Multiple source ceiling speakers

[tomwarner89]

Hi guys, First time poster.

I am looking for a solution to my ceiling speakers, I am wanting to have them with a dual input;
One from a surround sound system, and the other source coming from a raspberry pi zero with the justboom amp hat attached. I have cabling in place from my surround sound to the speaker location, 20 gauge speaker cable

I already have a set of speakers connected in my kitchen to a RPi which works great for streaming audio from your phone, ipad etc.


Would I need a passive mixer or something else to feed the speakers?

 

[jay32267]

I see the Rasberry Pi Zero has an HDMI connector. I imagine this is an HDMI out. If so, get an HDMI audio extractor. Take these signals and input them into an open input in your surround sound system. This way you keep wiring to a minimum.

 

[tomwarner89]

Hi Jay,

Thank you for your reply, I already have an D IN input to my surround sound from my TV.

I was thinking more along the lines of a passive mixer like this, but with RCA plugs instead of the 3.5mm jacks : https://www.instructables.com/id/Altoids-Tin-18-Stereo-Mixer/

Just unsure on the resistors as they are 8ohm speakers driven from an amplifier so don't want to blow the components on first test run, as the resistors spec'd in this are very small, and my speakers run at about 60w

 

[jay32267]

Hi Jay,

Thank you for your reply, I already have an D IN input to my surround sound from my TV.

I was thinking more along the lines of a passive mixer like this, but with RCA plugs instead of the 3.5mm jacks : https://www.instructables.com/id/Altoids-Tin-18-Stereo-Mixer/

Just unsure on the resistors as they are 8ohm speakers driven from an amplifier so don't want to blow the components on first test run, as the resistors spec'd in this are very small, and my speakers run at about 60w

 

[jay32267]

Here's the thing. Basically you have two "levels" of voltage. You have your speaker level voltage and your signal level voltage. You can use a mixer with signal level voltages but generally not with speaker level voltages.

So if you have a signal level output on your Pi Zero you could use a mixer like in your link. But also you could do the same thing with a simple switch as long as you didn't want to mix the sources which it sounds like you don't want to do that anyway.

...but....if you are looking at speaker level voltages, that mixer probably won't work.

The signal level voltages are on the input side of the amp and the speaker level voltages are on the output side.

 

[americanaudiophile]

https://www.crutchfield.com/p_543AB22/Russound-AB-2-2.html?tp=2997&awkw=75640837465&awat=pla&awnw=g&awcr=47637427705&awdv=c&awug=9004455
If you try using a regular speaker selector that will common the grounds of the surround sound and Pi which may cause problems like blowing up stuff.
20ga wire is really not thick enough even for surrounds so if the opportunity arises change to 16ga.