According to Wikipedia "as of 2007 digital audio converter technology is limited to a SNR of about 124 dB (21-bit) because of real-world limitations in integrated circuit design. Still, this approximately matches the performance of the human auditory system"
http://en.wikipedia.org/wiki/Audio_bit_depth#Floating_point So, yeah, apparently there's no circuitry technology to go anywhere near 32 bit, so a 32 bit DAC seems weird and pointless... I guess a good way to approach this issue I raised is to be able to define what is the internal dynamic range in Pd for values between -1 and 1. cheers 2015-04-23 15:02 GMT-03:00 Alexandre Torres Porres <por...@gmail.com>: > WOW... I just learned something important! So, my whole point here was > that I had the idea that DAWs like Ardour support 32-bit considering only > values from -1 to 1. But that is just wrong! > > I just learned you can put a sound file with values in the hundreds / > thousands in 32 bit float, load them into your DAW, and scale it down. > > I tried it by creating a sine wave in Pd with values from -100 to 100, > exported as 32-bit float with writesf~, loaded into soundforge, then scaled > it down 40 dB, and the sine wave was there! > > So yeah, Pd's audio resolution is the same as DAW which say they handle > 32-bit float sound files. My whole issue was that Pd had a different way of > dealing with 32-bit float, but not at all. In Principle, other softwares > out there also deal with 32-bit float outside the boundaries of -1 to 1!!! > > That just answers my question then... once and for all and for good. > > I guess the discussion I ended up promoting is a parallel issue... let me > rephrase it then. > > Regarding 24 bit DAC converters in sound cards, the 24 bits in there are > just for values from -1 to 1, right? > > If so, then 32 bit float isn't really "8 more bits". And you've been also > saying 24 bit converters are fixed, not float. So there's a weird > relationship between this conversion from 32 bit float files to the > soundcard. > > But then, I guess I'm happy with all I've learned so far. > > thanks > > 2015-04-23 13:26 GMT-03:00 Jamie Bullock <ja...@jamiebullock.com>: > > >> On 22 April 2015 at 19:44:26, William Huston (williamahus...@gmail.com) >> wrote: >> >> On Wednesday, April 22, 2015, Jamie Bullock <ja...@jamiebullock.com> >> wrote: >> > >> > Pd is 32-bit *floating point*, so you have 32-bit resolution between -1 >> and 1. >> >> I don't think that's right. >> >> The range of a single precision floating point number is from >> >> -3.4028234 × 10E38 to 3.4028234 × 10E38 (not from -1 to 1) >> >> >> True, but I didn’t say the range of 32-bit float was -1 to 1! >> >> There are only 23 bits of precision for the mantissa + 1 for sign in a >> single precision float. >> >> >> Also true, but when I said “resolution” I didn’t mean “precision”. >> Because the exponent can be negative, resolution scales dynamically from >> 1..0 according to the value of the exponent, whilst precision stays fixed >> according to the number of bits in the mantissa. Thus for very small values >> the resolution (or quantisation step size) is far finer than can be >> represented with the mantissa alone. >> >> What I was trying to put across (poorly!) in my original reply is that >> unlike fixed point where for lower order values fewer bits are available in >> the binary representation, with floating point, just because e.g. -1..1 is >> a smaller range than -3.4 x 10E38..3.4 x 10E38 it doesn’t imply “fewer are >> bits available”, e.g. >> >> Sign Exponent Mantissa >> 0 01111110 11111111111111111111111 -> 0.99999994 >> 0 00000001 11111111111111111111111 -> 2.3509886E-38 >> 1 01000000 0000000000000000000000 -> -1.0842022E-19 >> 1 011111110 0000000000000000000000 -> -1.0 >> >> Strictly speaking, I guess only 31 bits “count” in the range -1..1 due to >> a maximum of 7-bits being significant in the exponent. >> >> best, >> >> Jamie >> > >
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