I have since decided this is NOT a great idea. Due to it being an amplified audio source, there is clipping on the output at 100% volume. This was not readily apparent on my home theater setup, but when plugged into other output devices it was. I then started seeing the same issues with the output to my receiver while playing music with a heavy bottom end.
A way to fix this issue is to review this guys guide and use the resistors like he did. I will be posting an update to this soon (maybe). https://www.reddit.com/r/googlehome/comments/7ioe2u/i_added_an_aux_audio_port_to_the_home_mini/
So a while back I picked up a Google Home Mini. So far it’s been great. From reminders, to weather, streaming music, cooking timers, facts… you know all the stuff the thing will do. But there is one thing, above all else, that my family uses it for, and that is streaming music. While the sound is impressive for such a tiny unit, I still find it lacking. And although you can pair two of them up wirelessly and use them as a stereo pair, I desired something with a little more umph. I wanted to be able to hook it to my receiver. But without any kind of external analog audio in/out, I was out of luck. Until the new wore off…
My home theater receiver is kind of old. About 10 years. Way before wireless things were mainstream. It’s a good unit. 7.1 at 110w/channel. I have it paired with some pretty hefty speakers and a sub. While not a blue-ribbon setup, at peak levels (with no distortion) you can hear it outside my house through the brick. With that kind of sound output, I would much prefer to be able to stream music through it. Sure I can fire up the Xbox and stream Amazon music from there; but I have this nifty voice-activated doo-dad.
Let’s see if we can break something!
Materials required:
- T6 Torx Bit
- T9 Torx Bot
- Plastic Spudger (or equivalent)
- Razor Blade or Exacto Knife
- Soldering Iron & Solder
- Hot Glue Gun
- 3.5mm audio cable. (Mono or Stereo)
- Fine Tweezers
- Helping Hands of some type.
- Marking Pen
- Multimeter
Thank’s to the Google Search I found a handful of people have already hacked the Mini, so it was easy to see how it comes apart. None were too crazy detailed, so I will break it down step-by-step in this article. I had also not been able to find anyone who had performed the same mod. Similar, but not the same.
So, here we go… the Mini.
From reading online, it seemed that the four screws holding the two halves together were under the rubber bottom. Most other modders noted that you will likely destroy the rubber trying to take it off, which I did not want. So taking note of the other persons photos, I noted that the four screws were in a cross pattern 45 degrees rotated from the micro USB connector.
I eyeballed with my spudger about where that would be and began digging in the rubber for a screw. They are almost impossible to feel from the top, and the manufacturer decided to have a plastic backing on the pad. So it took a bit if poking around.
Found it! Now with that found I could index the other four off it this one using the logo on the bottom as a center point. These screws are a T6.
Spudger again. Marked with a ballpoint pen. Let’s dig some more.
This time I dug around with a steel pick until I could feel the sides of the screw, then tore out around it. Made 4 much smaller holes.
Then I was able to remove the screws.
I then cleaned up the extra rubber with a razor blade.
Now separate the two halves. Be careful because there is a Flat Flexible Cable (FFC) in there. That makes it power up and stuff (FORESHADOWING!).
I again used my steel pick, but this time to gently lift the lock on the FFC.
With that, it is time to take out the four screws holding the speaker in. These are T9.
Again, be careful separating the two halves as there is a speaker connector going up to the PCB.
Disconnect it.
Now to separate the speaker reflector cone thing? from the top cover. Switch back to your T6 torx.
And apart. There are no cables in between these parts.
There on the right you can see the audio connector, just begging to have something soldered to it.
The PCB has adhesive holding it to the top cover. Use your spudger to gently pry it away.
Those black o-rings are actually super sticky. They are great to keep the piece steady on the bench, but also a pain to pry up from the bench!
Donor Cable. (I found a white one right after I finished the project.
Headless donor cable.
VERY CAREFULLY strop off the sheathing to expose the cables. I recommend cutting shallow and working the cable off. At this point, the cables are coated in lacquer. I started by carefully scraping as much as I could off without damaging the wires.
This is enough lacquer off to be able to use a multimeter to test the continuity of the cables and 3.5mm jack to make sure I know what’s what. The rest of the lacquer will come off with the soldering iron.
I soldered the Right and Left channels together since the Mini is a mono speaker. This way, my receiver will still play out of both left and right speakers.
Now I reassemble the speaker loose (no screws) to map out a path I can run my cable.
I figure I can route it next to where the speaker plug is almost all the way, so I clam it together and use that cable as a guide for marking the base.
First thing, I drill with a small drill to establish my hole and angle. I want this coming straight out the side, not perpendicular to the curve.
Next, I enlarged the hole to its final size
Finally, I chamfered the hole a bit to smooth it out. Looks great! (Don’t enlarge the photo.)
Now to move on to the PCB and the wires. I again used the multimeter to tone down from the speaker connector and find additional places to solder the wires. I wanted to stay away from the speaker connector as not to melt it (FORESHADOWING!).
Then I soldered the wires up.
Then I was all like, “Oh no! I didn’t run the wired through the hole in the case first! So I desoldered it, ran the wires through the case the resoldered it. But oh-what-fun, when I tried to disconnect the speaker wire, it pulled right off! ACK!
Nothing broke though. And look at those nice big posts just begging to be soldered to. It worked out well because where I did have the ground wire was flimsy.
Again I put everything together loose for a test run.
I hooked up the “line out” to a Bluetooth speaker that had a 3.5mm jack, and lo and behold it worked!
So now is the fun part that I hate. Hot Glue. When I don’t care, it goes on super nice. When I DO care… well, see below.
This doesn’t look too bad… Until you notice there is a wire going over a screw hole. And hot glue on a contact pad.
Trying to “re-do” hot glue is always a… wait for it… waaaiiiit… a “hot mess”!
Putting everything back together went pretty smoothly. I routed the wire up just where I wanted it to go. As a note, in the picture above the cable is on the left of the speaker cable, but it would have been better suited on the right.
Put the clamshell halves together, being careful to route the cable away from stuff.
Also note, I had intended on adding strain relief to the cable to keep it from getting yanked out, but it is tight running through the case and not really necessary.
Here is the kit all put together. Works like a… uh, no. It didn’t work. I was bummmed.
BUT! I took it apart and I had simply forgotten to connect the FFC. A push and click later, and BINGO! It works great!
All in all, the project took about a lunch break to do, and it works incredibly well. I plug it into the AUX in jack on my receiver and have great sounding, AND convenient streaming device. I listened for about two hours without any issues. The speaker on the Mini also still works, so if my receiver is off or on the Home Theater channel, the Mini sill works at it should. Nothing lost, a lot gained.
I did also try plugging my smartphone, and since 3.5mm cable is wired directly into the speaker header, it DOES play. However the smartphone is not really powerful enough to drive the Mini’s speaker. Plus I don’t know what pumping juice INTO the board would do to it.
For the future?
- I want to try to find a 3.5mm jack on DigiKey that I can squeeze into the case and have a truly slick AUX Out jack.
- I want to build a portable bluetooth speaker setup with the mini embedded.
- I want to try to pair several in an array.
