iPhone7 Stereo High-Low Amplifier

thingiverse

Passive amplification is amazing for what it can do to the audio from a tinny little speaker. The iPhone7 adds a stereo speaker at the top of the phone face alongside the previous speaker on the bottom of the phone. This passive amplifier has pickups in both locations to reproduce the stereo sound and double the amplification. Also, many amplifiers are quite tinny in their amplification because they expand the cone very quickly. This amplifier is all about length, the pathway for each high band amplifier is 200mm long and expands 8x over this length. The mid and low-band frequencies are treated to a 400mm path expanding 5x over that path. The lower expansion over a longer distance helps the low band amplify better. While not the same quality as a good Bluetooth speaker, it sure is a lot more fun to build!