Adding Bluetooth to your car/home stereo for $7

Here is a quick afternoon project to update your stock tape player/auxiliary input in your car (or home) stereo. I did this with some free time yesterday afternoon, and it only took me about an hour (including wiring in an additional power source).

Let's get started. First things first, if you have an Aux-In on your deck, you can skip this set. If you have an older vehicle like I do, tape player adapters can be had for peanuts. I think I got this at Target about a year ago, and it works great. Some will argue the sound quality isn't worth it, but I find it is just as good as some CD players by comparison.

Pro tip: Here is a shot of the inside of the adapter. I took it apart about a week after purchasing it because I noticed a terrible squealing noise coming from the tape player. I know most tapes emit a noise, but there is no tape actually being spooled up/down, so there was no excuse. I removed all the gears, and bam, the the only sound coming from my radio was my music. The only reason I can think of as to why they even put the gears in there to begin with is- and im just guessing- maybe some tape players require both spools to rotate at the same rate, just as it would if there was tape being transfered back-and-forth. So make note of that possibility before dumping the gears; thats why I took the picture in the first place (to reference).


Ok, now we have a clean source of input to our deck, but this isn't 1998, we don't need wires all over the place. Here is a screenshot of just one of many bluetooth receivers. This is what is going to be doing all the work. As you can see, it costs very little, so I was willing to take the gamble if it didnt work, and considering range wasnt going to be an issue, I figured it just might work out (first impressions on quality at the end). 

The setup is straightforward, there is a standard 3.5mm audio input at one end of the dongle, and a male USB connect at the other. Plugging the USB to a power source (i.e. cell phone charger) powers on the device, and begins listening for a bluetooth source (as indicated by a rapidly blinking LED). Once paired, and every time you power on the device after, it will act like any other bluetooth speaker/headset and begin forwarding the source's audio to the device (then to the 3.5mm output). Simple as that.

Thats it. All that is left now is cleanup. I like to keep things tidy and hidden; I could have settled for having the audio cable hanging from the tape deck, and the bluetooth receiver plugged into the only outlet in the car... but gross. Not to mention it would kinda defeat the purpose here.

Routing the cable behind the bezel require very little extra work, and makes all the difference in appearance.

Audio input routed under and inside the center console.

Bluetooth attached to a car charger, attached to a 12v outlet. I wired the outlet to cut it's power when the car wasn't running, since there is no off switch on the dongle. (Yeah, that's electrical tape. Yeah, I'm gonna replace it with butt connectors.)

Everything bridged together...

Tidy up the console

All done.

There you have it. With very little effort and very little cash you can add wireless connectivity to any stereo that already has an auxillery (3.5mm) input or accepts tapes. Now, It looks like there is enough room inside the hollowed out tape adapter to house the bluetooth receiver (without it's case), all that would be required then is a power source which would be easy enough, but I was going for simplicity here. Maybe another afternoon...

Notes on quality:

 Don't expect bose or beats quality here, it is $7 after all. That said, the highs are great, the mids aren't bad, and the bass is... there. You'll want to tweak the equalizer on your source, and if it's a phone, go ahead and look into getting an equalizer app; that should solve issues there. After tweaking the levels on my phone, it sounded just like it did when it was hard-wired to the tape deck- A.K.A great. If you're adding this to a hi-fi system, you probably wont need to do anything different. I already had mine going through a seven band EQ, so bass wasnt really affected.