Sometimes, getting that narrow-band, old-transistor-radio type tone is just what a song needs. Many EQ and filter plug-ins offer some kind of “telephone” setting, but if you want to have some fun getting that effect in a more hands-on, old-school analog way, here’s a trick you can play around with: mic up a set of headphones!
Begin by recording a track into your DAW as you would normally.
Once you have your source track laid down, place your headphones, connected to the headphone out on your audio interface, on a desk or table, and lay your microphone between the earphones.
Create a track and set up to record the microphone.
Solo the track you want to process and play it back through the headphones with your monitors muted. The idea is to use the microphone to capture the sound coming from the headphones onto a new track.
The result will be a track that is your original part filtered through the headphones. It should sound narrow-band and lo-fi. You can try all kinds of fun miking tricks, too:
Try different types of mics and different polar patterns.
Try different types of headphones; cheap, expensive, closed ear, open ear, more accurate, less accurate.
Place the mic on a mic stand and hang the headphones over the mic.
Try different mic positions in relation to the headphones.
Move the mic away from the headphones.
Place the mic off-axis.
Experimentation is the name of the game!