3D printed waveguides

[augerpro]

Very cool! How do you like the PR's with the SB woofer?

[augerpro]

Finally done working out of town, so now I can get some testing done and answer all the questions piling up.

I've started some designs for the Scanspeak D3004/6600 and R2904/7000. These will all be 6.5" width mouths and greater as I've found these large diaphragms just don't behave well in small waveguides. And with the extended low response and great HD behavior, it just makes sense that most people would be looking to cross these tweeters low. I'm also going to revisit circular mouths. When I first started testing performance went up a lot when I switched to elliptical mouths, but other design properties were still unrefined and so I want to make sure elliptical is still the way to go with my current knowledge. Also, I've seen some people get reasonable results with tweeters I've used on circular waveguides like the Visiton, and I want to understand why that is.

First up are the 6.5" waveguides:








The circular mouths are looking pretty good. I'll need to continue this investigation and create versions for the other tweeters I have once I nail down some best practices. Another thing to note is I'm going to improve the tweeter/waveguide interface. Right now there is a bit bigger gap than I'd like right at the throat.

[augerpro]

Almost forgot I did a circular guide for the T25B. Here is a 6.5" followed by the elliptical version from a few months ago.

[augerpro]

I've updated the T25B files at my website to include the new tweeter interface from a few pages ago.

[augerpro]

New designs! This round I improved the tweeter interface for the Scanspeak drivers and the results are much improved. I also designed new aspect ratio versions of the 6.5" Bliesma T25B waveguide to investigate a middle ground between my typical 1 : 0.618 aspect ratio and the circular waveguide I posted a couple months ago. I also did vertical measurements to shed light on some recent discussion on the response tradeoff between circular and elliptical mouths.

I'll get the new design files up on my website this week.

[augerpro]

I've also started working with the Peerless DA25TX00 "corundum" dome tweeter. The first results aren't worth posting but confirmed my fear that the challenging throat interface is going to be critical to do exactly right.

[augerpro]

I've posted the files from the last round at my website

[hex168]

Any chance you could take a look at the Peerless BC25TG someday?
https://www.parts-express.com/Peerle...eeter-264-1040

Here is its performance without a waveguide (note the distortion at 96dB, and AmirM's subjective review):
https://www.audiosciencereview.com/f...-review.13624/

The crossover used in the speaker measured above is on the first page of this thread:

https://www.audiokarma.org/forums/index.php?threads/dennis-murphy-pioneer-sp-bs22-lr-diy-modifications.610820/#goto_displaymodes

[augerpro]

Does the faceplate come off easily? Can you take a pic? Be warned I haven't had great luck with fabric domes.

[PWR RYD]

I've posted the files from the last round at my website

What is your website address?

[augerpro]

somasonus.net

[PWR RYD]

Awesome! Thanks Brandon!

[augerpro]

You bet, enjoy!

[TNA]

"I've also started working with the Peerless DA25TX00 "corundum" dome tweeter. The first results aren't worth posting but confirmed my fear that the challenging throat interface is going to be critical to do exactly right."

What are you planning to do for the interface?

[augerpro]

As is usually the case, the throat must be quite close to the outside of the surround for the smoothest top octave, but the faceplate of the Peerless prevents this with any simple design. The fix is easy enough when using CAD + 3D printing, so I'm hopeful the next test will be pretty good.