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This 5″ Tang Band W5-1685 is a highly unusual mid-woofer in that her voice coil is “Underhung”. What that means is her voice coil is always in the magnetic field as oppose to the normal overhang design where the voice coil height is greater than the magnetic gap height. I’ve struggled with this W5-1685 for many years. While I can get the crossover to work in various 2-ways, she just doesn’t excite me enough. She is no where close to the Scanspeak Illuminator 15WU. That mid-woofer is a “Killer”. The best I’ve encountered so far. Trouble is she cost a fortune. In this exercise, I’m trying to find the sweet spot of the W5-1685. Perhaps somewhere in her bass is good enough for me to use. I listened to her using a 10 liters bass reflex with the HiVi C3N-III. Crossover is the same 10mH. From the onset, it was difficult to digest. Her bass was so ordinary. Even after a few days, her bass did not improve. I was beginning to lose faith with this Tang Band. Is this her best? Undeterred, I abandoned the 10 liters box and mounted her into a 13 liters bass reflex that I used in the previous auditions. From my box modelling, the loading looks good (Fig 1). System Q is at 0.648. This indicates an overdamped alignment which I like. F3 (-3dB) is at 49Hz. It’s not an issue for me. There’s no point trying for 40Hz when the upper bass sounds awful. If she sounds good in this 13 liters box, I can always EQ for 40Hz.
The W5-1685 sounded right in a 13 liters bass reflex. However after playing for 5 days, her bass suddenly deteriorated. The upper bass is now bloated and slow. She sounds like a woofer having a higher Q and worse still, a peak in the 100Hz region. It was then that I took another look at the box simulations, this time using my DATS T/S.
To my horror, Fig 2 is exactly what she sounded like after breaking-in. I am in a bind. I decided to model her in a sealed box to see the alignment.
The W5-1685 in a 13 liters sealed box is far better (Fig 3). The peak is gone. Hopefully, that bloated upper bass will disappear.
Incredibly, the W5-1685 sounds right again when I converted to a sealed box. Her upper bass tightened up and her timing is now in step with the HiVi C3N-III. In She Works Hard for the Money (Donna Summer), the bass is clearly audible. Her attack is not as fast as the top of the line Seas U18 and the Morel CAW634 but then again, she doesn’t cost as much. The bass in Woman is as punchy as the HiVi F8. That says a lot because the F8 is 8″ whereas the W5-1685 is only 5″. Lastly, Santana’s Supernatural Day of Celebration, the bass has that mesmerizing growling effect. If I want to make it sound more captivating, I’ll simply apply a 40Hz EQ. Updated on Mar 19, 2024 Can the W5-1685 do without EQ or Subwoofer support ? Amazingly, she can. I found this out when I loaded her into a 27 liters box. Initially, it was a bass reflex. Although the bass was passable, it was not something I can live with. The music was completely off. I then sealed up the port and the bass timing and attack were restored. Now, she sounds like in a 13 liters sealed box but with bass extension down to 40Hz.
Fig 4 is the alignment of the W5-1685 in a 27 liters sealed box. Visually, there’s not much difference with a 13 liters sealed box but audibly, the 27 liters is more musical.
I thought I wasted my time working with this Tang Band W5-1685. I am glad I did because I finally can design a 2-way with this underhung driver that I’m happy with. I see the W5-1685 doing bass duty in a slim 27 liters sealed box tower with a full-range driver sitting on top. Unless otherwise stated, all measurements were made in Full Space (4pi). Mic at 36 ins, tweeter axis. Impulse Window=5ms. No smoothing applied. |
March 9, 2024HIFI DRIVERS, Projects
Fig 1 – Manufacturer’s T/S
Fig 2 – DATS T/S
Fig 3 – DATS T/S Sealed Box
Fig 4 – W5-1685 in 27 liters Sealed Box