Connect Speaker pHAT to other speaker


Hey Guy’s and Girls

Today I’ve got my Raspberry Pi zero and my Speaker pHAT.
Together with my 1x 3" Speaker 4Ω (5W)…
It’s for my vintage portable radio that was broken so I wanted to make A vintage Pi (portable) radio.

So now I’m wondering how to connect the Speaker pHAT to the other speaker.
Not the small one that’s in the delivery but an other one.
I asume I can just connect the speaker to the pHAT with some soldering.
But can somebody please tell me + and -?

I’ve got the mounting article over here:


It shouldn’t really matter which way you connect it up, with a single speaker. If you had two speakers and wired them up in opposite polarities then I think you might have phase problems, but in your case it shouldn’t make any difference.


O great! So the + and - doesn’t mather for this project?
Where i connect the red and the black side.
That would be great…
Somebody said that I had to figure out where the + side is on the Phat board and what the - side was…
Could not figure it out…


Nope, it shouldn’t matter… connect them whichever way you want!


Hi Sandy,

just a question that fits in this topic. I wanted to use 2x 3W (4Ohms) Speakers with the speaker phat. This adds up to to 6W. Up to how much power can be safely drawn from the speaker phat without having issues with heat or power draw? How should I connect the speakers for the max. output? Thanks in advance.


hello, i have 2 of these ,but im no pro,so i done have full answer for you ,but i will say Speaker pHAT only has a mono amplifier,so i dont think there would be any benefit to adding a second speaker ,but i could be wrong , I also have a pHAT DAC and use it hooked to my home stereo[great sound ] and would suggest using one of them for better sound maybe,of course that depends on what your using it for …


Thanks for the info, Caperjack1953. Yes, you are right that the speaker phat only has a mono amplifier and adding a second speaker might not be a very good idea. I wanted to know if it‘s save to draw that much power from the pi zero for 2x 3W speakers.

I‘ve switched the speaker phat with the speaker bonnet since it has 2 amplifiers and provides stereo sound. It seems to be save to draw enough power for 2x 3 Watts speakers (4 Ohms) with the bonnet.


Connecting two speakers in parallel won’t hurt anything, I’d use two 8 ohm (or higher) speakers though because when wired in parallel two 4 ohm speakers equal only 2 ohms. While two 8 ohm speakers in parallel will equal 4 ohms. I don’t think its advisable to go any lower than 4 ohms.@sandyjmacdonald can confirm or deny that. You’ll just get mono sound out of two speakers. And each speaker will get half the power. If you don’t adjust the volume level, each of the two speakers will be half as loud as the one speaker was. ;) And I’d match the two speakers impedance wise. Don’t use a 4 and an 8 ohm for example. Do that and one speaker will always be louder than the other.


lol, didn’t see your last post until I posted mine. Looks like problem solved and you will have true stereo sound. =)


No problem, thanks for your help though :)