Directivity Index Focused Builds

[RockLeeEV]

Okay, I know there's plenty of people out here who have done full-on constant directivity speakers with huge horns etc. And that's fine. They certainly have their place.

When I think of most speakers, commercial or DIY, I think of 1" tweeters being mated to 7 inch woofers with a crossover designed around on-axis response.

But when I think of Toole's research, I can't help but think of the speakers it actually produced - things like the JBL LSR6332, Infinity Primus P363, or Revel Salon2. They really use pretty shallow waveguides in multi-way speakers... wider dispersion than an Econowave or Summa but a lot more controlled than your average typical speaker.

So I guess I was jusr wondering what "Toole-style" DIY speakers exist. The ones that are coming to my mind right now are the Troels DTQWT, The various Seas DXT bookshelfs, the Zaph TMM, and that's about it.

I was just wondering if anyone cares to post other such "shallow waveguide" speaker designs worth considering building. Anything out there with an elliptical waveguide? Further, anything with a fancy overpriced beryllium tweeter?

[AllenB]

Of course, constant directivity doesn't have to be narrow directivity. It can be omnidirectional. Although such a speaker would not achieve the same set of goals, it wouldn't necessarily be bad.

I guess I'm suggesting that the most shallow waveguide is a flat baffle. Knowing what we know now...well, I for one will never build a conventional speaker the same way as I used to.

[badman]

Originally Posted by AllenB

Of course, constant directivity doesn't have to be narrow directivity. It can be omnidirectional. Although such a speaker would not achieve the same set of goals, it wouldn't necessarily be bad.

I guess I'm suggesting that the most shallow waveguide is a flat baffle. Knowing what we know now...well, I for one will never build a conventional speaker the same way as I used to.

Beat me to the punch, totally agreed. I can see doing a massively multiway direct radiator with careful baffle design as a near-omni. Think B&W Nautilus.

[AllenB]

Ah yes. I was thinking more a 180 degree design. A dome tweeter could reach low to be met by a very small woofer (that would only be used to around the Schroeder frequency) that was mounted on a wide baffle or even soffit/wall/corner mounted. Or even yet, ditch the tweeter, use a very small full range woofer on same wide baffle for a little pseudo narrow directivity at the top end.

[RockLeeEV]

Originally Posted by AllenB

Ah yes. I was thinking more a 180 degree design. A dome tweeter could reach low to be met by a very small woofer (that would only be used to around the Schroeder frequency) that was mounted on a wide baffle or even soffit/wall/corner mounted. Or even yet, ditch the tweeter, use a very small full range woofer on same wide baffle for a little pseudo narrow directivity at the top end.

If we toss aside vertical directivity concerns and just focus on the horizontal domain, how about a ribbon tweeter crossed low to a 2"dome (IE RS52)?

On that note, does something like the Salk Soundscape (RAAL crossed to an 3" accuton) seem like it has matching directivity index?

[mondogenerator]

or what about a 4-5" woofer mated to a 2" cone/inverted dome tweeter