B

Bandpass Enclosure
Subwoofer enclosure with two chambers: sealed rear, ported front. Driver enclosed, sound exits only through port. 4th-order bandpass most common. Very efficient at tuning frequency, narrow bandwidth. Excellent for SPL competition, poor for music. → See also: Ported, Sealed
Chapter 10.4

Bass Boost
Amplifier feature adding 0-12 dB boost at 40-60 Hz. Generally unnecessary and can cause clipping. Better controlled via DSP parametric EQ. Use sparingly (≤6 dB) or not at all. → See also: EQ, Clipping
Chapter 4.4

Big Three
Three electrical system upgrades: (1) alternator positive to battery positive, (2) battery negative to chassis ground, (3) engine block to chassis ground. Typically upgraded to 0 AWG wire. Reduces voltage drop and noise. Essential for systems above 1500W. → See also: Voltage Drop, Ground
Chapter 11.3

Biquad
Second-order IIR digital filter. Fundamental building block in DSP EQ and crossovers. Five coefficients (b0, b1, b2, a1, a2) define filter behavior. → See also: IIR, Parametric EQ
Chapter 12.3

Bl (Force Factor)
Product of magnetic flux density (B) and voice coil length in gap (l). Units: Tesla-meters. High Bl = strong motor = low distortion = tight control. Typical: 10-20 T·m for subwoofers. → See also: Qes, Thiele-Small
Chapter 10.1

Bluetooth
Wireless audio streaming standard. Uses 2.4 GHz band. Range: ~30 feet. Codecs determine quality: SBC (baseline 320 kbps), AAC (better), aptX (352 kbps), LDAC (990 kbps). → See also: A2DP, Codec
Chapter 5.2

Bridging
Combining two amplifier channels into one mono channel. Increases voltage swing and power (~4× power into same impedance). Minimum impedance doubles (2Ω stable amp becomes 4Ω when bridged). → See also: Mono, Impedance
Chapter 11.5

Butterworth
Maximally flat frequency response filter alignment. Second-order Butterworth (Q=0.707) is most common. For sealed enclosures, Qtc=0.707 gives flattest response before rolloff. → See also: Linkwitz-Riley, Q Factor
Chapter 10.2