Dammar!

[badman]

Hi all:

What have people's experiences been with dammar modding paper cones? I picked up a bottle today, and treated some paper with it, didn't notice much change besides the paper getting the 'oil' appearance and smoothness (and smelling good).

Could it all be an effect of the smell of dammar giving positive feelings (or vibes, if you will)? It's used for aromatherapy after all.....

[badman]

So there's nothing to be added? No theories of mechanism? Nothing?

[tktran303]

Well I remember Troels Gravesen used to (or still does?) do experiments with Dammar coating on his paper cones.

If I recall correctly, it usually caused a broadband drop in sensitivity (as expected, since the cone is now slightly heavier) and had a slight affect on frequency response (smooth out some breakup modes (but introduce some new ones)

As a DIYer, I cringe at the thought of applying oil to a expensive driver. Once you apply the Damar, it's kind of a one way street, if you know what I mean.

The other thing is that it's definitely user dependant, and with no guidelines on how much, where, and what coating (Damar brand X purchased in Australia, is often different to Damar brand Y purchased in Denmark) to use, what are the chances of me replicationg his great discovery?

All in all, it seems to be a private affair with not much replicatability. (I think I pulled a George W. Bush there- replicatability- is that even a word?)

IMHO drivers should have been optimally pre-coated at the factory. At least they have hundreds to experiment on and formulate an optimal solution, can ensure consistency of the coating product, and guidelines of methods to coat.

ScanSpeak 15W-8531K- non coated
eg. ScanSpeak 15W-8530K- coated

In this case, the coated version is better:

http://www.zaphaudio.com/5.5test/compare.html

[badman]

hi tktran:

Yes, my impressions have been that dammar seems a purely subjective treatment at this stage, but some experienced modders seem to like it (Thorsten Loesch, Dave Dlugos), which begs the question- how much can it be doing?

Can anyone point to a mechanism for it's working? Is it actually believed to stiffen the cone? Or just improve self-damping? My casual experiments with it on paper seems to have affected little change.

Yes, it'd be nice if drivers were all treated at the factory, those that really could use it. But then, perhaps their design goals are different from ours sometimes, and the 'improvement' is more a matter of optimal customization. And of course, they're on a budget, like all of us, and perhaps the additional cure times, and production and whatnot preclude the use of some treatments for some drivers.

Anyone care to discuss EnABL?

http://www.positive-feedback.com/Iss...ndingwaves.htm

I'm thinking that probably cardstock is the best choice of materials to test this. Seems like an interesting method- what's rather convincing is that he doesn't seem to have fudged his data- the second datapoint doesn't show any real improvement, just a moving of the behavior, it's the third datapoint that does, and even then, there's still points at which the standing waves are higher in level in the treated cone- no free lunch, but still a broadband improvement.

Hm.... while we're on it, anyone have any other thoughts on cone treatments?