Does MDF need to be painted?

MDF should be sealed with primer and painted. However, kept indoors and away from high humidity and moisture, it should remain stable for quite a number of years. At some point, you'll notice the exposed edges will start to separate and begin to expose the fuzziness of the fibers. Priming and painting will slow this process down by many years.

A coat of primer, a couple coats of paint, two or three hours. What could be easier? Well worth the effort. Get one of those small, smooth rollers for the paint and yo can get a nice finish.

You could use peel and stick veneer sheets. You can get a very nice look if you use real wood products and have a steady hand on a razor knife (straight cut and bevel together). Takes less time since you don't have to remove or mask drivers.

Take them to your local Panelbeater or Automotive paintshoppe - they can spraypaint them with ie high-gloss black or whatever colour you like.
If MFD is well sanded and sealed and sprayed with high-grade enamel it looks absolutly stunning. See the Revel Saloon speakers - that is how your subs should look after a good spray-job.

Do not use cheap sticky paper or such rubbish...

Kind regards,
Dewald Visser