Putting a mic on the hi-hat is something that seems to be a knee-jerk reflex a lot of the time when recording drums, but actually the hi-hat might work just as well without one if you get the right drum overhead position, which is useful if you are short on channels. You might have seen the top snare mic angled to double as a hi-hat mic to save channels, but this is more of a live-sound trick because in a stereo mix the snare is almost always dead centre and will pull the hi-hat to the middle with it. There isn’t really a huge downside to putting a hi-hat mic up, as you can always choose to not use it if the mix works without it. The big advantage of having a dedicated hi-hat mic is that it gives you much more control over four areas; tone, volume, closeness and localisation.
Probably the main reason for rigging a hi-hat mic is so that you have control over where it sits in the stereo image. When you pan the overheads left and right, the hi-hat should just drop straight into place at one side or the other. However the hi-hat can be drawn into the middle of the image when you introduce the snare mic, and a dedicated hi-hat mic is useful to counterbalance this effect and keep the hi-hat clearly defined in one location.
Tone and mic choice
The tone you get from a close hi-hat mic is likely to have a weightier sound to it compared to the sizzly high-end on the overheads. This can make the hi-hat too overpowering and dominant in the mix, so eq carefully to compensate. The choice of microphone will change the tone too; small diaphragm condensers like the km84 and AKG 451 are studio favourites because of their bright top end response, and for a slightly softer sound then the reliable SM57 works well (and is much cheaper!).
Most of the time you are likely to get enough volume through the overheads, but a close mic is perfect for when you find that it needs to be a little more present in the final mix.
Closeness and mic placement
By mixing in the close mic, you can make the hi-hat sound much closer than just the raw overhead sound. This is useful if you want a really “in your face” drum sound, but genreally you will find that you use the mic to anchor the hi-hat in the stereo image without bringing up the volume much or making it any closer. Placing the mic a little further away than usual will help with this, as it will have a bit more ambience and spill from the drums which makes the hi-hat sound less intrusive. In the region of six to eight inches from the hi-hat is a useful starting place, unless you want a really close, clean and defined sound in which case two inches from the rim and two inches up, aimed straight down at the hat works as a general rule of thumb.
Although your gut instinct might tell you to mic up really close to avoid all the spill from the rest of the kit, try getting the right hi-hat sound on just the overheads first, and if you want a bit more definition or a closer sound then put another mic up. Starting with a slightly ambient hi-hat mic and then moving it closer as needed, will blend the hi-hat into the mix better than a mic that is so close that using it to improve the image will ruin the tone or make it too loud.
[image via Star Guitar]