Advice needed - planning audio zone control with OH

I have a five-zone whole house audio system set up. I use Shairport-Sync (Apple Airplay), running on the same RPi3 as openHAB. The audio is piped through a USB sound device to a amplifier, to a splitter, then to impedance-matching volume controls at each zone.

I like the setup; the only frustration is when I want to mute audio to a specific zone. Currently, I’d need to go across the house to manually turn down the volume controls.

It occurred to me that routing the audio through DPDT relays, which were controlled by an OH-connected Arduino, would allow me to expose switchable zones that I could control through OH’s app or with the HomeKit. I already have an MQTT configured Arduino with extra pins.

Here is my question: I looked into commercial products, and found this 8-channel DPDT board. I’m pretty comfortable with electronics in general but am fairly inexperienced with audio. Before I spend the money, I wanted some input as to whether there’d be potential side effects of using this relay board in this way.

My other option is to build my own relay board. I’m comfortable with PCB design and Fritzing (looking for a good project like this to dig into Eagle). If this is the preferred route, I’d appreciate a suggested relay and perhaps a schematic for connecting it to 5v logic.

I did some research and testing, and I think the best (and tidiest) solution is to build a custom PCB, with integrated screw terminals for connecting all the speaker wire and RY5W-K audio relays.

On the off chance someone finds this thread and wants to do this themselves, I’ll publish a GitHub repo with my Eagle files once it’s done.

Interested to find out how you got on @Dome

I have a multi-zone audio setup where I’d like to use a bank of DIN-rail mounted relays to switch each speaker zone. DPDT relays were too expensive so I opted for Omron 5A general purpose relays. If speakers aren’t moved zones, then only one pole needs switched to each speaker - hoping that will work so I don’t need to double the amount of relays :slight_smile:

I’m using Arduinos via MQTT to control things about the house, so hoping to just reuse the same code base for this purpose.

Hah, well, I built the PCB and I couldn’t get it to work. I got frustrated and busy, and never really put a lot of troubleshooting effort into the board. Then, I bought a new house, and decided to get a Monoprice 6 zone amp. FWIW, I do love this amp as you can pipe different music to different rooms.

Sorry I can’t be more help, but if you use pre-built relays you could probably cut out much of the potential points of failure. I haven’t gotten everything set up yet in the new house, but I did have a lot of good luck with Arduinos/Particle boards and MQTT.

Let me know what you come up with!

For my lighting and heating controllers I’ve used old consumer units (with DIN rails) to house cheap ebay relay boards connected to an arduino and w5500 ethernet adapter. The pre-built relay modules do make it really easy and are powered with the same 5v supply as the arduino.

For audio, I’d like to use ‘proper relays’ to avoid killing the sound and also audio seems to be a low voltage, high current application so this seems to fit better in my mind.