I have just bought a nice pair of Beovox 3000 flat panel speakers. They are in pretty good shape and work well (I have them at work with my Beomaster 4500 + Beogram CD4500). 

What sort of crossover network they have and are there electrolytics to replace? If yes, how many and what ratings? I couldn't find a service manual for them and I have had them only for few hours now so I haven't opened them (yet ) and I don't have a torx-driver here at the moment. They play nicely (a bit low on bass, though they are just against wall on the top of a pile of boxes!) and fit the 4500 system well. I guess they are meant to hung on the wall to sound correct?

Hi Ville

The crossover have in total 5 caps, 2 electrolytic caps, 10uF resp 15uF. 2 polyester types 3.3uF, 1 polyester 330nF. All components in the 3000 are mounted on a small pcb so its very easy to replace. Use some silicon glue to fix the caps to the pcb to avoid vibration noises. Also make sure to get the speaker cabinet airtight again when reassembling. The old foam gasket might be bad. I removed the old gasket and used a tiny string of silicone before reassembling my speakers, not too much because then its difficult to open them up again in the future.

I replaced the electrolytes to polyester types in my Beolab 3000 and 5000 speakers and they sounds wonderful.

You are right, these speaker uses the wall to amplify the bass and are meant to hang on a wall to sound correct. However there is a lot of difference between the 3000 and the 5000 in bass response. I would recommend to use the 3000 together with a subwoofer like beovox cona. In my livingroom setup I use 2 BL3000 and 2 BL5000 and there is plenty of bass and actually no need for subwoofer.

/Fredrik

To finish the story:

After the post above I didn't get to replace the caps until last week. I bought new caps from Martin and replaced them today. The rear of the cabinet is fastened by 10 Torx T15 screws. Between the two halves of the cabinet there is a foam gasket which I removed immediately as it was almost disintegrated. The crossover board is fastened by two more T15 screws and the wires to the speaker elements have connectors so very easy job. Two caps, 10uF and 15uF, 100v, bipolar, to replace. 

I replace the foam gasket by double sided foam tape I bought from eBay, 6mm x 5m roll. The width is a spot-on, it's perhaps a bit thicker than the original. 

It was certainly worth the work; the bass is cleaner and stronger, thanks to the cabinet being better air-tight again. Now I can stand their sound without "needing" the help from the subwoofer, before the bass was just too weak, now it's much better for the speakers of this size. The highs were a bit harsh but now they sound sweet and clear. Clearly much better!