Can this be doped ?

[Dr Bunsen Honeydew]

So a famous *speaker designer* is at odds with what Stu hears - I know which one I trust. I have met too many speaker designers who are complete arses to fall for that. All they are interested in is keeping their jobs, they spend more time trying to bullshit the bosses than bullshitting us - same mad corrupt industry as always.

[karatestu]

You are probably right Dave. Maybe why I had to keep adding more and more bison kit before and then they sounded totally lifeless. They are not right now but I am going to play some before giving up.

The doped Kevlar drivers will probably be the only way to a truly satisfying sound with these. Some modification will be needed however as they are slightly smaller than the original ones. That was one of the reasons I was trying to persevere with these aluminium ones. Time to get the chainsaw out ?


All part of the journey.

[Vinyl-ant]

I found something similar to what dave mentions with Mark audio chr70s, metal coned full rangers. Had them in a pair of mltls I designed. They were pretty good up to a point but once they let go and the cone hit resonance a certain frequency all hell broke loose with them. They went from nice to very shrieky and awful. I had them in pairs in series (4r drivers) and as soon as they went near breakup they were bloody awful. Because they were small the shriek-point was right in the voice band so vocals went from nice to unlistenable at the drop of a hat.
Swapped them for chp80s instead and added a tweeter with cap and the speakers were ok. Perfectly nice, just didnt do anything for me so they went to the tip

[_D_S_J_R_]

So a famous *speaker designer* is at odds with what Stu hears - I know which one I trust. I have met too many speaker designers who are complete arses to fall for that. All they are interested in is keeping their jobs, they spend more time trying to bullshit the bosses than bullshitting us - same mad corrupt industry as always.

He was confirming what Stu has found as far as I can see...

Doping paper, plastic or Kevlar woven ones primarily, he agreed wholeheartedly with your findings and listening on cones made of conventional materials, so no challenge whatsoever! We were talking metal cones specifically and how much more difficult they are because of their different characteristics making them more difficult to deal with, that's all. I was responding to Stu's comments and his findings and thought the info might be useful. Apologies Stu if it wasn't.

[karatestu]

I think i am going to have to admit defeat with these aluminum continuous cone (no dustcap) drivers. As i have so many projects on the go i am going to put the inductor back on the mid bass . That and a 3.3uf electro cap was all they had in them originally. So these will be partially doc modded.

To recap what i have done;

1) removed wadding
2) removed some internal wood with a chainsaw
3) stuck lots of 7mm and 8mm steel inside
4) blocked the port
5) changed 3.3uf electro cap for a russian pio
6) doped the inside of the tweeter's dome with plastidip
7) doped the exterior of the mid bass with plastidip
8) soldered the internal wiring to the drivers
9) sealed all joints


So i will mount the crossover components (1 inductor & 1 capacitor) on the back of the speaker externally as i dont want to lose anymore internal volume - the russian pio is massive. Its a shame that the bison kit did not work. I had to add more and more and more and the thing ended up lifeless and dull. After removing the bison kit (soaked in paint thinners) i sprayed the mid bass with plastidip just to see what that did. It was not too bad but the mid range was still over powering. Fun to listen to for a while but annoying in the long term.

At least i have LOADS of steel in there, removed wadding and blocked the port. Learned a few things and i am very satisfied with how much they weigh (extremely heavy for a small stand mount). Maybe in the future i will swap the mid bass out for a doped kevlar but don't hold your breathe. Too many other things to faff about with.

Stu