Bookshelf speaker series dynaudio emit system 2 way system principle passive frequency response 50 23000 hz impedance 6 ohm power supply passive colour black front colour black housing surface veneer vinyl speaker enclosure bass reflex number of tweeters 1 treble chassis 28 mm tweeter material tweeter tissue tweeter type tweeter calotte number of midbass drivers 1 bassmidtone chassis 150 mm bass reflex port position rear firing port widt