Tubular TL Subwoofer Designed & Built by Nick Huntington This design is an 8' tube transmission line using a 12" Radio Shack 4-1350 DVC driver*. The driver is siliconed directly to the tube and sits on a milk crate to facilitate the terminus. Fortunately I have 9'8" ceilings! The line is stuffed with miraflex to a density calculated using the equation from John Cockroft's Speaker Builder Magazine article for a Hybrid TL (Speaker Builder 1 1998). Subjectively this works well and the construction is dead easy. *The old ones were designed by Albert Von Schweikert, evidently, and they came in a white box. The current 1350A's come in a blue box. The 40-1350A which is probably all you will find anymore, has about 2mm Xmax.
Radio Shack 4-1350 DVC   Line Configuration     Sd 856 cm2 (~90 in2)     Physical length 8 ft   Vas 547.7 liters     Physical fs at 1/4 wl 35 Hz   Cms 00 e-4 N/m     Begining cross section 107 in^2   Cas 00 e-6m5/N     Terminus section 107 in^2   Mms 00 g     Taper 1.2 : 1.2 Sd   Fs 21 Hz     Stuffing Miraflex   Bl 00 N/A     Re 5.72 Ohms     Qms 7.14     Qes .575     Qts 0.42 (coils in parallel)     Pmax 60 Watts     Xmax 8.8 mm     SPL 92.3 db/2.83v/1m
[ Back to Projects | Tube TL | Earlier Version | System ]