USB-A Powered soundbar
I am new here and new overall in the DIY game. So please be gentle with me.
I'm trying to make a 3d printed DIY soundbar that would be using USB-A for power and signal from a computer screen. For a perfect example, I can use a soundbar Dell AC511m the only problem with that one is its small size and low RMS power (only 2x 1.25w).
I would like for mine to be bigger and more powerful while still using the same power and signal source. Can anyone recommend a good amplifier board and a pair of good speakers that would work on USB power alone?
Should I use a woofer or tweeter too? Please help I don't know what I am doing but I am ready to learn.
USB is quite limited (until you get to
USB 3 but that’s a whole different animal) so that puts a hard limit on the total system performance (hence why the Dell is so limited).
In pure DC terms you have 2.5Ws of peak power above which the internal limit kicks in. 5W on some systems but it’s not a guarantee as I recall
I’ve used some very “loud” class D amps but the actual amount of sound is determined more by the efficiency of your speaker drivers. Adding an extra driver (per channel) is more efficient in terms of reproduction but increase the system loss and moving coil speakers are quite inefficient at perhaps 5-10% actual power transmitted to the speakers converted into sound.
Then there’s the case design. Get that wrong and internal reflections cause phase distortion and even resonances and losses.
USB power is notoriously noisy too, so you’re really looking at a world of pain for no real gain.
If it’s a cheap power supply you’re after, many laptop units can supply 19v (which is broadly standard these days) at many amperes knocking USB 1 and 2 into history where they belong. The 500mA limit was quite practical for multiple devices back in the day - but it was designed for low- power or self-powered devices.
USB 3 devices can negotiate voltage but that requires a controller board in the device.
Take everything I say with a pinch of salt, I might be wrong!
(Cybertruck avatar is a riff on my inability to deliver my designs in reasonable time so far.)