Internal recording (qualitywise)


#1

Hi,
I’ve been with my OT for a few months now, and enjoying it quite a lot. I wanted to ask you guys is there any quality loss when doing internal recording? What I would like to do is to, for example, cue two tracks, do internal recording (source=cue), and then assign the recorded audio to one of the cued tracks, so I’ll have one free track whenever I feel like adding new sounds to song.

You’d say why wouldn’t I check it myself :slight_smile: I actually did, I am just not sure yet. It looks like when combining low end, like kicks and bass, a bit quality loss is audible – the bottom end kinda becomes a bit less punchy. (I made sure I am listening to same dB level by assigning original and recorded audio to scene A and scene B and adjusted levels.) But on the higher frequency recording (hats, snares), I haven’t noticed this.

Also, from one of youtube videos (I think cuckoo’s, couldn’t find it later), I’ve seen that when doing internal recording, source audio level should be set to max, because otherwise after normalizing, the recorded audio may sound low quality. This is true. And I set the source to max level when doing internal recording.


#2

OT can record in either 16bit or 24 bit. So that is s something to be aware of. I have not noticed any loss in fidelity when recording at 24 bit, which is what one would expect.


#3

Every (re-)recording which involves some sound processing like summing two or more audio streams degrades the quality. That’s a trivial fact due to the limited resolution (16 or 24 bit).

But at least when you are using 24-bit mode you should be able to do it a few times before it becomes (too) noticable.


#4

There are also various threads about gain staging on OT that are worth reading to be aware of the signal path.


#5

True. But my understanding was that it could do resampling in two ways:

  1. DAC and then ADC – that’s, first the sound(s) converted to audio signal and then back to digital which then output as audio signal. And because of the extra layer of conversion, degrade in quality happens.
  2. Doing resampling by digital means – that is, no DAC and back to ADC occurs. Sound(s) digitally merged together and then DAC happens.

Obviously, OT uses 1. method otherwise we wouldn’t deal with levels and gains. I am not sure, but I think Ableton does it all digitally, then DAC happens. I don’t have much experience in Ableton either, just never experienced artifacts in audio after resampling or after normalizing the final song. So that’s why I think it does resampling digitally.

Recording in 24 bit is something I’ll try definitely. It didn’t occur to me that 16/24 bit difference could be noticeable.


#6

No, the OT uses also method 2, unless you route the signal out of the device via its analog outputs and back in again. It would be stupid to leave the digital domain sooner as necessary.

In contrast to the OT Ableton uses internally 32-bit floating point numbers which gives you enough headroom to perform audio processing like there is no tomorrow. Nevertheless you need to deal with level and gain. If your gain staging is not right, you will hear it sooner or later.


#7

This made me happier :slight_smile: I guess my understanding about levels and gains isn’t good. Thanks a lot for the replies!


#8

Levels and gain concerns are not exclusive to the analog domain. They should be considered in the digital just as well.


#9

Also there’s dithering. Pure speculation, but I wouldn’t be surprised at all if the OT didn’t dither internal recordings, which would mean that even if DAC output are dithered, internal recordings would have quantization error that wouldn’t be present on a live output. And if the DAC output isn’t dithered either, there would be two generations of quantization error when you recorded internally and then played back, so in either case there would be a subtle but potentially audible (depending on your monitors, and your sensitivity to quatization error). At 24 bit it would be a LOT less audible.

I’ve done quite a bit of blind A/Bing between dithered and undithered audio over the last few years, and it’s subtle but there’s definitely an audible difference even at 24 bit for me - audible enough that now that I know what to listen for, the handful of times it’s happened I could tell if I’ve accidentally rendered a mix without dither without having to do any comparisons at all). I rarely rerecord internally in the OT (usually I’ll either record to a DAW and then resample from that, or loop one of the outputs through external effects and back to the inputs, and resample that way) so it isn’t something I’ve lsitened for but what you’re describing sounds similar to the way quantization distortion sounds to me.

But again, pure speculation (and for me personally, it’s something I would have no problem with accepting as part of the OT SOUND).


#10

Interesting point. I definitely need to improve my knowledge on the audio processing. I’ve seen dithering options in Ableton, but never researched how it affects the sound, and went with the default. Still, 24-bit tip was very helpful. Now I use 24-bit for recording as well as for flex machines. The samples I am using are short, so the memory isn’t issue for me. I haven’t been able to check its effect on recording yet. If later I see anything worth to post, I’ll add to this thread. Thanks a lot for sharing your thoughts.