Homebrew phase plugs

[loninappleton]

I am taking another swing at homebrewing phase plugs. I looked high and low for the ones I made but I think they went with the sale of the old RS 1197s. One of the Radio Shacks picked up some dirt during the modding job.

After doing the Damar treatment on one of multiple experiments, I found a good Pioneer that had no scratchiness. It already had the
dust cap off.

The phase plug is made with a craft project wooden egg and some doweling. I'm wondering if the improvement in the new setup I have will make some dramatic difference that peeps report with phase plug.

Last time I didn't get much of a noticeable change. But with the addition of Damar and a new plug ( which I made sure would clear the
path of the cone) may add to the music.

[loninappleton]

The little rascal is coming along but this time through I tried to solve the drill out the itty bitty screw hole problem without a drill press.

I have lots of old screws from computer cases. These are both small and have flat heads like Conformat screws: flat heads that sit flush.

Over drilling the hole with a brace and bit allows the computer screws to be just pushed in to check level and maybe permanently affixed with a bit of glue.

Countersinking such a recess would be another problem.

Next, painting on a racing stripe to the shaft.

Nah, just kidding.

[loninappleton]

Well with nothing to work with but a hack saw and a clamp on portable miter box, there's a fair amount of elbow grease with sand paper. No biggie I'm not in a rush. Having doctored the stock dowel dimension in this way the plug fits in both the modded Pioneer and an older one I thought was shot. Yay!

The question is, since I am just fooling around-- if I get the system down how long are they supposed to be? I mean these Pioneer are discontinued-- but here's the specs at Parts Express:

http://www.partsexpress.com/pe/pshow...TOKEN=90160100

Other thing is small work requires small tools and adjustments.

A small machinist square would be ideal. With the square end on the surface, a square will reveal how much of a leaning tower (or ziggurat I suppose) you are playing with.

I think I can get the bottom square with a bit of a circular stick on label cut in half-- depending on how much light I can see down there. Without a lathe this is mostly eyeball work.

Quite frankly I never thought I'd get past the problem of a frictionless cone path in previous attempts. I've tested 2 Pioneers and they are both free of rattle with test tones used to check excursion.


One of these modded Pioneers may be worth attempting an Enabl job. That still freaks me out.

[Cal Weldon]

But they sound so sweet.

[loninappleton]

Cal Weldon,

I have a stupid question. Do these jobs ever come out with an odd amount of dots?

[Cal Weldon]

I wouldn't know. planet10 Dave played Santa a little early this year. Those were a set of raw RS 40-1354's that I won at a raffle at the Van Isle diy fest at his place. He stole them back only to feel guilty and return them in that condition. You will have to ask Dave about the pattern.

[Cal Weldon]

As far as your phase plugs go I'm trying to wrap my head around your idea. Are you starting with a dowel and adding the egg to the end so it's sort of a bulb?

[Alex from Oz]

Originally posted by loninappleton
I have a stupid question. Do these jobs ever come out with an odd amount of dots?

No. EnABL on the drivers always uses the same number of blocks (dots). The pattern is scaled up or down according to the size of the cone.

[loninappleton]

I know there's a pdf around someplace for the pattern. I didn't know if that was theoretical or a practical guide.

Thanks Cal.

[Cal Weldon]

It was Alex that helped you, I'm the one with the question about the shape of your plug. Gotta pic?