[lumbergh]

That’s the picture I did use, but it’s hard to see the height of the port.

I think I have gotten the other dimensions very close now.

If someone provides measurements of a real conversion kit I can update the model.

 

I am happy with the result of the converted RL 45 and considering the condition of my bass drivers I suspect a lot of them still are in good enough shape to warrant a conversion.

[lumbergh]

Now I have completed the conversion of my RL 45s.

I had scaled the picture incorrectly before when measuring and the original port should be very close to 50 mm instead of 40 mm as I previously though.
Because of the limited space the height of the pipe must be small enough to fit so the resulting area is likely not that much bigger though.

Fb was very close to the target 40Hz when I used the 44 mm port, i.e. the port had the same area as a 44 mm diameter tube.

The files can be found at thingiverse

And this is what it looks like:

I spray painted the front facing side of the plates to get them more air tight.
Acrylic latex caulk was used on the perimeter because it can be removed easily if need be.
Wet room caulk was used elsewhere, for extra mass and damping.

 

[lumbergh]

I tried replying earlier but that must have gotten lost somehow.

Anyway, this is easier than I initially thought then.
I had looked at the schematic for earlier versions of BM 6500 and noticed that the signals to control the tuner were different, but I see now that on later versions they are not.
I’m assuming the static RAM still needs to be replaced too for it to work with a stock ROM though.

Are EPROM files available somewhere?
This would become a bit moot if I need to buy a BM 6500 to get the ROM from anyway.

[lumbergh]

Amazing work! It would be fantastic to get my BL 5000s up and running again.

I’d like at least one kit if they are still available (check your PMs).

[lumbergh]

So a SW version 1.0 Beogram CD 4500 would work then?

I think I read somewhere that the software of at least the Beocord 4500 changed at some point to get two-way.

 

That EPROM sounds very interesting, exactly what I’m looking for, and I think I have an 8032 somewhere.

It is modified for the different static RAM, pinout and no RDS of the BM 5500 then?

And where could that be found? Googling turned up nothing.

Both file or actual EPROM would work for me.

I suspect though that it would be possible to modify a 16k ROM to just react to a different address to get it to work, but the communication might be more different than that.

 

I don’t need timer programming so a BL 1000 would be the last resort, but I’d really like to get two-way working without the bulky MCP, but that means that I would need to fix my BL 5000s too.

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