Backing track articles - connecting an mp3 player or iPod to your PA system

Don't end up with a distorted sound or a
blown speakers/amplifiers because you
connected your mp3 player to your PA
system the wrong way

History of backing track playback
There are many ways to 'playback' backing tracks when you are performing live onstage. Back in the 60's, singers used old 'reel to reel' tape machines and in the 70's cassette tape became the favourite media for playback purposes. I remember using cassette many years ago - I had an old Sharp double cassette deck which had a facility to 'detect' silences on the cassette tape which (theoretically) would be the 'gap' between one song and the next. It worked, but not very well, and I still had to wait a couple of minutes for it to 'find' the next song!

However, the invention of the Minidisc in the 90's changed all this. Singers could now record their backing tracks on to a 74 minute or an 80 minute blank Minidisc - it would hold the same amount of songs (or more) than a cassette tape, but the advantage of minidisc was that you could instantly select any song on the minidisc and cue it up to begin in just a few seconds rather than having to rewind or fast forward your old cassette machine to the desired song. Minidisc was digital so there was no tape hiss. Quality was greatly improved over the old cassette tape method of playback and minidisc became the entertainment industry standard for backing track playback...until now...

The invention of MP3, and more especially the popularity of Apple's iPod, have revolutionized the way singers use backing tracks nowadays (see Sensational iPod website for a more in-depth discussion of using an iPod for playing backing tracks). These hard-disk based players have all the advantages of minidisc and more - they offer digital quality recording (and if you use a high enough bit-rate they can output quality superior to minidisc), you can instantly find any song and cue it up to begin, and instead of holding around 20 stereo backing tracks (which is all a blank minidisc can hold) they can hold THOUSANDS of songs.

Add to this the fact that they can fit in to your pocket and have no moving parts so are more reliable, you can see why they have become popular with singers!

Connecting your mp3 player or iPod to your PA
At the moment, mp3 players are mainly designed with the personal stereo market in mind (joggers, teens etc) but as time goes by mp3 car stereos, cell-phones etc are being produced with mp3 capabilities so it's only a matter of time until we see 'professional' mp3 players being produced which will suit the exact requirements of the professional and semi-professional singer.

In the meantime, the small portable/personal mp3 players can still be used on stage and, in fact, we strongly advise that you consider using an mp3 player as playback for your backing tracks. If you don't like change and are a little bit wary about giving up your whole minidisc set-up which you've been comfortable with the past few years, then at least consider having an mp3 player as a back-up. I guarantee that within a couple of gigs you'll be using the mp3 player all the time and never return to minidisc again!

The thing you may notice about your mp3 player is the lack of a line-output. Although some players do have line-outs, most small mp3 players only have a stereo headphone output (because they were primarily designed for personal listening). This isn't a problem. The headphone output can be used to connect your mp3 player to your PA.

Before you do though, there are some steps you should take to set the volumes to ensure that your levels will give you the best sound possible. If you don't follow these steps, it could result in a distorted sound, or even worse, damage to your amplifier or speakers.

Step 1 - connect the cable
Connect the mp3 player to your PA using a cable with the proper jacks at each end to suit your player and your mixing desk. Typically, mp3 players have a stereo mini-jack while a mixing desk will have canon inputs or quarter inch jacks. Check your owners manual first to make sure you are using the correct cable. Many hi-fi stores and music shops will actually make you up a cable specially for the job if you tell them your specifications (ie the jacks you need at each end of the cable).

Step 2 - prepare the volumes
Set ALL the volume levels low to begin with. The mixing desks 'trim' control (sometimes called the line-level) should be fully turned DOWN. The channel on the mixing desk that you are going to be connecting your mp3 player to should be turned down too, but not fully down, keep at it maybe around a quarter (or if you have a 1 - 10 volume indicator, set it to about 3). The master volume on your mixer can be left at it's usual volume. Your mp3 player should have it's volume set to about a quarter of it's full volume (ie if you have a volume scaling from 1 - 10, set it to about 3).

Step 3 - adjust and set the volumes
Play a song on your mp3 player (pick a fast and lively tune). You should hear the song playing now through your PA system. Adjust the volume to the desired level. There will be 3 volumes you can adjust...the volume of the player, the volume of the mixing desk channel and the volume of the trim/line-level. The first volume to adjust should be the trim/line-level control. If your desk has an LED readout, it should tell you when the signal is peaking so adjust this volume until you see the red light - then turn it back a notch or two. Next, set the volume of the mixing desk CHANNEL until you are happy with the volume.

That should be it! Under some circumstances you may have to increase the volume of your mp3 player too. That's not a problem - you can do that, but if you do, just keep an eye on that trim/line-level control to make sure it's not peaking because if the signal peaks, you will get a distorted sound.

If in any doubt though, never risk over-driving your speakers or amplifier - ask a sound engineer to make the settings for you if you are unsure (you'll find sound engineers working in most music shops and it's worth even paying one to come out to one of your gigs and set your whole sound, not just your backing tracks levels). Article 3 deals with using backing tracks on stage and is well worth reading.

Article Written by Kenny Campbell
(This article cannot be reproduced without express permission)