Why a 4” coiled BTL? Well, because we can. New for 2019 is the first 4” coiled sub in the BTL Series. The BTL4-Ferrite is the latest in the progression of Fi subwoofers geared towards thundering daily drivers. Utilizing a favorite 3 stack ferrite magnet design using US steel cut on our water jet and finish machined on our CNCs, there is plenty of motor force in the FEA derived design for both daily and SPL use. Utilizing a solid pole and a venturi aided pole profile, the forced cooling keeps thermal temperatures under control. A classic 3 stack of ferrite magnets provide the Gauss while 4 Fi designed 10″ heavy progressive spiders keep things under mechanical control. Utilizing a special 144 tinsel count leadwire that is double sewn to the spider pack, there are no losses in power transfer to the coil (available in either standard stitched with terminals or the hybrid stitched with bolted termination.
Working in ported, 4th or 6th order applications the 2019 BTL4-Ferrite Series raises the power handling and thermal performance of a classic line to new levels . As always, the BTL is “Built To Last”.