I have been recording now with Jack and Ardour and I really like it. I just did a few tracks where I noticed a few clips during the recording from my Presonus firepod (the clip indicator momentarily flickered here and there) and sure enough I have 2-3 red indicators where the kick drum peaked. Does this mean I have to throw the track away as it will distort on mixdown to CD or can I continue with the track and just keep the level down when I do the final mix. I cannot hear any clip when I listen to the track playback in the mixer in Ardour but I’m concerned about the possibility of audible clips in the mixdown to 24 bit or whatever.
If the signal has clipped during recording then the distortion caused by the signal clipping is part of the recording and will remain there no matter how you subsequently change the level. However, if it is only momentary then it may get masked as you add other tracks to the mix. If you can’t hear it then its probably not necessary to ‘throw the track away’ - although its always better not to have distorted recordings to begin with. Unless you’re really short of disk space you probably don’t have to throw the recording away, just have another try and then keep the best one - or depending upon what it is you are recording, you might even be able to edit several different ‘takes’ together…
note that in analouge-audio there are always peaks wich no meter will indicate. for that reason a headroom is always indicated. also you need headroom for posteffects like EQs, etc. so its indicated to have a max-level of -6dB in the ardour track during recording. some say even -15dB,
Lower Levels ++
When tracking, set your levels down a lot lower. I used to record on the hot side like yourself, believing that the resolution will increase because more bits gets used. The truth however is that the noise floor of the microphone also gets recorded louder, and the dynamic range of the microphone remains the same. Also remember that the used resolution per track goes down in mixdown as well, because of the summing effect.
Record in 24bit (which I assume you are already)
Set your input gain on the preamps to peak (not average) on -12 to -6dB MAX This way even if the drummer hits the kick a bit more enthusiastically than in the sound check, it will never clip.
Another point to consider is that audio equipment is not designed as conservatively as in the past, meaning that the power supplies are adequate to supply voltage to the amplifiers, but the headroom is not quite high enough on the analogue side. This means that you might get some harmonic distortion as your signal input to the encoder chips gets hotter. A smaller input signal will provide higher analogue headroom, and ultimately provide a cleaner signal, and better transient response.
thanks guys! so my question really is - if I cannot hear distortion now, will it suddenly pop up in mixdown? Can I edit the waveform if so? I don’t intend to add many effects to the kick (already compressed / gated it on the way in) and the only post processing will be a normalization and volume boost in mastering.