10FHW

ENCLOSURE RECOMMENDATIONS: 10FHWX4-117
Driver: 10FHWX4-117 (10FHW) — 10" hi-fi subwoofer, 4 ohm
Key T/S: Fs=25.0Hz, Qts=0.39, Qes=0.40, Qms=13.72, Vas=57.9L, Sens=86.5dB
Power: AES 200W / Cont 400W / Peak 800W
Xmax=12.15mm, Xmech=20.15mm, Sd=330.1cm², Bl=12.7T·m
Le=0.62mH | Two aluminum demodulation rings

DESIGN HIGHLIGHTS:
  - Anodized aluminum cone — high rigidity, low mass-to-stiffness ratio,
    extended pistonic range, clean and precise bass reproduction
  - Very high Qms (13.72) — exceptionally low mechanical losses; the
    suspension (rubber surround + Nomex spider) contributes virtually
    no damping. Electrical damping (Qes=0.40) dominates entirely.
    This is a characteristic of precision hi-fi subwoofer design:
    the amplifier and enclosure provide all the system damping.
  - Two aluminum demodulation rings integrated into the magnetic circuit
    — reduce inductance modulation and flux compression under drive,
    lowering distortion especially at large excursion
  - Glass fiber voice coil former (50.8mm) — improved thermal stability
    over paper, handles sustained 400W continuous

RECOMMENDED ENCLOSURE TYPES:
  PRIMARY:   Bass Reflex (Vented) — Qts=0.39, Qms=13.72; near-optimal
             vented range with excellent motor control
  SECONDARY: Sealed (Acoustic Suspension) — for DSP/active systems with
             Linkwitz Transform; also viable passively in near-Butterworth
             alignment (25L, Qtc=0.707) for system integration
VENTED ALIGNMENTS (Primary)
Port: 75mm diameter round, flared both ends
Vd = 330.1 cm² × 12.15mm = 401.1 cm³

NOTE: The very low Fs (25 Hz) combined with small-to-mid box volumes
produces long port tube lengths. A passive radiator is the preferred
solution for alignment (a); alignments (b) and (c) use practical
port lengths.

  a) Compact Deep Bass
     Net Volume: 30 liters
     Tuning (Fb): 28 Hz
     Est. -3dB: ~28 Hz
     HP Filter: 22 Hz (24dB/oct recommended)
     Port: 75mm dia × 560mm long [impractical — see note below]
     Passive Radiator (strongly recommended): Sd ≥ 330cm², mmd ≈ 95g
       tuned to 28 Hz (add tungsten or lead putty mass to PR if needed)
     Port Velocity (if ported): 16.0 m/s ✓
     Notes: Despite the acceptable port velocity, a 560mm tube does not
            fit practically inside a 30L cabinet without folding. A PR
            eliminates this constraint, reduces cabinet complexity, and
            maintains full tuning accuracy. Compact footprint ideal
            for bookshelf-integrated or under-furniture placement.

  b) Balanced Response
     Net Volume: 45 liters
     Tuning (Fb): 26 Hz
     Est. -3dB: ~26 Hz
     HP Filter: 20 Hz (24dB/oct recommended)
     Port: 75mm dia × 433mm long
     Port Velocity: 14.8 m/s ✓
     Notes: Optimal balance of extension, output, and enclosure size.
            Recommended general-purpose hi-fi sub alignment. Port length
            is practical. Suits standalone subwoofer cabinets for 2.1
            and multi-channel systems.

  c) Extended Deep Bass
     Net Volume: 60 liters
     Tuning (Fb): 22 Hz
     Est. -3dB: ~22 Hz
     HP Filter: 18 Hz (24dB/oct recommended)
     Port: 75mm dia × 453mm long
     Port Velocity: 12.5 m/s ✓ (very low — excellent for hi-fi)
     Notes: Reference-level deep bass extension. Low port velocity
            minimizes turbulence noise — this is the quietest alignment
            at maximum output, ideal for critical and studio listening.
            Well suited for floorstanding enclosure integration.
SEALED ALIGNMENTS (Secondary — Active / DSP Systems)
The very high Qms (13.72) makes sealed enclosures particularly
effective: the amplifier provides all system damping, which is ideal
for DSP-managed amplifiers with adjustable damping factor. The aluminum
cone's high rigidity ensures clean transient reproduction in sealed
systems without port-phase artifacts.

  d) Compact Sealed (10 liters)
     Qtc: 1.00
     fc: 64 Hz
     Est. -3dB (passive): ~50 Hz
     Est. -3dB (with Linkwitz Transform to 0.707/25Hz): ~25 Hz
     Notes: Smallest practical sealed alignment. Requires DSP correction
            for subwoofer use. Xmax of 12.15mm provides ample headroom
            for the bass boost below fc.

  e) Balanced Sealed (15 liters)
     Qtc: 0.85
     fc: 55 Hz
     Est. -3dB (passive): ~47 Hz
     Est. -3dB (with Linkwitz Transform to 0.707/25Hz): ~25 Hz
     Notes: Well-damped sealed response. Good integration platform for
            2.1 systems with a sub-satellite crossover at 80–100 Hz.

  f) Butterworth Sealed (25 liters)
     Qtc: 0.707
     fc: 45 Hz
     Est. -3dB (passive): ~45 Hz
     Est. -3dB (with Linkwitz Transform to 0.707/25Hz): ~25 Hz
     Notes: Maximally flat passive alignment — no eq required from
            fc upward. Useful in passive 2-way systems with sub crossed
            below 80 Hz. DSP correction extends the bottom octave.
            This alignment combined with room gain (~+4dB below 50Hz)
            gives effective flat-to-room response to ~20 Hz.

ROOM GAIN NOTE:
In typical domestic rooms, boundary reinforcement provides +3–6 dB
below 50–60 Hz, effectively extending in-room bass response by roughly
one octave. Alignment (f) passive + room gain approximates an anechoic
-3dB of ~20 Hz in most rooms — without any DSP bass correction.
APPLICATION SUMMARY
  - Hi-fi 2.1 and multi-channel home theater subwoofer
  - Studio monitoring with active sub-bass management
  - Audiophile subwoofer enclosures (standalone or integrated)
  - DSP-managed active systems (sealed preferred for phase alignment)
  - Passive 2-way sub configurations in larger floorstanding systems
  - 4-ohm impedance suits high-current amplifiers; parallel wiring of
    two drivers (4+4=2Ω) for amplifiers rated into 2 ohm