Hi Mark. There's another good question. I've read a bunch of stuff on dithering but I haven't noticed the difference. Which do you use, shaped or triangular? Jan On Wed, 2004-06-23 at 12:39, Mark Knecht wrote:

} I have never heard the choice of dither make any 'noticible' difference } in my recordings at normal high volume levels, but I suspect that good } dither doesn't hurt normal volumes as much as bad dither might. That's } just a guess though. } } cheers, } Mark Try it with noise... You can completely change the sound of noise with very slight adjustments. {ie... dither... reverb} Working with music is actually sort of liberating by contrast. {You can actually move the sliders with a mouse rather than typing in the numbers or nudging things with the arrow keys.} ---------------------------------- E-Mail: RickTaylor(a)Speakeasy.Net Date: 24-Jun-2004 Time: 17:10:35 This message was sent by XFMail ----------------------------------

RickTaylor(a)speakeasy.net wrote: I'm sure you're right Rick. I was looking at some technical dither stuff yesterday. The noise floor different dithering plugins insert is not flat, or the same, over frequency, so that could certainly effect different types of music differently. I don't have a clue what the LADSPA dithering solutions are doing in this respect. It's all quite interesting. - Mark

Steve Harris wrote: Steve, I misspoke really. I guess I should have just said Linux/Alsa/Jack dithering solutions. It's sort of immaterial to me whether dither is done within LADSPA as an output plugin in Ardour or done somewhere else like Jamin where maybe it's totally built in. My comment was intended to acknowledge my lack of specific technical knowledge in the environment that most people on this list work in. Clearly the idea that there is a float t int conversaion taking place is I guess pretty obvious when you talk about dithering, even to me, but LADSPA internals are certainly not my forte! ;-) Thanks for the clarifications though. It does raise an interesting difference between something like Ardour, I guess, and Pro Tools where I can insert a dithering plugin pretty much anyplace in the signal chain if I choose to. Maybe the RTAS standard makes some decision to go to int based on where the output is going? I don't know. Cheers, Mark

Steve Harris wrote: <SNIP> Yes, that's correct. Although there are some strange paths I hadn't quite considered. 1) The hardware and Pro Tools is native 24-bit, so I think everything that goes to the hardware is actually 24-bits deep. 2) If I insert a dither then presumably what's sent to the hardware is 24-bits deep with the bottom 8 bits zeroed out and the upper 16-bits containing the audio + dither. you hear 16-bits over 24-bit hardware. Still OK. 3) Since bouncing is non-realtime, when bouncing with a dither inserted it likely bounces first a 24-bit file ala #2, then converts it to 16-bit by stripping out data. There is an option for conversion on the fly vs. afterward. Still make sense, I think. 4) If I insert a dither in the middle of a session on a single track then it's unlikely that the output is converted to int unless Pro Tools/RTAS is design to convert it right back to float so that the track can mix with the rest of the session. I don't have a clue what really happens in this case. I've never had a reason to use this, but it does raise the question of how to best import a 24-bit track into a 16-bit session. I've have to do this once or twice. Possibly I should have dithered the track. I'd guess the normal conversions just strip the bottom 8-bits? Anyway, interesting, I suppose, to some of us. Sorry for consuming bandwidth for those that are not. Cheers, Mark

Steve Harris wrote: very low signal == only the bottom 8 of 24 bits have data, while the upper 16 are all zeros? Interesting idea if I understand you correctly.

On 24-Jun-2004 Mark Knecht wrote: } Steve Harris wrote: } > On Thu, Jun 24, 2004 at 07:51:04 -0700, Mark Knecht wrote: } >>I'm sure you're right Rick. I was looking at some technical dither stuff } >>yesterday. The noise floor different dithering plugins insert is not } >>flat, or the same, over frequency, so that could certainly effect } >>different types of music differently. I don't have a clue what the } >>LADSPA dithering solutions are doing in this respect. } > AFAIK there aren't any LADSPA dither plugins. Its very dependent on how } > the float output is converted to int before sending to the card, and } > LADSPA doesnt define that, so it doesnt make a huge ammount of sense. } I misspoke really. I guess I should have just said Linux/Alsa/Jack } dithering solutions. It's sort of immaterial to me whether dither is } done within LADSPA as an output plugin in Ardour or done somewhere else } like Jamin where maybe it's totally built in. My comment was intended to } acknowledge my lack of specific technical knowledge in the environment } that most people on this list work in. Clearly the idea that there is a } float t int conversaion taking place is I guess pretty obvious when you } talk about dithering, even to me, but LADSPA internals are certainly not } my forte! ;-) I have a feeling that it's just plain not important to most folk using the stuff. If I'm processing sound with something... it's just important that It work. I'm generally too involved with my own concerns to analyze it to that degree. {:}Sorta' like trying to explain Ohms law to me while I'm desperately trying to save a failing harddrive.} } Thanks for the clarifications though. It does raise an interesting } difference between something like Ardour, I guess, and Pro Tools where I } can insert a dithering plugin pretty much anyplace in the signal chain } if I choose to. Maybe the RTAS standard makes some decision to go to int } based on where the output is going? I don't know. ---------------------------------- E-Mail: RickTaylor(a)Speakeasy.Net Date: 24-Jun-2004 Time: 17:00:02 This message was sent by XFMail ----------------------------------