Acoustic pinboard
I have tried to control diffraction by 45 degree champfers around the tweeter/mid-range cabinets of my speaker projects for a number of years ala Avalon, Peak Consult. As an added measure I usually fit a grille with a wool felt insert surrounding the tweeter and mid-range. However one recent project has such a small distance from the driver to speaker edge, there was not enough room for the grille frame to be a comfortable distance away. I found a damping material with enough stiffness to form the complete grille without a frame. It is called Acoustic Pinboard.
Pinboard | Acoustic Pinboards At Bunnings Warehouse
A single thickness would have sufficient stiffness but I laminate two 9 mm thicknesses purely to get clearance from the drivers.
It is easy to cut and staple the grille cloth to. I cut the 45 degree edges with a combination of tilted bandsaw and sliding mitre saw. The panels run through a table saw ok too. The only awkward issue is using a router to cut the circular holes. Because the board is a polyester mat, I have to turn my router to its slowest speed and move the board through as fast as I can, or it tends to melt and gum up the blade. If you are not fussy about the smoothness of the apertures, I consider a sharp long bladed cutting tool would give less of a problem.
I found it works very well, subjectively as well as my previous felt versions. When I do this again, I will try the acoustic pinboard as an outer frame with a wool felt inner lining.
What I heard was that without the grille, the sound seems "busier". The drivers seemed to throw sounds around the room more, making focus less sharp
With the grille in place the central vocals are more precisely located, there is a clearer layering, extreme left/right sounds are better seperated out, and outside the speaker effects are more precise and easier to distinguish. If I had to pick a one word description, it would be "calmer" but no apparent loss of detail, in fact the reverse.
I have tried to control diffraction by 45 degree champfers around the tweeter/mid-range cabinets of my speaker projects for a number of years ala Avalon, Peak Consult. As an added measure I usually fit a grille with a wool felt insert surrounding the tweeter and mid-range. However one recent project has such a small distance from the driver to speaker edge, there was not enough room for the grille frame to be a comfortable distance away. I found a damping material with enough stiffness to form the complete grille without a frame. It is called Acoustic Pinboard.
Pinboard | Acoustic Pinboards At Bunnings Warehouse
A single thickness would have sufficient stiffness but I laminate two 9 mm thicknesses purely to get clearance from the drivers.
It is easy to cut and staple the grille cloth to. I cut the 45 degree edges with a combination of tilted bandsaw and sliding mitre saw. The panels run through a table saw ok too. The only awkward issue is using a router to cut the circular holes. Because the board is a polyester mat, I have to turn my router to its slowest speed and move the board through as fast as I can, or it tends to melt and gum up the blade. If you are not fussy about the smoothness of the apertures, I consider a sharp long bladed cutting tool would give less of a problem.
I found it works very well, subjectively as well as my previous felt versions. When I do this again, I will try the acoustic pinboard as an outer frame with a wool felt inner lining.
What I heard was that without the grille, the sound seems "busier". The drivers seemed to throw sounds around the room more, making focus less sharp
With the grille in place the central vocals are more precisely located, there is a clearer layering, extreme left/right sounds are better seperated out, and outside the speaker effects are more precise and easier to distinguish. If I had to pick a one word description, it would be "calmer" but no apparent loss of detail, in fact the reverse.