Recording an acoustic guitar, but want to bring out more of the bottom end fullness? One solution — assuming your guitar has a pickup — is to record the pickup output via a DI at the same time as you record the microphones. When it is time for mixdown, filter the pickup signal with a lowpass filter, so that all that is left is the low end. Shape this further with EQ, perhaps add a dash of compression, and blend to taste with the miked-up guitar tracks. Go lightly; you’ll find that it doesn’t take much of this acoustic guitar “subwoofer” track to fill out the bottom end.