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warping tracks for use with CDJ's. & loss of audio quality

Posted: Tue Feb 15, 2011 6:54 pm
by loki1985
Hi peeps

Quick question.

Im a dj and i use live to pre-arrange a mix before i play it at a club (i use live to quickly find out what tunes mix well together so i know i can mix these tunes out and they will sound good).

I have some tracks in my live set that have been recorded from vinyl, so ive had to warp these tracks excessivly so that there always in time with the metronome (i also change "beats" to "complex pro" for better quality).

My question is this; If i put a track in ableton, warp it, then export it, will doing this reduce the quality of the audio in any way? Im thinking that if i warp & export all the tracks i want to play out they will be a lot easier to beatmatch as they would have been warped and wont go out of time as much when mixing, but im worried about any loss of audio quality when doing this.. also, what should i export them as, 16 bit (with/ without dithering?)or 32 bit?

any help would be greatly appreacited

thanks

nath

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Tue Feb 15, 2011 7:22 pm
by 102455
What type of tracks are you talking about?

As a general rule, tracks that have been recorded in the years since click tracks and drum machines became commonplace should have a fairly solid tempo, and not require much warping. Tracks from many years ago, pre drum machine and pre click track, will be the wobbly ones that need warping.

If you're burning them to CD and playing on CDJs then there's not much point exporting them any higher than 16 bit/44k1.

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Wed Feb 16, 2011 3:40 am
by Khazul
What record decks you using to digitize from? I dont find I need to warp much at all from mine.

In answer warping will degrade the audio. Allways worth listening critcally to anything warped with complex pro - most of the time its OK, but sometimes it just kills transient badly, or make some sound like they are doubled - kicks can sometimes sound like a not-quite matched mix etc - which really messes with your head as you may end up trying to fix it thinking your mixing is off. Mostly not really any different to the effects of tempo-lock mode on a CDJ-1000, or Harmonic effect pitch shifter on a DJM-800.

One thing I would suggest - dont bounce to CD at peak volume, nudge a dB or so off anything that has been warped, especially if sourced from CD rather than vinyl. Will mean they are a tiny bit quieter, but nothing that isnt normally within the range your used to dealing with via mixer level trim anyway.

Export should be 16bit/44.1Khz as that is what CD format is.

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Wed Feb 16, 2011 5:21 am
by loki1985
Thanks for your replys guys, appreaciate it!
Khazul wrote:What record decks you using to digitize from? I dont find I need to warp much at all from mine.
I a recorded a few tracks from a freinds vinyl LP using an old numark DD 1650 turntable. im a bit of a perfectionist with warping so I like to make sure the kicks & snares are esactly where they should be according to the grid in live. this enables me to perfectly beat match a mix using 2 audio tracks in live (and quickly find 2 tunes that mix well together!)


The main reasons i want to warp, export, and then mix these individual exported tracks on cdjs is to A) adjust each tracks gain so that every track is about the same volume (db) (this would mean i wouldent need to mess about with gain during the dj mix), B) on the tracks that have been recorded from vinyl I could cancel out any speeding up that happens when you digitize a vinyl (as the needle gets closer to the middle of the vinyl the track speeds up slightly, making beatmatching awkward (i counter this using warp markers), and C) I have a few tunes that dont drop where you think they would (eg like a extra 1/2 bar where the drop should be) making them nearly impossible to mix/ double drop. Id like to chop these extra bits out to make the tune drop where i want it to for dj mixing purposes. (if you dont get what i mean listen to DaVIP vs Damien Marley - Confrontation, theres a extra 1/2 bar just before the drop that throws your mix off compleatly if not removed.)

Khazul wrote: warping will degrade the audio
im djing next month on a very expencive, loud system. will this loss in audio quality be that apparant? because Im not willing to trade off a noticible loss in audio quality for exchange of easier beat matching/ making edits of tracks id like to mix... That said id really, really like to be able to warp, edit and bounce these tracks for playing out, but ONLY if the audio quality will be similar to that which it went into ableton at. Your thought on this? (surley the loss of audio quality wont be noticible?!)
Khazul wrote: dont bounce to CD at peak volume, nudge a dB or so off anything that has been warped, especially if sourced from CD rather than vinyl.
so if i had 10 tracks, all in ableton at diffrent volumes (due to how each tune was masterd) would it be ok to bounce each track at say -3db? because as i said earlier this would mean i have to worry less about setting the gain when mixing as i know each track peaks at around -3.

Khazul wrote: Export should be 16bit/44.1Khz as that is what CD format is.
i take it i should not be dithering the tracks when exporting at 16bit?


sorry to rant, but if i smash it on the decks this time im guranteed more sets in the future and a residency, so i really want to do this right!

thanks!

ps. the tracks im mixing are dubstep. so very sub bass heavystuff!

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Wed Feb 16, 2011 8:48 am
by Khazul
OK - your biggest audio loss will probably be the digitizing (depdns what cartrige, new stylus or not - etc). Anything else you will hear when warping, but in particularly you may want to listen for any of the following:
- Doubled transients - subtle, but very annoying to DJs where they are on kicks as it confuses you when beat matching - you keep wanting to fix your match when that isnt the problem.
- Softened transients - on material where the transients were not very good anyway and your playing in a much club sound system - can result in a lifeless track in extreme cases - often a tendency to just want to turn such tracks up - doesnt work - better off mixing out ASAP if its that bad.
- Little warbles in the sound around detailed warping.
- Changes in formats - ie certainly sounds seem a bit wierd, particular piano, guitars, vocal.

The first two you often come across on CD descks anyway if using a pitch lock. (called tempo lock on pioneer CDJs).

Re: chopping and skips - yes they are a pain - I use to mark up the label of vinyl to remind me which side, rough cue if there was a transition quirk. Noone seems to do that anymore with CDs and digital DJing - edit it out etc, or just remember its there - use clip fades if required to smooth anything out around the pastes.

Re: level - yes -3 will be fine for your purposes.

Re: dither - just use the default triangle dither - that will be fine.

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Wed Feb 16, 2011 12:52 pm
by misiu
Khazul wrote: The first two you often come across on CD descks anyway if using a pitch lock. (called tempo lock on pioneer CDJs).
Thanks for pointing that out Khazul.

How does Live's time stretching compare to for instance the CDJ 1000?
I've read that in Live using Complex pro warp mode you are basically using Zplane’s Elastique Pro algorithm, correct?

I'm a bit suprised that NI Traktor as well is using Elastique from Zplane and still users claim that Live's audio output is "quiet" and not as "crisP" as Traktor's (yes, using the same audio interface). But is this a fact or just plain BS?

How can this be?
Has it to do with Live's audio summing engine?

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Wed Feb 16, 2011 6:53 pm
by Khazul
Personally I think the high quality stecth in Traktor pro is far superior to that in Live. Perhaps they are using elastique 2?

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Wed Feb 16, 2011 8:08 pm
by 102455
If you're playing Dubstep, you shouldn't really have any need to warp - because it will have been produced in recent history, using modern production techniques so the tempo should be pretty solid.

The only fluctuations (if any) will come from either the vinyl pressing being off centre or variations in the drive of a dodgy turntable.

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Thu Feb 17, 2011 8:52 am
by misiu
intresting... according to zplane's website:

Live 8 - élastique Pro V2.x
Traktor 2, 3 - élastique efficient V1.0

http://www.zplane.de/index.php?page=des ... references

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Thu Feb 17, 2011 10:55 am
by Khazul
misiu wrote:Traktor 2, 3 - élastique efficient V1.0
Those are very old versions of traktor - ie before traktor pro.

If traktor pro and live 8 both use the same version, then I guess it must down to the way the audio is manipulated for warping before correction is applied?
Probably alot easier to do a clean pitch shift when the audio stream and pitch/stretch parameters are static.

Re: warping tracks for use with CDJ's. & loss of audio quality

Posted: Thu Feb 17, 2011 11:56 am
by misiu
Khazul wrote: Those are very old versions of traktor - ie before traktor pro.
yes, if they do use the same version of elastique, i'm suprised the reference list is not more up to date...

i can only find this article that claims traktor pro also uses version 2.x
http://musicindustrynewswire.com/2009/0 ... 163620.php
Khazul wrote: If traktor pro and live 8 both use the same version, then I guess it must down to the way the audio is manipulated for warping before correction is applied?
Probably alot easier to do a clean pitch shift when the audio stream and pitch/stretch parameters are static.
i dunno, maybe a discussion more suitable on gearslutz.com :D