The biggest problem with many amateur guitarists is poor tone, and that's the first thing you might want to correct before you start placing a microphone for recording. Get down and listen to your amp and guitar combination on microphone level - that is where the microphone would be placed when recording. Adjust your tone so that you're happy with it, but remember one thing: the low-end will be increased with a microphone placed close to the source, which is known as proximity effect. Like any other piece of kit, the same microphone can give tremendously different results depending on how it is used. To get the sound you are looking for takes a bit of expertise and a lot of experimenting.
Even the best microphones available can sound "boomy" and unusable if not used correctly. So, is microphone placement an art or a science? Well, it's a little of both, but often just a matter of experimenting until you hear something you like. To begin with, get a flashlight and press it against the cloth on your amplifier.
This is to locate the centre of your speaker cone, once you've located the centre, mark it with a pen or some chalk. Next mark the edge of the speaker. Take your microphone and stand it perpendicular to your amplifier at a 90-degree angle and point it at the centre mark you made earlier, this is known as on axis. Do some recording and listen to the sound files. You'll find that the sound is aggressive, tremble filled, and maybe a little harsh. Now move the microphone to the second, outer mark you made.
Again, record some tracks and listen to the results. You'll notice that the sound is a lot mellower than the first with less high end, however can sound a little dull or muddy. The next step is to do a third recording with the microphone boom moved in on an angle between the points you made, this is known as off axis.
This sound is a mixture of the two, not as aggressive as the first however not as dull as the second. Re-listen to the recordings and see what you like. From here it is really all about experimenting until something grabs you, use on and off axis positions, use different parts of the speaker. It's important to get the initial sound as you like, as it's something less to worry about later with an eq, as sometimes you may not be able to fix it. You might also try using two microphones on your amp - one close up and one farther back and mix and match the two. You also need to remember, when running your amp in a recording situation, recording it at the highest volume possible while still achieving your desired tone is really recommended.
But, how can you really blast your amp without annoying the neighbours? Well that's where something called an isolation box comes in useful. Take a look at my article on Isolation Boxes.
Ian Marples has been playing guitar for over 10 years, and now runs the website http://www.uncleslinky.co.uk to help other guitarists learn how to succesfully record music at home. For similar information to this article subscribe to his FREE Newsletter by sending a blank email to firstname.lastname@example.org