Rythmik Audio F18

➤ Combines finesse with powerful, high-output bass performance

➤ F18 is the largest single-driver sealed subwoofer designed for high-power home theatre applications

➤ Delivers dynamic, accurate, and deep bass performance

➤ Achieves at least 8 dB higher output at 20 Hz compared to 12″ sealed model F12

➤ Produces over 11 dB higher output than competitor 12″ models (SB**) based on data-bass.com measurements

➤ Powered by a Hypex audiophile-grade Class D amplifier

➤ Utilizes a stiff aluminum cone with servo feedback for enhanced performance

➤ Delivers lower distortion than competing 18″ servo subwoofers (e.g., DD18+)

➤ Maintains equal or higher maximum SPL output from 10 Hz to 100 Hz

➤ Records extremely low THD levels even at maximum SPL output

➤ Servo technology is scalable across all subwoofer designs and driver sizes

Direct Servo Technology
➤ Patented Direct Servo technology used in all subwoofers

➤ Provides precise cone control for tight, dynamic, and accurate bass

➤ Reduces driver non-linearities for cleaner sound reproduction

➤ Allows use of lighter drivers without requiring excessive amplifier power

Key Benefits of Direct Servo
➤ Significantly reduces box resonance and internal bass re-radiation

➤ Eliminates thermal compression under normal operation

➤ Improves efficiency, delivering higher output with less power

➤ Enables deep bass extension with superior transient response

➤ Reduces mechanical creep and memory effects

➤ Achieves very low effective in-box Q value (~0.25, ~0.1 for driver)

➤ Produces tighter and more accurate bass compared to conventional designs (Q 0.75–0.80 or higher)

➤ Driver: DS1820 18″ high-excursion driver with custom sensing coil

➤ Driver Materials: One-piece black anodized dish aluminum cone with rubber surround
➤ Cast aluminum basket
➤ Multiple aluminum flux de-modulation shorting rings

➤ Amplifier: 900W RMS Hypex Class D with patented servo control

➤ Dimensions: 20.5″ (W) × 20.5″ (H) × 21″ (D)
➤ 23″ depth including grille and heatsink

➤ Shipping Weight: 140 lbs (125 lbs gross)

➤ Frequency Response:
➤ 14 – 200 Hz (0 dB / -2 dB) with LFE inputs
➤ 10 – 250 Hz (±3 dB) with LFE inputs
➤ 14 – 90 Hz (-2 dB @ 14 Hz) with Line-in inputs

➤ Crossover:
➤ Selectable slope: 12 or 24 dB/octave (PEQ and XLR versions)
➤ Low-pass range: 25 – 100 Hz

➤ Rumble Filter (High Pass): 12 Hz, 18 dB/octave (-6 dB @ 10 Hz)

➤ Phase Response: 90° phase shift at 20 Hz (measuring mic has 18° shift)

➤ Phase Adjustment: 0 – 180° continuously variable

➤ Bass Damping Factor Settings:
➤ High (Q = 0.5)
➤ Medium (Q = 0.7)
➤ Low (Q = 1.1)

➤ Finishes: Black oak and black matte vinyl

➤ Warranty:
➤ 5 years on driver
➤ 3 years on electronics

➤ Guarantee: 45-day satisfaction guarantee