Small Portable 3" Speaker?

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I have been browsing these forums for some time, following projects, seeing different designs etc.

So I thought it was time I jumped in on the action and created a project of my own, by all means I don't know much about the DIY audio business but I am willing to learn and want to get stuck in.

I am looking to make a portable speaker with a 3" driver, I have been looking at the Monacor SPH-30X/8.

Things I am unsure about:
- Mono amplifier in order to power this driver (as most of the amplifiers I have seen only offer 2 channel, the only mono amplifiers kits I have seen are like 7W or less)
- How small the enclosure can be in order to still create a generous sound
- What rechargeable battery is recommended to power such a driver for say 10 hours+

All help will be appreciated.
Thanks in advanced.
 
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Tough one to answer and I'm no expert on speaker design.

Small (and how small is small :)) sealed enclosure usually means low bass output.

(I once had a small pair of rear satellite speakers intended for a car parcel shelf... probably was a 3" driver and the box was sealed and only around 4" square. Those speakers on the end of a 150 watt Pioneer A80 amplifier sounded amazing for what they were but they needed plenty of clean power).

A battery puts limits on things. 12Volt ? SLA type (small sealed lead acid). The voltage puts a limit on the power available into a given load. You can't get more than a couple of watts RMS into a typical speaker from that. A "bridged" amplifier increases that by 4 times (in theory), in practice probably less.

Some very knowledgable folk over on the single speaker forum,
Full Range - diyAudio

so perhaps a new thread there might help on the speaker design aspect.

With a battery you need to make the most of evey volt so efficiency counts. I suspect an audio amp (probably a suitable chip amp) intended for car use might be the best bet for amplification. I'm assuming 12 volts though as you didn't say. For music a small SLA battery would easily last 10 hours on a charge.
 
I'd be happy to provide some dimensions etc if you wanted to build this:

http://www.diyaudio.com/forums/full-range/232393-portable-speaker-hiwave-bmrs.html

I've had friends asking me how much it was to build (probably ~£80-100, didn't keep exact track), and then commenting that it sounds way better than anything you can buy for that money.

Its approximately the size of a medium box of tissues, but sounds better :D

I discuss battery choices and things like that in the thread, feel free to ask any questions here, on my thread, or via PM if you like.

Edit - just realised how old this thread is.
 
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