I’ve ordered some things and am about to embark on a 2nd volumio project.
Before I start I’m looking to make this work as well as I can so any feedback is welcome as it’s all still new to me. I’d love any hints and tips. I want to know if you think i could do things better… so please let me know.
My plan is to turn a vintage radio into a volumio player. The radio i’ve bought is like this (can’t figure out how to post pictures!!)
I plan to strip out the old speaker from the radio. I’d then add a raspberry pi (used a 3b+ in the other build - is there any benefit to getting a 4?)
I then was thinking of using the hifiberry miniamp (was also looking at the amp2 - but i thought it might be overkill for the speakers and i’m not planning on using the dials for hardware volume control) and 2 of these
You don’t need to solder, you can use crimp on faston connectors. But, don’t be scared of soldering!
The difference between the speakers you initially linked to and the FaitalPro’s will be night and day. A lot will depend on the space you have to fit the speakers. Do you have enough space in the opening for two 3" speakers? Is the case deep enough to fit the speakers?
With regard to the mono speaker, have you tested the speaker that’s already there? If you have a voltmeter, check it’s resistance. If it’s between 4 and 8 ohm it should be usable. If it is suitable, and it still works, it could be the best speaker to use.
The miniamp can deliver 3 W, GPIO19 output is 3,3V.
If the impedance increases, the current will decrease to a point that it can’t provide enough power to drive the speaker.
As the output voltage is fixed at 3.3V, the power can be calculated like P = (U x U) / R
so if the impedance of the old speaker is 10 Ohm => (3.3 x 3.3) / 10 =>10.89 / 10 = 1.089 W
The justboom delivers 40W, so this means it has more power to drive this speaker as it is powered by a 15V external PSU.
Using the same formula:
(15 * 15) / 10 = 22,5W, that roughly 22 times more power to drive the speaker.