There are many things you can do to increase variation, but nothing like double tracking.

Different amps, different cones, different mics.
Assuming you have one amp and only those two mics to work with, I would think your level of variation would be somewhat limited.
Both are similar mics, for one.
Try another mic if you can. If not, try putting one on the back of the amp, if it is open. Remember to invert phase on one of the mics in this case.

The easiest way to check phasing is to switch between stereo and mono when monitoring - if the sound drops out noticeably, you're out of phase.
If there is little change in the density/volume of the sound, you're okay.

The cab isn't open at the back.
I also read that bass drums mics would work nice from the back I have EV RE 27 and Beta 52.

I also thought about putting another mic further back, capturing the whole box.

... but would say using two mics is the same as re-recording?

I assume you're referring to having 2 or more tracks playing the same part.
In which case, no, using 2 mics does not give you anything even close to having two performances.
The beauty of double tracking a part is much more about the slight differences in the playing not the sound.

I'd really suggest looking into reamping if you aren't already using this technique. Once you have a dry recording of the guitar part isolated at the pickup level, the tonal and mixing power you have is incredible. Here is a trick that I have adopted.

Take a single guitar track (say, the L channel rhythm track) and send it to your amp for reamping. You can run the same track into different OD pedals or EQ's prior to the amp to give it a slightly different sound than the R channel guitar track, or you can stack different sounds on top of each other for the same channel using the same reamped file. Huge guitar tones ensue. This is still different than double tracking, but it should give you some ideas to work with.

And to get back to answering your question, double micing a single recorded track has never really accurately emulated double tracking, at least for me. Two different beasts.

Recording is an incredibly time consuming process, even for professionals. Looking for a short cut in the recording process is like going through an express car wash. The microphones you are using to record are perfectly fine for the application, but the truth is that there isn't a better replacement for tracking and stacking. Different takes gives you the variations between tracks necessary to achieve a wider stereo image. Usually reamping is used when the guitar player from a session isn't available and won't be until mixdown is complete, in this case to achieve a greater guitar "presence, depth, or thickness" reamping would be used. Or maybe even recording through two different amps during one recording, using one microphone per source, and having each source isolated from the another. The reamped or dual source signal would then be hard panned, processed, and set milliseconds apart in order to obtain a close effect to stacking (but remember that there may be times when you do want a reamped effect). But if you want a professional sound you have to do what many are unwilling to do, after all that's what sets professionals apart. Track and Stack!!!

i often use multiple mic and amps when recording guitars. BUT it all depends on the songs. If the song has a lot of chugging and fast rhythm playing i op to go with multiple amps and mics and go with one pass at the song. BECAUSE heavy riffing stacked over and over again will only become more mushed up because of the many variations in timing. so this way i get very detailed guitar parts 4-6 tracks worth and many options to blend those tracks. when recording indie/alternative with not so much gain/distortion i always have the player double track the parts because the small variances in the performance will broaden the stereo spectrum.

Dont be afraid to put 2 mics on a single speaker, just make sure you have them equal (as can be) from the grill and let it rip. putting the mics in different positions relative to the speaker ie: one on the center and one on the edge BUT equally close to the grill is an option too. EXPERIMENT, look a the wave draw for phase problems and have a good time

for anyone that wants to hear my explanation of using multiple amps and mics with one performance you can reference my website's audio section and listen to "Lie the World" by Sleeping Shelby. each guitarist did one pass on each verse chorus and bridge with 4 amps and 8 mics (using a Radial JD7 for the splits). in the mixdown i use NO eq other than highpass filter for all distorted guitars.

good luck
jimmy

natural, post: 356778 wrote: no, using 2 mics does not give you anything even close to having two performances.

Quoted for emphasis.

thanks for all the great advice!

Can a person emulate the track and stack process through multi-tracking or sending the single track to a bus with different guitar amps and pedals inserted into the signal path? I use Logic Express which has the guitar amp designer plugins and pedal plugins. so what if a person could...

Record one good track and leave it clean.
Send the signal to two separate (or 3 or 4) buses and input an amp and foot pedal board onto each bus.
Tweak each bus track for the desired sound by amp choice and pedals desired.
Take the regions on one or more of the buses and shift them forward or back in time a few miliseconds or use a plugin to do the same.

Would this work? Maybe it's a lazy way out and wouldn't give as good of a final product. I don't know. Might save a lot of time and be worth trying out.

mdb, post: 358312 wrote: Can a person emulate the track and stack process through multi-tracking or sending the single track to a bus with different guitar amps and pedals inserted into the signal path? I use Logic Express which has the guitar amp designer plugins and pedal plugins. so what if a person could...

That's called tone blending. Lots of reampers do this because they can. Blending different amps is a pretty popular technique in modern metal and gives huge rhythm sounds. Still not the same as double tracking.

mdb, post: 358312 wrote: Take the regions on one or more of the buses and shift them forward or back in time a few miliseconds or use a plugin to do the same.

Comb filtering. Wouldn't sound the way you hope it would sound.