Getting that crystal clear mix tips

[Definity]

Hi i was reading PAFO thread about how he could make his mix's more smooth. This got me thinking about the steps people would take to making a more professional mix, i am a self taught muscian and producer for 4 years and would love to know how to get a higher standard of mastering/mixing from the pros equitment/methods and so on. I have now found out about DAC and how they can higlight certain things that dont seam to be present straight away in a mix, also about how important it is to have a decent set of monitors. But what about sound cards/audio interfaces i have got a 24bit 192khz soundcard like most, but leaves me thinking what is the differance between the 1500 quid inerfaces and the 150 quid ones? are some actual better quality even though they are the same bit and sample rate? i was hoping some pointers in the right direction should help me increase the quality of my tracks so is there any websites, books, tutorials, personal knowledge or equitment which could help me would be a MASSIVE help to me and others!
Thanks
Def

[terminal3]

Well, the opposite of a DAC is an ADC, which is the part that converts what's coming from your preamps to something the computer can read.

That's essential - your soundcard needs to have a great ADC, however, I'm of the opinion that the ADC stage on most modern-day interfaces is pretty good, especially compared to just a few years ago. You can buy better ones, of course, and it's a worthy upgrade, which I would do AFTER I've spent money on room treatment, mics, monitors, preamps and DAC stage, roughly in that order. There's a law of diminishing returns on the money you can spend on ADCs... same for DACs I suppose. The top-end ones by Lavry, Prism etc will cost 20x a low-end one, but they're probably not gonna give you a 20x improvement.

The problem is, it costs many thousands just to attain those last few percentage points to perfection...

Anyway, if you're going to be recording acoustic instruments or voices, you'll need to take care at that ADC stage, mind the preamps, use the best microphones you possibly can and you'll get stuff that sits well in a mix, can be layered, treated etc. and will basically reward you sonically.

Now, if you're working strictly in-the-box - that is, you're generating your sounds from softsynths or using samples/loops, etc, your ADC stage matters not*. Your monitors/room/DAC are more important than ever, of course, because you'll be relying on them to give you a clear "picture" of your mix.

* - OK - not entirely true. This only applies if you're also MIXING strictly in-the-box. If you use outboard hardware, here's where it gets interesting. The DAC suddenly matters more because you'll need to send a track or a mix to an outboard unit and you want it to be as sonically true as possible. Then you'll need to bring it back into your computer once the box is done, so the ADC stage will matter again. Basically, each "round-trip" through the converters is going to cost you some sheen if your conversion isn't up to scratch.

Right - this is a nice segue into the next part of the equation, and that's your mixing tools. You can use plug-ins, or hardware, or both.

In most cases, hardware is sonically superior to plug-ins. However, there are some plug-ins that will get you almost there. In my experience, EQ plug-ins are better that compression plug-ins thus far (as in, they do a better job doing what they're supposed to do and sounding good doing it).

There are some processes that can ONLY be achieved with plug-ins (RNDigital's Dynam-izer, Melodyne's voodoo, and Sonnox' Inflator are just a few examples), so in that case you're working with those.

Basically, with plug-ins, audition carefully and never over-do it. As a rule-of-thumb (with some genuine exceptions) plug-ins that have been published more recently sound better than those published 6 or 7 years ago, because DSP algorithms have come a long way.

There are other factors that contribute to the overall sonics of your production. If you have to mixdown to CD you'll likely have to dither at some point, and choosing the right algorithm for the material at hand will help. If at any point you need to convert the sample rates of anything, you'll find that not all sample rate conversion software is made equal and it's possible to degrade sonics just by using a lousy one (visit SRC Comparisons for more info on that!)

Gain staging is another critical, critical factor that will affect how your final mix sounds. Do it right. Rather than explain it (this post is getting pretty long already I'm gonna link to an article about it by Alan Hyatt from PMI Audio - scroll to the bottom of the page) - PMI Audio Newsletter June 2004

and another article about doing it in the digital world -

http://emusician.com/tutorials/max_headroom/

The final (arguably!) issue to deal with is latency. Some programs, like Pro Tools LE, do not automatically compensate for latency created by the processing time that plug-ins need. Some do - Cubase will somehow, I'm told (I don't use it), Logic will. But if your software doesn't, you might need to find a time-shifting plug-in to delay audio by x number of samples so you can get everything in phase. Even minimal comb filtering caused by out-of-phase tracks will sound muddy, and if stuff is REALLY out of time it'll just sound sloppy.

Anyway, in summary -

Make good recordings! This is the absolute basic of the art anyway. Leave headroom (when you're using 24 bits you don't need to push it nearly into the read - leave at LEAST 6db, maybe more) - this will allow you to apply EQ and compression and other effects with more ease and transparency.
Use the best preamps, the best microphones, and the best digital converters you can possibly get your hands on. To paraphrase a little British corner shop, every little helps here.
Pay attention to your room acoustics, your mic placement, pay attention to the details of the take (if you're doing vox, for example, listen for pops/sibilance, and make adjustments when you can!)
If you're working with more than one microphone, check the phase and fix it as needed.

Once you've got those ace recordings in your DAW, mix carefully. Mix for dynamic range, don't worry about smashing-it-to-hell (yet!). Use EQ both creatively and as a tool to cut out frequencies that'll fight one another (the first thing I do when I lay down guitars or vox is put an hpf down at 80hz and adjust from there - I don't need any of the sonics below that for those tracks, and that sort of stuff starts to clog up and get muddy - that's just one example).

Compress for effect or for dynamic range control.

Choose your plug-ins carefully. If you are integrating outboard hardware, remember what I said about converters. Don't forget to do recall sheets if you mix with hardware! If you come back to the song later you'll need to remember what you did.

Finally, remember to check your mix on as many systems as you have access to - iPods, computer speakers, boom-boxes, etc - this will help you see how it's translating.

The best thing you can do once your mix is perfect is send it to a mastering engineer. If you master yourself you don't have the impartiality that you should have, and while I do recognise the necessity sometimes of self-mastering (I have to do it all the time!) there's a definite value in using a 3rd party. Do your homework, though - there are a lot of fly-by-night e-mastering operations around there that really can't be trusted. Anyway, I'm sure this isn't an affordable step all the time, but if you have a track you're REALLY proud of it's a great investment.

That's all that comes to mind now... if I think of any other tips I'll let ya know.

EDIT addendum - to address one of your specific questions - the difference between a £150 interface and a £1500 interface - well, it's the sum of the parts in most cases. The expensive interface combines much better quality preamps and conversion (and possibly other features as well, including DSP, variety/quantity of ins/outs etc.) - usually the cheap one is going to use the least expensive AD cheaps, the most basic preamps with lower-quality components, and there's usually not going to be as much thought into the overall design, it'll be constructed as inexpensively as possible in order to keep down the cost. In a lot of cases, it's partly the components you choose, but also what you do with them that makes a big difference.