I am not sure if I misunderstand you. About the b&w nautilus I was thinking about the long tubes that is also a chamber behind the drivers. Try and google "b&w nautilus" and you will see what I mean.
I think this kind of "snailhouse chamber" could be an interesting headphone design. It is all patented by b&w I am sure and therefore all creativity and development stops right there of course.
I think this kind of "snailhouse chamber" could be an interesting headphone design. It is all patented by b&w I am sure and therefore all creativity and development stops right there of course.
The Q701 Bass Port is actually flared similar to the B&W Nautilus Bass Port. The flare diameter is ~ 2.5 mm and the "tube" is ~ 2 mm.
The stock self-adhesive disk covering the Q701 Bass Ports looks impermeable to me and the glue is very strong.
I tried to modify the tube effect with thin craft felt, 3mm open cell foam, and punching various hole sizes in double-sided tape vs silicone furniture bumpers. The felt and open cell foam had no effect, functioning pretty much like the stock self-adhesive disk. Changing the hole size in silicone furniture bumpers seems to allow for a tunable bass port: smaller = less bass, larger = more bass.
Angle Hair over the ear side of the driver sucks out the lower mids around 500 to 700 Hz by ~ 5 dB.
Removing the stock foam ring on the ear side of the baffle causes even greater suckout by ~ 8 dB.
The best sounding bass port mod to my ears (so far!) results from:
1. Fully open bass port after removing the stock tape disk + add an equal size Arctic Cotton disk overlaying the stock foam disk + Paxmate on the underside of the plastic grille receptacle, only at the bottom, leaving all 4 "vents" fully open (2 small at the top, 2 large at the bottom).
2. Partially open bass port after removing the stock tape disk + silicone disk with 1.5 mm hole placed over the open bass port + self-adhesive craft felt instead of Paxmate, as above.
I have measurements and photos of each mod combination. I will post everything in a new thread this weekend and post a link in this thread for anyone interested.