Horn for iphone

Hello everyone,

I wanted to 3D print a horn for my iPhone. Mostly just for fun but it should actually work.
I can handle hornresp but obviously i don't have ts parameters, so it's back to the roots (what I can't to).

What can we do with that? How long and big should the horn be and what could we expect in terms of performance.
Is it even possible to do something remotely useful?
LMK what you think.

Measuring the speaker, we probably have an horn throat of 11x3mm

Those are 2 measurements: The upper one is close to the speaker (1cm), the lower one is further away (10cm)
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This ceramic horn is still in production, but it is very big and expensive. Another phone horn made of ceramic but smaller and way cheaper is sold with the commercial name Scaramaz by the Italian ceramic manufacturer Crescentini. If you search the WIPO global design database for application number 005778529 you will find the drawings of the actual product and two alternate versions, they may be of inspiration. The mouth diameter is 150mm and the rectified total horn lenght is approximately 250mm.

This arrangement does not work well on most phones, but iPhones have an unusually good internal speaker almost free from nasty resonances, so the result is acceptable although lacking on low frequencies.

On Thingiverse there are several phone horn projects ready to be printed, but none of them looks convincing. The shape does not look functional, and ABS or PLA need more stiffening to avoid resonances. Also most of them require the phone to be placed vertically on the stand, but due to the new functionality on iOS 17 it is best to place the iPhone horizontally, with volume buttons down and power button up. Do you plan to release your 3D model?

I've also seen adapters to fit the mobile phone over an antique horn speaker (the adapter replaces the base with the transducer), but they aren't commercially sold.
 
The only measurements I've seen have been for a X amount of gain compared to the bare phone. The better ones seem to claim around 10 dB, but none I've seen say over what frequency range. Even one of the patents I looked at didn't have the dB or frequency divisions labeled so you could tell what the device really did.

If you're going to do some actual design work, measurements, and multiple prototypes, you may want to start off in stiff cardboard, just so you can do them rapidly. Maybe you can also be the first person to publish some real measurements showing what different designs do :)