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Post by Johnkenn on Mar 5, 2016 15:09:56 GMT -6
Pardon me for being a knucklehead, but clear this up for me. The only reason you ever add dither is when you are changing the bit rate, correct? For example - I am now staying in 24 bit the whole time, usually not converting to 16 for CD (because no one uses them)...So, should I add dither when making an mp3? That's compressing and not truncating during summing, correct? Also, I'm mixing...then going out to a summing box and then printing back in at the same bit rate. I actually use the Svartbox as my AD, so it in going out of the summing box to the analog in of the Svart, then recorded into the DAW via SPDIF channels. (That's actually an extra conversion, guess I should be going back line in.)
ANYWAY - do I need to add dither when sending a track to outboard processing, printing a master, etc? Even though I'm staying in the same Bit rate?
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Post by tonycamphd on Mar 5, 2016 15:27:49 GMT -6
the answer is... Yes... maybe haha, you need to dither the channel output with a dither plug on every single output DA to your summer... IF YOU PROCESS THE CHANNEL at all ITB, if you don't touch the channel ITB, you can leave it be. example, Vox channel, no fader movement, no plugins= no dither needed before DA Vox channel, with fader automation or any plugins= requires a dither plugin in the last insert slot before DA My lnx AES16e card/mixer will automatically apply dither if i move a fader .01 of a db, otherwise it doesn't. If you search your forum here, there is great info on dither, sir Bob Olhsson has shared a ton of info on it.
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Post by tonycamphd on Mar 5, 2016 15:31:41 GMT -6
I'd also say that when summing multiple channels OTB(vs dithering just a master ITB), noise shaping becomes more important as you want to shift the noise away from the frequency core of your signal, IE. shift the dither noise up on bass, down on vox etc.
PSP X dither is a beast of a plugin, and it has "digital black" that shuts off processing power when you don't use it, dither is important, truncation noise is NOT random, and it's very unpleasing to the ear, it's not going to be heard on one track, but when combining a bunch of channels, you get a build up of the unmusical noise and the upper and lower harmonics that go with it, I believe this is one of the primary causes of the mystical unicorn named Digititus.
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Post by Johnkenn on Mar 5, 2016 15:53:24 GMT -6
So - every channel going to my summing busses? Or dither just on the sum busses? My brain hurts. And ahm not samart.
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Post by wiz on Mar 5, 2016 15:56:38 GMT -6
Just to clear up the terminology.. its Bit Depth, and Sample Rate... 8)
Technically, you should add dither (as tony said) when changing bit depth, anytime. Whether its being done for you, or you have to instantiate a dither plug in, or not ,and how and where you do that are the questions I have never gotten an answer to.
I run tracks out and into the box all the live long day.. most have what you have heard from me over the last 18 months has done this. I have never put a dither plug in on an out yet.
Now, f*&ked if I know if logic or the DA or the noise generated by the DA is doing dither for me.. I can't find out.
It is on my to do list to check out.
Has anyone on here ever done a test of this stuff? with current popular DAWS and Interfaces?
So to answer your question John, I know the theory but I can't tell you how to do it in practice.
When bouncing from the DAW project (say 48Kz 24 bit) to mp3 in Logic, I don't even have an option for dither.. so I would say NO. I dither when I bounce the final project out to a lower bit rate.. if its going to CD and that usually happens in whatever software I am using in Mastering.
So I would say .... don't worry about dither going to outboard, till we have a definative answer on how and where to do it, and when bouncing out a mp3 from your DAW project don't worry, if you are going to make a CD for someone or send them a wav file that is of a lower bit depth than what you project is for some reason, dither it.
cheers
Wiz
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Post by M57 on Mar 5, 2016 16:13:58 GMT -6
When bouncing from the DAW project (say 48Kz 24 bit) to mp3 in Logic, I don't even have an option for dither.. Yeah - but you do when bouncing or exporting to .wav or .aif, etc. in Logic. mp3's are so compressed and chopped that there's no point to dither, right?
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Post by tonycamphd on Mar 5, 2016 16:24:50 GMT -6
JK, this is a pita topic, yes it's true that it's very hard to find a solid answer to dither/daw feeding the outboard issue, myself and wiz have had this conversation a few times and it always leads to stereo head scratching, but from everything i've read on the topic, and a lot of what Bob O has stated, in conjunction with my Lynx mixer doing nothing if it see's the DAW as nothing more than a tape machine, but then automatically applying dither on every DA channel out IF A FADER IS MOVED, has led me to tentatively believe that adding dither is the right thing to do. I also contacted Lynx to find out if this is the case, and I was told it is the case(but not very convincingly), the act of moving a fader .01db causes DSP, DSP creates truncation errors/quantization noise.
I too would like a more detailed and definitive answer on this, it really bothers me that i can't rest assured on it.
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Post by wiz on Mar 5, 2016 16:25:59 GMT -6
When bouncing from the DAW project (say 48Kz 24 bit) to mp3 in Logic, I don't even have an option for dither.. Yeah - but you do when bouncing or exporting to .wav or .aif, etc. in Logic. mp3's are so compressed and chopped that there's no point to dither, right? I don't know about whether there is a point to it... because of the mp3 algorithm .. just saying... its moot.. cause there is no option... 8) cheers Wiz
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Post by tonycamphd on Mar 5, 2016 16:26:17 GMT -6
When bouncing from the DAW project (say 48Kz 24 bit) to mp3 in Logic, I don't even have an option for dither.. Yeah - but you do when bouncing or exporting to .wav or .aif, etc. in Logic. mp3's are so compressed and chopped that there's no point to dither, right? you should dither anytime you change sample rates/bit depths, insert a plugin on your master channel if the DAW doesn't do it automatically.
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Post by tonycamphd on Mar 5, 2016 16:27:57 GMT -6
So - every channel going to my summing busses? Or dither just on the sum busses? My brain hurts. And ahm not samart. any channel feeding D/A to a summer should have it, if your bussing ITB, and coming out a stereo aux, just dither the stereo aux feeding the D/A...
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Post by wiz on Mar 5, 2016 16:28:30 GMT -6
JK, this is a pita topic, yes it's true that it's very hard to find a solid answer to dither/daw feeding the outboard issue, myself and wiz have had this conversation a few times and it always leads to stereo head scratching, but from everything i've read on the topic, and a lot of what Bob O has stated, in conjunction with my Lynx mixer doing nothing if it see's the DAW as nothing more than a tape machine, but then automatically applying dither on every DA channel out IF A FADER IS MOVED, has led me to tentatively believe this is the case. I also contacted Lynx to find out if this is the case, and I was told it is the case(but not very convincingly), the act of moving a fader .01db causes DSP, DSP creates truncation errors/quantization noise. I too would like a more detailed and definitive answer on this, it really bothers me that i can't rest assured on it. Good points... see, I don't even know if you have the option to stop lynx applying dither... what T and I have talked about.. what the lynx is doing, logic might be doing anyway... or I think I read somewhere that some interfaces apply dither, or indeed the noise floor of the DA is a kind of dither... I always have meant to explore this more, and actually when I met Bob O, I was intending to ask him about this.. problem was we were all having too much fun that night...man I wish we spent more time together, that RGO dinner was a blast!!! cheers Wiz
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Post by tonycamphd on Mar 5, 2016 16:40:57 GMT -6
JK, this is a pita topic, yes it's true that it's very hard to find a solid answer to dither/daw feeding the outboard issue, myself and wiz have had this conversation a few times and it always leads to stereo head scratching, but from everything i've read on the topic, and a lot of what Bob O has stated, in conjunction with my Lynx mixer doing nothing if it see's the DAW as nothing more than a tape machine, but then automatically applying dither on every DA channel out IF A FADER IS MOVED, has led me to tentatively believe this is the case. I also contacted Lynx to find out if this is the case, and I was told it is the case(but not very convincingly), the act of moving a fader .01db causes DSP, DSP creates truncation errors/quantization noise. I too would like a more detailed and definitive answer on this, it really bothers me that i can't rest assured on it. Good points... see, I don't even know if you have the option to stop lynx applying dither... what T and I have talked about.. what the lynx is doing, logic might be doing anyway... or I think I read somewhere that some interfaces apply dither, or indeed the noise floor of the DA is a kind of dither... I always have meant to explore this more, and actually when I met Bob O, I was intending to ask him about this.. problem was we were all having too much fun that night...man I wish we spent more time together, that RGO dinner was a blast!!! cheers Wiz I'm not sure the self noise of the DA is high enough in level to use electro mechanical noise to function as dither? i'm not sure the JW consoles we have are noisy enough either? the thing that i'm hyper paranoid about is that creepy digititus sound slithering up on me, I feel the unmusical up and down harmonics created by the QN, building up track after track is probably the culprit? but again... i'm unsure. I will say I feel like that digititus thing is far less prevalent in my own ITB environment today, than it was even 5 years ago, i couldn't even stand it at all then, now though i'm not thrilled with my ITB results, i'm not thoroughly disgusted either, thats progress i'd say.
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Post by Bob Olhsson on Mar 5, 2016 16:53:29 GMT -6
Samplitude is the only DAW I've run into that defaults to dithering properly. (That's why people swear it sounds better!) The old Pro Tools TDM systems had an optional dithered mixer plug-in that handled it. Now in 32/64 bit float land you need to add plug-ins to Pro Tools 11 and 12. All I can suggest is trying it. I did and never looked back from always using it.
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Post by Johnkenn on Mar 5, 2016 16:58:37 GMT -6
Just to clear up the terminology.. its Bit Depth, and Sample Rate... 8) Technically, you should add dither (as tony said) when changing bit depth, anytime. Whether its being done for you, or you have to instantiate a dither plug in, or not ,and how and where you do that are the questions I have never gotten an answer to. I run tracks out and into the box all the live long day.. most have what you have heard from me over the last 18 months has done this. I have never put a dither plug in on an out yet. Now, f*&ked if I know if logic or the DA or the noise generated by the DA is doing dither for me.. I can't find out. It is on my to do list to check out. Has anyone on here ever done a test of this stuff? with current popular DAWS and Interfaces? So to answer your question John, I know the theory but I can't tell you how to do it in practice. When bouncing from the DAW project (say 48Kz 24 bit) to mp3 in Logic, I don't even have an option for dither.. so I would say NO. I dither when I bounce the final project out to a lower bit rate.. if its going to CD and that usually happens in whatever software I am using in Mastering. So I would say .... don't worry about dither going to outboard, till we have a definative answer on how and where to do it, and when bouncing out a mp3 from your DAW project don't worry, if you are going to make a CD for someone or send them a wav file that is of a lower bit depth than what you project is for some reason, dither it. cheers Wiz HA...Now I made you say it...
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Post by Johnkenn on Mar 5, 2016 17:07:01 GMT -6
So - every channel going to my summing busses? Or dither just on the sum busses? My brain hurts. And ahm not samart. any channel feeding D/A to a summer should have it, if your bussing ITB, and coming out a stereo aux, just dither the stereo aux feeding the D/A... Here's how I'm approaching it - I'm bussing to Stems/AUXs...then assigning those to the 1-2, 3-4, 5-6 and mono 7, mono 8 outs (going to the summing mixer - I only have 8 channels). From what you're saying, I should have dither on those outs. I'm certainly gonna try it...Those don't move, though - but obviously the busses that are feeding them have plugs and are/possibly automated. I then print that to a two track back into the DAW. THEN, I put mastering plugs on that channel and go out Stereo to the Summing mixer and print back in on a Final Print 2 track. I then consolidate that file. What you're saying is that every time it goes out of the digital domain and comes back in, there should be dither between it. Even though it's not changing Bit Depth.
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Post by Johnkenn on Mar 5, 2016 17:08:13 GMT -6
Samplitude is the only DAW I've run into that defaults to dithering properly. (That's why people swear it sounds better!) The old Pro Tools TDM systems had an optional dithered mixer plug-in that handled it. Now in 32/64 bit float land you need to add plug-ins to Pro Tools 11 and 12. All I can suggest is trying it. I did and never looked back from always using it. Interesting.
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Post by Johnkenn on Mar 5, 2016 17:09:11 GMT -6
any channel feeding D/A to a summer should have it, if your bussing ITB, and coming out a stereo aux, just dither the stereo aux feeding the D/A... Here's how I'm approaching it - I'm bussing to Stems/AUXs...then assigning those to the 1-2, 3-4, 5-6 and mono 7, mono 8 outs (going to the summing mixer - I only have 8 channels). From what you're saying, I should have dither on those outs. I'm certainly gonna try it...Those don't move, though - but obviously the busses that are feeding them have plugs and are/possibly automated. I then print that to a two track back into the DAW. THEN, I put mastering plugs on that channel and go out Stereo to the Summing mixer and print back in on a Final Print 2 track. I then consolidate that file. What you're saying is that every time it goes out of the digital domain and comes back in, there should be dither between it. Even though it's not changing Bit Depth. So - Bob Olhsson - would I be dithering properly in this scenario?
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Deleted
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Post by Deleted on Mar 5, 2016 17:28:30 GMT -6
Sooo, thr rule that you learn officially is - dither whenever going to a smaller bit depth. As far as i understand - this is not the whole thing. It is whenever a re-quantization takes place that leads to requantization distortion.
Now - many people do not understand when they REALLY change the bit depth. Say, you have a project in your DAW with the options "24bit/96kHz". After the rule of thumb you would not have to dither when exporting 24bit file of whatever sample rate, right? WRONG. You processed the audio (otherwise you would not use a DAW). And this is done in the *internal* resolution that your DAW uses. Which is 32bit or 64bit floating point. So you see - coming from that to 24bit (integer) file OR DAC, dithering is mandatory. No matter what your DAW says about your project ("24bit") - this is the *target* or *interfacing* format. Not what your DAW uses to process the audio.
Now, it can get complicated at this point. In the older days, there were DAWs that really used 24bit integer internal format. There - no dithering for correct export (24bit->24bit). So - when talking about "lower bit depth" it is absolutely mandatory to find out, how your DAW works and how it's handled. Example: In Sonar, i have total control over the export format and can set the use of dither or even NOT using it, e.g. if i want to use a different dither in a plugin. In Mixbus, i have NO option to choose dither for 24bit export. According to Ben from Harrison, this is done automatically. I can only speculate about the reason, but it would be a good explanation, that many folks FORGET to dither in 24bit export or are confused - because of the oranges and apples in "what bit depth is my project in" vs. "what bit depth uses my DAW actually for processing". So - you need to read the DAW manual AND/OR need to ask the developers. Otherwise you would have to measure if they use it. By analyzing the noisefloor/distortion.
So now, which dither should be used. According to Bob O. triangular (TPDF) dither is the best option. Because it does not mess with the high frequency range. It gives a sufficiently low noisefloor already and it is flat across the frequency range. Also - whenever ANY dither comes LATER to processing, ONLY triangular dither is to use. Now, often you do not even know if there is a dither later. Say - the consumer uses a digital volume setting. Is there another dither involved after yours? YES. So yours is not the last in the chain and triangular is mandatory. (Just something to think about...) You want to give it to premastering? Triangular dither. Triangular dither is a sure bet for your audio. Always.... As opposed to whatever other dither...
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Post by Deleted on Mar 5, 2016 17:44:01 GMT -6
And i have to admit that Bob O. brought me to re-think about it and read up old university stuff. :-) Thanks for that...
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Post by Bob Olhsson on Mar 5, 2016 18:07:26 GMT -6
A .1 dB. volume change expands bit depth beyond what the CPU can handle. Virtually all D to A converters and AES-EBU/SPDIF connections truncate to 24 bits. The only time you don't need to do it is when there is absolutely zero signal processing going on.
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Post by Johnkenn on Mar 5, 2016 18:50:05 GMT -6
So why not just dither every channel, all the time?
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Post by wiz on Mar 5, 2016 19:06:37 GMT -6
So why not just dither every channel, all the time? The problem is... we have no idea what our DAWS are doing... well.. its my problem... 8) cheers Wiz
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Post by tonycamphd on Mar 5, 2016 19:25:29 GMT -6
any channel feeding D/A to a summer should have it, if your bussing ITB, and coming out a stereo aux, just dither the stereo aux feeding the D/A... Here's how I'm approaching it - I'm bussing to Stems/AUXs...then assigning those to the 1-2, 3-4, 5-6 and mono 7, mono 8 outs (going to the summing mixer - I only have 8 channels). From what you're saying, I should have dither on those outs. I'm certainly gonna try it...Those don't move, though - but obviously the busses that are feeding them have plugs and are/possibly automated. I then print that to a two track back into the DAW. THEN, I put mastering plugs on that channel and go out Stereo to the Summing mixer and print back in on a Final Print 2 track. I then consolidate that file. What you're saying is that every time it goes out of the digital domain and comes back in, there should be dither between it. Even though it's not changing Bit Depth. Yes, because the channels that you are processing are using DSP and that is causing truncation errors that result in noise, the only time you should leave the box at 24bit without dithering is if you're using your daw as an unglorified tape machine.
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Post by tonycamphd on Mar 5, 2016 19:27:25 GMT -6
So why not just dither every channel, all the time? because once you send it to an aux, you'd have to dither it again on that channel(because you processed more), thats why the only place you need to dither ITB is on the down sampling/bit reduction bounce.
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ericn
Temp
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Dithering
Mar 5, 2016 19:39:13 GMT -6
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Post by ericn on Mar 5, 2016 19:39:13 GMT -6
Samplitude is the only DAW I've run into that defaults to dithering properly. (That's why people swear it sounds better!) The old Pro Tools TDM systems had an optional dithered mixer plug-in that handled it. Now in 32/64 bit float land you need to add plug-ins to Pro Tools 11 and 12. All I can suggest is trying it. I did and never looked back from always using it. Over the years in PT land I just learned to leave the Dither on ! Call it lazy , but it just always sounded better.
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