Bluetooth and Usb Audio System

This project was built in between and alongside the building of my “home(made)cinema” system using nothing but off-cuts, spare speakers and a broken car stereo.

The car stereo in question is the Philips cmd310, a single din stereo which had a iPod dock inside it, the iPod dock on mine had stopped working... well, I say stopped working, but it was more a case the Apple prevented it from working properly... the dock was a 30-pin, I’d moved into a phone with the lightning connector. Using an adapter it still worked and read the iPhone -until the next software update ...all of a sudden “this accessory is not supported”

So the stereo ended up thrown in the pile of unused (and hoarded) audio equipment.

Since I had no need for the stereo or indeed the dock connector, I opened the whole thing up, removed all the circuit boards from the front panel, unplugged and threw away the dock connector, then set about half-sizing the front panel.

What I ended up with was a half-din sized plastic bezel for the control board to go back into.

I mounted that into the top of the box, then the rest of the circuit board was mounted at the bottom.

One channel from the amp runs the 6” speaker (taken from an old and tired home cinema subwoofer) and one 1” tweeter, another channel runs just a tweeter.
Strictly speaking it’s not really stereo (unless you’re only measuring high frequency) but it sounds extremely good as it is. I’d have preferred it to be proper mono, but then there is a tiny bit of imaging (and I do use that term loosely) because the tweeters are connected to different channels.
-I just avoid playing anything from the Beatles on it, or half the song is missing!!

There is a 7aH battery mounted inside, and a charger. As this was made from spare parts I didn’t have a figure8 socket - so I just cut a 1” hole in the rear of the unit and glued the charger directly to it, so the lead can plug straight into the existing socket on the transformer.
Copious amounts of glue ensured this was airtight. The weight of the charger itself would’ve eventually caused it to fall off the back if I’d not positioned it to be resting on the battery.

Battery charge level is monitored via the led battery display removed from the original “diy mobile soundstation” on my first instructable.
This display, and the ignition wire to the head unit are switched in via a 12v illuminated green switch towards the rear of the top panel.

The original head unit had connection for usb, so the cabling for this was extended and the socket mounted as a through-hole just above the half head unit, enabling playback from usb.

Bluetooth range is not fantastic, but it was only ever meant to be strong enough for use it a car. When connected though, it stays connected and sounds pretty decent.

I extended the original aerial socket to be mounted on the rear panel, just in case the mood ever takes me to listen to radio (admittedly, something I never do, but the option’s there)

Also on the rear panel is a bass port, this is the only thing I bought purposely for this unit, it was discontinued at maplin so I got it for 48p or something like that, and I’m glad I got it, mainly for ventilation as there’s a battery being charged in there, but also because if the port is covered up it doesn’t sound nearly as good.


The two followings pictues are : the original head unit (stock photo)
And the primary use of the finished project... having it playing in the background when painting!!

What I regret about this unit is the fact I took no pictures of any stages of making it.

I am usable to remove the sides of the snot without causing too much damage. The bracing inside is what the screws on the sides go into, which would come out easily enough, but the edge trims are superglued on afterwards, I fear that removing them will cause too much damage.

The sides of this unit have some old cabinet handles flush mounted into the sides as it’s quite a weighty little thing.

Originally it had feet on it, but I had to remove these once I’d made the DVD player for the home cinema in my other instructable as I’d run out.
Full disclosure - the feet on all of my creations are actually door stops :) but they do work perfectly well as feet!!

All the rough edges, both on the sides of the cabinet and around the headunit+usb sockets have been tidied up with wood trim. The usual right-angled strips used in everything I’ve made thus far, and sloping edge trim around the component, also the same as the cinema system. As with the cinema, these sloping edges are not varnished, but stained with antique pine woodstain, to contrast with the varnish of the rest of the unit(s)

It was quite fiddly to cut the trims for around the usb socket as you can imagine, using only a junior hacksaw and nothing else.

All in all....

The results are Pretty good - but not perfect.
That’s the whole point in making it myself I suppose.

I could’ve spent £50-ish on something similar (probably) - and it would be perfect... well, the fit-and-finish would be, as it’d have been mass produced in a factory somewhere with precision tooling and exacting tolerances by several machines...
...also it’d most likely be plastic.
but then it wouldn’t be mine...
well, strictly speaking once I’d paid for it it WOULD be mine, but at the same time it wouldn’t actually be “MINE”
-and I’m not being big-headed when I say this -but it probably wouldn’t sound as good, play as loud, or last as long between charges.
Which is the reason I make all the things I make.

The very reason all of us are on instructables.


Thanks for taking the time to read this, and all my other stuff.