I was prompted to have a go at building this soundsystem after spending a weekend away with a freind who had a blockrocker portable PA. I decided I must have one, but after discovering they were £130 decided it was a bit rich for me. Luckily I came across a thread on urban75 entitled 'The building your own portable soundsystem thread' and thats what kick started me.
What I used:
1. 2 X Soundlab 6.5" full range speakers (50 Watts) - About £10 each
2. A Lepai TA2020 class T amp - About £20
3. A 12V 6800 mAh Rechargable li-ion (comes with recharge plug but needs a US adapter, also comes with correct cable for to plug straight into the amp)
4. A case, these should be quite sturdy, and some depth with also benefit the sound, I was donated a record flight case that measure 12x12x9, so unfortunately I couldnt fit both speakers on one side, so I decided to have them on opposite sides. Flight case donate by DJ Rerun - but you can pick something similar up for about £20 on ebay ;)
This is the case I used with the speakers already installed
5. Nuts and bolts (8), Speaker cable and connection spades - Picked these up from halfords for next to nothing.
Nuts & Bolts:
Prepare the electrics
So the first thing to do was to wire everything up and make sure I had no faulty equipment. This was straight forward enough, if you've ever wired up a car or home stereo, its exactly the same.
1. Run the battery cable to the amp
2. Wire speakers to amp using cable and spades (chose spades instead of solder to make it easier to swap drives out if they get damaged) - This amp can actually run up to 4 of these speakers if you wire them in a paralell configuration, I am just running to, so stuck with a standard wiring configuation.
3. Plug in a headphone to phono cable to the amp, attach an mp3 player, fire it all up and make sure it works (at this point there'll be no bass, because the drives are not held in a structure, its the box that helps provide the low end frequency).
Installing the speakers in the box
As I dont really have any power tools I took this to work to do, it was quite straight forward. If you are planning on using an aluminium flight case make sure you have metal blades and drill bits. My case is hardboard with a foil coating on (to make it look metal).
1. Place speakers face down on side of box where you want them to sit, and draw around the outside. I then drew an inner circle 1 cm in from the original circle, this is because the speakers have a lip where the bolts go to hold them in place.
2. Drill a hole big enough to fit a jigsaw blade just on the inside of the inner circle
3. Use drilled hole as starting point to cut out speaker hole.
4. Repeat on the other side.
5. Put speakers in place and drill correct size holes for the bolts.
6. Bolt speakers in.
Installing final electrics
This is very straight forward, you basically wire everything up the same, the difference this time is that as I go I Stuck the amp and battery to the inside with velcro, this makes the amp easy to remove if i decide not to use this system any more, and also makes the battery easy to remove for recharging.
And voila, one finished soundsystem, take it in the garden and piss your neighbours off.
I am planning on making some additions to this set up, i have a bluetooh receiver for audio i want to try and install, so i can play music wirelessly from my iphone. I also want to drill a hole so i can pass a cable out to plug into dj equipment. Ill add info to this blog when its done.
Update: Bluetooth headset working, Im just using a Jabra BT3030 dog tag bluetooth receiver on the end of the input cable.
Video of the beast running......