To me, this is the real reason to do a cassette — all the incredible DIY options and customizable pieces. When I think of a band doing a DIY cassette, I think of them handwriting the album name on the cassette label, I imagine cute doodles on the case, I think of them writing a “To: Fan” “From: Your favorite band X” There are just SO many ways to customize this and put a real DIY feel to it that can skyrocket the connection you make with your fans.
Avoid this by following the 3:1 rule, which stipulates that the distance between multiple mics should be at least three times the distance between the close mic and the source. For example, if you have a close mic 8″ from the sound hole of your acoustic guitar, your ambient mic should be at least 24″ away from the other mic, or the same sound source. The big change in amplitude between the two signals will mitigate the comb filtering, and you can accentuate this by angling the mics in different directions (provided it sounds good).