I've let this thread go about 'recording to the computer' but it seems like everyone is saying things that aren't strictly true. So here is my 'best practice' for recording a DJ mix:
1. You have to record such that the loudest peaks of your audio do not overload your computer's audio input. This has 2 parts to it -- you don't want to overload the analog audio circuitry with too hot a signal, and you don't want to overload the analog to digital converter. So when you're warming up, monitor the computer's input level -- every audio recording program will show you a bouncing meter -- you want your peaks to hit a few dB below 0dB. It helps to get used to watching the meters on the DJ mixer, and try and get an idea of where on the mixer's output meter the computer begins to clip. then mark the mixer with a piece of tape and keep an eye on your peak output level. To be safe, I try and set the peaks to hit about -6 to -3 dB. Even if you go over zero a few times in a mix don't despair -- if the peak is very short, the clipping won't be audible. In particular clicks and pops on the vinyl will peg the meter. 2. Once you've recorded, you mix is going to be quieter than what you're used to hearing. If you've avoided peaking, your mix should sound pretty decent. Unless you have bad equipment or crap records. The key to bringing your mix up to 'standard volume levels' you're going to have either compress, or limit the result. Both will have the effect of lowering the peaks of the signal, so you can raise the overall volume level, without going over 0dB. I'm not a fan of compression in this context. Your records are already compressed, both during mixing and mastering. Adding more compression just sucks the life out of the music. A limiter is much better because a limiter is a 'brick wall' -- if you set the threshold at -6dB, that is the new peak level of your audio. A limiter usually doesn't have an attack control, because you don't want it to slowly reduce gain when you hit the threshold, as a compressor does. A compressor will 'let through' the peaks during the attack phase. You can get a free VST limiter plugins that are pretty good. See this site: http://www.beat-kaufmann.com/demos/equipment/limitertest/index.html I set the limiter threshold by visually looking at the recorded waveform. Your audio data will show obvious level spikes that rise above the surrounding audio. This is usually the kick drum in dance music. If you zoom out you can see how much louder the kicks are relative to the rest of the audio, and you want to set your limiter threshold to be just a bit above the 'average' audio level. Then the limiter will just work on the peaks. 3. Once you're run your audio through the limiter, then you can normalize the file. I don't normalize all the way to 0.0dB, because this can cause distortion when you encoode to MP3. -0.2 or -0.3dB is close enough. Once you normalize, check the RMS level of your recorded mix. Select a loud passage of your normalized audio, and use your audio editing program to calculate the statistics for it. I generally shoot to have the loudest sections at an RMS volume of between -12 and -10dB. This in my experience correspondsd well with the levels on commercial CDs, and in most cases, you'll still have some of the natural dynamics of the music left. If your RMS levels are too hot -- say, above -10dB for long stretches, you've set your limiter threshold too low. Undo the Normalize and the Limit processes, and tweak the threshold upwards. Conversely, if the audio's RMS leve is much below -12dB, you've set the limiter threshold too high, and you can lower it. You can do a bunch of other stuff after you've record your mix -- balance the EQ better, edit out clicks and pops, etc, but your emphasis should be on getting your mix to sound good before tweaking it in the digital domain. I can tell when a DJ mix has been overly sweetened, and it removes detail and sounds fake to me. I don't mean to lord it over everybody about this, but I've been recording and mastering for a long time. I guarantee if you follow the above methods, your mixes will sounds decent.
