Mic placement.

When recording a speaker cabinet or combo amp with a dynamic mic, apply creativity to the mic placement. 

If using a mic such as the SM57 or SM58 keep in mind it's pick up pattern. Its pattern is usually Cardioid in nature. Therefore by placing the mic in the middle of the cone you will get a not so filled sound. However, placing the mic in the lower right or left hand position of the speaker will yield better results. 

Look at the frequency response of the mic and the speaker specs, but as a rule of thumb place the mic's capsule on the lower right or left area of the speaker. 

Understanding "compression" ratio.

What is compression?  Simply put, compression in sound is a way of trimming the levels to take them to a different level and give the signal a different shape. Now, one of the factors in compression is the ratio. So, what is it?

Well just like with any proportion, the ratio in compressor is given by a proportion as well. Therefore, a ration of 5:1 could be understood like a fraction. What this means is that the signal above a certain threshold will be compressed to a proportion of 1/5 the original. So, without getting too complicated:

A ratio of 5:1 in compression simply represents a compression in signal level of 1/5 the original. 

Compress the heck out of what you need :) 

The issue with recording with 2 mics

With recording one sound source such as an acoustic guitar, one needs to be aware of phase issues when using 2 mics or more for the same source. 

A sound wave against another sound wave, when in relationship to the same source could present this problem. Therefore correct any sound issues by playing with the on/off switch that handles that particular channel's polarity. 

Any phase issues could be resolved this way. Another way is by simply making a premix in a board and going into one channel of the interface. 

Great playing!!!