Compressing reversed audio

It is a lesser known technique for sure. Mike Stavrou who writes for Audio Technology here in Australia (and also has written that very good book 'Mixing With Your Mind') swears by it.

If you think about it then the reason it works so well is the compressor is acting in quite a different way on the end of the sound first and the start of the sound last. And it handles transients differently because the way the transient is presented to the compressor.

Stav also talks about doing your mixes in reverse as well. He says they come out sounding a little better than normal and you end up with a more percussive mix compared to mixing in the normal manner. I have not spent time on the reverse mixing concept so much but applying compression to reversed audio definitely sounds better and it also means you can use a lesser compressor to get a much better result than normal. 

verry interesting ....

Very interesting concept. I'll try this one out today and post a sample...

Please note Herb after compressing reversed audio, when you return the audio to normal the compression does NOT undo itself. The compression remains and it can sound good too. It works very well on vocals.

There was a good article in Audio Technology by Stav about this technique but you cannot view previous articles from the AT website like you can from SOS.

If people are really wanting to see this I could track it down, scan it and send it to those who are interested. But I will have to find the original article first.

Well I listened to that sample and there are a few points. Firstly the VC64 is not a good compressor on vocals. In fact I don't think the VC64 is good for much at all. I have used it on harmonies and used a little EQ and compression and the widening effect but that is about all. It is not a serious vocal compressor and I don't think you should treat it as such. There are so many compressors to my ear that sound better. You are doing yourself a disservice running the all important vocal sound through it. The design is a great idea but I think you just have to be mindful what you are using it on. 

So for that reason it is not a great test. Use a better compressor. Also listening to your vocals you are singing more normally if you like and you are probably right in that the reverse effect may not be that different.

I think it is meant to work better on vocals that are very dynamic and contain not only smooth attacks but very sharp and fast attacks as well. Vocals or instruments that might give an average compressor a hard time but in reverse it might cope better if you know what I mean.

timidi


Hey Kalle. do you have a link where you read about this?
Thanks

What I read was a shortish forum comment by an engineer who says it's his routine procedure for bass ... in finnish language, sorry.

I doubt  this is any good for vocals, because in human voice we spot the unnatural elements so easily.
(Oh..I see a comment that it DOES work well on vocals...just have to try myself).

The concept of applying compression to reversed audio of course has nothing to do with musicians playing live. It is more about getting a different sound out of a compressor. And what better way to do that by applying the compression to audio that is reversed rather than normal.

This all relates to backwards mixing which is also another topic. From Mike's book Mixing With Your Mind here is some information.

The following also applies to using compression on a backwards mix. The compressor in this situation smooths out a mix like peanut butter. The Attack becomes the Release and the Release becomes the Attack. But it does not get punchy because it cant grab the head. The head is the tail now so you don't get the sensation of it grabbing the attack. It is smooth but not punchy. It has the effect of ducking the Attack with anticipation. It is a beautiful effect but more like peanut butter than a boxing glove.

Backwards mixing arises out of the need to make better analog tape copies of a multi track tape from one tape to another. It is better to do this backwards. You get a better copy or print. But we don't have to worry about this these days. 

Here is an approach to better EQ of instruments or sounds.

When you listen to audio backwards and you are hearing none of the transients but what you hear more clearly is the tone of the instruments. Normally you hear a thwack which distracts you from the tone for a split second. With backwards audio you hear the tone sneaking in from miles away and then at the end when you least expect it there is a click which was the attack. Your focus changes, instead of EQing for the attack you are naturally more focussed on the resonance, the ring and the tone of the instrument, which when you think about it comprises most of the envelope anyway.

Backwards audio removes the language out of the music. Instead of being distracted by your native language or that of a saxophone, the language gets stripped out leaving you only with shape and harmonics galore. Even rhythms seem to vanish. This is a whole new psychoacoustical playground to dive into. Removing the language forces and unbiased view of the sounds.

You don't have to mix backwards of course but reversing audio even temporarily will open up some interesting possibilities in terms of not just how a compressor may work or behave but also hearing the sounds in a way that may facilitate better EQ approaches etc..

It's been a while since I tried the backwards-compression trick, but IIRC at the time I had come to the same conclusion as Mike and others who suggest it's really not worth the trouble. I wouldn't go as far as to say it's an anti-music abomination :) at least not any more than using a compressor in the first place.

This strikes me as like turning the house around because the nails are pointing in the wrong direction.

If compressors are stealing your song's percussive elements, lengthen the attack time. It's a heck of a lot easier :)

Great way of thinking about it, Jeff.

I remember doing art in school and the teacher got us to copy drawings of faces etc but to do it upside down - for the same reasons you mention above. I remember the result was always so much better doing it upside down. But the technique was limited and probably most useful for people with a lack of artistic drawing skills. Maybe a similar principle applied here? Great for the novice to check his/her mixes but once some serious skill begins to develop it becomes less and less important and limiting. But if it's just a quick check every now and then, can't hurt anyone!

the theory has to do with being able to compress more with out lossing, altering or creating transients.
It's got to do with the compressor being able to work slower, due to the the nature of reversed signals.

I am a bit more interested in how EQing might work in terms of using backwards audio. As mentioned in my post #14 you have more time to hear the real resonance of a sound more and you are not being distracted by the attack transient. So if you are having a problem EQing a track try reversing it temporarily and see if it is any easier. Then put it back to normal and see how you went. You might be surprised.

I think the thing with the reverse compression is that using a compressor the normal way around is going to suffice obviously but it might be worth trying different things to see how they go compressing in reverse. Imagine a hit with a nice transient followed by a decay segment down to zero. Think of how a compressor would handle that normally. Then think reverse now. Slow tail first leading up to loud sound that drops away fast. How is the compressor going to handle that. The overall result is meant to be a smooth very even form of compression (peanut butter) rather than trying to achieve a percussive punch effect. (eg boxing glove)

Stav uses this analogy. Normal way around is like pressing your foot into the sand real fast but withdrawing it slowly after that. Reverse is a bit like pressing your foot into the sand slowly but pulling it out fast. The second method will make a better foot print.

I usually reverse compressed audio...uh...I'd rather have this bottle in front of me than a frontal lobotomy!

I dont listen to my music backwards, for fear of finding hidden messages...

Speaking of..did Stairway to Heaven really say anything when played backwards?

LpMike75

    Speaking of..did Stairway to Heaven really say anything when played backwards?

I hear Black Dog (craigb will get what I mean).

jsaras


I usually reverse compressed audio...uh...I'd rather have this bottle in front of me than a frontal lobotomy!

You missed a key word on an old joke: "I'd rather have a full bottle in front of me than a full frontal lobotomy."  

Anyhoo, interesting discussion about mixing backwards, must certainly liberate you from hearing what you expect.

Did a fun project once where I learned to play part of Sabre Dance backwards, recorded it, then reversed it to be in the correct order but reverse-sounding.