Hello!
I am planning a two-way speaker with the ScanSpeak D2608/913000 tweeter in a waveguide and a ScanSpeak 22w/4534g00. Therefore, I made a test-piece on my CNC-machine, and am asking for comments on the frequency responses at different angles.
The sidewalls of the waveguide enlarge on the contour of a circle with 225 mm diameter. The waveguide itself has a diameter of 225 mm and is 36 mm deep. Find attached an image of the waveguide construction and the prototype.
The measurements shown are gated, unsmoothed, measured at 1 m distance, and at angles from 0 to 90 degrees from top to bottom.
I am a bit concerned about the lack of directionality between 2 and 8 kHz. The 0, 15 and 30 degree measurements are a bit bundled up. What do you think?
Thanks for any comments!
I am planning a two-way speaker with the ScanSpeak D2608/913000 tweeter in a waveguide and a ScanSpeak 22w/4534g00. Therefore, I made a test-piece on my CNC-machine, and am asking for comments on the frequency responses at different angles.
The sidewalls of the waveguide enlarge on the contour of a circle with 225 mm diameter. The waveguide itself has a diameter of 225 mm and is 36 mm deep. Find attached an image of the waveguide construction and the prototype.
The measurements shown are gated, unsmoothed, measured at 1 m distance, and at angles from 0 to 90 degrees from top to bottom.
I am a bit concerned about the lack of directionality between 2 and 8 kHz. The 0, 15 and 30 degree measurements are a bit bundled up. What do you think?
Thanks for any comments!
Attachments
It would be my assumption that the bunching from 2-3.5k is edge diffraction from the narrow baffle. The bunching at 7k is a puzzler, though.
That could be the case. The baffle is 250 mm wide, so that makes sense. I will add chamfering at a later stage.
I am assuming that it could be related to the 32 mm throat diameter. I have a 1 mm lip there, which I cannot really remove. There might also be a small gap between tweeter and waveguide.
From my limited experience I think you have hit the nail on the head! Work on getting it fitting tighter.
If you can't get a perfect fit/seal you might try using a felt ring between the baffle and tweeter. I know some have done that with commercial waveguides that aren't a perfect match for the tweeter. Dampers: Felt Defraction Ring for Tweeters