dobster wrote on Wed, 18 October 2006 03:29 |
i've been seeing some arguments that sending tracks directly to a/d outputs from within a DAW sounds/sums better than sending tracks to a bus or master bus and then to the a/d output. isn't it all 1's and 0's? any validity to this? |
dobster wrote on Thu, 19 October 2006 00:31 |
yes dan, absolutely. my mistake..apologies. I meant D/A, thanks for the oversight i've been seeing some arguments that sending tracks directly to d/a outputs from within a DAW sounds/sums better than sending tracks to a bus or master bus in the DAW and then to the d/a output. isn't it all 1's and 0's? any validity to this? |
dobster wrote on Wed, 18 October 2006 03:29 |
i've been seeing some arguments that sending tracks directly to a/d outputs from within a DAW sounds/sums better than sending tracks to a bus or master bus and then to the a/d output. isn't it all 1's and 0's? any validity to this? |
dobster wrote on Mon, 23 October 2006 02:56 |
hey Ian...thanks so, how does one quantify whether or not a DAW possesses there rounding errors or not? and if that bus fader is at "unity" then is there much of a difference then going directly to the D/A directly? |
dobster wrote on Thu, 19 October 2006 21:16 |
Dan thanks for the response I'd like to know then, how would you feel about the idea of recording the output of a digital track in the DAW with some type of non-linear processing plugin in realtime? thanks |
dobster wrote on Tue, 24 October 2006 01:53 |
thanks Jon and Dan... jon, just to clarify, what if you bus @ unity then? meaning, no level adjustment at the bus? dan, is it possible to create a plugin that upsamples momentarily locally on a track to process and then downsample again? or is that just a dumb idea? |
Jon Hodgson wrote on Mon, 23 October 2006 10:04 |
Any DAW will have rounding errors HOWEVER, in setting the level and summing (as opposed to say, EQ) the process is so simple (one multiply and one add per channel) that the error is only going to be half a bit maximum. You are not going to hear a half bit error in a 24 bit system. |
dobster wrote on Tue, 24 October 2006 17:44 |
Dan, excellent clarification... So, what i gather is, a good solution to digital processing of non-linearity overall is to either use outboard analog gear to perform those operations assuming great converters though. Or, and forgive me if this still isnt the right idea, use a quality upsampler, export the tracks to the upsampler using great converters, once again, and then into the DAW to process? But this as you said, still requires alot of CPU right? Because then the local sample rate must change to match those newly converted tracks. damn it, somebody make that upsampling plugin! So Ian, thanks for that and as I understand it then, floating point should be more superior to fixed, no? And even better is to use a high native bit depth and on top a high floating point for processing within that DAW |
danlavry wrote on Tue, 24 October 2006 19:00 |
It is best to have that final truncation done with dither. At first glance, that 1/2 least significant bit may not "look as bad". But it is worse then it looks, and here is why: If you add dither, the overall noise energy will be a little higher, but it will be "spread out" evenly across the spectrum. |
ruffrecords wrote on Tue, 24 October 2006 22:19 | ||
I agree any final truncation should be done with dither for the best sound. The interesting word though is "final". I suspect 'final' applies to any mix within the DAW for example just after a bounce. If it does then it implies noise will build up with successive digital bounces just the way it used to in analog days. Ian |
dobster wrote on Wed, 25 October 2006 03:06 |
I should ask, when you say truncation does that include going from the inherent floating bit of a DAW down to the file bit depth, say 64 or 32 back down to 24? should a simple dither be added here? |
Jon Hodgson wrote on Wed, 25 October 2006 10:32 | ||
In purist terms, yes. In the real world, it will probably make no difference (depending on the signal and/or what you do with it after the conversion). If you're going to send the result to a DAC and out through your playback system, then you'll be adding more than 1 bits worth of analogue noise anyway, so that will completely swamp any artifacts from truncation. If you were converting to 16 bits it would be a different story. It would also be different if you took that 24 bit integer stream applied gain to it (effectively the same thing). |
dobster wrote on Wed, 25 October 2006 19:22 |
Right, non random by its nature will even stick out audibly speaking, yes? So the dither sort of act as stilts while keeping a "constant" random flow under the actual music; keeping it steady in some way. I've listen to a file with and without dither and with the dither, certain harsh points were gone? or, not as harsh? point is, it sounded more natural with the dither. Thats why it makes me think of analog and possibly the kind of "stilt" and electronic noise personality analog circtuiry possesses. From what I learned here, i will assume any one track within a mix i process outside the box I will not look to add noise or dither to ITB because of the conversion adding its own dither. |
danlavry wrote on Tue, 24 October 2006 22:48 |
Hi Ian, In principle, any truncation, should be dithered, because as I pointed out, not truncating may lead to energy concentration in some specific frequencies. The energy concentration I am talking about may have peaks far above the noise floor of a dithered signal. Again, the average value and the rms value of the un dithered signal may be lower, but the peaks of the un dithered signal may be higher then the dithered noise floor. So in principle, any word length reduction (truncation)should be dithered. |
ruffrecords wrote on Thu, 26 October 2006 10:37 | ||
Hi Dan, I agree. I wonder what happens though in a typical DAW? Suppose you make a stereo sub mix of a drum kit, for example; presumably this sub mix has been dithered during its creation? Repeat this for other elements of the music then make a final stereo mix of the sub mixes. Presumably dither is applied again? I know the answer will be DAW specific but there must be some general principles to follow. Ian |
danlavry wrote on Thu, 26 October 2006 17:55 |
I am not sure what all the DAW do. Ideally, the DAW would keep everything without truncation until the end of the process, when one MUST truncate to "fit" the data into some format (such as AES or SPDIF). snip I have said it before a number of times, but here again: There is the issue of bits for digital processing and DAW. There is the issue of bits for conversion. |
ruffrecords wrote on Thu, 26 October 2006 22:40 | ||
Of course, it makes sense for the DAW to use as many bits as necessary until it has to dither. I suppose on PC DAWs with unlimited tracks and FX this is mostly not an issue because dither probably therefore only needs to be applied to the final mix. Everything else is just processing of the original data. I suppose my interest in intermediate dithering is born out of the way I tend to work plus the fact that I have done a lot of bouncing in 40 years of recording. I don't use a PC, I use a stand alone DAW, an AKAI DPS24. For various reasons I tend to bounce and print several submixes. These, along with the remaining tracks are mixed to the final stereo mix. Clearly it is important to the quality of my final mix that the printed bounced sub mixes are dithered, and not truncated, before they are printed. Ian |
ruffrecords wrote on Thu, 26 October 2006 17:40 | ||
Of course, it makes sense for the DAW to use as many bits as necessary until it has to dither. I suppose on PC DAWs with unlimited tracks and FX this is mostly not an issue because dither probably therefore only needs to be applied to the final mix. Everything else is just processing of the original data. I suppose my interest in intermediate dithering is born out of the way I tend to work plus the fact that I have done a lot of bouncing in 40 years of recording. I don't use a PC, I use a stand alone DAW, an AKAI DPS24. For various reasons I tend to bounce and print several submixes. These, along with the remaining tracks are mixed to the final stereo mix. Clearly it is important to the quality of my final mix that the printed bounced sub mixes are dithered, and not truncated, before they are printed. Ian |
danlavry wrote on Fri, 27 October 2006 13:05 |
I suppose my interest in intermediate dithering is born out of the way I tend to work plus the fact that I have done a lot of bouncing in 40 years of recording. I don't use a PC, I use a stand alone DAW, an AKAI DPS24. For various reasons I tend to bounce and print several submixes. These, along with the remaining tracks are mixed to the final stereo mix. Clearly it is important to the quality of my final mix that the printed bounced sub mixes are dithered, and not truncated, before they are printed. Ian |
Quote: |
I have not examined in detail the internal working of a DAW, but at first glance, I would think that more bits calls for much more then then just more storage and a wider buss. It may call for a more powerful compute engine. Regards Dan Lavry http://www.lavryengineering.com |
Ronny wrote on Thu, 09 November 2006 21:18 | ||||
The beauty of printing the process rather than running it in real time, is that the power of the computer engine need not be extravagant. The less power and processing speed, the longer it typically takes to print, but that's about it from my experience of printing processes, rather than trying to run a bunch in real time. The benefit is that the computer can take the time it needs to process the signal effectively. For real time processing, yes, the more process' that you run, the more power that you'll need, for printing processes not so important as the computer doesn't have to keep up with the power needed for real time processing. You have less chance of errors to occur and you completely eliminate the latency that you get from processing in real time chaining through various processors. |
Ronny wrote on Thu, 09 November 2006 20:39 |
However not all printed processes while remaining at the native rate in the DAW need user applied dither. For example if you are operating at 32 bit, process and print at 32 bit, you won't need to add dither until you truncate the wordlength, no word reduction, no dither needed in most cases that I'm aware of. Someone can correct me if they know different. |
danlavry wrote on Thu, 09 November 2006 18:56 | ||||||
I agree, but many of my customers want to hear what they are doing as they are doing it (real time). Say you are a mastering engineer and you have to do a sample rate conversion from 96KHz to 44.1KHz. Say you have 2 options: 1. Use a real time SRC, a bit costly to buy, and may yield good results. 2. Use an much less expansive software SRC that will take an hour or a few hours but yield very good results. What would you do? There are many people in the music production business that need to monitor every step they do by ear. In many cases, they like to do multiple tasks simultaneously and listen to what they are doing. That way, if something is "off", you can "fix it" immediately, instead of waiting for a long time. I am not advocating one way or the other. It depends on needs, style, experience... Regards Dan Lavry http://www.lavryengineering.com |