Speaker Diffusers

[David R. Carlso]

Needing help in locating info on speaker diffusers. I ran a search and the only things I could find was on wall treatments, what I'm looking for is what you can do to help a speaker have better dispersion of the higher freqs(less beaming). I know there are varous was to due this like the light bulb looking thing you see on some high end drivers, but what else is there for the DIY type person to try?

[kevinh]

http://rpginc.com/


They have a research and library area with some good pdf's Hope this helps.

I have no affiliation with this company.

[bluezzman]

I interpret this poster is trying to widen the sweet spot of the high frequency range with a phase plug type of insert.
tks
scott

[OzMikeH]

Ionovac tweeters have a grille over the front of the horn, I suspect to help widen the beam but I'm not sure.

It's a plastic grille, it looks very similar to that used for ducted Air conditioner intakes and some flourescent light fittings.
squares are about 10mm, plastic is about 1.5 mm thick and the whole sheet is about 10mm thick.

The specific item you are talking about is called a phase plug.
To try it out you can cut the dust cap off and stick an appropriately sized socket on the magnet, (as in socket and ractchet for undoing bolts). Small wooden phase plugs can have several countersunk screws put in the back to stick them to the magnet. for the huge light bulbs they really need to be screwed into a thread tapped in the pole piece of the magnet. People have been known to make a wire frame to support a real light bulb too.

[GM]

http://audioprogress.free.fr/

[David R. Carlso]

Widening out the high freq beaming is correct.
I have come across the socket and the site for the Lowthers, but some where there is got to be some info on slot type diffusers, V-shaped etc.

[GM]

Good luck with that, I've never seen any for use with a wide BW driver probably for the simple reason that an elaborate phase plug will be required to compensate for path-length differences just like in a compression driver.