Building a small ghettoblaster for mostly indoor use (TA2020)

[m4uer]

Hi all

I want to build a smaller boomblaster/ghettoblaster for my girlfriend as a gift. She loves to listen to music, but is right now playing music from her computer.

The reason I want to build one myself, is I want it to sound better than those plastic iphone-ghettoblasters you can buy, but I still want her to be able to take it outside to play without having to plug it to power.

I want to use one of the TA2020 amplifiers, because I've heard they are good, and because they are build with on/off power button, minijack and volume control.

I want it to be pretty small - as small as possible, with still a decent sound quality, bass and loudness (even though she rarely plays loud - sound quality and bass is more important).

I have some questions:

Would it be smartest to build it mono? I mean with only one speaker? I thought of that to save space.

Would it be smartest to buy full range speakers, also to save space and weight from a filter?

Which speakers would you reccoment? I am looking at some JBL car speakers, full range 4" ?

I hope someone can help. The most important thing is size and weight - it should be easy to carry around in one hand (I'll build a little handle on it).

Thanks

 

[gmarsh]

I built a little portable boombox a while ago using TI class D parts (more or less equivalent to a TA2020 amp) and 4" coaxial car speakers, powered off a 3.5aH SLA battery, all mounted in a plywood enclosure with a handle on top. I lack pictures of it.

Few observations from that adventure:

- It's not very loud - 4" speakers aren't all that efficient. But it's sufficient for indoors, or a "campsite" radio.
- There's very little bass. Car speakers aren't designed to reproduce bass effectively, as they rely on the cabin gain of the car they're in for that.
- Larger speakers (6.5's, say) will probably work a lot better for both loudness and bass.
- You absolutely have to fill the speaker compartments with acoustic foam, to prevent odd sounding and obvious resonances from happening, and I'd make the volume behind the speaker as big as you can.

But despite all of that, it still sounded excellent compared to almost every iPod dock I've ever heard.

 

[kristleifur]

You could have a look at V-Bro's Megamini for inspiration: 41Hz Audio - Megamini the active little beast