Diffraction, anyone ?

[VantheMan]

Has anyone any opinion about possible diffraction effects on the WD25T ? You know, what with the drivers being so close to each other, blah blah.

In my case, the Millennium tweeter version : At a mate´s (speaker looney) suggestion, I did a lash up with a rectangle around the tweeter, made of foam with a rectangular cutout offset towards the inside edge for the tweeter " to breathe" through and I could swear there is a an interesting difference in presentation. So convinced am I that I have sent off for some thick natural wool felt and hope to make a much better job of it all using 3 layers of 5mm felt.
The felt is real boutiquey designer stuff, guaranteed to be 100% natural wool from pampered sheep. Sold via acraft shop for making soft toys for equally pampered babies like my WD25TEX. At 6 quid a sheet, it´s bound to sound better !

More anon, maybe.............
Happy Christmas to one and all.

[Greg.]

There is a recognised tweeter tweak of putting a foam ring around the tweeter dome edge. Particularly useful for tweeters with wide dispersion characteristics to reduce reflections off walls and ceiling. It also tends to give a cleaner, more precise and focused treble image.

[bob orbell]

So convinced am I that I have sent off for some thick natural wool felt and hope to make a much better job of it all using 3 layers of 5mm felt.
The felt is real boutiquey designer stuff, guaranteed to be 100% natural wool from pampered sheep. - What a shame, I have a large box of this stuff from Hi Fi Collective, I only used a small amount, if anyone would like some, please contact me. Bob

[VantheMan]

I remember buying some diffraction rings years ago when I was using Totem Arros. Their effect was a bit yes and no as far as I remember. A circular hole surrounding a dome tweeter smacks of symmetry and from what bit I’ve understood from what bit I’ve read on the subject, symmetry is pleasing to the eye but the last thing you want - hence some speakers are “paired left/right with respect to the position of their tweeters - diffraction-wise especially when your speakers don’t stand in free space but maybe are near fireplaces, alcoves or bulky furniture whose edges can be doing the same diffraction job as the edges of yourspeakers, the last thing you want is for the sound waves to reach such edges simultaneously. In other words these anti diffraction tweeter felts are, to a certain extent, self defeating if thay have round holes and are positioned symmetrically with the tweeter dome. Wilson Audio even use a starburst cut out in their felt to avoid symmetry.
As you can see I don’t really have a clue so trial and error and gut feeling will be my guide when I finally get myfelt.

[TimN]

Could you upcycle your crappy Linn or Rega felt platter mat? Best use for them baaaa none.

[Chris]

It looks like the felt chosen is an important part, the thickness and absorption properties.

"Even the felt ring around the tweeter is chosen with care, an attitude permeating this speaker’s design ethos."

https://www.tonepublications.com/rev...-loudspeakers/