Exploring a "Voxel WAW" Hybrid – Thoughts?

Hey everyone,


While browsing through some old threads recently, I came across a neat little project from Paul Carmody dating back to 2013—the "Voxel" mini sub. For those unfamiliar, it’s a compact 7-liter subwoofer build using the Tang Band W5-1138SMF, capable of reaching down to about 35Hz (F3) in a surprisingly small footprint.

You can check it out here:
🔗 Voxel Mini Sub Thread

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It sparked an idea:
What if we could adapt the Voxel design into a full-range "WAW" (Woofer-Assisted Widebander) system?


I’ve had a pair of SB Acoustics SB65WBAC25-4 full-range drivers collecting dust since they went on sale a few years ago. The thought was to let the Voxel handle the low end, while the SB65 tackles mids and highs on the front baffle.
Here's a link to the SB65's test data:
🔗 SB65 Driver Info

20151215080158_Photo1-SB-Acoustics-SB65WBAC25-4.webp



The drivers appear to have fairly compatible sensitivities. I’ve seen recommendations to cross the SB65 around 400Hz, and Tang Band’s spec sheet shows the W5 plays clean up to about 1kHz, so there seems to be a usable overlap.


I’m still fairly new to WAW-style designs and full-range applications, so I’d love to get some input before jumping in. Has anyone tried something similar? Any thoughts on enclosure tweaks, crossover approaches, or potential pitfalls?


Appreciate any insight—always grateful to learn from the experience of this community.


Cheers!
 
I'm all for waw/fast designs, but in this case, don't expect meaningful bass down to 35Hz with that little enclosure and 5" sub.

The SB65 is absolutely wonderful, but it's not easy to cross. Certainly not as easy as slapping a capacitor and be done. It needs to be measured on baffle, with the woofer and tweaked so they match well. Even though I love the SB65, it's the one that always gets me to work the most trying to match it with other drivers. The reward is really nice when you get them right.
 
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Perceval, thank you for the response. Do you perhaps know of any DIY waw/fast designs that utilize the SB65 you could recommend? I was trying to scour the internet in hopes of finding such but haven't had much luck. 🤔
I've heard all these great things about these drivers, yet haven't found many builds utilizing them. (Outside of Line Arrays):violin:
 
I actually have built the Voxel and it has great bass (even shaking some questionably built windows)

Clearly is SPL limited by design but it gives clean bass for its size and ease of build

Said that, I don't have idea if you could make it work with that full range
 

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Sounds like a great idea zeltergiest.
Something I have been wanting to do for awhile.

What makes it incredible simple is a 90 degree woofer
Or side mounted woofer.
This also keeps the form factor skinny for the wideband.

Integration would be incredible easy.
Smooth and easy not much more than a cap and a coil for crossover.
The side mounted woofer makes the crossover easy.

Once the wideband is even on a simple highpass.
Distortion and clarity goes way up.
I was always looking at 6.5" woofers even 8"

But I think this woofer is interesting and workable.
Might have been the ticket all along.
The wideband seems to have a good SPL match at a quick glance.
 
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Yes, Jim's CBT array comes right up when keying in the SB65, doesn't it? 🙂 It is a great design.

Having built OB, woofer TL and the SB65 as wide range, and a little sealed project, I can say that the SB65 is not as easy as slapping a cap on it, and an inductor on the woofer.

I wouldn't go much lower than 400Hz with the SB65. Its strengths are high extension close to tweeter territory, and its ability to reproduce fast transients like plucked guitars, percussion, anything that has a quick attack. It even sounds amazing on woodwinds. But it needs help below 400Hz to make it shine.

I don't know of any made and available designs for the SB65 besides Jim's CBT. It's a shame because it is a great driver.
So, you'll have to do the work. But it will be rewarding.