Pros
- Higher efficiency, +5db more than sealed
- Low woofer excursion
- Good choice for high SPL applications
Cons
- enclosure can be big
- difficult to design, no room for error
- too much efficiency make sound poor
- The more order you go, the less quality you got
4th order enclosure
- enclosure in front of speaker act like low pass filter
Alignments
S and Ripple
S = 0.7 → Ripple = 0dB S = 0.6 → Ripple = 0.35dB S = 0.5 → Ripple = 1.25dB
Sensitivity
lower sensitivity (likes -3dB) higher bandwidth
Triple chambers
- 2 drivers facing each other inside ported chamber
- multiply volume of ported chamber by 2
6th order enclosure
- no alignment yet
- Bose patented this design
- very low, very low
- parallel 6th order bandpass
- series 6th order bandpass