Motor mounted phase plug

[trusound]

So I was bored today and had some crazy sleep deprived idea from the night before..

So I grabbed 2 Tupperware bowls that had a similar shape that I wanted and taped them to the back of the PM6A's...

And to my surprise it made a difference.. not huge or monumental by any means.. but from a subjective level.. I gained more focus and oddly enough my center image raised a foot..

I plan on making a better plug with a better shape this weekend but wanted to know if anybody else has tried the same thing?

SORRY FOR THE CRAPPY CELL PHONE PICS!!!

 

[planet10]

It streamlines the back of the driver... reducing turbulence, and reflected time-smear when in an enclosure and early diffraction in an OB.

dave

 

[trusound]

dave.... I have seen that pic a million times and yet have never noticed that motor shape until you just mentioned it.... lol

 

[twest820]

I've contemplated doing something like this for quite some time but never got around to it. trusound, do you have directivity measurements with and without the tupperware?

Dave, shouldn't it be laminar flow at most SPLs? Off the top of my head I'm not coming up with Reynolds numbers high enough for turbulent flow.

 

[TerryO]

A cone made up of felt might work even better.

Best Regards,
TerryO

 

[planet10]

Dave, shouldn't it be laminar flow at most SPLs? Off the top of my head I'm not coming up with Reynolds numbers high enough for turbulent flow.

Don't know. Just like on a baffle thou, sharp edges cause diffraction.

dave

 

[trusound]

A cone made up of felt might work even better.

Best Regards,
TerryO

strictly just felt? so it's close to being acoustically transparent or a phase plug wrapped in felt?

 

[trusound]

I've contemplated doing something like this for quite some time but never got around to it. trusound, do you have directivity measurements with and without the tupperware?

Dave, shouldn't it be laminar flow at most SPLs? Off the top of my head I'm not coming up with Reynolds numbers high enough for turbulent flow.

Just going from my understanding this should be more laminar flow... I'll get some directivity measurements once I get real plugs made with a better shape and contour..