Depending on how much time & effort you want to expend, you could make
optimised enclosures for the speakers by measuring (or obtaining from
Pioneer) their Thiele-Small parameters which are used to calculate the
optimum box size and type for a particular speaker. Once you have these
parameters there are various programs available to work out box dimensions &
port sizes etc.

If that sounds like too much bother, just knock up a box of approx 0.5 cubic
foot internal volume and mount the speaker in it and see what it sounds
like. If there's not enough bass cut a hole in the front of the box and add
a length of 1.5-2 inch diameter tube and experiment with the length of the
tube until it sounds better, or you might not need the tube at all just the
hole. You can also experiment with modifying the volume of the box by
bunging in bits of expanded polystyrene to reduce it. BTW don't make the box
a cube or it will sound terrible due to standing wave cancellation etc. Try
to make each dimension of the box different. Golden ratios are a good start.

As BW suggests a timber frame covered in fibreglass would be
strong/light/weather resistant with the addition of some bitumen sheet stuck
to the inside of the panels to make them a bit less resonant. If the
speakers have plastic cones they should be fairly weather resistant as well,
so all you'd need on the front would be a grille to protect them in transit.

"Sam Bond" wrote in message
...
I want to build a portable amplifier for a musical instruments used
indoors and
outside for incest (or morris dancing). As far as I can find, commercial
ones
are rather expensive and wouldn't stand the odd shower of rain.

I've come across a couple of 40watt Pioneer 3 cones speakers and a
"booster"
amplifier (2 * 100w, might be a bit dodgy if I'm not careful with the
levels).
The amp actually has a couple of 600mv inputs so until it's working I
shan't
bother with a preamp.

The question, really, is how to box the speakers. All I can find by
Googling
seems to be hi-fi, large-ish adn not designed for out use.

I was thinking of shelf type chipboard (it seems rigid and comes foc from
the
garage) as MDF is rather too heavy. The odd thing about most of the guitar
amplifiers I've seen are open backed, but most but not all of the bass
amplifiers are closed! I don't want a big box I have to carry it, the
instruments and the battery! The speakers are only 5" in diameter, so how
small
a box can I get away with? Do I fill it with furry stuff? Do I stick a
hole or
even a "port" in it?

Any help gratefully received!

Sam

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