Recording electric guitar: aiming 'across' the cone? (discussion)

[Ben Asaro]

I recently heard some very nicely recorded electric guitar, and it was tracked with a condenser microphone aimed 'across' the speaker cone, it almost looks like it's at a 90 degree angle to the speaker cone.

I am wondering if there is any validity to this technique, as it sounded REALLY nice ... I will, of course, be trying it myself, but am just curious if anyone else is using this mic'ing technique, as most people seem to point the mic straight at the cone.

Also, are there any phase issues one has to be concerned about when mic'ing across the cone?

[Mike Senior]

I recently heard some very nicely recorded electric guitar, and it was tracked with a condenser microphone aimed 'across' the speaker cone, it almost looks like it's at a 90 degree angle to the speaker cone.

I am wondering if there is any validity to this technique, as it sounded REALLY nice ... I will, of course, be trying it myself, but am just curious if anyone else is using this mic'ing technique, as most people seem to point the mic straight at the cone.

I've never heard of anyone doing this (even when researching this article), but I can see some reasoning for it nonetheless, because it would avoid the on-axis HF peak that most condenser microphones have from affecting the sound as much. I'd also expect it to reduce the proximity effect on the mic somewhat, which otherwise makes condenser mics sound rather bloated when positioned up close. Must try this myself now, because it does make rather a lot of sense when I come to think of it...

The only potential drawback I can see would be that it might increase spill on the guitar mic in an ensemble-recording context, but that might not be a problem in practice depending on the balance between the instruments in the room.

Also, are there any phase issues one has to be concerned about when mic'ing across the cone?

Shouldn't have thought so -- this is mostly a consideration with multi-miking. However, I'd probably not aim the mic at the floor, because that might exacerbate comb-filtering from that first early reflection, which I'm not usually a great fan of personally.

[shufflebeat]

Not a recording scenario but related:

I've been known to use a jc120 live and have an ongoing debate with techs about how one should place a mic, bearing in mind that the chorus is only applied to one speaker, put a mic on the dry one - no chorus, put a mic on the wet one - kinda weird clumsy chorus.

My own experimentation suggests micing across the cone pointing towards the wet speaker is the best compromise, phasing issues have not been overwhelming, or even whelming actually.

[Hugh Robjohns]

I'd also expect it to reduce the proximity effect on the mic somewhat, which otherwise makes condenser mics sound rather bloated when positioned up close.

Good point worth expanding upon. If placed at 90 degrees to a (linear) wave-front there can be no pressure gradient across the mic, and therefore no proximity effect at all in a directional mic.

However, in the case of the guitar amp, the mic is too close to the speaker to be considered as a far-field condition with a linear wavefront -- it will still be seeing a spherical wavefront for most frequencies, so the proximity effect will probably be reduced as you say, but not eradicated completely.

Turning the mic to look across the speaker cone will also reduce the risk of pressure shock on the capsule, which might be useful if it has a low maximum SPL capability -- it's much less likely to bottom out.

And finally, the off-axis response of a large diaphragm mic has a very different response to the on-axis, with considerably less high-end and an early roll-off, no presence boost and rather more low end. I suspect using an LDC in the way described lends it something of a ribbon-esque character which would usually works well with a guitar amp.

H

[Ben Asaro]

Thanks for the input! Definitely going to try this soon.

[damoore]

Have not done this with a capacitor mic, but it certainly is very effective with an SM57. The immediately obvious effect with an SM57 is a cutting of the highs because of the differences in directivity at different frequencies.

It is also worth experimenting with position across the cone. There is lots of wonderful physics going on in a guitar speaker cone that you can use to your advantage. Some of that washes out when you are far away from the cone, so it can also give you a harsh tone if you don't place your mic carefully.

[The Elf]

I've been known to use a jc120 live and have an ongoing debate with techs about how one should place a mic

Central XY SM57s work wonders for a JC120. Don't get too close in though.

I'm only talking about recording, though...

[shufflebeat]

I've been known to use a jc120 live and have an ongoing debate with techs about how one should place a mic

Central XY SM57s work wonders for a JC120. Don't get too close in though.

I'm only talking about recording, though...

Take two microphones into the live room? Not me! I just want to thrash and go...