Ian.
What I mean by a 'cube-speaker' is one of those mini HiFi, self contained speaker units. They are rectangular, heavy metal or plastic boxes and usually come in black or white with a matching metal grill.
I've seen some at Radio Shack. I don't know if you have Radio Shack in the Philipines but you may be able to get something similar at your local car or boat audio shop. I have a pair of 'Kraco' brand cube-speakers The boxes measure 6"W x 4"H x 4"D, and don't require you to cut large holes in your interior trim. You only need a couple of screws or bolts for the mounting brackets. You might need to fabricate brackets to custom fit in your footwell area or wherever you decide to put them.

My 250 originally had the Becker Europa Chrome stereo radio with the 4 speakers. The small square ones in the front footwells were bad so I got new ones from Mercedes and they still sounded horrible. So I installed a pair of Sony 6 x 9s in the cardboard covers under the dash. If your car doesn't have room under the dash for 6 x 9s then a pair of 5 or 6 inch round speakers would probably work OK.

Later, my original Becker radio died so I found a Becker Europa Cassette radio at a flea market for $20. It's the later style with the black faceplate, probably from a 1980 240D. It goesn't have the pretty chrome like the older ones but it doesn't look as ugly as alot of modern radios. In my 250 the radio mounts in the black underdash console, so the black faceplate looks OK there.

The original dash speaker is probably a metric size, close to about 3 x 8. It may still be availible from Mercedes or you will need to adapt something else.

Happy Motoring, Mark

__________________
DrDKW