SNAIL HORN AMP - Passive Phone Speaker

SNAIL HORN AMP - Passive Phone Speaker

A passive horn speaker for your phone, shaped like a snail shell. No power, no battery, no Bluetooth. Just stand your phone in the slot and the horn does the rest.

HOW IT WORKS

The sound from your phone's bottom speaker drops through small slots into a chamber under the phone. From there it travels through a 290 mm spiral horn that grows wider all the way, and comes out of a 92 mm mouth that faces you. The longer horn is coiled into a spiral, so it stays compact on the desk.

SUPPORT MY WORK

If you like this design, a coffee helps me keep making new free models:

https://buymeacoffee.com/quattrodesign

WHY I MADE IT

Most gramophone-style phone horns are made for one phone model and stop fitting when you get a new phone. This one has a wide slot and a sound inlet under the whole speaker area of the bottom edge, so it keeps working when you change phones.

WHAT TO EXPECT

Clearly louder and fuller sound than the phone alone, especially voices, podcasts and midrange. It will not give deep bass. Real bass from a horn would need a mouth more than half a metre wide, and the phone speaker sets the limit.

COMPATIBILITY

- iPhone 12 and newer (mini up to Pro Max)

- Most Android phones with the speaker in the bottom edge

- Works with a case up to 13 mm thick, as long as the case has an open speaker cutout

SIZE

- Footprint: 220 x 109 mm

- Height: 113 mm

- Phone slot: 92 mm wide, 13.5 mm deep

- Phone leans back 12 degrees for easy viewing

PRINT SETTINGS

Made and tested on Anycubic Kobra 3 / Kobra X. Also fine on Bambu Lab, Creality, Prusa and other printers.

- Material: PLA / PLA+ (PETG also works)

- Layer height: 0.2 mm

- Walls: 4 (gives solid 1.6 mm horn walls = best sound)

- Infill: 15 % gyroid

- Supports: NONE. The horn has a 45 degree ridge top and bottom, so it prints clean inside and out. Turn supports OFF, or the slicer will fill the horn with support you can't remove.

- Brim: 5 mm recommended

- One piece, prints as it stands. Fits a 250 x 250 mm bed.

HOW TO USE

1. Clean any stringing out of the mouth and the slots in the slot floor.

2. Place it on a table with the mouth facing you.

3. Put the phone in, screen facing you, speaker edge down. Push it all the way back so it leans on the backrest.

4. Play some music and enjoy.

Note: there is no charging cable opening. A cable hole next to the speaker leaks sound, so it was left out on purpose.

LICENSE

(c) 2026 Kim Quattro Finstad - Quattro Design. Personal use only.

For other licenses (e.g. commercial use), e-mail [email protected]

SUPPORT MY WORK

If you like this design, a coffee helps me keep making new free models:

https://buymeacoffee.com/quattrodesign

Thanks for printing! Post a make, I'd love to see yours.