damaged cone usage (push push?)

[planet10]

phase plugs

Shoog has the right idea.

These are a nice little driver. They need a bit of puzzlecoat on the front or back (or both) to damp some HF ringing. (after my experiments with them, a fellow i corresponded with tried a large number of cone damping materials and puzzlecoat worked best).

An externally hosted image should be here but it was not working when we last tested it.

Picture from my 1st MCM 1855 project

Do a dustcap-ectomy on a 2nd driver. That will make them a bit better. Then add a phase plug to fill the hole (to stop the soup can resonance in the cyclindrical cavity). A nicely shaped wooden or plastic phase plug can give additional benefits but a cyclinder of wool-felt works too.

Then go ahead with the push-push. Then you can rotate them a 180 degrees and compare no cap to capped.

The 1st thing i did when i got my batch of these was to remove the dustcap (my lab is littered with dustcapless drivers)

dave

 

[capslock]

Just saw a post on a German forum where somebody claimed the leakage in drivers with phase plug and a basket that is open behind the spider (e.g. Excel) was so big that the Q of any sealed design became very poor and that in a ported design you could acutally hear the air going through the gap between VC former and phase plug.

 

[kneadle]

I have two options, then:

1) Let Planet10 do it first and tell me how it goes.

2) ask, "is a phase plug permanent, or can I try it to see what it does?"

Thanks,

Dave

 

[planet10]

1) Let Planet10 do it first and tell me how it goes.

You might wait a while

2) ask, "is a phase plug permanent, or can I try it to see what it does?"

If you use the steel washer method, you can install & remove the phase plug as often as you need -- just be gentle and the plug can't have too high a mass.

dave

 

[planet10]

Just saw a post on a German forum where somebody claimed the leakage in drivers with phase plug and a basket that is open behind the spider (e.g. Excel) was so big that the Q of any sealed design became very poor and that in a ported design you could acutally hear the air going through the gap between VC former and phase plug.

You also have to worry about leakage thru the surrounds (cloth surrounds) and retransmission of yukky noise from vented pole-pieces.

Another reason to look at low pressure enclosures (open baffles, TLs, Voigt pipes, aperiodic boxes)

dave