Octatrack: 16bit or 24bit Mode?

Elektron Gear Octatrack
#16

Ohhh … cool! Okay so the 24 bit mode means nothing to the ability to play 16 bit or 24 bit, very cool, cheers for the illumination Anfim.

currently, even if the only advantage is a lower noise floor, i am actually going to keep rocking with the 24 bit preparations … i like making trippy effect preparations on audio files, then sampling just a tail of a sound here and there … the lower noise floor of 24 bit is helping me make abstract content explorations, remixing content a number of times in differing ways, without an accumulation of noise floor.

personally just using ableton to record and prepare the Machinedrum/Prophecy sounds/grooves … don’t have an Octatrack to test sound quality A/B comparison for the Pitch/Rate …

but if 24 bit does help ith lower noise floor, maybe less “noise floor” means better retiming, especially if re-timing to a slower tempo, as the Octatrack must “make-up” some audio content, so to speak, extending grains of audio to fit the new time.

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#17

an interesting a/b comparison would be the quality of re-pitching of an Octatrack recording at 24 bit and 16 bit of the same inputed audio, like a drum beat with a bass line.

record the input at 24 bit, then retime the captured loop and record how that sounds to a soundcard …

record the same input running 16 bit mode, assign the loop to a flex machine, retime and record the results

#18

Here we go. Recorded a shitty drum loop and a shitty bassline on one track each in 16 bit, then duplicated the tracks, changed recorders to 24 bit and recorded again. In the recording I’m switching between the two pairs, while dropping the rate on all 4 tracks using the fader. The first one you hear is 16 bit, then every time you hear a bit of silence it goes to 24, then back and forth. At the end I also set timestretch to auto for all 4 tracks, and drop the bpm down to 30. There’s a tiny bit of mic noise because I forgot I had a 57 plugged into the mixer (doh) but it shouldn’t make a difference. Everything went through a mackie 1202 then a focusrite saffire pro 24. Exported as a 24bit wav, then normalised.

https://drive.google.com/file/d/0B_dkIH5xlcuPQUExQ0d0UWpTUU0/view?usp=sharing

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#19

The OT does have two settings for this. One for flex which when set to 24 will play samples at 24 or 16 bit depending on the sample, and when set to 16 will convert all samples to 16 when loading. The other setting affects whether recordings will be made at 16 or 24 bit…
Higher bit depth not only increases dynamic range but does play a role in digital processing as well, google around and you’ll find scientific articles about this…

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#20

Just found this…hard to keep track which is which but if I can trust my ears, there‘s definitely a difference…one version (I take it that‘s the 24bit) is less „grainy“, sounds like it has fuller bottom end and seems just a little cleaner, more defined to me…oh my.

EDIT: Funny enough, tried to replicate the experiment on my Octatrack Mk2 and for the life of me couldn‘t hear any difference lol.

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#21

Do people tend to work in 24 or 16 bit or end up with a mixture? I have a stack of samples but of course at different bit rates. Is it better to stick to one bitrate, and batch convert before loading, or for example let flex format convert on loading/saving using the 16 bit setting here?

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#22

Best quality or maximum time? You have to choose. I chose maximum time, for longer recordings (3-5 mn) and most of my samples are 16 bits.

Max RAM time with 16 bits : 8m28s
Max RAM time with 24 bits : 5m39s

I tried 24 bit recording, I didn’t hear the difference. Same noise floor apparently. Probably better for mixing. Some people use 24 bits only. I need to make better tests to check if it worth it.

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#23

Actually higher bit rate is mostly useful for recording because of the much lower noise floor. So you can record at lower levels and thus less risk of clipping. For mixing it really doesn’t matter.

I wonder if the conversion within octa also uses dithering when converting. Otherwise I probably would batch convert with dithering before loading them into octa.

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#24

Would you test it with sine waves in 16/24 bits?

#25

I don’t own an octatrack just yet :wink: just following the thread and reading the manual haha. Just thought I’d chime in with some theory. But would love to know if octatrack does that :slight_smile:

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#26

Thanks @sezare56 @DaveMech
Octatrack arrives this afternoon so keen to start off on the right foot (or bit rate :slightly_smiling_face:)

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#27

If it doesn’t influence mixing, 16 bits should be better to save RAM…Mono samples save RAM too. OT records in stereo only. Not possible to convert to mono files with.

I just played / recorded a sine followed by silence with OT, CUE out > Input A, in 16 and 24 bits. Apparently no sound / noise floor difference, played in 16 or 24 bits.

I’m totally open to hear something that’d prove (by ear) that 24 bit recording really worth it with OT.

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#28

It really depends on how loud you are recording. 24bit in general (also in a daw environment) is useful for lower level recordings to avoid any clipping. If you would record at that same low level at 16bit and then turn up the gain after to make it louder, the noise might become more apparent. (noise floor difference is about 40db between 16 and 24bit).

So it won’t matter much if you record loud enough indeed. And it is better to have as little convertion stages as possible. Therefore I think if I had an octa I’d record at 16bit as well. Maybe the exception would be if I want to record a guitar or bass guitar directly into octa. Because transients will be less predictable

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#29

I made the same test playing the sine - 24 db lower. Same noise level with 16 bit or 24 bit. :thinking:

#30

Have you normalized both afterwards?

It is possible that you still would have to play back the recordings at a considerable level to hear the difference. Room noise, speaker noise etc. All have influence to and could mask it. Preamps / converters also have an influence even.
Hard to judge from here :wink: (also have to play back the 24bit recording as is and not have it be converted to 16. Same goes for the 16 bit recording, play as is witniut conversion).

What I said above is simply the theoretical difference between 16 and 24. If you don’t hear a difference don’t worry about it too much and just enjoy making music :wink:

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#31

No I only used OT FX compressor gain, same settings for both (16/24 bits) on 2 tracks, headphones.

I compared them with 16 and 24 bits playback.
This deserves a topic btw!

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#32

I wouldn’t use a compressor gain to boost the level. You want to have the signalpath as clean as possible to check this. So no eq /fx / Comp etc. I think something like time stretch should also be turned off etc. As I read it influences sound as well.

Try playing the sine at -40db and then some silence afterwards. . Then save the recordings to the flash card. Load them into a daw environment, normalize them both and then check with meters.

Edit: maybe a bit off topic indeed

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#33

I have a few dragons to finish first!

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#34

Yes indeed, 24 vs 16 and mono vs stereo and how they relate to file size, etc would be a handy reference, with audio examples and screen shots etc. where applicable.

FWIW I mostly always use 16bit too, I’m not particularly concerned about noise floor and most of my sampling is electronic sounds or pre-recorded sounds where the noise floor is often already higher than the difference of using 24bit would benefit, mostly.

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#35

is that per track or project?