A potentially stupid question about mic'ing cabs....

Lewy

Let's say you've got a 4x12 with Vintage 30s in it. If you close mic one of the speakers in that cab with something like a SM57, at that point does it make any material difference to what kind of cab it's in as far as what the mic's capturing is concerned. Might you as well be mic'ing up a 1x12 with a Vintage 30 in it for all the difference to the captured signal it would make? Obviously the experience in the room or the signal from mics at a greater distance would be different, but close up?

ecc83

A 4x12 cab is a lot less rigid* than a 1x12 and as a consequence they creak, groan and generally vibrate. Much of that additional noise will be transmitted through the speaker cone, in short it will sound different from a 1by. Another factor is that no two speakers sound exactly alike not even hi fi units much less your "ball of chalk and string" git' speaker! Therefore it is always worth trying each cone in turn for the sound you want.

There is what is perhaps THE best article written on miccing guitar speakers. I shall find thee a link.

*This is in direct contrast to hi fi speakers. https://www.soundonsound.com/techniques/guitar-amp-recording

Dave.

Lewy

ecc83 said:

A 4x12 cab is a lot less rigid* than a 1x12 and as a consequence they creak, groan and generally vibrate. Much of that additional noise will be transmitted through the speaker cone, in short it will sound different from a 1by. Another factor is that no two speakers sound exactly alike not even hi fi units much less your "ball of chalk and string" git' speaker! Therefore it is always worth trying each cone in turn for the sound you want.

There is what is perhaps THE best article written on miccing guitar speakers. I shall find thee a link.

*This is in direct contrast to hi fi speakers. https://www.soundonsound.com/techniques/guitar-amp-recording

Dave.

Thank you! Wis'd

ICBM

Lewy said:

Let's say you've got a 4x12 with Vintage 30s in it. If you close mic one of the speakers in that cab with something like a SM57, at that point does it make any material difference to what kind of cab it's in as far as what the mic's capturing is concerned. Might you as well be mic'ing up a 1x12 with a Vintage 30 in it for all the difference to the captured signal it would make? Obviously the experience in the room or the signal from mics at a greater distance would be different, but close up?

Yes - not a vast difference, but some. The interactions between the four speakers via the enclosed space, plus the internal refections from the larger cabinet, mean that it doesn't sound the same. The difference is orders of magnitude smaller than between different speaker models though, or probably even just moving the mic a bit.

ecc83

Not likely but if every you get the chance...With  someone blasting the beans off a 4X12 cab, listen to it wearing 'industrial' ear defenders. These will cut out virtually all the mid and HF and reveal the sounds of the cab I mentioned.

Dave.

Cirrus

The volume of air sealed behind the speaker affects the way it moves. A closed back 4x12 has more volume of air behind it to compress and expand, so the speaker is more free to reproduce low frequencies (these require bigger movements of the cone). It's also more free to continue to resonate after the signal driving it has stopped, and the physical dimensions of the cab's interior - top to bottom, front to back and side to side - have their own resonant frequencies that the enclosed air "wants" to vibrate at. These are lower the bigger the cab is.

All that means the exact same speaker will move differently depending on what cab it's in. All else being equal, 4x12s literally sound bigger than 1x12s because our ears know to pick up on those cues.

Of course in music and recording, it's rare that all else IS equal...

ecc83

Another thing about a speaker in a 4X12 is that it is always wired in series with another. This is an absolute no-no for any kind of hi fi and virtually buggers any electro-magnetic damping of the cone (but that's the sound we have come to love!) Mind you, valve guitar amps don't give much damping anyway so it might not matter in practice?

And BTW OP. this is FAR from a "stupid question"! Getting the sound you (think?) you want from a mic and 'in the can' has caused thousands of people thousands of hours of blood,sweat,tears and bad language.

One tip that seems to be pretty universal? Use LESS distortion than you think you need.

Dave.

fretmeister

ecc83 said:

One tip that seems to be pretty universal? Use LESS distortion than you think you need.

Reported.

ecc83

Whaaaat?! Am I being put before the beak? What did I do? I might talk bllx sometimes but surely not a hanging offense?

Dave.

DartmoorHedgehog

ecc83 said:

Whaaaat?! Am I being put before the beak? What did I do? I might talk bllx sometimes but surely not a hanging offense?

Dave.

Pretty sure it was a joke Dave - about daring to tell guitarists not to use maximum distortion  

(I'm on your side with that one BTW - the other guitarist in my band used to call my dirty sound "clean")