Tang Band Hybrid 2-way

[Timn8ter]

I've started on a fun little project some may be interested in.
It's a combination open baffle/sealed two-way using inexpensive Tang Band drivers.
A W3-871S is mounted on an open baffle above a W5-704S in a sealed box. All material is 3/4".
The front baffle is 17"H x 9"W.
The sealed box is 11.5"H x 10.5"D x 9"W.
When measuring the W3-871S on the open baffle it was pretty flat until it got to about 1500Hz. It then displayed a huge bump before rolling back down again and below 500Hz it had little output.
The W5-704S displayed very good frequency response throughout well above 5kHz.
My goal was to keep the project as simple and inexpensive as possible. Unfortunately a first order crossover was not going to get a good transition with that big hump from the W3 in there. At this point a 2nd order XO is looking pretty good. The crossover point is pretty close to 1000Hz. The overall frequency response is quite good up to 10kHz. Above that point the W3 has a couple of peaks but I'm willing to leave it at that rather than making it more complicated or adding a tweeter.
Bass response gets in the 70Hz range so a subwoofer is pretty much a requirement for much of the music I listen to.
In this configuration the W3 needs almost no padding to match output with the W5. The overall crossover is a nearly textbook 2nd order.

Tweeter section: R1 = 2, C1 = 8.2uF, L1 = .70mH
Woofer section: L2 = 3.0mH, C2 = 15uF
Polarity is reversed for the tweeter section.

There are some obvious compromises. Because of the sealed woofer section bass response is somewhat limited. The W3 on an open baffle handling all the HF duties means it has narrow dispersion in the upper range. These compromises are outdone by the excellent mid-range and the "non-box" sound thanks to the OB portion of the design and the narrow HF dispersion limits room interaction. For a speaker that can be built for around $100 a pair the cost/performance ratio is quite good IMHO.
Everything is pretty rough right now as I've not finalized the design but it's looking very promising.
No pictures yet. Comments or questions welcome.

[69stingray]

Timn8ter-

Sound like fun! I am looking forward to pics and outcome. Just curious, what is the size of the sealed enclosure for the W5? Have you measured the actual 70 Hz range or is that a modeled response?

Also, how does the T/S parameters of the W5 compare to the Mfg. & Zaph’s?

[Timn8ter]

I used a test disk and a SPL meter in room at the listening position to get an idea of the bass output. Not a scientific measurement but enough to get an idea of what it was doing.
My T/S measurements were probably closer to Zaph's than the mfg. Much the same but not identical which is to be expected.
The sealed box internal volume is about 11 liters.

[Timn8ter]

I finally took some pictures.
Front shot of the empty but painted cabinet.

[Timn8ter]

Pic showing the back of the empty but finished cab.

[Timn8ter]

Picture of the front with the drivers loaded.
Sorry about the overflash, I was in a hurry.

[Timn8ter]

And the back with drivers loaded. I painted the cup of the W3-871S to make it a little more presentable.

[69stingray]

Nice looking project, any comments on the sound yet?

Both are nice looking drivers on that black baffle.

[Timn8ter]

Thanks. Keeping in mind these are inexpensive drivers I like the way this setup sounds. I'm using them with a 10" Adire Koda sealed subwoofer. The sound is nicely 3 dimensional which I attribute to the open baffle W3-871S. Good detail and excellent imaging. I should've kept a picture of the response measurement. I'll do another one so I can post it here.

[Timn8ter]

FR, unsmoothed, on axis.
It's easy to see the break-up above 10k. This could be addressed with a filter but I'm starting to consider rolling off the W3 and using a super-tweeter.