Tweeter modification

[5th element]

I have always wondered if the cones on B&W tweeters and some midranges were really something to shout about or just a gimick designed to sell more speakers. Anyway a few months ago my dad discovered this stuff called polymorph when wandering around maplins and he purchased a tub. Today we were adding some moulded bits to his bike (all about aerodyanics etc) and I decided to modify a tweeter I had lying around.

THese were sold to me about 4 years ago as Morel MDT30s from wilmslow audio, they had the MDT30 stamp as a sticker on them and no other markings. They dont look like MDT30's but who knows its only the faceplate which looks different.

OK well I removed the plastic cup these come with, a really simple affair without any stuffing inside. Anyway I then moulded this plastic stuff completely free hand to the reverse of the tweeter and came up with this (see picture). I am yet to measure them but listening to them with a highpass at 300hz 1st order (single cap in series) the results are promising. I should have compared it to the other one but all in good time. I will post back when I have measured the two and compared them.

[SY]

It's a squid!

[pinkmouse]

This may mean nothing to our foreign friends...

[5th element]

ITs a squid haha, Ill get back sometime, hopefully tomorrow with measurements of this thing in comparison to a non modified version.

I would have thought that if conical tubes on the chamber of a tweeter did give much better performance that all the best tweeters would come with them, I shall see.

Pinkmouse, if that nero thing is from danger mouse then I dont really get the joke I barely remember watching the show when I was younger. If however you are implying that my tweeter looks like that white catterpiller then I get it or maybe I dont It premiered in 1981 I wasnt even born yet

[Vikash]

Penfold ruled.

I don't understand why you're putting the squid on the back? They don't need an enclosure, and it's not in the right place to have any dispersion/diffraction benefits. So i'm stumped.

Is DM your cousin PM?

[5th element]

Originally posted by Vikash
Penfold ruled.

I don't understand why you're putting the squid on the back? They don't need an enclosure, and it's not in the right place to have any dispersion/diffraction benefits. So i'm stumped.

Is DM your cousin PM?

I simply had the materials available to try this, B&W think its worth doing, so I thought Id give it a go. I can certainly try listening and measuring dipole, that might work best anyway. Or with the tweeter in its own separate enclosure with very large internal volume relative to the tweeter as to be equivalent to free air.

[pinkmouse]

Did you run it through SW yet? The B&Ws are also stuffed, you might want to try that. The other thing is to try modeling the with MJKs software, IIRC, there is a sheet for terminated lines.

Originally posted by Vikash
Is DM your cousin PM?

Nah, He's a domesticated white mouse, I'm more of a wild and ferocious dormouse...

[Puggie]

Originally posted by Vikash
Penfold ruled.

I don't understand why you're putting the squid on the back? They don't need an enclosure, and it's not in the right place to have any dispersion/diffraction benefits. So i'm stumped.

Is DM your cousin PM?

If I understand correctly, he's taken the rear chamber off the tweet so its no longer a sealed unit and replaced the realed chamber with a tapered pipe.

[Vikash]

Originally posted by pinkmouse
Nah, He's a domesticated white mouse, I'm more of a wild and ferocious dormouse...

Meet your nemesis:

Ferocious? By comparisson your avatar looks more like he's escaped from an institution.

Originally posted by Puggie
If I understand correctly, he's taken the rear chamber off the tweet so its no longer a sealed unit and replaced the realed chamber with a tapered pipe.

oh right. I didn't know the B&W's were open backed into those cones. I just assumed it was for looks on the tweeters. It'll be good to see what results you get 5th.

[Vikash]

Originally posted by 5th element
I can certainly try listening and measuring dipole, that might work best anyway.

Is it really dipole, since the dome surface area is completely backed by the top of the pole piece. Opening the chamber (or altering the encosed space behind a dome tweeter) would seem to have little benefit in terms of back wave reflection, unless the pole had a considerable size vent perhaps.