This instructable is for a two way speaker switch designed to allow 2 stereo audio amplifiers to share 1 set of speakers (one at a time). Note that because this is just a passive switch it can also be used to switch 1 amplifier output between 2 sets of speakers.
In my case I wanted to share a pair of rear surround speakers between a surround sound amplifier and a bluetooth amplifier fed from an Echo Dot. By toggling the switch I can have the Echo Dot playing through good stereo speakers or revert back to normal surround sound usage.
I chose to use a manual toggle switch as described here as that suited my use but there is room in the enclosure to replace the switch with 2 miniature DPDT relays + remote control if required.
Step 1: Parts List
- 3D printed enclosure (https://www.thingiverse.com/thing:2476819)
- 3 4-way push loudspeaker connectors (available on eBay)
- 1 4PDT miniature toggle switch.
- 12 push on blade connectors
- Red and black hook up wire.
- 6 2.5mm self tappers
I was originally intending to solder directly onto the loudspeaker connectors but found with the parts I got that these seemed to be steel and would not take solder. So I used push on blade connectors instead. If the speaker connectors are tinned / solderable then these parts can be omitted.
Step 2: Prepare the Enclosure and Switch
Print base and lid of the enclosure
Mount the 3 speaker connectors using self tappers
Solder 12 wires onto the toggle switch. Use red and black wire, and twist to make it easier to identify the pairs. The central column on the switch will be going to the output (feed to the speaker) and the outside columns will be the feeds from the two amplifiers.
Cut the wires to length to be able to connect to the terminals with a little bit of wiggle room.
If the speaker terminals are non-solderable (like mine) then attach the blade connectors. The blade connectors I had were really for crimping but I cut off the insulation and most of the crimp part and just soldered them on. They took solder fine. If the blades feel a bit loose going onto the loudspeaker contacts then just squeeze them with plieres before fitting to give a tight fit.
Step 3: Final Hook Up
Put toggle through enclosure hole and lock into place with a nut.
Push the blades (or directly solder) the wires onto the speaker contacts. I use the bank opposite the switch for outputs and I made the right speaker of each of the 3 banks the right most pair when viewed head on. This makes it easier to remember how to hook up the amplifiers and speakers. If using it for one amplifier feeding two sets of speakers. then the amplifier would go to the set opposite the toggle and the 2 pairs of speakers to each side.
One can do a test at this stage with a meter checking for continuity between the inputs and outputs for each toggle position.
Slide lid onto box.
The 3D print has an optional thin flat plate which can put onto the switch mount before the nut. I use this so I can hide the enclosure behind a piece of furniture with all the wiring hidden and just the toggle switch showing.