The order of 4 or sealed rear chamber bandpass system is essentially a system of watertight enclosures with the addition of an acoustic filter for the driver. The resulting system usually provides a lower cut-off frequency, the compromise that a larger case. The space can be reduced by two drivers in isobaric configuration.
4th-order bandpass systems generally show better able to handle the functions that the other major systems are considered. The transient response and is second only to the sealed enclosure systems, making it a good choice for subwoofer applications.
Since all output 4th order bandpass system is via the port, the largest diameter possible for the port area should be used to minimize noise from the port. The ports must be incinerated where possible, for the same reasons.
|Mini Subwoofer 5 -6″ Bandpass 4th Order Isobaric|
4th order Isobaric Subwoofer Box Design
The 4th order bandpass system rarely allows a perfect bandpass response – there is usually an out-of-band noise present in the production. A notch filter can be used simply to reduce the noise as audible. Otherwise, a lowpass filter used in series with the driver, but the in-band response system may be affected if this approach is taken.
As the speaker sound 4th order band pass issued by the openings or ports on the port side of the box, the port noise inevitable.
This unwanted noise can be minimized by a notch filter and the largest diameter possible for the port of the area should definitely be used. Another option is to burn the ports of the 4th order bandpass room as this will certainly help to reduce unwanted extra from the subwoofer.
WOOFER / MID MODEL – 5MP60 / N
- Nominal Basket Diameter 5 “/ 125mm
- Impedance 8 ohm
- RMS Power 50 Watts
- Program Power 100 Watts
- Frequency response 50Hz – 12.0kHz
- Sensitivity (1W/1m) 91dB
- Voice Coil Diameter 1 “/ 25.8mm
- BL Factor 6.4 N / A
- Voice Coil Length 14 mm
- Air Gap Height 6mm
- X Damage (peak to peak) 20 mm
- Magnetic Assembly Weight 2.2 lbs / 1.0 kg.
- Edit Information
- Diameter 5.28 “/ 134mm x 5.28” / 134mm
- Bolt Circle Diameter 5.4 “/ 137mm
- Baffle Cutout Diameter —
- – Front Mount 4.72 “/ 120mm
- Many of the 4 mounting holes
- Volume displaced by driver, 019 m 3 / .5 liter
- Total Depth 2.68 “/ 68mm
- Net weight 2.64 lbs / 1.2 kg.
- Weight 2.8 lbs / 1.27 kg.
- Basketball aluminum diecast
- Polypropylene cone
- Rubber Surround
- Voice Coil Wire Copper
- Thiele-Small Parameters
- Resonance Frequency (FS) 60 Hz
- Impedance (Re) 5.33 ohms
- Coil Inductance (Le) 0.4 mH
- Mechanical Q (Qms) 1.604
- Electrical Factor (Qes) .35
- Total Q (Qts) .29
- Comp. Equivalent Vol. (Vas) 35 FT3 / 9.8 Liter
- Voice Coil Overhang (Xmax) 4.0mm
- Reference yield 5%
- Volume Displacement 34 cm3
Source : alectronics.blogspot.com