Another thread about summing in scope

[Mike Goodwin]

wow fast reply! I resample my softsynths internally at 32bits.

[ReD_MuZe]

as i said, you get no increase resolution in 24bits. just increased headroom, which scope cant handle anyhow since its all 32bit integer (inside atoms its 40bit float but that doesn't matter).

u cant "resample" to 32bits you can only "quantize" to 32bits.
resampling has to do with changing the sample-rate.

the 8 bits in scopes 32bit integer are lost unless you have 64bit asio drivers, and even then you cant hear those lost bits because your DA/AD are only 24bits.

besides it doesn't matter
scope sounds great even if you quantize it to 8 bits:P

if your audio sounds "grey" and "lifeless" its 99% not because of any specific software but more related to recording, mixing and arrangement choices.

to me scope is a musical instrument not a science lab.

[valis]

redundant, Red already replied

[Psilion]

The reason I mentioned using 32 bit float all the way when comparing summing is that it is at least theoretically possible that you get a difference using 24 bit files for input and output that is not related to summing.
It doesn't matter that you cannot record or listen to float if the purpose is to test if the signals cancel each other out, and you can create and convert bit depth in the same application for all tests and only leave the summing to the different DAW's.
Neither going from 24 bit to 32 float or vice versa should really create any noticeable differences regardless of if you use dithering or not, but neither should summing and I trust when you say that the main modern DAW's can handle that without problem. But there has been software that failed already simple "summing tests" and I guess there might still be some software that still does. And in that case to find out what is the problem you have to test different parts of the audio engine separately.

But if you don't notice a difference there is really no reason for concern and it's certainly possible to make good sounding music in any software...and if you cannot get the same result in one piece of software as another it might not be worth the effort to try to find out why and better to just stick with whatever does work best for you.

Regarding recording 32 bit float I would say that is indeed possible. No, it doesn't give you more resolution compared to a 24 bit fixed recording provided that the 24 recording is done at full scale, and the input signal you record can't be 32 bit. But the resulting file when recording also from an analogue source can be 32 bit float which can be useful say if you want a bunch of tracks which all uses full 24 bit resolution but with a recording level that might be over or under full scale.

[garyb]

at some point, the "sound quality" makes diminishing returns against, file size, resources, end format, amount of acclaim generated, cost etc.

at some point, it's either about music, or the machines. when it becomes about the machines, it becomes pointless, except to the engineer building a better machine, or the repair tech.

if it's about the music, there's no need to split hairs. if the music is good, 8 bits is plenty, 24 is better 32 is better, still and 128bit 128khz pcm is even better. but 8 bits is enough to start a riot or become fabulously wealthy.

Scope.
Motion Picture Academy Award for sound.
two consecutive years Grammy nominations for "Best Instrumental".
good enough.
get to work.

engineers, continue as you are! carry on!



jmho

[Mike Goodwin]

Scope.
Motion Picture Academy Award for sound.
two consecutive years Grammy nominations for "Best Instrumental".
good enough.
get to work.

engineers, continue as you are! carry on!



jmho

Cheers to that!

[ReD_MuZe]

at some point, it's either about music, or the machines. when it becomes about the machines, it becomes pointless, except to the engineer building a better machine, or the repair tech.

+1

[katano]

at some point, it's either about music, or the machines. when it becomes about the machines, it becomes pointless, except to the engineer building a better machine, or the repair tech.

+1

+2 (left mouse button clicks)

[capacitor]

A very positive thread

[Warp69]

besides what is 32bit float? it has the resolution of 24bit integer :>

Ehm what?

If you define that the 24bit int have the following range [-1 ; 1] (normal audio) then 32bit float exceed 24bit int many times in precision. Remember that 32bit float has 1 sign bit, 8bit exponent and 23bit mantissa.

The smallest number for 32bit float (Normalized) : 0/1 0000 0000 000 0000 0000 0000 0000 0000 = (+/-) 2^-126 = (+/-) 1,1754944*10^-38

The smallest number for 24bit int : 0/1 000 0000 0000 0000 0000 0001 = (+/-) 1,192093*10^-7

[ReD_MuZe]

smallest and biggest numbers have no impact on the resolution of the audio chain.

when you convert float to integer you cannot take advantage of the extra headroom, and therefore you need to optimize the signal and then loose the 8 bits, else you will not retain even those 24 bits.

[siriusbliss]

besides imho talking about summing is waste of time

I agree with you ReD_MuZe.

Greg

[Warp69]

besides what is 32bit float? it has the resolution of 24bit integer :>

Thats not correct.

The value of 3918 in 24bit int represents 0,00046706200 = FP : S/0 E/0111 0011 M/111 0100 1110 0000 0000 0000
The value of 3919 in 24bit int represents 0,00046718120 = FP : S/0 E/0111 0011 M/111 0100 1111 0000 0000 0000

The value of 0,00046712384 can not be represented in 24bit without rounding error, but 32bit float hasn't any problem = FP : S/0 E/0111 0011 M/111 0100 1110 1000 0100 1101

As you can see from the above the FP has 12bit (look at the mantissa) more precision (resolution) than int.

[Mike Goodwin]

Holly crap. Let me know when you figure that one out and then please explain it to me in a language I understand

Stardust will you share that bag of popcorn with me?

[ReD_MuZe]

when you convert to 32bits integer from 32bits float you don't get more than 24bits of resolution.
it has nothing to do with smallest or largest number. to do the conversion you have to drop the decimal point.

in 32bits headroom comes directly on the expense of resolution. especially since floating point deals with imaginary numbers.

[Warp69]

24bit int audio have 2^23 (8.388.608) possible steps between 0 and 1 which equals a contant precision of 1,1921*10^-7.

32bit int audio have 2^31 (2.147.483.648) possible steps between 0 and 1 which equals a constant precision of 4,6566*10^-10.

32bit float audio have the following steps between 0 and 1 :

0,5 - 1 : 2^23 possible steps (exponent : -1) - equals a precision of 5,9605*10^-8 (twice the precision/resolution of 24bit int)
0,25 - 0,5 : 2^23 possible steps (exponent : -2) - equals a precision of 2,9802*10^-8
0,125 - 0,25 : 2^23 possible steps (exponent : -3) - equals a precision of 1,4901*10^-8
0,0625 - 0,125 : 2^23 possible steps (exponent : -4) - equals a precision of 7,4506*10^-9
0,03125 - 0,0625 : 2^23 possible steps (exponent : -5) - equals a precision of 3,7253*10^-9
0,015625 - 0,03125 : 2^23 possible steps (exponent : -6) - equals a precision of 1,8626*10^-9
0,0078125 - 0,015625 : 2^23 possible steps (exponent : -7) - equals a precision of 9,3132*10^-10
0,00390625 - 0,0078125 : 2^23 possible steps (exponent : -8) - equals a precision of 4,6566*10^-10 (the exact same precision/resolution as 32bit int)
..
..
..
..
..

And it continues down to exponent : -126

If you convert 32bit float to 32bit int (audio range [-1;1]) you'll get :

(+/-) 0,00390625 - (+/-) 1 : no rounding errors
0 - (+/-) 0,00390625 : possible rounding errors

If you convert 32bit int to 32bit float (audio range [-1;1]) you'll get :

(+/-) 0,0078125 - (+/-) 1 : possible rounding errors
0 - (+/-) 0,0078125 : no rounding errors

[Mike Goodwin]

If you convert 32bit float to 32bit int (audio range [-1;1]) you'll get :

(+/-) 0,00390625 - (+/-) 1 : no rounding errors
0 - (+/-) 0,00390625 : possible rounding errors

If you convert 32bit int to 32bit float (audio range [-1;1]) you'll get :

(+/-) 0,0078125 - (+/-) 1 : possible rounding errors
0 - (+/-) 0,0078125 : no rounding errors

Thanks for the popcorn Stardust

Warp thank you for this very detailed post! I cant say that I completely understand the math mind you. Would you be willing to put this into a non mathematically sentence or two for me?

p.s. I am going to try and demo your verbs today

[ReD_MuZe]

ola warp :>
ur math is slightly off. float doesnt have a range of 0-1 (it has a range of + - 3.4028234 x 10^38) and niether does integer (which ranges from -1 to 1 in scope's fractional int type).
we are using signed types for audio.
second of all the quiet bits don't have 23bits of resolution, as each range looses precision.

32 bits can give the same amount of combinations if its float or integer - it doesnt matter.

float doesnt have more resolution. it has more headroom. and maybe if you use fully normalized audio you can keep the 32bit precision. but thats not what sequencers and drivers do. you usually use just a small fraction of the headroom and the rest is just cut off on conversion.

just try and record something louder than 0db in scope in 32bits :>

[Warp69]

Ola ReD_MuZe - I respectfully disagree.

ur math is slightly off.

No! Please reread everything I wrote.

More information - http://en.wikipedia.org/wiki/IEEE_754-1985 & http://babbage.cs.qc.edu/courses/cs341/ ... ences.html

float doesnt have a range of 0-1 (it has a range of + - 3.4028234 x 10^38) and niether does integer (which ranges from -1 to 1 in scope's fractional int type).
we are using signed types for audio.

The range 0-1 was used for demonstration purpose only - which should be pretty clear. Please reread my posts.

Second of all the quiet bits don't have 23bits of resolution, as each range looses precision.

Yes it does. Floats lose precision only when you increase the exponent and gain precision when you decrease the exponent. Please read the links provided.

If you believe Im wrong then please prove me wrong

[Tau]

What amazes (amuses) me is that while they don't agree on the math, both Red and Warp have proven to be excellent programmers - no one can deny that... I would say there's more than one way to skin a cat

T