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-   -   Digital Clipping 16, 24, 32, 64bit (https://www.gearslutz.com/board/mastering-forum/434188-digital-clipping-16-24-32-64bit.html)

Dreamchaos 24th October 2009 04:21 PM

Digital Clipping 16, 24, 32, 64bit
 
Can someone explain the differences in headroom in digital recording and at what point do you begin to clip at the different bit rates, here is what I understand;
16bit clips at -0,
24bit has a little bit of room past -0db maybe 3 db of room.
32bit what amount before clipping?
64bit where does clipping begin?

Am I understanding this correctly?

bob katz 24th October 2009 04:23 PM

Quote:

Originally Posted by Dreamchaos (Post 4712539)
Can someone explain the differences in headroom in digital recording and at what point do you begin to clip at the different bit rates, here is what I understand;
16bit clips at -0,
24bit has a little bit of room past -0db maybe 3 db of room.
32bit what amount before clipping?
64bit where does clipping begin?

Am I understanding this correctly?

No, this is incorrect. 0 dBFS is the same level for all wordlengths for all intents and purposes, within thousandths of a dB. The longer the wordlength, the lower the lowest signal which can be encoded.

BK

UnderTow 24th October 2009 05:59 PM

Quote:

Originally Posted by bob katz (Post 4712549)
No, this is incorrect. 0 dBFS is the same level for all wordlengths for all intents and purposes, within thousandths of a dB. The longer the wordlength, the lower the lowest signal which can be encoded.

BK

Hey Bob,

I suspect the original poster is referring to 32 bit float and 64 bit float in which case they do not clip at 0 dB FS.

Dreamchaos,

I am feeling a bit lazy to do the maths now but if my memory serves me right, 32 bit float has 1536 dB of dynamic range. About 800 of which is above 0 dB FS. 64 bit float has even more. You could say it is close to unclippable.

The thing to remember is that this is only valid while remaining in floating point! If you need to get a signal out to you speakers for instance, it will clip if you go above 0 dB FS for the simple reason that all converters use fixed point formats.

On the other hand, you can have a bus or a track inside a floating point DAW go above 0 dB FS without clipping as long as the signal is reduced in level before it gets converted to fixed point (or hits a plugin that can't handle signals above 0 dB FS for whatever reason).

PS: 24 bit fixed point format also clips at 0 dB FS. There is no extra headroom.
PPS: Another thing to remember is that although floating point signals don't inherently clip above 0 dB FS, you can not be sure that any plugin fed with such a signal will behave correctly. Staying below 0 dB FS just makes life easier. There are enough things to worry about without having to worry whether plugin developers took bad gain staging into account. :-)

Alistair

bob katz 24th October 2009 10:17 PM

Quote:

Originally Posted by UnderTow (Post 4712814)
Hey Bob,

I suspect the original poster is referring to 32 bit float and 64 bit float in which case they do not clip at 0 dB FS.

Right, I was strictly referring to fixed point. The rest of your post is absolutely true.

Dreamchaos 24th October 2009 10:19 PM

Quote:

Originally Posted by UnderTow (Post 4712814)
Hey Bob,

I suspect the original poster is referring to 32 bit float and 64 bit float in which case they do not clip at 0 dB FS.

Dreamchaos,

I am feeling a bit lazy to do the maths now but if my memory serves me right, 32 bit float has 1536 dB of dynamic range. About 800 of which is above 0 dB FS. 64 bit float has even more. You could say it is close to unclippable.

The thing to remember is that this is only valid while remaining in floating point! If you need to get a signal out to you speakers for instance, it will clip if you go above 0 dB FS for the simple reason that all converters use fixed point formats.

On the other hand, you can have a bus or a track inside a floating point DAW go above 0 dB FS without clipping as long as the signal is reduced in level before it gets converted to fixed point (or hits a plugin that can't handle signals above 0 dB FS for whatever reason).

PS: 24 bit fixed point format also clips at 0 dB FS. There is no extra headroom.
PPS: Another thing to remember is that although floating point signals don't inherently clip above 0 dB FS, you can not be sure that any plugin fed with such a signal will behave correctly. Staying below 0 dB FS just makes life easier. There are enough things to worry about without having to worry whether plugin developers took bad gain staging into account. :-)

Alistair

Yes this helps me and is kind of what I figured out. Kind of sucks that every thing is still converted to 16 bit for music. The manufacturers have dropped the ball in my opinion, they could have pushed 24 bit music cd's by now and brought the player to market, but now we are stuck with something even worse in the form of mp3's, and they sure are pushing that format.

UnderTow 24th October 2009 11:34 PM

Quote:

Originally Posted by Dreamchaos (Post 4713480)
Kind of sucks that every thing is still converted to 16 bit for music. The manufacturers have dropped the ball in my opinion, they could have pushed 24 bit music cd's by now and brought the player to market, ...

Not really. 16 bit is OK as a delivery format. I don't think there is much point in complaining about that when so much music is crushed so much as to make the point irrelevant.

Alistair