An Acoustic Musician's guide to Digital Recording

by Harvey Reid

(first published in FRETS magazine, 1988)


If you are like many acoustic musicians, you are puzzled by the advent of digital recording and music technology and wonder what's in it for you. Even if you have a CD player, you can't seem to find many of your favorite recordings on CD, you don't feel the need for MIDI toys, sequencers, samplers and synthesizers. You hear that Stevie Wonder spends $200 an hour in the digital studio, and you hear all about how cold and harsh digital sound is. You feel hemmed in by all the technological music out there. (Technology has not been our friend lately, except for the electronic tuners.) You've been enjoying analog music and recordings just fine all your life, so why change now? What is in this digital revolution for the acoustic musician? The answer is simple: If you are willing to work around some of the constraints imposed by digital recording, you can produce a better finished product more conveniently and for less money.

Digital recording has received an unfair amount of negative press, no doubt much of which comes from those who have a financial investment in analog recording. Digital recording is just a way to copy another sound. Since most people don't have sound sources that are all that "clean" anyway, there has been a lot of concern about taping CD's, since they are the only clean source consumers are likely to have. (There would be no point in making a digital tape of a scratchy old record, for example.) But there has been little talk about what an advantage digital recording is to musicians who have a clean sound source readily available to them; namely themselves. Digital recording is perfect for acoustic musicians, and most of you don't know it yet. The classical music world already has jumped full-force into it, and it has reached a point where you can hardly sell a non-digital classical recording unless it is a reissue of some famous old recording.

Sound recording is very much analogous to photography. You don't always want ultra sharp photos, and the blurred effects and grain in photos can make them artistically more appealing. Analog tapes can deliver the message of music very well, but they do have hiss and wow and flutter just like photos have grain. You'll probably have to re-adjust your ears to get used to all the minute little sounds that will show up on your digital tape. Analog is not bad, and you shouldn't feel as if that is no longer an option. It's just that digital sound is fabulous. There are still good reasons to use analog recording, but whenever there is a choice, you'll be better off to go digital. Over the next few months, I'm going to discuss the merits and pitfalls of digital recording, explain how it works and how it is different from analog, show you some tips and tricks and some things you have to do differently in the studio, and do some investigating into what is the best equipment to use. Here's an overview of the pros and cons of digital recording. First the bad news...

DISADVANTAGES...


* There is no convenient way to splice digital tape. For complex reasons involving the way digital tape encoding is done there is no way to use a razor blade to do splices. (Each data bit is stored several places for example, as part of error checking.) The pause buttons on the VCR machines are slow and imprecise, and if you need to splice, you have to first transfer your tapes to a 1630 "U-matic" machine in real-time and then splice it on a digital editing machine. With costs at more than $75/hr, you are in several hundred dollars minimum in transfer and editing time and tape costs. This means you pretty much have to record whole takes "live." (This is changing now with the advent of Pro Tools, a Macintosh computer based program that will let you edit and splice with an investment of a few thousand dollars worth of computer equipment and hard drives.)

* Digital tapes can experience drop-outs. At random times, the digital system breaks down, usually due to particles of dust on the tape or bad or uneven pieces of tape. When this happens, there is a loud pop or a blank space in the music, and there is nothing you can do except re-record. It may not happen more than once a month, but you can lose precious things this way. DAT machines are far less likely to have dropouts than the earlier F-1 machines.

* You have to listen to your whole digital tape to make sure it is OK. When you finish recording or even copying a digital tape, you have to listen to the whole thing before you can send it out or be sure it is perfect. The tape machines don't have three heads like tape recorders that let you monitor the tape during recording.

* There is still no affordable digital multitrack*.  The digital machines for the masses are 2-track stereo. You can do some ping ponging with 2 machines or you can record analog and mix to a digital 2-track master (a very common practice known as digital mastering...), but basically the digital game for the average guy is direct to 2-track. Multitrack digital recording is very expensive, and can cost hundreds of dollars an hour. (This is changing also with the advent of the ADAT 8-track multi-track digital machines made by Alesis and now Tascam that cost about $4000.

ADVANTAGES:


* Digital recording sound quality is extraordinary. In spite of what anyone says, if you do any careful comparisons of sound quality you will have to admit that digital does as good or a better job of recreating the music accurately than analog. Fabulous frequency response, much better dynamic range, no hiss or wow or flutter, no distortion, incredible signal to noise ratios. I think that people who don't like digital sound are just uncomfortable with the detail it gives. You hear everything. Clothing, finger squeaks, breathing, strings hitting the frets. These are part of the sounds you and your instruments make when you play them.

* There is no generation loss in making copies of digital tapes. You can ensure safer storage of your master tape by having more than one perfect copy, and you can save a lot of sound quality and relax by sending digital copies of your master tape to pressing plants and tape duplication companies that are identical to your original. With analog tape, you don't dare send your only master tape to a tape duplication company, and you have the added expense and sound quality loss whenever you make an analog safety copy. Tape duplicating companies will accept your digital master tapes, thus further ensuring you a better product to sell.

* Digital tape is cheap. 2-track master quality analog tape can easily cost you $50 for an hour just for tape. 16-track, 1-inch analog tape cost $80-$100 for 30 minutes, and 2-inch reels can cost twice that. "Budget" digital machines use VCR and DAT tapes that cost as low as $5-$10 for 2 hours. This encourages you to do as many takes of a song as you feel like, since they don't cost $20 each in tape costs alone. I used 15 VCR tapes on my first all-digital double album project for raw tapes, masters, safeties, etc. Cost: $120. I would have spent close to $1000 on analog tape. (Actually, I wouldn't have, because I wouldn't do 20 takes of a song when I knew how much the tape costs. Another advantage of digital- tape is cheap, so you aren't afraid to do another take. Sometimes that's the magic one.) I recently scored the magic take on take 36.

* Digital recording time is often cheaper in studios. Wear and tear on multi-track machines causes many studios to charge more for their use. You can often get a deal for direct to 2-track master recording.

* Live to 2-track recording is more normal and less stressful. As a musician, you are used to playing songs from beginning to end. In the studio, you can spend all day overdubbing, punching in little phrases and fragments of verses. I find this unnerving, and I get rattled much faster in multitrack settings. There's something refreshing about doing it from beginning to end, and if you blow it you blow it, and if you get it you got it. It takes surprising amounts of studio time to back up, listen, practice the punch-in with the engineer, try a take, rewind, come back in the control room to listen, do it again, etc. It's possible to do three or four complete takes of something before you can even get started patching up a slightly imperfect take. In the long run, live recording is cheaper and more relaxing. When you are too tired to play the song right, you quit for the day. Many of the great recordings in the history of Bluegrass, Blues, jazz and classical music were recorded "live" in the studio.

If your goals involve recording your music just as it comes out of you, there is no more sensible format than 2-track digital. You don't have to spend a lot of money, and you can make recordings at home or in a small-town studio with two mikes if you are willing to just sit in front of them and play. With some tricks that we'll discuss in later months, there is no reason that you can't make a recording for several hundred dollars that sounds as good as anything in the world. And in a world where consumers now have CD players, there is finally a good reason to really pay attention to sound quality. When people were playing your audiophile record on a lousy turntable and making cassettes with the wrong bias settings and with the VU meters set all wrong, it hardly seemed worth it to spend those extra thousands of dollars for better recording quality when very few people noticed. Now it's getting to where it matters. If you make a CD from an analog master, chances are that even your mom could hear the tape hiss. Next month­p; how digital recording works.

HOW DIGITAL RECORDING WORKS

Digital Alchemy ­p; Converting Music into Numbers


It's probably worth mentioning here right at the beginning that digital audio recording is an entirely different thing than MIDI, which if you are an acoustic musician, you are sick of reading about. MIDI (Musical Instrument Digital Interface) stuff in general is music that is created in a machine such as an electronic keyboard, and that only becomes actual sound waves at the very end of the process. The guys in their basement MIDI studios with all the drum machines and synthesizers and gadgets and computers are not recording real sounds with microphones, and when they do, they use regular tape recorders just like us. What we are talking about is the use of digital technology to record the sounds of real music in near-perfect quality. Whether you know it or not, this is revolutionizing the recording industry, and tape recorders and records as we know them are rapidly becoming obsolete...

Music as Information

Digital recording processors use a method known as digital sampling to convert an electrical signal from a microphone into binary information which, like any computer information, can be stored on tape or on a floppy or hard disk. The advantage of this is that numbers can be retrieved from imperfect storage mediums and still be recognized as numbers. It's like reading a book with dirty pages- you still know what the words mean. The digital recording stores a description of the music and not the music itself. In its best forms, digital recording allows you to escape from tape hiss and rumble and wow and flutter and all the other problems that occur as a result of the physical properties of the storage medium in records and tapes. Digital recording is not necessarily better than analog, though, and much depends on the sampling rate and the error correction systems involved. The sampling rate refers to how often the recording takes a "reading" of the electrical signal. The rates are described according to how many bytes ( a unit of computer information storage). A 48K sampling rate assigns 48,000 bytes of information to each second of the music, and a 24K rate half of that. Music takes up quite a bit of memory, as compared to familiar computer information, such as words in a word processor document. This article takes up 14K on my word processor, which would be equivalent to about 1/3rd of a second of 44.1K compact disc quality sound. My whole 40 megabyte (= 40,000K) hard disk on my computer, which holds all my programs and months and months worth of work, would be able to hold only 8 minutes of music (44.1K per second x 60 seconds is 2.6 megabytes per minute.) A compact disc holds about 74 minutes of music, or about 365,000 pages of text! You could sample music at a lesser rate and get more music per K, but the sound quality would suffer. Many people think that even the 44.1K compact disc rate is too low, although many DAT machines now use a 48K rate. Because these rates are different, "consumer" DAT machines cannot make direct to digital transfers of CD's to DAT machines, and you have to either employ a professional DAT model with switchable sampling rates or else decode the digital signal and then re-encode it, thus passing it through an analog step. This doesn't degrade the signal much, but your digital copy is no longer a perfect clone of the original CD.

Storing the Information

Computer recording systems are only now starting to employ huge hard disks to allow instant access to the musical data, and most digital systems use tape (reel-to-reel, VCR or DAT format) to store it in a practical way. The digital recorders then have the task of storing and retrieving the information properly. There are several approaches to the task that employ redundant data storage and error correction. Redundant data just means that each piece of information is recorded in more than one place, so that if a particle of dust or a glitch in the tape occurs, the music will still be unaltered. (This is why you can supposedly scratch a compact disc with a knife or drill a hole through it and it won't affect the music, since chances are you won't destroy all the redundant pieces of a particular chunk of data). Error correction systems are very complex, but basically, if any data is missing or inconsistent, what they do is find a way to interpolate a value between two other known values, or continue a previous value so there is not a blank spot. All digital recording equipment, including CD players, use some sort of error correction, and the sophistication of the correction system has a lot to do with the sound quality, reliability and price of the machines. Good error correction greatly reduces occurrences of the dreaded drop-outs or blank spots when the numbers are not retrieved properly from the tape.

Choosing a Format: Types of Digital Machines

There are several different companies now manufacturing digital recording machines, although SONY has pioneered and dominated the field since its inception about 10 years ago. Most digital machines are simply 2-channel stereo, but larger recording studios now employ 24 and even 48-track digital equipment that allow full overdubbing and multi-track techniques, as well as a mind-boggling assortment of other automated features. It is also possible to synchronize more than one multi-track machine together. There is no way to do overdubbing or multitracking with a 2-track digital machine, unless you use 2 machines and ping-pong. (This must be done through a mixing board, so it won't be totally digital.) If you absolutely have to do multi-track recording, then you will have to rent a multi-track digital studio or else record on an analog multi-track and then mix down to the 2-track digital for your master tape. (This is known as digital mastering.) In this series of articles, I am trying to steer you toward the use of a 2-track digital machine to record live acoustic music...

Because of the extreme cost of multi-track digital, in your first digital session you will most likely use a PCM machine (Pulse Code Modulation); either a 2-track SONY F-1 series machine (no longer manufactured, but still in use in many, many studios and by most cassette duplicating companies) that uses VCR tapes, or a DAT (Digital Audio Tape) machine that uses tiny micro cassettes. You may run across a DASH recorder, (Digital Audio Stationery Head) which uses reel-to-reel tapes. These are the only digital machines that allow razor blade splicing of digital tape. An advantage of the F-1 VCR format machines is that you actually use your normal VCR or Beta machine for storage and just hook up the processor to code and decode the music. If something goes wrong in the tape transport, you just get a different VCR. DAT machines all are built into a single package, and you can't just use the processor. The F-1 machines use the rotating VCR heads to store encoded digital data in the video portion of the tape. (Under some conditions, it is possible to record on the audio portion simultaneously in a sort of 4-track, though it won't be the same quality.) CD mastering and professional digital recording are usually done on very expensive SONY 1630 or "U-Matic" digital machines that use big, 3/4" video tapes for storage, allowing much more physical space to store information.

In order to do any "splicing" or cueing with an F-1 or DAT machine, you must rely on the machine's pause button . The pause buttons on the F-1 machines were slow and inaccurate, like any VCR machines, and produce a faint click when activated. (We'll discuss some ways to get around problems with them in a future column.) DAT machines have silent pause buttons, and they are almost instantaneous in their action, making it much easier to start and stop recordings, or to due sequencing or cueing. If you need to splice something that is recorded in DAT or F-1 formats, it first has to be transferred in real-time to a U-Matic or DASH machine. The splice is then done with a digital editing machine, which is basically a computer. If you are planning to make a compact disc from your recording, then you will need to convert to the U-Matic format anyway, since at this time CD plants generally don't accept PCM and DAT masters.

When you use an F-1 or DAT machine for recording, you really don't know how much error correction is going on, except by watching the tracking control and error lights. It's always a gamble, and to be completely sure you have to listen to every digital tape from beginning to end to spot any dropouts. The U-Matic and CD formats allow you to know exactly how much and where error correction is happening, and electronically find out whether or not there are dropouts. In fact, when you make a CD, you don't even get a test pressing! The machines know whether or not the data was transferred, and if all the numbers are accounted for, the music is perfect.

Copying Tapes

A great advantage of digital recording is that copies can be made that are "clones" of the original, and beyond the normal variations and error-corrections that go on in any digital information storage, copies are identical to the original. (Just like making backup copies of your computer files.) Analog tape suffers "generation loss" when copies are made, as we have all learned from trying to make tapes of tapes. The hiss adds up pretty fast. With one F-1 machine you can hook up two VCR decks, and do a digital to digital transfer to copy your tapes. You cannot make any adjustments to the sound during this process, and if you want to do any EQ or volume adjustments, you must have 2 processors, and route the signal through a normal mixer between the machines. It requires two DAT or DASH machines to make clone copies of your digital tape. None of the F-1, DASH or DAT digital formats currently allow "read after write" listening, so you cannot monitor the recording quality off the playback head during copying as you do in normal analog recording. This means that to ensure perfection, you have to listen to all copies of the tape completely after a copy is made.

Hopefully you now have an idea of what digital recording is all about, and you'll be able to stay with us as we go through the steps of making an affordable digital recording of acoustic music. Next month we'll talk about how you approach the actual recording process, and what sorts of things you have to do differently in the studio.

Harvey Reid resides in Portsmouth, NH, and has been a full-time acoustic musician since 1974. He has recorded, produced and engineered 5 solo albums for the Woodpecker label, including a recent double album compact disc. He is a frequent contributor to FRETS.

Tips and Tricks to Get the Most out of Digital Recording


"The Sonic scrub." Because the digital machines are so sensitive, and because there is no tape hiss to cover up the little background noises in the studio, you really need to do a "sonic scrub" before you start to record. Even if you have done a lot of recording, you will no doubt be amazed at what shows up on the tape. If you are used to performing live, you aren't even aware of the tiny nuances of sound that show up on a recording. It's a good idea to spend some time before a session in the quietest place you can, listening carefully to yourself and your instruments. On digital recordings you can actually hear things like the sound of your mouth opening before you sing. You can easily make a noise just lifting the skin of your moist arm off the top of the guitar as you shift arm positions. Check your instruments carefully for string rattles, buzzes and other noises.

Be extra careful of mike choice and placement. Digital recording makes the already important issues of microphone choice and placement more crucial than ever. A digital recording done with sloppy mike placement will not sound as good as a well-engineered analog recording. Experiment with different mikes­p; they can sound very different from one another. If you don't have a lot of experience, at least work with the producer and engineer, and get involved in the decision making. You can learn a lot at home with just a mixer or tape deck, a good mike, and some headphones, exploring an instrument with a mike to find the distance and the angle and the direction for placement that gives the best sound. When you go into the studio, you'll already have a good idea of where you want the mikes.

Keep good notes. I always bring some blank cassettes into the studio, and do my critical listening at home on my own time. When you do 16 track recording, and you are paying $20 a song just for blank tape, you really have to decide then and there which take to use, and you rarely keep more than a couple around at any given time unless you are rich. With 2 hrs of DAT or Beta tape costing $10 or so, you can afford ten takes of every song if you want. And you are spared that sick feeling when you think you can do a better job, erase over a good take, and botch it. It's bad for morale, and the rest of your session can suffer. Also, it's just as expensive to listen to your takes in the studio as it is to record them, and I don't always do it. I often have the engineer run a simultaneous cassette when I'm really in the mood to just play, and then I can do the song 4 times, and maybe only listen to the one I though was best. Once the levels are set, you can just roll and play music. You can then compare the others at home on your own time. With 2-track recording, it's already mixed, so there's no need to spend all that time setting up the board for a rough mix to take home. Just take a cassette right off the digital master or run a cassette all through the session.

Always slate your takes. This means that you say the name of the song and the take number before you start to play and always keep track which ones are which on the cassette you take home. Make sure the engineer takes extra good notes, too, and check to see if you agree on take numbers. It can be a mess when you have 10 or 20 takes of 10 different songs, with false starts on half of them! And if your project is like most, it is weeks and months between start and finish, and you'll want to refer to those notes later. Deciding which is the best take is a really hard part of this kind of recording, and you don't want to pay studio time to do it, nor do you want to lose track of which is which.

Be very careful at the beginning and ends of songs. If you are using a VCR-style machine, make sure you leave about 5 seconds of silence at each end of a song, since the pause button is slow to react and you need room before and after a take to start and stop the machine when you go to assemble the master tape. Actually the best thing I've found to do is an idea courtesy of Jeff Landrock, engineer at FISHTRAKS in Portsmouth, NH, where I record. Jeff called on his rock and roll background to rig up a noise gate (a machine that lets you set a minimum level for sound, below which nothing passes through) that is triggered by the first note of music. This way, there is total silence until the music starts. It doesn't sound like a big deal, but if you are making a CD, you will hear the total digital silence between songs, then some breathing and room noise before the music starts. The noise gate is an easy way to solve this problem without doing expensive digital editing. The same technique can be used to remove the tiny "pops" that are left between songs on the tape by the pause buttons, especially on F-1 machines, when you assemble the master tape from many work tapes. * (This is not so much of a consideration now if you are going to make a CD, since the beginnings and ends of songs can be cleaned up digitally in the digital mastering process.

Watch volume levels! It seems to be a lot harder for an engineer to set average volume levels for a song with digital readouts rather than the VU meters used on tape machines. You have to be careful with peaks in digital recording, since errors from too much volume can be unrepairable. Make sure you have plenty of headroom. It appears that even mastering engineers for major record companies have this problem, because the CD's I buy are very irregular about how loud they are with respect to each other, and even from cut to cut on the same CD, especially compilations. Chances are that over the duration of a recording project, you will have cuts that aren't of equal volume. It's a very good idea when you finish your master tape to use 2 digital machines and make a copy of the master through a mixing board. (Converting the signal to analog and back won't degrade your sound noticeably, and can save you a lot of money on editing, which has to be done with an analog board anyway.) You can then use the volume pot to adjust the relative volumes of songs. Ideally you would have made a cassette of the first master and studied it at home to learn which songs are too loud or soft.

Don't worry about the "magic" first take. With direct-to-digital, you need to throw away the first few takes anyway, as you get the levels and EQ and reverb and mix right. In the process doing test takes you can warm up, stretch the strings, and find the noises in the instruments and the room. I find myself easing gradually into going for the best take, rather than blasting out trying to do a macho perfect first take. You don't want to waste a perfect performance when the levels might be wrong anyway. And when you're recording with other people, you'll find that no one ever really learns the song from the tape you give them the week before; they always end up finding their part in the studio while you're paying for it. So I like to learn the song with them, and if I don't know exactly what I am doing, we can all feel better and work together from a similar place. It sounds crazy, but when you are recording live, and if one person blows it and everybody else has to re-do it again, tensions can build. A big part of what you want to capture in a group is the interaction among the players, and the tension can help create excitement and some special moments in the studio, and it can hurt things. A good producer can sense which is happening. The patterns of tension, resolution and suspense that build up in a performance are a crucial part of what makes one recording better than another. Don't think of that part of recording as a problem. It's an opportunity to possibly capture a great moment in fabulous digital sound quality.

Use the right tape. The F-1 VCR based machines can be very finicky about tracking, and you can have trouble recording a tape on one machine and playing it back on another. Many engineers recommend "exercising" the tape, which means to fast forward and rewind it a bit to make sure it works smoothly. Many people recommend not using the first several minutes of a tape, since there are often the most problems there in tape transport. VHS and BETA tapes that are longer than 1 hr may not work right. Believe it or not, digital recorders are finicky, and different brands of tape work well with certain machines and not others. It's probably not a good idea to re-record too many times over the same tape, just as you do with analog tape.

I'd love to hear from anybody out there who has been doing digital recording and has some wisdom or experiences to share. It's an exciting time for home recording. Next month we'll hear from some people in the industry about what they think of digital recording.


Harvey Reid has been a full-time acoustic guitar player, songwriter, traditional musician, and free-lance minstrel since 1974. He has recently released his 11th solo recording on Woodpecker Records. He lives on the coast of Southern Maine, though he did live in his car for over 5 years, which made him philosophical.


WOODPECKER MULTIMEDIA
PO Box 815 York Maine 03909  USA
phone (207) 363-1886


Lyrics About Harvey Reid
Concert Schedule Lyrics
Catalog of Recordings Buy From Us
Say Hello to Us Booking Information
Books The Song Train
Newest Recording About Joyce Andersen
Newsletter About the Partial Capo
Listen to Audio Lyrics
Hot News Listen to Audio
Guitar Tunings Interviews
Articles & Essays Reviews
Publicity Info Out of Print Music
Publicity Photos Lyrics
Downloads Listen to Audio
Say Hello to Us Favorite CD's
Harvey's Gear  

Harvey Reid Concert Schedule |Harvey's Blog | About the Liberty Guitar Method|Catalog of CD's and Tapes|Discography|About this Web Site & What's New Here | Hot News | Woodpecker Home Page | About Harvey Reid |The Song Train | Video | Audio | About Joyce Andersen | Books by Harvey Reid | Get On the Mailing List... | Concert & Record Reviews | Interviews with HR | Lyrics to Harvey Reid Songs | Harvey Reid Annual Newsletters | HR's Guitar Tunings | About the Partial Capo | Articles & Essays by HR | HR's Gear | HR's Favorite CD's | HR's Career History | Booking Info | Publicity Info & Download Files |


This web site concerns the music and life of acoustic musician & music educator Harvey Reid.

If you don't find what you want, or if you have comments or questions, please email to