe level (peaking around -6dBFS) and then get it mastered by someone who knows what they're doing.

Dynamic processing seems to be the big thing hobbyists get wrong in their productions, especially when it comes to overall loudness of a final mix. Slamming everything hard through a limiter leads to smaller sounding mixes, not bigger. Remember that the final decision of how loud your track is going to be is the listener's hand on the volume knob, not your compressor. :thumbright:

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Re: how important is compression

Post by bouzoukijoe1 » Mon Sep 24, 2012 7:17 pm

but for standard web uploading for demo tracks and videos (particularly in video, if you record picture and sound separate), surely there are cases where you still need to compress a little, no?

I think there's still a lot I have to learn with basic mixing so there will be minimal need to compress for day to day audio sharing, but there will probably still be cases where I will want the loudness to be decent enough and "normal" compared to rest of the videos and tracks on the web right? for example if I normally set my computer to 50% volume and everything generally is in the ballpark, the wav or mp3 audio should sound close to that at 50% volume setting of my computer. the problem is on some tracks I've recorded, the overall loudness is low and I can't raise the input level without peaking and it's much quieter than other mp3s and videos I hear on the web. in those cases, there doesn't seem to be a way around compressing according to what people are saying.

it's sort of similar to digital photography... I have photos that I shoot in hi-res from my camera, but for normal web uploading and day to day sharing including email, I still normally compress it to JPEG even if it's not for "professional" use.

isn't it the same in audio? our synth gear is designed to produce professional quality audio, but to share it normally on the web, it has to be processed in some way so it's at least fit for web use. usually I think this is handled by auto-gain software built into consumer microphones and video cameras, but when I record at home directly from synth to mixer to a recorder's line input, I don't have AGC in the signal chain at all.

normally I don't run into a problem with loudness in home recordings, but every once in a while I encounter this peak/clipping problem. seems like compression is the only solution at this point.

I believe the term for this may be "normalization", but I'm not exactly sure yet. still learning...

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Re: how important is compression

Post by Stab Frenzy » Tue Sep 25, 2012 5:07 am

A few quick points:

1. You're confusing data compression and dynamic compression re: jpegs.
2. Normalisation is a mathematical function not one designed to sound good, IMO it has no place being used for audio ever.
3. Compression and limiting = AGC.
4. Yes you do need to use compression to make your music sound good but hitting a comp really hard to get the level really high isn't going to make things sound good. Compression is a complex thing and you need to learn to use it properly, it's not as simple as buying a compressor, putting on a preset and things magically sounding better and louder.

Read up on how to use compression and use some plugins for a bit until you have an idea of how to use it. Practice makes perfect.

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Re: how important is compression

Post by bouzoukijoe1 » Tue Sep 25, 2012 6:30 pm

sounds like you're still ignoring my statement about the peaks though. my mix as it comes out of the mixer sounds relatively ok, BUT there are big peaks when I view the waveform after recording (in Audacity). the peaks are keeping me from increasing the loudness, since every time I increase the loudness, the peaks start to clip. try not to get caught up in semantic arguments if you can wrap your head around what I'm trying to explain. I'm not really an expert at technical terms, but I think you should be able to understand.

I'm not really hitting the comp hard, as you refer to it. I'm not trying to make it "sound good" using compression either. I'm merely trying to reduce the difference between the peaks and the rest of the sounds in the mix so that I can raise the loudness to normal loudness levels.

I might have to grab a shot of the waveform so you can understand better. the words can be confusing if you're thinking of something else. let me dig up the last recording if I can still find it...

sorry, side note: I just found a thread on another board as I was looking for example of before and after compression waveforms.

http://fawm.org/forums/thread/3125/:
@degausser, yep, that's exactly what normalisation does. Yes, you want to normalise the master track, normal thing is to render to wav in your daw then normalise and create mp3 in audacity or similar. Never apply any processing to an mp3 directly, you'll lose quality!
@nyjm, yes, what compression does is reduce the peaks of your track, making the whole thing quieter. But you're missing an important step, which is turning up the gain afterwards - the fact that the peaks have been reduced allows you to turn it up higher without clipping. Normally compressors have an option called 'makeup gain' which does this automatically according to the ratio, but if not then just crank it up (after the compressor, not before!)
I think the person ran into the same problem as I am.

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Re: how important is compression

Post by Stab Frenzy » Wed Sep 26, 2012 4:28 am

I'm not ignoring it, 'peaks' could mean anything and so you might need more compression or compression might make it worse. If you have a peak caused by a transient from a drum for example the peak could be so quick that the compression would just bring down the level of the body after the transient, so after increasing the makeup gain you'll end up with peaks that are even higher.

I know exactly what you're saying but until you really know what you're doing you can either have it sound loud or sound good. Just keep practicing and learn how compressors work and you'll get it eventually.

The comment you quoted about normalisation is wrong, you really don't want to normalise your master. For a start you lose quality when you normalise and also you end up with peaks at 0dBFS which can lead to inter-sample peaks that cause distortion. You should be aiming for a ceiling of around -0.3dBFS using a brickwall mastering limiter like the McDSP ML4000.

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Re: how important is compression

Post by CS_TBL » Wed Sep 26, 2012 12:17 pm

When I'm mixing my own orchestral (virtual of course) pieces I only use a master compressor for the whole lot. Not because the track really needs it, but to bring the dynamic range closer together. In terms of loudness, the difference between pianissimo with a few instruments and fortissimo on the whole lot, can be quite extreme. And most people would prefer a kind of consistent amount of loudness - think of listening to music in the car where you set the volume to overrule the engine.

Sometimes there are these notes which are louder than other notes, one particular sample of a particular instrument just happens to be a tad louder than the others. And I'm not talking about standing waves here, I do the detail-mixes on headphones. For such incidental occurrences I simply use custom made track envelopes. So, 'incidental manual compression'.

For more pop-style music I can imagine using a compressor as a bit of an effect; for me the pumping effect is a creative choice.

And finally, I'm all in-the-box, I couldn't care whether people say hardware/tubes are better, or whether they sound different. As long as the compressor I use has boatloads o' parameters to tweak, I'll manage. Of course different compressors sound different, a Roland synth sounds different compared to a Korg synth. But does that mean that you can't put either one to good use? Anyway, that's the tone tweaker in me talking; I am in charge, not the machine, and certainly not the marketeers of all these companies that claim to have the ideal solution for me.
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Re: how important is compression

Post by Stab Frenzy » Fri Sep 28, 2012 3:17 am

This is a cheap mastering limiter that supposedly sounds good, which should let you get your final level up.

http://www.masseyplugins.com/buy#plugins/l2007

Don't abuse it though. ;)

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