DanRad Posted October 10, 2011 Share Posted October 10, 2011 I have just recently found that my "digital head room" has all be disappeared. I have always mixed in real time, on to 2 tracks of the sequence which are "returned" internally from the interface. (MOTU 828 MK II) I have often gone into the red with no problems. I listen as I mix and when I've checked in the past.. all is well, even with +3 or 4 db over. Now for some reason, any overage gets a nasty digital click. I did this experiment showing the clipping/clicking. I don't get it when I "Bounce" instead of mix live. To my knowledge, I haven't changed anything. Thanks for any help. Dan Rad Link to comment Share on other sites More sharing options...
lagerfeldt Posted October 10, 2011 Share Posted October 10, 2011 Whether digital clipping is clearly audible or not depends on the material. Softer material without masking potential will clip audibly even with fractions of a dB above full scale. Other material can potentially be clipped several dB without much audible distortion. The solution is to never clip when recording or bouncing a mix. If you choose to clip intentionally I recommend you do this during a separate mastering process. This way you have full control and can change your mind. Furthermore, there's no reason to record to 2 tracks. Bouncing will do and is problem free. If bouncing and recording to 2 tracks (digitally) yields different results, then this is either due to an error in your interface or your interface routing, or more likely because you've enabled normalizing (overload protection) in your bounce dialog. But remember that any D/A - A/D conversion (outputting and inputting through physical cables from and to your sound card) will always sound different from bouncing. Whether you prefer the former is a matter of taste. You can read more about digital levels in my PDF here: http://www.popmusic.dk/download/pdf/levels-in-digital-audio.pdf Link to comment Share on other sites More sharing options...
DanRad Posted October 10, 2011 Author Share Posted October 10, 2011 Thanks for your reply. I've been "mixing live in the box" for over a decade and do it for a few reasons. I'm confused as to why what I hear (no clipping) would be different than what I get (clipping). These are serious spikes in the waveform. Again, I've done this for years with some overages never being a problem. It never goes through an AD DA part of the chain, just back into another pair of channels. Anyone have any ideas as to what may have changed to cause this? Any help is appreciated. dan Rad Link to comment Share on other sites More sharing options...
lagerfeldt Posted October 11, 2011 Share Posted October 11, 2011 I believe I already answered that. Which part didn't you understand? These are serious spikes in the waveform. Do you mean that you're getting spikes in the waveform that weren't there to begin with? Sounds like a sample rate sync problem in your sound card. That's not related to clipping. Link to comment Share on other sites More sharing options...
Simon Morrison Posted October 11, 2011 Share Posted October 11, 2011 The clicking sound may be digital artifacts caused by the I/O buffer being set too low - try increasing the I/O buffer size: Preferences > Audio There is more of a strain on the CPU(s) in live mode. Link to comment Share on other sites More sharing options...
DanRad Posted October 11, 2011 Author Share Posted October 11, 2011 Thanks for all those replies. It is curious that the problem has developed with no changes that I'm aware of to my set up and preferences. The issues only come up on overages of any kind on my main output being rerouted and recorded as I have always done and had no such problems. This does lead me to suspect something hardware O/I based. But why would it be that what I hear has no spikes, even when "in the red" but when printed, there are obvious clicks which are visible in the wave form? I've tried different clocking situations to no avail. Any other ideas are welcome. Thanks Dan Rad Link to comment Share on other sites More sharing options...
lagerfeldt Posted October 11, 2011 Share Posted October 11, 2011 Try posting a picture of the waveform. My guess is some kind of sync problem since that can cause exactly those kind of spikes. Link to comment Share on other sites More sharing options...
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