.

Q) How, in fact can any audiophile justify spending more than $1000 on a CD player, when the CD drive in my PC costs less than $100 and can read the data effortlessly and without error at 40x the required rate for digital audio?

I guarantee, a state of the art CD player will out perform a stock computer CD player. Just the example I stated above due to physical handling and vibration would make that apparent. But the key for you would be to take your PC down to your local audiophile store and give it a whirl. Set up your unit plugged into some converters, and have a plug ready to go to compare it with a big CD unit. Play the same CD and challenge the sales person to show you a difference. Be sure to be listening on their finest speaker system, like some $20k Dunlavy's or something better. Use the $1.5K cables and the $15k power amps. Then email me and let me know what you find!

Musical instrument cables and high-end mic cables make a difference too.....

Q) I am assuming here that the DAC used is external to the CD player, which would be the case more often than not in an audiophile rig or studio. I'm not sure what I'm missing here. Thanks.

Yes, the Digital Audio Converter was external to the computer which was playing the audio files. It's key here to have speakers, amps and a room that reveal the differences. On a typical home system, or on some less-defined studio monitors the differences are masked.

Q) If CDRs are so error prone, I don't see how they can be used as a data storage media.

Good question. Perhaps for data, they can take redundantly rechecked data, rewrite it, and notate it such that the entire file is accounted for. I'm not a programmer by any stretch of the imagination... my strength is music. Here's a great article to check out: http://www.emedialive.com/EM2000/starrett5.html

As far as your punchy snare is concerned... I suspect the difference was the contact of the computer with the floor which changed the characteristics of the room,

The room is nearly 19' x 19' and the computer was 15' away from the speakers below ear level (on the floor) next to the mastering console. The computer was lifted 2" off the floor on the isolator pads. Would you say there's much change in the room acoustics there?

I find it easier to believe that the effect was more placebo than anything else.

Easy doesn't always provide the answer. One of the two other engineers who heard exactly what I heard is a 30 year+ veteran with name credits. The musician in the session who didn't hear the difference was a 19 year old guitar player involved in his first professional recording.

Digital was predicted to be a flawless medium at one point - and look at how much effort is put into improving it's sonic qualities! 44.1 48 88.2 96k etc.... Next generation digital audio - already in the making - will be a great improvement over what we're hearing now. We'll see if you can get me away from analog then...

In the meanwhile I've come to understand the problem of 'jitter' quite well. I understand completely why a CD burnt at 2x, even though it may contain less errors, can sound worse than one burnt at 1x. There are a few more links I came across - particularly good was jitter.de which explains jitter (the cause of your problems with 2x cds) very well, with photos of an oscilloscope showing the effect very clearly.

CD reading with audio error correction:
http://www.exactaudiocopy.de

A wealth of info on digital audio:
http://www.epanorama.net/index.php

More about digital audio and CDs than I have time for...
http://www.cdrfaq.org/faq04.html#S4-18

High speed CDR recording error study:
http://www.emedialive.com/EM2000/starrett5.html

An explanation of 'jitter' - This is a good one!
http://www.digido.com/jitteressay.html

Got another day or so - and a little extra time while it loads....?
Start here http://www.cdrlabs.com/phpBB/
Then click here http://www.cdrlabs.com/phpBB/viewtopic.php?t=3210&start=0&postdays=0&postorder=asc&highlight=40x

Whew! Let's get back to music:

Q) John, there is an over all harshness to my CD, especially in the vocal sound. I used a Neumann 149 mic into a tube pre, a DBX 160 compressor with no eq into my Roland VS 1680. I know I made the mistake of having the CD replication company handle the mastering, but if everything is digital, why am I getting that harsh sound? The level of my CD is softer and not as full sounding as most commercial cds. -Paul

A) I would recommend a de-esser to soften any peaky sibilance which can be a source of harshness....but I suspect more. Just to be sure, tell me the other recording events that led up to the pressing.

>I eq'd and compressed everything in the 1680, then made a dat mix. I transferred the dat mix back to fresh 1680 tracks to finalize my levels, sequence, and overall eq. I mixed that to another dat and sent it to the factory for mastering and pressing.

Whenever you change eq, compress or change levels in a hard disk system, you are making calculations in the computer. The actual word length is changing and the original "analysis" made by the A to D converters is being changed. The sound is being altered, and generally this means that some depth and resolution in the tone is lost. This translates into a harder, shallower, less detailed sound. Smoothness, width, depth, and openness are some of the first qualities to go whenever these new calculations are made.

Key: Transferring your first dat mix back to the 1680 means a loss of 2 digital generations. Dat machines and hard disk systems have moving components, moving tape that are subject to jitter and errors particularly if your digital cable isn't the best money can buy.

Plus, if you are using "mastering" presets or plug-ins, keep in mind that the recalculations are being applied to everything in your mix, not just some individual tracks. In other words, if you compress one track, it's just that track being compressed. Let's say it's a vocal track. You add some reverb to the compressed vocal, but the reverb is open and unaffected. When you compress the stereo mix buss, now you are recalculating the reverb as well as the kick drum, the vocals, the keyboards... everything. While the new calculations may help make the mix sound louder, the detail and depth of your reverbs (room sound, spatial effects) will start to lose some of their coherence.

Granted, there's no tape hiss. But if you eq'd a lot in the Roland, transferred back and forth, eq'd some more, didn't have a high-end mastering engineer refine your master (and the plant may have cut glass at 2X or more) it's no surprise that the sound is harsh.

Solutions: Use a de-esser, use an analog eq on your vocals going into the 1680 and through an insert when mixing. Then, either bring the 1680 to the mastering session (which gives you the flexibility to actually make mix changes on the spot!) or mix to analog 2 track. If you can't get an analog machine, rent some high-end A to D converters going into your DAT machine, Masterlink (best) or CD burner. Don't use TDK DAT tapes - unfortunately there are fewer and fewer brands - try Dennon. Finally, bring your original source masters to a pro mastering place, and you'll be much happier with your final product. Remember to mix using a monitor controller that has instant level matching ablities!

Q) I am pre-mastering to CD. When I "normalize to peak", is the subtracted headroom helpful to the mastering engineer? Should I not normalize to peak? -Larry

A) Normalizing is a commonly misunderstood function, and it's not a huge benefit for the mastering engineer. Once a musician gave me his CD with a song on it that was 10 dB lower than the "standard" volume today for that kind of music. When I showed him how low the level was, he replied, "But I normalized it!" What he learned is that it takes serious mastering to make a hot CD that retains the dynamics too.

Normalizing only does one thing. It brings up the level of the entire song or file to "digital zero"... the loudest possible level without overload errors. This level, however, is only as loud as the highest peak point within the file. So if your song hangs at around -20, but then one peak snaps out at +5, everything will reference to that peak, and go down from there. Everything stays proportionally the same.

Headroom is the amount of available signal prior to clipping or distortion of the sound. If a mastering engineer is loading in your music using analog processing first, then it doesn't make any difference whether or not you normalize, because he/she will simply adjust the analog processing devices to accommodate whatever level is there.

However, if the mastering engineer is taking a digital signal into the mastering system and processing it in the digital domain, then the answer to whether you should normalize is based on these questions: Who has the better digital system, you or the mastering engineer? What over all volume level are you looking for on your final CD?

If you normalize your song/file, your computer is going through calculations that change the one's and zeros of your original signal. Huge amounts of level change will add some hardness and shrink the "sound stage". If you want more level, decide if you think your computer is better than the one the mastering house uses. If you're using Pro Tools and the mastering house is using Sonic Solutions, let the mastering house do the level changing. Optimize your gain structure within your system to get a good meter level on your mix, but don't compress the stereo mix buss, "brick wall limit", or go into clipping. Let the mastering engineer take it to the correct volume level.

Q) If I save the contents of a hardware sequencer back to a zip disk, is there a possibility of data loss? -Quin

I wouldn't suspect that's the case, but one never knows.

Sometimes after saving my arrangement to zip and loading it back into the sampler I am surprised by a change of sound

Certainly if there's time between hearing the music and the reloading of data, it's easy to be in a different "space" such that things would have a different feel. Things that can effect the sound also can be the temperature of the amps, synths, air, board, etc. Things do sound better after they warm up - much of my gear stays on 24-7.

If you think you're loosing sequencer data (a different animal than audio data since jitter isn't an issue) I would record something into a reliable DAT or CD burner, then go through whatever you do that's causing you to question (wait a day, reload, whatever. Once everything's warmed up the same amount as before, and assuming the mix is exactly the same, record to DAT and then compare. If you're losing lots, I'd call the manufacturer and ask what they recommend.

Q) I once bought some memory for my sampler and noticed it was a different brand from my existing memory, not expecting any difference at all I loaded the new memory and proceeded to sample some drum sounds that I was very familiar with. Immediately I heard a difference in sound almost as if the frequency extremes had been stretched. Unfortunately, because the supplier had sent the wrong type of memory, some of the available memory was disabled. I had to reorder the correct memory type.

Again quoting an email from Lee du-Caine: For this mystery, it sounds like completely the wrong kind of memory really was sent. i don't mean just a different brand of the same kind, but some kind of memory which operates in a slightly different way, for instance it may have been outputting the bytes and stuff in slightly different order, which would make a BIG difference to the sound! Though I would have thought such different memory would be a different physical shape/connection, to avoid such problems! But who knows, it may have been some strange old-fashioned RAM type which didn't have a unique connector shape.

"Some of the available memory was disabled" makes me think the memory was not being dealt with correctly at all, perhaps it was even a faulty chip. for a device like a sampler, the RAM is only being used to store digital audio data, so the sampler will just send RAM data straight to the output. it would probably assume that the correct RAM type has been installed and is working properly, particularly if its not a modern one.

© Copyright 1999- 2005 John Vestman with special thanks to Bob Katz for more science than I have time for, and Peter Lindsey for all the cool links, and Lee du-Caine for lots of great info!
Date created: 11/28/99 • Last modified: 09/02/03
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