leveling tracks for live sets and avoiding clipping

[wombcorps]

hey people, a quick question here in releation to live sets. i mainly play other peoples tracks and play bits of mine live, got ableton 8, an apc40 and an edirol ua-25 soundcard.

i level each track on a blank ableton page except for the sonalksis freeG plugin. while i am warping them, i level them to not go above 0 on the track volume control.

so i loaded some 'warped and leveled' tracks into a fresh new live set page, and even before i'd loaded effects, just playing 2 tracks was rarely, but sometimes, making the master channel run into the red and clip. can anyone link me up to some info online that goes into more detail on how to prevent this? i know that most people will say 'turn the master down', which i have done in previous performances but im then loosing out on volume and have seen people playing with the master around -2 with no clipping. i had mine turned down to -5 and it didnt clip but that few extra db makes all the difference.

so if ive levelled all of my tracks to below 0, how am i meant to predict what the max will be on the master? even before fx etc.

[Tarekith]

http://tarekith.com/assets/Leveling.html

[wombcorps]

nice one, i'd read that before and its pretty much how I level my tracks now

however the master still seems to be clipping when 2 tracks are played simultaneously, even though all of my tracks are leveled to 0?
What sort of level should i have on my master when playing live? ideally i'd like it to be no less than -2 but as tracks seem to clip when played together its bang on impossible for me to figure out why/how to set up my master for livesets.

this is before any fx/send/returns, ive just opened a new project in ableton to test.

also, ive noticed some weird stuff from some of my clips. heres an example:

track one: RMS L 6.77 R 7.32
track two: RMS L 8.56 R 11.70

both were leveled as close to 0 as i could get, but its quite hard getting the RMS similar with some tracks. could this be the way they were recorded, as i know that some of my tracks are vinyl rips, some are wav masters and others are 320 mp3ws ive bought off websites. how can i get the RMS to similar numbers while maintaining 0 (or as close to) on the volume. also is it a bad thing that the L and R RMS in the second example above are so different?

sorry for the barrage of questions!

[Tarekith]

Well, if you had read that then you would know that you can't level them to 0, you need to lower the clip volume slider some for exactly the reasons you're seeing, you'll clip the master. Audio channels SUM when you play more than one. So if you have one track at close to 0, and another playing at te same time at close to 0, then of course together they will go way over 0dB.

[Cryptic UK]

I think hes getting mixed up with track and clip volume

[wombcorps]

ahhh i see

i'll say now that ill be playing 2 tracks at the same time, so how should i compensate (if we say all my tracks are leveled to 0)? I guess i'd turn all of the channel faders down by the same amount but by how much?

should i be leveling my tracks to 0, then turning down the faders when preparing a live set? or should be faders be down during leveling.

[Khazul]

The simplest rule is you will need to drop the level of a 0dbFS peak mastered track to at least -6db per two tracks that will be playing at the same time.
This does not account for using the cross fader or fx.

If you expect to be playing 4 tracks at the same time, all mixed into the master bus directly, then drop the peak levels to (2 x 6 = 12) -12dbFS (again assuming material allready mastered to around 0dbFS).

The mid point of the cross fader gives you an extra 3db of headroom and the mid point dips A and B by 3db each, you could get away with -3dB each with two tracks, or -9db each on four tracks, with two feeding each sode fo the cross fader, however I have noticed that while the crossfader *should* be -3db in the middle, in pratice it seems to be about -2.96 or so, so you actually need a little more than 3db.

Easiest - by drop all to at least -12 allways, the cross fader will give you an extra 3db. If you are going to be doing vetry resonant fx processing, or heavy bass boosting etc, then consider -18db at least.

Also you may want to stick a compressor limit combo on the master bus. The compressor could be set for very slow attack and very slow release so that it acts as a slow auto-gain control and doesnt really have any affect on the dynamics of what you are playing, perhaps using its side chain EQ to boost the upper mid range on the side chain, then you can pretty much get away with whatever sonic abuse you want without splitting ear drums and pumping raws digital clipping into the PA


The 6db per track comes from 6db being a doubleing of volume, so take an audio track, duplicate it in live and play it at the same time (ie doubling it) gives you a 6db increase in level.