I'm super excited to jump in and learn more about building an external stereo speaker from an older salvaged macbook laptop. I loved using the laptop to reference how my music sounded to get a better understanding of the playback for people using their laptops to listen to music. Anyway, this laptop has finally died and I would love to repurpose the speakers within (maybe also the class d amplifiers?) and just plug an auxiliary cord and listen. I think this is a fun project yet I'm hitting walls with my understanding of circuits and reading schematics.
I envision removing the left and right speakers from the logic board as well as what powers and drives those speakers (which I believe is the class d amplifiers)
I have found a schematic of these audio circuits and envision creating a circuit board containing these components. I also envision adding a 3.5mm aux input and volume knob to this circuit to input sound and control the volume.
I feel that with the directions of the schematic, adding a volume knob and a 3.5 mm aux input isn't too crazy of an undertaking. Is there anything I am missing?
Is this doable in your opinion? Also any thoughts or recommendations for this project? I feel like the learning curve on this project is extreme but I'm super excited to learn and welcome all feedback and suggestions! Thank you in advance.
Best Answer
You also have to deal with how much of the sound comes from the speaker's enclosure.
Unless you're sawing up and recycling the relevant parts of the macbook case (or re-using the entire case as the enclosure) you're left with a huge problem determining what aspects of the case design really matter and replicating them, or tuning the frequency response of the electronics to match the (ah but how do you measure it?) response of the enclosure you're fitting them into.
This is not trivial and may be quite surprising. Not only will the precise hole pattern of the grille matter, but the designers probably accounted for acoustic reflections off the LCD screen.
Or consider what you are making as an entirely new product with its own sonic characteristics.
The subtleties can fill entire books and while a laptop's speaker will not even remotely qualify as "high quality" in that book's terms, Apple's designers will have gone to some length to make the best of the space and power they had.