Purpose of Dome on Tweeter...

"Focal also uses inverted dome tweeters, and you can see the differences in design here,"

Wilson uses Focal tweeters.

"03-13-15: Tls49

If not, why aren't they just pushed in at the factory?

That would be the inverted dome tweeter like Wilson Audio uses."

I thought that was a joke. Pushing the domes in at the factory? How could it not be a joke?

Sorry Zd, slept late this morning, let's get another cup of coffee.

As far as jokes, the best one was what a wife of a potential speaker buyer said when the grill was removed exposing the woofer with a substantial phase plug,

"Oh, little boy speakers"

Myself and the rest of the guys were speechless.

I figured as much. Even I was joking when I was asking why they don't push the domes in from the factory; it was basically for those people who might respond that it has no effect on sound.

I figured that the dispersion would have to be changed when the domes are dimpled and halfway pushed in. I don't get why these sellers disclaim the nicks on the cabinets but say nothing about the dimpled and dented tweeters. I've actually read ads where the seller will claim that the speakers are in excellent shape besides the scuffed and scratched (and nicked) cabinets but I can clearly see that the tweeters look dented in. When I ask about the tweeters being dented the seller will respond that "yes, the tweeters are dimpled / dented but it in no way effects the sound"...

In another ad for a pair of unknown speakers with a mtm arrangement (dynaudio looking drivers) the seller states that he's an audiophile who's had many speakers but these are the best sounding speakers he's heard apart from a blown midrange driver.

I've got an incredible sports car for sale that runs great and is in excellent shape apart from the knocking motor and dents in the hood, doors and trunk. The roof is in nearly perfect condition and the torn seats are an easy fix. Buyer will have to tow the car because it currently won't start because of a dead battery which is an $80 fix and 10 minute repair that I just don't have time to do!

The purpose of the dome shape is rigidity. Domes are very strong for their weight.

At frequencies where the dome is effectively rigid, the dispersion is essentially that of a piston of the same diameter. The dome shape does not improve dispersion in and of itself because it's not a pulsating dome, it's a moving-back-and-forth dome.

At frequencies where the dome is in breakup mode, the dispersion tends towards that of a ring radiator, with the diameter of the ring being the diameter of the voice coil. Some of the inverted dome tweeters have a voice coil that is smaller in diameter than the perimeter of the dome, and therefore have a little bit better dispersion when they go into breakup mode.

A pushed-in tweeter dome no longer has the geometric rigidity it was intended to have, and even if you manage to pop it back into shape, the material may have been weaked where it was creased and so its behavior may be degraded.

Duke
dealer/manufacturer/occasional user of dome tweeters