Wakeboard park "Dock Box" ... design advice needed


2011-12-25 3:21 pm
Hi guys,

So I'm working at a wakeboard cable park this summer and want to get some noise down onto the dock.

I'm thinking about using one of Arjen Helder's new TA2020 bluetooth amps so that people using the cable can come and play stuff from their phones etc.

TA2020 MKII Bluetooth Tripath amplifier 2X 25 Watts 12V fully finished | eBay


The whole thing needs to run off battery so I'll pick up a 12v lead acid to run it.

So the questions;

Enclosure - I want to build something about 12" cubed - is it as simple as just chucking a cube together out of MDF or do I need some internal structure/porting and dampening material?

Drivers - what's a good and fairly cheap option available in the UK? I was going to look at using a pair of 6" component car speakers like Vibe slicks or some such - is their a better option?

Battery life - I'd like to get a good chunk of the day out of the system - the cable operates from 9/10ish till 6pm so 8 hours max at a reasonable volume but certainly not overly loud.

Any other considerations I may have overlooked?

thanks in advance!

I've recently done something* that sounds perfect for what you're after.

* its not quite finished yet, as I'm yet to do the pre-amp. It currently runs out of my laptop.
Its a pair of
55-1455 - -- - DUAL COIL WOOFER 8" | CPC - they'll fit nicely into your cabinet volume, once you've divided off for the rest of the components. Pair of 40mm plumbing pipes cut to ~11cm long provide additional low end.
plus a pair of 3" coaxial drivers from a Kef HTiB system.
plus two of these
NEW MKll TA2024 Fully Finished Tested PCB Power Digital Amplifier Board 2x 15W | eBay

Sounds rather good, and its listenable at around 50m away. Maybe futher: we ran out of park to test it on.

To finish, an active crossover is needed, so that a bluetooth module or MP3 player can be used. Currently its a cheapie 6-channel usb soundcard with Foobar2000 with the crossover plugin.

You'll need a deep discharge battery for optimum battery performance. I use a pair of these as they're the best deal I could find...
With the ~10dB peak to average ratio of music, these should be good for roughly 9 hours. Heavily compressed music will drag battery life down as the amplifiers will be continuously operating near full-power. But with "normal" music with the peaks clipping (a little under 110dB), 9 hours is a good guess. Note this is running both amplifiers from those batteries.


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2011-12-25 3:21 pm
Budget is pretty small to be honest - maybe tops £150

Been looking again at the qubinator specs - just can't seem to work out what drivers I could use as the P.Audio HP10Ws are both expensive and rare - anyone got any input on 10" drivers that would suit a qubinator?


2011-08-04 2:54 pm
You could use a smaller cheaper battery but I once tried a 12V 7Ah with the Helder TA2020 and it would shut down at 80% volume. So I recommend you use a 12V battery with at least 10Ah or more. The more Ah (amp hours), the more hours of music per charge. I ordered a different TA2020 amp from China and it ran for 11 hours at high volume on that same cheap $20 12V 7Ah Sealed Lead Acid battery that would shut down the Helder amp.