Hey bear , I know why I couldn't find it - I didn't post it.
Here is part of a rough transcript of a presentation I did a while back, hope its of use: (I didn't check it - no time!)
As some of you already know, I have been / am involved in testing and development of some recording gear for various companies. My main interest is digital stuff, ‘coz that’s the future. By now I’ve got a pretty good idea what you can and cannot do with analogue, so that has lost its immediate appeal for me, I rather concentrate on making the future sound gooooood!
What makes digital audio sound good?
The basics:
Digital audio quality depends on bit rate, clock speed, quality of conversion and clock accuracy. Which one comes first? What is the most important? No choice, really. That must be one of the only choices in life that offers no choice, they are all equally important.
I won’t go into all the boring technical stuff here, but CD quality, 16 / 44.1, sucks major and sounds like sandpaper, it never was an alternative to analogue. Consider that every extra bit almost doubles the quality of audio, and you’ll start to realize that 24 / 48 is a pretty cool improvement. Now we are back to, potentially, good sound quality.
I won’t bother to go into the 24 / 96 stuff, despite all the shouting you hear about it. People say its great, wonderful etc? Cool! I’ll be the first one to use it – properly – once all the technical details have been solved, and there are plenty to be solve before you can complete a project to perfection at 24 / 96. Lets leave it at this; if you listen to a DVD A, with L,C,R at 24 and RL, RR at 16 – you are listening to a project which has been mastered TO 24 / 96, not likely one recorded IN 24 / 96.
So, that’s the first thing over with. To get a good quality recording you have to think 24 / 48. And don’t forget to dither it down properly to go down to CD quality, or you’ll just fuck all your good work up again.
You have to get your analogue signal to digital, and back again. In other words, you need converters. Not just converters, you need good converters. Let me help you out of your misery here. Good converters are getting cheaper. Now for the depressive bit, a converter is circuitry around a chip, or chipset, audio quality depends on the design and inter-relationship of these 2 elements. I find it pretty amazing therefore that some companies are now offering “high quality” converters at a retail price marginally above the wholesale purchase price of one single decent chip?
Unfortunately, it is possible to build a converter cheaply, with an apparent ‘decent’ sound, against what seems to be a good spec. Unfortunately you could also design a converter at a much higher spec, which sounds like total crap.
More about converters later.
Next, the clock. Another bit of free news for you. 1. If your heart doesn’t beat in a regular pattern, you’re in deep shit. 2. If you’re a drummer and you can’t keep a regular pattern, you’re likely to cause #1 to the other band members. 3. If your music doesn’t keep a regular pattern, it will sound like crap.
Same goes for all your digital recording gear. If it doesn’t ‘keep the beat’, it will discombobulate.
Let me spell it out once and for all:
THE QUALITY OF YOUR EQUIPMENT’S DIGITAL CLOCK RELATES DIRECT TO THE QUALITY OF YOUR SOUND. Not very often understood this, most people cannot see that a digital clock effects the quality of sound. To explain this as simple as possible, please note that you are NOT recording sound, you are recording DATA. This data needs to be kept in-line, with every sample accurately in its place. If not, when this data is turned back into music………………. Get the picture?
Lets put another ugly baby to permanent rest. NO! The clock in your gear is not good. Don’t bother coming back at me with “but my…..” It won’t wash. As in converters, some good news. You can now get a highly accurate external clock for less than a third the cheapest ones did cost a couple of months ago, the quality is going up and the prices are going down.
Next fairytale. You distribute clock with your audio signal, just daisy-chain from your machine down. Yes, that is what everyone does. And no, it does not work, it sorta barely scrapes its act together. If you hear a clock pulse without audio coming out of your generic build-in generator you’d be in shock about how uneven it is. If you’d listen further “down the line” – you’d call 911 and would try to revive it with an electric shock.
In order to get an accurate clock you need a quality external sync generator. In order to ensure all equipment runs to the same clock at the same time, this sync generator need to feed each piece of gear individually. Another thing the industry has yet to address properly – you simply cannot transmit audio plus a clock through AESII, you really should keep the audio and clock separate.
PRIORITIES:
Now this bit is, I think, important.
I constantly hear “I’m saving up for a new microphone” and “Next on my list is a good tube preamp” etc.
Let me ask you one simple question. Would a top quality microphone and pre make a bad clock and bad converters sound better?
If you want to get something resembling “pro quality” (whatever the hell that means) sound, you will need to get your priorities right, address the quality of your recording system first, before spending anything on anything else.
If I had a DAW, my first priority would be a good AD converter. After that, a good DA converter (often forgotten). Next would be a good clock. Only after that would I consider improving other things.
Example. I could record a vocal through a $4000 mic and a $3000 pre into, for instance, Pro Tools, using a 001, or even a Digidesign 888.
I could record the same vocal again, this time using an $89 Shure, into a small Mackie mixer as a pre, into a good AD converter, with Pro Tools clocked by a quality external clock.
My choice would be the latter, I’d get a better overall result. On top of that, I have just saved myself about $4000. (OK – now I’ll go and buy a good mic).
Get my drift?
That’s the first bit. For those of you who think I’m just bashing gear manufacturers, no I am not. Everything is build at a cost, if it wasn’t most of you would never have the chance to record something sounding remotely as good as you are already doing. Apart from that, this is new technology, it is developing, and more things are becoming apparent all the time.
To illustrate the above, Yamaha’s brand new digital console, the PM-1D, costs $120.000
It needs to run with an external (non-Yammers) clock, or its sounds, well….. let’s say not very good to be polite.
Next. Back to converters. If you remember, its possible to build a converter with high specs on paper, but one that sounds like crap. This begs the question, how the heck can you test / tell a good one from a bad one?
Prior to listening to a converter, lets ask the question: “what are you listening for?”
A good quality converter will show improved debt and detail. You will hear increased clarity and apparent volume in the whole spectrum, and particularly in the low and high ends. A track will seem more transparent, stereo imaging seems improved, you can clearly identify every detail (which also means – you can clearly hear all the F’ups in your playing / recording / processing / mixing J
A note to the above: This is why D/A converters, often forgotten, are the most essential part of gear for a mixing engineer. Without a good D/A converter you can’t hear half as much.
(Just to show you how people who SUPPOSEDLY know about this stuff screw up – I couldn’t wait to get my monitors going in the new control room. Set everything up, tested, calibrated, but I’d lend my D/A converters out. Got them back – had to do the whole thing all over again. 2 days wasted.)
Use one of the tracks you have recorded and are familiar with. Play it, as stereo tracks, analogue out from your system, to the inputs of the converter you are testing, recording the results back to your system. Make sure you set your recording levels at the same volume ON YOUR METERS as the tracks you played into the converter.
Now you will have the song 2 x, and can ab the results (you will have incurred some latency).
Another way. Select a couple of nice, full synth patches and drum loops. Open a new session and record them on two tracks each, one through your stock converter, once through the one(s) you are testing. Make sure you pan every stereo track l/r when you play back your recordings.
If you are testing more than one make of converter, things get more complicated. Some converters use the same chips or chip sets, like for instance the Apogee Rosetta and the Lucid 2496. The same dB headroom, similar overall specifications, do the testing as above and the result will sound very nearly the same. Yet, there is a difference, and above all, one is much more expensive than the other. How can you make the difference audible?
One way only, start tracking. Stacking things like vocals for instance. The more you stack, the more tracks you build, the more the difference will become apparent. The better converter will show higher definition, dynamics and stereo image.
Finally – if you do all the above WITHOUT a high end D/A converter, remember that whatever you are recording will sound a lot better than you can actually hear. So make sure when you print a mix, you do so without going through another conversion.