Modify a Visaton BG20


I have bought a pair of Visaton BG 20 fullrange loudspeakers.

The plan is to built an open baffle with a Beyma G550 18" pro audio woofer a good(read expensive) fullrange/widerange and a sort of dipole tweeter. AMT or whatever. Maybee two dome tweeters.

But first I would like to see how much I can get out of this cheap FR. Maybee I wont even like the OB sound? So before spending like 800 $ on FR´s I will try these cheap ones.

I have the Beymas allready.

I plan to modify them quit a bit. and listen to them in between every modification.

I have a few questions regarding these modifications. Let me do it step by step.

Here are my planned steps

1. Cut away the whizzer

2. a. Cut away the center dome

2. b. Maybe use some sort of glue/silicone just where the voice coil, the rest of the centerdome and the coen meets. Not sure about this is a good idea. might restrict the high frequencies but keep in mind I will add a super tweeter later.

3. Add a phase plug

4. a. Remove the cone and cut away the suspension??

4. b. Glue pieces of MDF on the outside of the gasket so the sides of the gasket are parallel to each other. This will hopefully stabblelize the gasket.

Glue the cone back back in place.

4. c. Glue a thread from the pieces of MDF on one side to the voicecoil former, to the other MDF accross of the first one back to the voice coil again and finally back to the first MDF. Do the same between the other two opposing pieces of MDF. So the suspension will now be those four pieces of thin thread.

4. d. dampen the inside of the gasket with some MDF that is rounded or has a triangular shape and probably some sort of felt too so the amount of reflected sound from the gasket out through the cone is reduced.

My maine problem is how to get the cone out of the gasket.

I have done it back in the early 90' with four 10 " Vifa woofers and a pair of Seas 6 " woofer/midrange but they had rubber surround not paper like the Visaton FR.

Any suggestions