All Rights Reserved © 1999 Thomas W. Day
(Originally published in Recording Magazine, May 1999 Volume 12, Number 8, p112, in the "Fade Out" guest editorial column under the title "Rounding Out the Sound.")
In the early 80's, a lot of engineers and musicians fell in love with our brand new digital masters. In the compromised world of vinyl, you would have to pick "the lesser evil" out of a group of master disks sent back from the mastering lab. The records that were made from those masters were, yet another, big step away from our master tape. With digital masters and CDs we got to hear what we originally recorded. The panning, bass, and volume are all where we put them. We seem to be taking that huge step for granted, lately.
The 90's seemed to introduce a new era of doubt for recording engineers. The ABX-shy golden ears crowd and other audiophile terrorists ranted about the loss of all those "pure" varieties of vinyl distortion (frequency, phase, and harmonic). For some reason, we listened to them and started trying to find ways to "round out" the clear, noiseless recordings we could make with our snazzy new digital toys.
There are lots of ways to take the edge (read "top end") off of what you put on disk. The current trendy method seems to be to stick a tube preamp between the mike and the digital gear and go on with life as you normally live it. I have some problems with that theory.
First, where are you going with all those "warm" tube amp even-harmonics? The basic idea behind the hoodoo is that solid state amplifiers add "bad" odd-harmonics to whatever they amplify. Tube amps add "warm" even-harmonics. If you believe there's something inherently evil about the extremely low harmonic distortion generated in modern semiconductor circuits, complicating (distorting) the signal you sent them makes no sense at all. You've created something extremely complicated that has to be "rounded out" in the solid state signal chain. A more conservative and informed "rounding" approach to smooth recording involves a collection of tactics.
Digital recordings got their "harsh" reputation when recording engineers tried to apply their dubious overdriven "tape saturation" tactics to the new digital equipment, resulting in lots of square waves showing up on all kinds of instruments. The same thing happened in the transition years from analog tube equipment to transistorized gear. The first thing you can do to round-out your sound is to keep your levels a safe distance from your headroom. Clip indicators flashing all over the board is a bad thing and your tube preamp isn't going to fix any part of that. After each technology evolution, design engineers learned to build in enormous amounts of headroom to compensate for deaf people in the sound room. Just having all that space for error doesn't require using it.
If you aren't trashing the input amplifiers with overdriven signal, you may be providing them with a harsh signal due to your microphone selection. Microphones and monitors are signal sources that even the lowest caret golden ears can identify in an ABX test. Microphones do not sound alike. Sometimes, two mikes of the same make and model will be considerably different. One of the basic distinctions between good engineers and everybody else is that the good ones have spent a lot of time experimenting with microphones, microphone placement, and stereo microphone configuration (XY, M-S, 3:1, etc.).
Some famous old tube condenser mikes will round off the edges of anything you care to record. Some of the newer FET condensers can do the exact same job for a lot less money. Of course, stuffing a delicate, large capsule condenser mike into a bass drum will give you a harsh, overloaded signal that no tube circuitry can round out. Part of the time you need to spend experimenting with microphones should be spent learning which mikes work on certain instruments and where those mikes are absolutely useless.
Finally, and critically important, you have to do your recording in a decent room. The tracks that need the most rounding-out are the ones that had a microphone stuffed into the guts of every instrument in the mix. If you want a smooth, clean sound that has depth and warmth, you ought to do at least a little bit of the recording in a room that has those characteristics. A grand piano sounds terrific in a decent room, heard from a decent listening position, but it will sound like a poor sample if you cram your head against the sound board. When was the last time you listened to an acoustic guitar with your head stuffed into the sound hole? Pickups are useful in live applications, but on record they make great acoustic guitars sound like mediocre ones. There is supposed to be an advantage to being in the studio. That advantage doesn't get used nearly enough.
Your ears should be the best audio reproduction equipment you own. The best way to achieve a smooth, well rounded recording is listen carefully and critically to what you are putting on tape (or disk). Don't blindly follow someone else's rules. If you have carefully studied your craft, you will have learned that Goldman's Rule applies to art in general, "Nobody knows anything." Our audience will put up with almost any godawful recording technique to hear great songs and performances. I think our goal should be to get between them and their music as little as possible. There have been great records taped directly to 2-track tube decks and on 128-track digital rigs. Patching a tube preamp between a poorly selected microphone and your mixing and recording medium will not correct for abuse of technology or mediocre music.