DrFord: Dither questions.

[SpinningDisk]

Hello Dr.,
Been having problems bouncing to disk and my Masterlink. Some cd players will play the bounced music and some won't. My question is: Do I need to dither down with mixing into my Masterlink or let the Masterlink do it when I burn a cd? I record in 24 bit at 48k. Do I need to do that only when I bounce to my desktop( instead of Masterlink)? Dither on master fader etc. I just get so confused about when to dither and when not too.
It's my my first day on. Been reading these forums for a long time ( since my 001 purchase) and I have found that you, Mr. Ford, have been excellent in giving out good information which has been very use full to me and I'm sure many other people. I thank you for any help you can give me. Situations help me out such as: when you bounce to disk at 24 bit you need to..........etc..
I know there is probably some forum on this subject. I can pretty much figure everything out my self by trial and error. Some reading and a lot of video watching. I just feel that it would be quicker to ask you.
Thank you for your time. Hope all is well.

Live and Let Live.

[albee1952]

Use dither when going from 24 bits to 16 bits, If your Masterlink is burning a 24 bit master disk, then no dither(but it may not play in any standard audio CD player, which I think is normal). Since you are also recording at 48K, you will sample rate convert to 44.1K (and 16 bit) for burning redbook audio CD's. The good Dr. may have more insight on this.

[SpinningDisk]

Hi albee1952,
Thanks for the information. My apology for the wrong bit rate. It's 44.1k that I record at. It's when I record to the desktop and burn a cd and not use the masterlink or the opposite. When I record out to the masterlink it appears to being going in analog. Haven't got it to work with the spdif. I just don't want to end up with multiple dithers if that's possible. I have never used the dither in any of my mix downs. I usually go right out to the Masterlink in analog then burn a red book. Is this wrong? Also I started too bounce to the desktop. Just wondering between my desktop and the Masterlink. I know the Masterlink will burn a 24 red book cd. Should I stick to what I've been doing?
Thanks again for your input albee1952. Hope all is well.

[albee1952]

I think you are likely a few steps ahead of me on this stuff. I was unaware that a 24 bit CD was also redbook. Can't understand why you aren't having success getting into the Masterlink via SPDIF. I would expect the Masterlink would need to set to slave to incoming SPDIF(and I assume there is a menu choice for digital input). I trust you are using a real SPDIF digital cable(and not a generic RCA audio cable which can trash the clock signal). Is it possible to create 2 master faders and assign one of them to SPDIF out so you can run both analog AND digital out at once? I'll watch this thread and maybe expand my knowledge!

[SpinningDisk]

Your probably right about the red book. It's probably some other formatt. I know I can burn a 24 bit cd to bring to the master house. It's digital in on my masterlink not spdif. Unbalanced RCA inputs. It says that all incoming digital signals will automatically set by the incoming signal. The problem is that I can't get a signal.
I'll try the 2 master trick. Is it better to mix down in digital or analog? It's just another piece of gear I have to turn on. Really starting to like mixing in the box. I'm so confused.

[DrFord]

Hey Spinning Disk,
Thank you for the ups, I am flattered, although I will admit there are MANY user on this forum who know MUCH MUCH more than I do. One in particular seems to be Albee, as I have seen him answer many things I could not. Another is O.G. Killa, who's knowledge is mindboggling.

As far as the Masterlink, when I was working at the Mint Studios in LA a few years back we used one and liked it alot.

First thing that jumps off is that you said Redbook could be 24 bit, that is incorrect, as the standard audio for CD players is 16bit / 44.1k. If you are having problems with burned CD's playing in some players and not others this could be your issue.

Quote from Alesis Site
A standard audio Compact Disc, meeting the standard set by Sony and Phillips, that can be played in any consumer CD player. Red Book CDs feature 16-bit audio at the 44.1 kHz sampling rate only.

You may be burning as a "CD24" and thinking that is Redbook Audio, when in fact, it is not.

CD24 discs are ISO9660 discs that incorporate better error correction than a standard Red Book audio disc. The error correction data takes up some space on the disc, so what fits on a Red Book CD may not fit onto a CD24.

As CD24 is an advanced type of CD file, (and most likely a proprietary file type) that could be the reason you can't play those CD's most places.

Another issue could be that you are not proerly finalizing the CD on the masterlink, and that is giving you Table of Contents (track listing info) errors, where some older CD players again are having problems. You can start a burn on a masterlink, and come back to it, adding more files to the end of the CD, as long as you don't finalize the CD. Finalizing is a specific task you will tell Masterlink to do.

Another problem could be how you are burning, as I believe the masterlink has several formats you can burn as, as well as several types of CD's you can burn (CDR, CDR+, CDR- and so on.) Try and stick to the generic versions a basic CD-R.

As far as the dithering question,
Quote from Alesis Website-
Yes, you can make 24-bit/96 kHz mixes that are DVD ready, and still create standard Red Book CDs from that playlist. MasterLink will use its state-of-the-art internal sampling rate converter and dithering algorithm to make a standard audio CD that sounds almost as good as the high-resolution originals, even though it's 16-bit/44.1 kHz.

As dithering from High Definition Audio to "Redbook audio" in the Masterlink is happening, no you do not want to use it during your "Bounce to disk phase" in Pro Tools. Adding multiple layers of dithering can be audible, however I have heard many on this forum say you would need to do it many times before it was truely audible unless you were playing a blank track and turned it up really loud.

What to send to Mastering House:
Most professional mastering engineers want to receive your material in the highest possible resolution, and many of them now have a MasterLink or a digital workstation that can read CD24 disks directly. If they're using analog processing, send your material as 24-bit, 96 kHz files. If they're using digital processing, they'd prefer 24/88.2 files (because then there will be a simpler sample-rate conversion to make a 44.1 kHz CD). For a complete album, you'll send several discs, since at these high rates a blank CD holds no more than 19 to 21 minutes of audio. To show the mastering engineer how you want to assemble the CD master, send written notes and a Red Book version of the CD sequenced the way you envision it.

Personally I prefer to be involved in the mastering session, as it is your product, and you need to be involved. Mastering can make or break an album and you can also make choices in mastering which can greatly affect the way your mixes sound, as well as bringing reference Mixes to the mastering engineer from well known albums you would like to resemble.

As in I bring Dr. Dre mixes from Chronic 2001 to most mastering sessions when I do Hip Hop because well Dr. Dre is the shiznit. I want my levels to be as close to his as possible. I do the same with Christina Aguilera when mixing / mastering Pop records.

As far as the connections, here's something to think about. Who has the best converters? Is it the Masterlink? Or is it your 001? (Between the 2 I would venture they are pretty even) In my situation, my Rosetta has much better converters than the Masterlink, So going in as Analog (in theory) should sound better. If I were to go in digitally, then I would be imparting the Digital to Analog conversion of the Masterlink on my audio, only to be resampled again by the masterlink to be recorded on the CD. Now that is unless the Digital input bypasses the converters, which I do not know the specifics, and you should look into or call tech support to find out so you have the best situation.

I don't know why your Spdif isn't working... for all intents and purposes (as Albee said) as long as you are using a REAL Spdif cable (they are digital not analog RCA though they use the same looking connectors) the audio should not need a "sync" as it should transmit audio just like analog. I would recommend testing the same mix using both digital and analog and see which one sounds better.

All this said, the question on Dithering is simple. Dither once per application (CD master - not Pro Tools) and dither specifically for that application. So if you are burning a CD, you should only dither when you are specifically bouncing for that CD. Once, and for the correct sample rate. Dither is only used when truncating word length from 24 bits to 16 bit (or less, but can't imagine why you'd need less nowadays). It is not used when changing sample rates.

On using the Masterlink at all? Well that's up to you. We used it at the Mint because we were summing our mixes through a Neve 24 bus console from the 70's. We wanted that warm classic rock sound and found it easier to go out of the console straight into the masterlink instead of routing the outputs of the console back into Pro Tools, and recording, and then bouncing again.

HTH. Feel free to contact me any time, there's a link on my myspace - click the star and you can email me directly.

[O.G. Killa]

Hey Spinning Disk,

Another issue could be that you are not proerly finalizing the CD on the masterlink, and that is giving you Table of Contents (track listing info) errors, where some older CD players again are having problems. You can start a burn on a masterlink, and come back to it, adding more files to the end of the CD, as long as you don't finalize the CD. Finalizing is a specific task you will tell Masterlink to do.

Another problem could be how you are burning, as I believe the masterlink has several formats you can burn as, as well as several types of CD's you can burn (CDR, CDR+, CDR- and so on.) Try and stick to the generic versions a basic CD-R.



I think the Dr hit the nail on the head. If your burned CD will play in some CD players but not others it could be you didn't finalize the disc, you are using the wrong media (CDR+ instead of CDR), bad media, or it could just be normal. Sounds weird doesn't it? I know...

Dr ford already explained the finalize and wrong media...so I'll go into the other two...

First off you have to realize, back in the 80's when the recordable CD was made, it was never EXPECTED to work in regular CD players. They were totally expecting to have to design players for it.

The reason being, a normal CD has a very thin layer of foil (the shiny metal, obviously) that is stamped with a die. This die has very, very,very tiny bumps on it. These bumps make tiny little pits in the foil. Then the foil is sealed on top of a plastic disc. The laser sees the pits and registers those as a binary "1". If there is no pit, then it is a binary "0".

A CDR uses a colored dye (that's why CDRs can be blue, green, or sometimes yellow). The dye is sandwitched between the plastic disc and a reflective foil and then the a sealant is put over the foil. A different type of laser burns little dots into the dye so the dots appear darker than the rest of the dye against the reflective foil background.

Nobody thought that the CD read laser would be able to discern the "dots" because it was designed to read the small change in depth from the "pits" in a regular CD. It was just coincidental when they happened to try a CDR in a CD player and it worked!

Because of this, some CDRs cannot be read in all players and it really depends on the type/strength of the burning laser, the dye used, and the type/strength of the read laser.

We have a multi studio complex that I work at mainly. And we've found, for example, CDs burned in the computer in studio B won't play in the rack-mounted CD player in studio B...yet, CDs I burn in the computer in studio C WILL play in the CD player in studio B. Same batch of media, same data, same program being used to burn the discs... But then, that same disc that won't play in studio B, will play in studio C and in studio A and my office...but the disc burned in studio C won't play in the CD player in my office, but will play everwhere else. So it's kind of hit or miss and will seem somewhat random. We've run into this even with CD refs we've gotten back from mastering. In some ways it's just par for the course.

Every CD has a read error rate to it. Oversampling and buffering can combat these read errors... But if the laser is having too much trouble trying to read the table of contents on the CD, it will just give up and say "error" or just not play. The amount to which your CD player can handle errors is determined by the make/model.

The other thing that could be going on, if it just happens once in a while (two CDs will work, then the third one doesn't) it is probably bad media. CDRs are really cheap and quality control on them is non-existent. Out of ever spindle of 100 CDs I go through there is usually between 5 and 10 that are defective... either they won't burn, or they won't play, or they skip, or I'll get a little click or crackle in a spot where these is none on the original file.

That said, try using a different brand of CDR and see if that remedies the problem. Otherwise you either live with it or get a different burner to make the audio CDs.

[SpinningDisk]

Hi DrFord,albee1952, O.G. Killa,
Thank you all for the information. I think your right about the RCA plugs. I think they are just audio plugs.I don't know how many times I've read through that Masterlink manuel DrFord.. It's not that big. Did read up on the dither information in the protools manuel. It starting to sink in a little more. It did say if I'm going into an audio deck that supports 24 bit, you don't have to dither. I take it all dithers aren't the same? I've been working on this cd for twenty five years. I think it is time. It's just that, I'll wright a song and before I can finish it another one comes out. I don't mean in a couple weeks. I mean the very same day. Been doing that for a long time. It's time to try and finish some of them. Don't have much time left. Hey O.G. Killa, a shout out to you. Your right about the cdr disk. I think they are just cheap. Not going to forget about you albee1952. I appreciate the information you provided. I'll put it all together and hope for the best. If it sounds right.......... That's right.
Thank you again everybody. Talk to you all soon.

Space Junk