Introduction: CD / DVD / BT / USB / SD Portable Audio System
If you’ve read about my other instructables, you’ll have read about the redundant emergency lights (well, the batteries from them) and about the demise of the “mk1” portable unit...
As good as it was, it was doomed from the start because of the materials. I’d made it from the back of a chest of drawers, it was covered in a nice looking veneer don’t get me wrong, and it looked the part from the outside - but at the end of the day it was just hardboard, or fibreboard, whatever you want to call it, so it was never really going to be brilliant structurally. Using it outside in the summer caused the majority of it to become unbonded.
The sadness didn’t last long though, as the majority of the parts we re-used to make the home cinema, possibly the first one ever to be made entirely by hand and from wood, the sadness also soon disappeared as that meant I had to built a new one to replace it :)
So, the above pictures are of a couple of the components going in this one, a double din dvd headunit, 2 EVOR04 digital spectrum analysers, some pioneer component speakers and some batteries.
Step 1: Design.
The design was pretty straightforward, and decided by the components. There’s not a lot of empty space on the front panel, especially height-wise, with the analysers mounted above the DVD player. The depth of the unit was decided by the DVD player itself. The width had to be at least as long as the two strips of batteries -and the handle... this handle is from our old Kenwood dishwasher, I removed it knowing I’d use it for something else as soon as it ceased being a dishwasher. It’s been in my shed for about 3 years just waiting for now.
This cabinet has separate enclosures for each channel’s speakers, which had to have cutouts and lashings of glue to seal around the batteries - which span all 3 chambers.
Step 2: The Speakers, the Headunit and the Power Meter
The speakers used for this project are aftermarket fitment for Renault, the shallow mounting required in these vehicles means the voice coil is above the cone, as is the magnet assembly, this makes them ideal for this system as the magnet prevents anything from touching the cones, and they actually look pretty nice with the magnet on the outside. The speakers are 5.25” and actually sound pretty good in their own enclosures.
They also have white LEDs around the back of them to give a warm yellow glow when turned on.
The headunit is just a generic Chinese unit, but is fully featured. There’s not really much more to say about it than that.
The power meter has a 20amp range and is mounted on top of the unit, the shunt which came with it is mounted on the batteries. The power input for this is connected to the batteries *un-switched* so it is on all the time, so it doesn’t need to be switched on the check battery level. The blue backlight can be turned on and off. Most of the time it stays on though.
The head unit is mounted in such a way that no part of the unit is in any contact with the cabinet, just in case it caused the cd/dvd to skip. Thick adhesive foam was wrapped around the outside of the unit and the cutout in the wood was 5mm less than the overall size. The foam is glued to the wood it contacts with so there’s no way it can fall out - despite only being “suspended” inside the cabinet.
Step 3: Building the Cabinet.
I had a nearly full box of wooden “Jenga” blocks which was destined for the bin, these helped immensely in the fabrication of the box, as they provide virtually all of the support for the DVD player, the foam wrapped around the unit wasn’t nearly enough to hold it in place alone, so more foam was added to sit on top of the jenga blocks.
These were also used to brace the dividers between all three chambers. The chambers on the outside house the battery charger in one, and the voltage regulator (for the spectrum analysers) in the other. The voltage regulator is connected directly to the remote output of the headunit. Originally I had the LEDs connected to this, but the power meter soon showed how much power the LEDs were using, so I put a switch on the back for these instead. A second switch was added shortly after - which applied power to the ignition wire on the headunit, as leaving it in all the time was draining 5.5w if the unit was put into standby, but removing power to the ignition wire caused it to use no power at all when the switch was off.
Step 4: Finishing the Unit
Once all parts were assembled I found my problem with the bottom cover... as I was glueing it all with hot melt glue, and because of the 2 dividers (and countless jenga blocks already glued to the sides requiring glue before the bottom cover was put on) there was no way to get enough glue on all surfaces before putting the bottom on, so I cut it into 3 pieces, doing the speaker chambers first, then the centre one.
Step 5: Tidying the Cabinet Up After Completing Assembly
The photo show above is the only photo I have which was taken prior to edging and surrounding the box, it’s of my son watching scooby doo on it.
This picture also shows how wrong the cutting went on the front panel. There is supposed to be another piece of the facia between the headunit and the analysers, but these cuts were too close together for the 5.5mm ply to stay in one piece. Instead it’s ended up being one odd shaped hole with a single piece of the original frame left in place. This one single frame made the surround quite difficult to apply. This is all cut from 5mm pine strip wood.
The edges are all made from right angle strip wood (as are all the things I’ve made thus far - to hide the crude and rough edges caused by cutting everything with a jigsaw... I don’t even have a workbench!!
All the angled edging wood was sanded down to give smooth edges (once I’d made a paper cover over the speakers, analysers and headunit -so they didn’t all get covered in sawdust)
The way it looks in the following pictures is how it still is now, despite it being made prior to me making the whole 7.1 system on my other instructable. The stack system has consumed so much of my time I’ve not even been able to finish this one off!!
I was trying to decide what to put on the wood, I don’t think the “antique or retro” look of the home cinema by way of Satin Dark Oak varnish would have looked right on this.
So I’m painting it satin black, as I have a small tin of it in the shed :)
That’s about all for this one.
Oh, some folk may have noticed that there’s a power meter on the top of the unit AND a voltmeter on the front, this was not an oversight, rather the power meter was an afterthought... I actually forgot I had it, but by the time I remembered I’d already made a cut out for the voltmeter.
If you want any more info on the speakers or to see where they’ve been used before: please copy this into an internet search