How To Mic A Guitar Cabinet

Unless you’ve decided to try gigging with only a direct box and some pedals, you’re going to end up miking up a cabinet both on stage and in the studio. Of course, if you’re doing big gigs, the sound team will take care of it, and similarly in the studio, you may not have to think about it.

Still, understanding at least a bit about miking your guitar cabinet puts you in a better position all around.

Mic Choice

As with any miking job, it’s probably a good idea to choose a mic! The typical choice for guitar cabinets is a unidirectional dynamic like the Carvin Audio M68, and it would be hard to have a problem if you go that direction. In a live setting, this will almost certainly be your go to, because the loud stage setting calls for as much isolation as you can muster, and because dynamics can take the brunt of your probably loud set up.

In the studio, you can also opt for a condenser, and this option may give your recording a sharper articulation and clearer high end. Just watch for overloading and consider using the built-in pad to prevent clipping at the mic. Condensers with varying polar patterns like omnidirectional or cardioid give you a chance to experiment with capturing more or less room tone along with the speaker itself.

Care should be taken if you want to use a ribbon mic for a guitar cabinet, as they can be quite sensitive to high sound pressure levels (SPL) – even to the point of damage. Still, ribbon mics are usually the smoothest option, and a ribbon with a figure 8 polar pattern can be great for a multi-cab set up. Just place the mic between the two cabinets. Again, watch the volume here to avoid damage.

Placement

Probably the most typical stage placement for a guitar mic is very close to the speaker (an inch or so) and off center – equidistant from the edge of the speaker and the center cone. That’s not to say it’s the only option, though.

Moving the mic closer to the center of the cone generally captures a brighter tone. It gets darker as you move it more off center. You can also back the mic off to eliminate proximity effect and reduce the low end.

Another consideration is the cabinet character. A unidirectional dynamic placed very close to the speaker as described above captures mostly the pure speaker tone. Backing the mic off may emphasize more of the cabinet’s unique character, and the studio is a good place to experiment with this, especially with a nice condenser.

The thing to think about when you do this, however, is you will also be emphasizing the unique character of the room you’re in. Speaking of which…

The Room

When it comes to recording especially, the space you’re recording in has everything to do with the sound you capture. More so than the mic choice, even. So, consider carefully where your cabinet is placed. For a completely neutral sound with no influence from the room, isolate the cabinet in a well-treated booth or closet. This is helpful if you’re recording a whole band together and are struggling for isolation.

You could capture something amazing with a unique sounding room as well. A big, cavernous space, a garage, or a beautiful traditional recording space may all yield great results. In fact, many a blues guitarist has sat down on the cabinet or the toilet in a tiled bathroom and gone to town. Experiment with rooms and environments to find a unique tone.

Multiple Mics

There’s no rule that says you have to mic a guitar with one mic in one spot. Using a combination of two or more mics may in fact yield the best results.

You might try two dynamic mics close to the grill, for example. One can be placed dead center, and one can be placed off center and mixed to achieve the perfect balance. Or try spreading them in the stereo field for an off-balance stereo effect. You can also choose more than one of the speakers in a multi-speaker cabinet. The back of the cabinet is also not off limits. Try a unidirectional right in the speaker frame window.

Combining a close mic with a room mic, or even a few different room mics at various distances is also common. Try dynamic close mic and a condenser 5 or 10 feet out, or if you’ve got a huge space, see what happens with a stereo pair of condensers or ribbons way in the back. That pair might be just the reverb effect you need to give the recording space and air.

The big thing to watch for with multiple mics (especially front and back of cabinet) are phase issues. In the mix, try reversing the phase of one of a pair to see which arrangement works better. You may find that with a phase reversal, certain frequencies are cancelled out that brings the sound in focus. You may also find that you liked it better the other way.

Listen, listen, experiment

If you take nothing else away, take this: use your ears, and experiment. Not only should you line up your head with the cabinet (rather than listening off axis as you stand above it) to dial in your sound - you should also listen to what your mic placement is doing at the end point. Listen in the house if you’re playing live and listen in the control room when you’re setting up a recording.

Be sure to experiment with placements to find out what subtle changes do and listen to your changes in the context of the whole mix if possible. Don’t be afraid to try something off the wall, too! 8 condensers arranged in a circle around the cabinet and then panned for surround? Try it! Splitting the guitar signal to 4 different cabinets, all miked differently? Let’s go!

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