Is 32 bit float better than 24bit?

Brings to mind the test a while back where they connected Monster cables to speakers and then wire coat hangers. No one could tell the difference. :laughing:

:laughing:

Jarno,

Iā€™m sure youā€™re right, but why not use dithering when it actually increases resolution and hence gives you a better quality file (even if you and I canā€™t hear it)? On the other hand, I always try to avoid extra processing (dithering in this case) if I can help it and keep the highest resolution until the end. Then I donā€™t have to worry about any of this. But if for whatever reason I have to lower the resolution at some point, then it gives me peace of mind to dither. If that doesnā€™t bother you, then good for you :slight_smile:

Take care!

You can very well use dithering when converting 32-bit-floating-point signal to 24-bit. It doesnā€™t hurt, but I find it pointless:

  1. Recording: Your converter doesnā€™t provide full 24 bits of significant information which means dithering (which only operates on that last 24:th bit) is meaningless.
  2. Processing single recorded 24-bit file: if your processing is not increasing dynamic range (expanding), same as above applies. The last few bits of the signal are pure rubbish ā€¦ dithering is again meaningless.
  3. Mixdown: If you record your mixdown in decent level (peaking more than say -12dBfs) and the dynamic range of your mixdown isnā€™t ridicilous (far more than any natural sound source) any quantisation errors to 24bit are meaningless.
  4. Bouncing a pure digital source (modelling VSTi): Now you have no rubbish generated by your A/D converters, so you may once again theoretically get better results with ditheringā€¦ but once again, in practise only if you have ridicilous dynamic range.

Now, when re-quantisising (note the word Iā€™m using: re-quantisising ā€¦ some uneducated people use the word dithering when they actually talk about quantisising) into 16 bits, Iā€™m fully supporting dithering. When going to 16 bits the quantisation error may create distortion as high as 0.003% (compared to full-scale, up to 0.03% - 0.1% on quieter parts of the music). These numbers are in par with distortion of analog recording systems and this is BAD distortion, not the nice harmonic one. So when going to 16 bits: DITHER! In 24-bits deficiencies of your A/D conververters outweight the quatisation distortion and itā€™s up to you if you want to dither or not.

In practise I donā€™t bother to dither to 24 bits, unless I have very good reaon to do it, but always dither when going to 16 bits.

I must admit I tend not to dither when going 32fp>24 as Iā€™ve never noticed any difference!

And nether has any (PT?) studio Iā€™ve sent 24bit files to :smiley:

But as I almost always work 32fp, I do export mixes at 32fp and I do have cubase set to 32fp as I tend to do quite a lot of offline processing!

Of course shaped dither to 16bit final mix, usually with the UV22.

Jarno,

I already know all of that. I was simply stating that I choose to apply dithering in the rare cases when I need to reduce the wordlength (whether I hear it or not). Itā€™s a personal choice :wink: In Sonar I was able to choose different bit depths for recording, mixing, bouncing and exporting. Since Cubase doesnā€™t have as much flexibility in this aspect (without me having to manually change settings), then I just set it to 32 bit and forget about it (even if my converters donā€™t go near that far).

BTW, the highest quality converters I know of go up to ~21bit (or -127dB FS). These are the Lavry Gold. I personally donā€™t know of converters that go lower than that, as you mentioned in an earlier post above. Perhaps you know of ones that do? If so, let me know.

Take care!

I think we agree with principles but disagree with our choises. Neither us shouldnā€™t be right or wrong. Itā€™s just matter of choise.

No I donā€™t. I havenā€™t bothered to search for those last extra bits. I donā€™t record classical music and I donā€™t think any of my mic/pre combinations have low enough noise floor to take advantage of more than 19 to 20 bits of A/D conversion. My original quote of ā€œ21-23 bitsā€ was just for being safe: If I had said 21 bits, I bet there would have been someone with converter capable of producing 22-bit A/D and I would have been hammered down completely.

Not at Xmasā€¦ Surely

Maybe youā€™re right. We arenā€™t at GearSnobs.com after all :stuck_out_tongue:

Thank goodness for that :laughing:

Amen, bro! ā€¦ while still have to question your choise to save your files as 32bit, because according to science it should be pointless unless very very very rare situations ā€¦ but thatā€™s again only the choise you make. And I can live with it ā€¦ and I hope you too can live with my choiseā€¦

Absolutely. My choice to save mixes at 32bit is basically because most of my mixes are done ITB and Cubase outputs 32fp so why go 24 then into wavelab and back to 32fp then down to 16 or whatever.

As I said earlier if Iā€™m sending files out, I go to 24 and usually donā€™t dither.

Exactly :slight_smile:

No I donā€™t. I havenā€™t bothered to search for those last extra bits. I donā€™t record classical music and I donā€™t think any of my mic/pre combinations have low enough noise floor to take advantage of more than 19 to 20 bits of A/D conversion. My original quote of ā€œ21-23 bitsā€ was just for being safe: If I had said 21 bits, I bet there would have been someone with converter capable of producing 22-bit A/D and I would have been hammered down completely.

Oh, I see. I donā€™t think you wouldā€™ve been hammered in this forum for saying that (at least not from what I can tell in the short time Iā€™ve been here). I was simply curious to know if there were such converters that could go lower, cause that would be quite the feat.

Take care!

The advantage of recording in 32 instead of 24 bits is that one of the ā€œnativeā€ word sizes of the x86/x64 is 32 bits. Youā€™d have to convert your 24 bit values to 32 bit before doing any math on them. So from a programming perspective it makes perfectly sense.

As was stated earlier, there is absolutely no advantage in recording at 32 bits since the file simply gets padded with zeros at the end (AD/DA converters only go up to 21 bits MAX, the three remaining bits are filled with self-noise from the components. Thatā€™s a $4,000 converter btw). The only reason I use 32 bit for recording, me personally, is because it is simply easier to set and forget than to have to remember to switch Cubase back from 24 bit recording into 32 bit bouncing/exporting mode every time I work in a project.

Cubase does itā€™s internal processing at 32 bit resolution, no matter what bit depth the audio was recorded with. There is no ā€œphysicalā€ conversion of the audio file taking place in Cubase until the moment you export, bounce or freeze a track. IOW, the computational math resolution of a piece of software has nothing to do with the resolution of an audio file.

Makes perfectly sense, but ā€¦ as I wrote in my earlier post, time needed for conversion from 24 integer to 32 bit float and back is neglible.

We are talking 32 bit FLOAT, not 32 bits. 32 bit float and 32 bits are not the same thing.

You arenā€™t recording in 32 bits, because your DAC is probably 20bits or at best 24. And, you probably arenā€™t getting full claimed bit depth from your DAC either. You are most likely getting between 18 and 22 bits MAX. Probably closer to 8 to 16. Use a bit meter on the incoming buss sometime while you record. You will be shocked.

Just donā€™t change bit depth of the file until your FINAL mastering step. The internal change from 24 bits file, to 32 bit float processing while mixing will NOT degrade your signal over time. Only when bouncing tracks or exporting stems will it be relevant. Even then itā€™s the cumulative damage that you are trying to avoid. Adding a dither to the noise floor for a bounce is going to be much worse than a LSB rounding error. Especially if you bounce a lot.

These days, studios work primarily at 24 bits (at least in my experience). They want you to send them 24 bit stems. So, when you export the stems and you are at 24 bits, then no dither is required. Each individual track will have some chance of rounding errors, but again those errors will be much less noticeable than a dither. If you had to go from 32 bit float to 24 bit, you would need to dither each of the stems. Again, this would be more noticeable than any rounding error. And you will get a cumulative dither when the studio dithers to the various target bit depths of CD, MP3 etcā€¦ Which = bad.

There are a zillion permutations here. There are scenarios where the 32 bit float file makes sense. But, IMO it isnā€™t for a normal song tracking/mixing/mastering project.

My 4.787899767878263529506662858 cents.

What I meant was, that anytime you apply an effect on a 24 bit file then, internally, itā€™s converted to 32 bits and the effect is applied, and then written back to disk in 24 bit format (truncated from 32 bit[!]). Imagine applying 5 offline effects one after another and you can appreciate the advantage of using 32 bits.

Cecil, 32 bits floats are 32 bits wide (aka. single precision, in programmer lingo). And Iā€™m perfectly aware that itā€™s single precision floats weā€™re talking about. Iā€™ve coded assembler/C/C++ for 20+ years.

OK, lets imagine ā€¦ EDIT: Took this part out because you get it ā€¦

start with an audio signal that is medium volume lets say it looks like at a sample
111111110000000100000000
convert that to 32 bits
11111111000000010000000000000000
process through filter one
11101101010001000000000000000000
process through reverb two
10110101000001010000000000000000
process through echo three
10110111000000000000000000000000
truncate (stopping at three plugs)
101101110000000000000000

What do we find?
101101110000000000000000 = 10110111000000000000000000000000
No problem!