Wired for Sound


    So your long lost uncle died and left you his studio, and you need to hook it up. Or maybe you just got rid of that Hammond, and decided to give MIDI a shot. Whatever your desire, nothing is more important than wiring your studio in a clean and concise manner. In today's modern studio, you have basically four types of cables to deal with; Audio, MIDI, Power, and SCSI. Now let me state for the record that I don't know everything, and that there are bound to be some better ways to do some of the things in here; I just haven't found them or been shown them yet. The object of this article isn't to make you some automaton who can wire things the same way as me, but to help you understand why I wire things the way I do, and hopefully give you some insight that helps your setup. Now let's start with an overview on just what each type of cable does, and how it fits into the big picture.

Long Live Tesla...

    No, I'm not talking about the band, but the man we owe it all to. Not Edison, he invented DC power, great for running things, not too great for getting it where it needs to go. Nope, that distinction falls to good 'ol Tesla, who figured out AC, and helped name another band, AC/DC. Let's start off with the default cable that any piece of gear needs to be wired up will require; the power cord. Now don't laugh, how you set up your power can drastically change the quality of what you get out. A good example of this was back when I lived in a loft; when I would be working, every once in a while I would hear this sound that was similar to a jacobs ladder, if it only pulsed once (you know that electrical dohicky you see in all those old mad scientist movies, with the electricity arcing up it). Well, you could sit there sometimes and not hear it for several minutes, and then other times, it would happen over and over in the course of a minute. Now this was frustrating to say the least, so what tipped me off to this being power, and not a damaged mixer? Well, if I plugged the headphones into the outputs on several units, when they were connected to nothing but power, I could still hear it (albeit faintly). It turns out that the elevator was what caused the noise, so whenever it went up, not down, I would get the interference, and only when it went past my floor. The solution? Simple, a filtered powerstrip, I had a Furman PL8+, and it wasn't doing the trick by itself. But the Furman, in conjunction with some TripLite powerstrips did the trick, and the noise was banished forevermore. The most common mistake people make when wiring their system is to have their gear plugged into different outlets; BAD! You should always make sure your gear shares a common ground, to make sure you don't get slight distortion from the variation between grounds. This can normally be heard by either a constant hum, or a sweeping phaser-like noise.

Phono for you...

    Now you can turn on your gear, but you can't hear anything; not a very good situation since we're trying to set up a studio to make music (presumably). In the audio space, you have all sorts of connectors; I'll try to hit the most common ones now, with about 1 line for each, then I'll jump back to 1/4" phono, since it's the main plug of choice in MIDI rigs. Ok, at the lowest end of the foodchain you have the mini plug, which is like the plug on the back of your SoundBlaster (if you're a PC guy), and is pretty rare on any pro gear. Next up is RCA, which is most common on consumer electronics, like the back of your CD player or VCR. Next you have the 1/4quot; phono plug, which is what almost all pro gear has as outputs or inputs. After phono you have XLR, which is normally used for mics, or for long cable runs. And finally you have optical, which is used is some newer products. There is one more subclass of any of these cables, and that's called a 'snake'. A snake basically is a group (usually 8, but sometimes more or less) of cables tied together in some permanent fashion. They're commonly used to wire up mixers to something else with multiple inputs (like drums, or a rack of gear, or whatever your multitrack is).
    For most of your wiring needs, you're going to be using 1/4" phono plugs (which I'll just refer to as phono from now on for convenience), since they are by far the most common today for input and/or output of sound in studio gear. Phono plugs are about as straight forward as they come, plug them into the output on the back of the instrument, plug the other end into the input on the mixer, and you're done. Now some things to keep in mind is that 99% of the gear out there uses MONO phono plugs (which have only one ring at the end), while STEREO phono plugs will have two rings. If you're in a music store, and you see a cable that costs more, but is the same length (and isn't a Monster cable), then check the plug, it's probably stereo. Now as I said, this isn't 100%, some keyboards do use STEREO plugs, the Emu EMAX 1 and 2 being two notable exceptions, so make sure to double check before assuming something is MONO (but in most cases you'll be ok). It's also important to note that the correct description of mono cables is tip and sleeve, whereas stereo cables are known as tip, ring and sleeve.

A bit of a balancing act...

    Once you start working more extensively with gear, you're probably going to encounter the nebulous terms 'balanced' and 'unbalanced'; what on Earth are they talking about? If you take a normal mono cable, you have two conductors or wires; one wire is usually running hot while the other is a ground. Now if you add another wire to that mono cable, you magically convert it from an unbalanced mono source to a balanced mono source. Sure, it's basically the stereo (tip, ring and sleeve) cable we were just talking about, except instead of carrying two audio signs it's carrying the same audio signal twice. What?! Why do that? Technically it's not carrying the EXACT signal on the second wire that it is on the first, it's carrying the sound 180 degrees out of phase. If you add two signals that are 180 degrees out of phase, what happens? The answer is nothing, or more appropriately, they cancel each other out. This is beneficial to cables because it's more than likely that any interference a cable picks up will be very similar on every wire. Now, do the phase cancelation trick a voila - you eliminate the audio you were carrying across the cable and are left only (hopefully) with the noise that was picked up along the way. Now, make that 180 degrees out of phase, and add it together with the first wire and blam! - any noise introduced along the cable is cancelled out, leaving only your audio in its true form.

Let's get those 1's and 0's moving...

    MIDI is the next hurdle, and probably the most difficult to deal with when you start getting into wiring a larger setup. Thankfully, the cable itself is very simple. It can only be plugged in one way, there's only one type of MIDI cable, and nothing bad will happen if you plug things in wrong, you just won't hear anything. There are some special concerns you have to be aware of with MIDI though, so let's get on to that...

Break out that paper!

    Before we get into talking about some of the gotcha's that cables have, let's talk a little bit about what you should keep in mind when laying out your system. When I'm composing, I have discovered that nothing wrecks a highly creative mood better than some piece of gear not working, and having to switch into 'troubleshooter' mode to figure out why. Did the MIDI fail? Is the mixer set up right? Is it even turned on? If you take one thing away from this article, I hope that it's this: Always have a default setting that you return all gear to. What do I mean by this? Well, figure out what a good general purpose setting is for your EQ, for your effects sends and returns, for each tracks levels, and then make SURE to set your system to this each time you start a new song. Why, you ask? Simple, it forces you to note every change you make, from a known state. Have you ever been tweaking with the EQ, and gotten it just right, and then, a week later, went back and you swear everything's set the same way, but it doesn't sound the same? You just got burned by not having a known position to start from. In this techno world we live in with flying faders and MIDI, it's becoming easier and easier to do; don't think that just because your Tascam 2416 isn't automated, you can't do this. You can, it just takes a little more work, but the end result in time saved (and killer mixes preserved) is reward enough.

Danger! MIDI Ahead!

    MIDI is about the most complicated of the cables you will probably have to deal with, but even at its worst, MIDI cables aren't that hard to deal with. MIDI cables are similar to audio cables, but instead of carrying sound, they carry digital information, to and from a device, usually a musical keyboard or rack module.
    Every MIDI device can have any of the following types of ports: Input, Output, or Thru. Input is simply that, the MIDI port that the device is going to listen for data from. Output is again pretty self-explanatory, being the port where the MIDI device will send any data it generates. The final type of port is the Thru port, which just passes the information from the Input port along, allowing you to hook up keyboards in a series. Not all instruments have all of these ports, but as a norm, they will have an Input and Output, and almost all will also have a Thru; some may also have multiple Outputs, but this is relatively rare.
    Before we go any further in the wiring aspect, let's talk a little bit about what MIDI information is set up like. Each MIDI Output or Input is called a Port, and each Port consists of 16 Channels. The easiest way to think of what a channel is, is to consider each channel to be a different musician playing a different instrument. Each musician can play more than one note at the same time (ie; chords), but they can only play the instrument that they're holding. This is relatively the same as the relationship between ports and channels; you select what instrument is playing on their respective channel, and then send the notes that correspond to that instrument on said channel. The important thing to realize about this is that most older devices will only use 1 channel (ie; can only play one instrument at a time), while most newer devices will be able to use up to all 16 channels, or some subset below that. Now, just because it CAN use 16 channels, doesn't mean it MUST use 16 channels; and this is important to remember when building a larger studio, where MIDI channels are at a premium.
    There are a couple other gotcha's you must be aware of as well before deciding how you are going to wire things up. First, if you use the device B to get its input from the Thru of device A, then device A MUST be turned on, otherwise it won't pass data on. This is by far the most common problem when a keyboard isn't receiving data. Next, make sure you have your MIDI cards Output going to the devices Input, and vice versa; if you get them backwards, nothing bad will happen, but you certainly won't be making any music. And finally, try to keep the length of the MIDI chain as short as possible, and passing Thru as few devices as possible. The reason for this is simple, each time the MIDI data passes Thru a device, it is delayed for some period of time; now this may only be a millisecond or less, but after several devices, you will find that the last piece will be very sluggish to respond. The length of the cable can also incur a delay, although it does take a pretty long cable for anything noticeable, when you factor in Thru usage, it adds up quick.

Enough with the warnings, I wanna hook up MIDI!

    Ok, so now you're ready to figure out how to hook up your MIDI devices. As a rule of thumb, here's a couple of things that I like to always try to do:

[1] Use Thru as minimally as possible.
[2] Never use more than two Thru's in a row.
[3] If you have multiple Ports, try to spread any high-use keyboards evenly (ie, don't put your favorites on the same port, since it is possible to overflow the amount of MIDI data that a Port can support).
[4] Don't worry too much about getting Output back from devices, except your master keyboard.
[5] Try to keep the total length of a MIDI chain less than 16 feet.

    None of the above are written in stone, you certainly can use more than two Thru's, and sometimes you will want Output from other devices, but on the whole they tend to be more true than false. Once again, I must stress keeping accurate records of how you have wired things up, to help make writing music as painless as possible (do you really want to try to remember what channel the M3R is on, or just look at your handy clipboard?).

What should I hook up first?

    In general, I would say that it's a matter of preference for the most part, but here's the order I normally hook things up, and why. First, I hook up power, because I like to verify that everything is working, or at very least turns on, and that I have enough outlets to get the job done. I would recommend getting one of the Furman one space rack powerstripes (PL8+) with the line meter on it, so you're aware of how much of a load you're putting on your electrical system. Next, I hook up the audio portion, and I usually play whatever demo tune is built into the keyboard to verify whether or not it is hooked up properly (if you're hooking up a guitar, or some mic, then do their appropriate test). Don't spend too much time tweaking at this point, just make sure it's working, and that the sound is going to where you think it should. Finally, I hook up the MIDI cables, and as I hook each device up, I test to verify that it is receiving and sending (if it does) properly. At the end of this, your system is wired up, but far from being done; you need to set levels, adjust panpots, tweak eq's, and do whatever else you feel makes your system really shine. About the only tip I have on this front is that I have a template song I use, which plays as many notes as I can into a given instrument, so I can get its loudest volume, then I use that to set the gains on it's respective channels. If you do this, make sure to pick sounds that are panned to the center, otherwise you might end up weighing the mix to either side.

Great! I think I have it, now how do YOU do it?

    Studios are about as varied and diverse as the people running them, but you can sometimes get a better picture of how things are done by simply seeing how someone else has chosen to do it. With that in mind, I have converted all of my studio diagrams over to HTML, and they're available right here:

Page 1: MIDI Overview
Page 2: MIDI Routing
Page 3: Audio Routing
Page 4: Delay Reference

    Let me give you a little setup on how I use these, and what they are... The first page is the one I use the most; it contains the channel routing, port, number of voices, etc of all my MIDI devices. I also note any special controller information or configuration notes at the bottom of this page, to help jog my memory when I'm in the studio. The next two are how I've chosen to route the wires: I very rarely refer to these, usually only if I am wiring things up, or if I'm troubleshooting something. I still think it's important to keep these handy, so that when you do encounter a problem, you don't need to go searching to find out how you wired things up. Finally, I have my delay time reference chart, which is simply there to help me program delays into misc gear; I don't use this too often either, but as with the routing info, when I do need it, I want it to be handy.
    All of these are kept on a clear plastic clipboard, right next to my sequencing computer, close at hand should the need arise, and it always does. I would recommend this configuration for most people, since it is also a quick and easy way to help someone else who is just coming into your studio familiarize themselves with the setup.

In conclusion...

    Well, hopefully you have gained at least one trick from this text, or perhaps it's made you look at how you wire things a little different. Once again, I would like to point out that I certainly don't know everything, and would love to hear any suggestions that anyone else out there would like to make. I would like to think that music is a tad more cooperative than competitive, and with that in mind, helping others is the best way to help yourself.