Phase plug construction and materials

[Volenti]

I have a pair of paper cone phillips drivers that I'd like to add a phase plug to (their a little rough in the upper midrange, hoping to improve on that)

Conviently the drivers have a vented pole so alignment and attachmant isn't a real problem, however I'm undecided on what to make the plugs out of, they'll be turned so either hardwood or alluminium (and possibly brass) are the choices.

any opinions?

I found information on phase plug theory to be quite scarce...

 

[sreten]

Phase plugs, if they do anything, extend the top end on axis
response somewhat, but this is highly directional and is rapidly
lost off axis.

They work by keeping the top end response of the unit more in
phase on axis, at wavelengths comparable to the size of the plug.

So we are talking about ~ 5kHz upwards.

In many speakers they are merely a fashion statement and of
limited use in the drivers application due to the crossover
frequency used.

And don't get me started on phase plug look-a-like dust caps.

I'd suggest the drivers problems are more likely related to the
termination of the cone edge - foam is good for bass but less
ideal for midrange.

Using a metal phase plug will give some minor thermal
advantages, but I don't think the material used will make
that much difference.

JMO 🙂 /sreten.

 

[planet10]

any of those materials should work fine. I like the idea of wood myself. I've been using tweaked lipstick containers stuffed with ductseal and a couple bolts imbedded edge on for magnetic fixing.

dave