10FHW

ENCLOSURE RECOMMENDATIONS: 10FHWX8-117D
Driver: 10FHWX8-117D (10FHW) — 10" Sub-woofer, 8 ohm
Key T/S: Fs=24.0Hz, Qts=0.37, Qes=0.45, Qms=2.37, Vas=65.9L, Sens=85dB (1W/1m)
Power: AES 200W / Cont 400W / Peak 800W
Xmax=12.15mm, Xmech=20.15mm, Sd=346cm², Bl=14.7T·m, Re=5.7Ω
Le=0.58mH | Two aluminum demodulation rings | Copper voice coil wire

SENSITIVITY VERIFICATION:
  Lm(1W/1m) = 85 dB
  Sensitivity(2.83V/1m) = 85 + 10×log₁₀(8/5.7) = 86.5 dB  ≈ CSV 86 ✓

GEOMETRIC XMAX CHECK:
  L-Winding = 32.3mm, T-Plate = 8mm
  Geometric Xmax = (32.3 − 8) / 2 = 12.15mm  — matches stated Xmax exactly ✓

VOLUME DISPLACEMENT:
  Vd = Sd × Xmax = 346cm² × 1.215cm = 420.4 cm³
  This is excellent displacement for a 10" driver — larger than many 12" PA mid-woofers.

MOTOR CHARACTERISTICS:
  Qts = 0.37 → Balanced motor-suspension design (0.36–0.45 range)
  BL = 14.7 T·m — high motor force for this class
  Two aluminum demodulation rings reduce effective Le and suppress
  inductance modulation (Faraday ring / shorting ring action):
    - Measured Le = 0.58mH (unusually low for a ferrite 10" sub)
    - f_Le = Re/(2π×Le) = 5.7/(2π×0.00058) = 1,564 Hz (well above operating band)
    - Result: very low 2nd/3rd harmonic distortion, clean transients
  Copper voice coil wire (not CCAW):
    - Thermal conductivity ≈ 400 W/(m·K) vs 150 W/(m·K) for aluminium
    - Enables sustained AES 200W rating without thermal compression
    - Slightly higher VC mass vs CCAW — acceptable tradeoff at this power level
  Extended space below voice coil (enlarged under-coil gap / back-plate clearance):
    - Allows unobstructed air flow through motor gap on rearward excursion
    - Hot air expelled efficiently from gap; reduces thermal saturation
    - Contributes to the Xmech headroom: Xmech = 20.15mm vs Xmax = 12.15mm
      (8mm additional mechanical travel beyond rated Xmax on each side)

CONE ASSEMBLY:
  Anodized aluminum cone (Sd = 346cm², effective diameter = 210mm):
    - High rigidity: piston-mode operation extends well beyond typical paper
    - Anodized surface layer adds hardness, corrosion resistance, electrical isolation
    - Higher thermal conductivity than paper — self-cools under heavy excursion
    - Higher cone mass compared to paper (contributes to low Fs = 24Hz together
      with the compliant Nomex spider + NBR surround combination)
  NBR (nitrile-butadiene rubber) surround: long-term compliance stability,
    superior UV and ozone resistance, suitable for outdoor/installation environments
  Nomex spider with stitched tinsel leads: high thermal resistance at 200–400°C,
    maintains spring constant under sustained high-power operation

MAX SPL ESTIMATE:
  MaxSPL = Lm + 10×log₁₀(AES) = 85 + 10×log₁₀(200) = 108.0 dB (1m, half-space)
  Peak SPL (800W) = 85 + 10×log₁₀(800) = 114.0 dB (1m, half-space)
RECOMMENDED ENCLOSURE TYPE: Bass Reflex (Vented)
PORT: Round port, 76mm diameter (standard for compact PA 10" enclosures)
Qts = 0.37 → classic vented alignment range; vented preferred.
Fs = 24Hz is unusually low for a 10" sub — this driver targets genuine
infra-bass extension in a compact format. All three alignments are tuned
below Fs, exploiting the very compliant suspension to maximum depth.

Industry norm for 10" vented enclosure: 15–40L (standard), up to 50L (large).
Computed optimal Vb ≈ 65–75L. Clamped to industry maximum: 50L net.
At 50L the alignment is slightly on the damped side, which benefits
transient control and mid-bass clarity. System designers with cabinet
freedom may evaluate 60–75L for maximum extension.

PORT VELOCITY AT XMAX:
  Vd = 420.4cm³  |  76mm round port (Ap = π×3.8² = 45.4cm²)
  Alignment          Fb     Port Length   Peak Velocity
  a) High SPL        28Hz   306mm         16.1 m/s  ✓ (PA limit: 22)
  b) Balanced        25Hz   370mm         14.7 m/s  ✓
  c) Extended LF     23Hz   465mm         13.3 m/s  ✓
  All alignments are well within PA limits. Hi-fi/install limit (17 m/s)
  is satisfied by all three — this driver is suitable for low-noise installs.
VENTED ALIGNMENTS (all with 50L net internal volume)
  a) HIGH SPL
     Net Volume    : 50 liters
     Tuning (Fb)   : 28 Hz
     Est. −3dB     : ~26 Hz
     HP Filter     : 25 Hz, 24 dB/oct (mandatory — cone unloads below Fb)
     Round Port    : 76mm dia × 306mm long
     Slot Port     : 190mm W × 46mm H × 616mm L
     Port velocity : 16.1 m/s @ Xmax
     Notes         : Maximum mid-bass impact and output; reduced cone excursion;
                     best for high-SPL touring subwoofers and SPL competition.

  b) BALANCED RESPONSE
     Net Volume    : 50 liters
     Tuning (Fb)   : 25 Hz
     Est. −3dB     : ~23 Hz
     HP Filter     : 22 Hz, 24 dB/oct
     Round Port    : 76mm dia × 370mm long
     Slot Port     : 190mm W × 46mm H × 738mm L
     Port velocity : 14.7 m/s @ Xmax
     Notes         : General-purpose PA / installation subwoofer; even frequency
                     response; good transient behavior; recommended default alignment.

  c) EXTENDED LOW FREQUENCY
     Net Volume    : 50 liters
     Tuning (Fb)   : 23 Hz
     Est. −3dB     : ~20 Hz
     HP Filter     : 20 Hz, 24 dB/oct
     Round Port    : 76mm dia × 465mm long
     Slot Port     : 190mm W × 46mm H × 919mm L
     Port velocity : 13.3 m/s @ Xmax
     Notes         : Deep bass extension into infra-bass; requires DSP protection
                     below tuning. Slot port preferred at this length — avoid single
                     round tube exceeding 50% of cabinet depth.

SYSTEM NOTE: With Fs=24Hz, this driver naturally extends lower than typical 10"
subwoofers. The low Fs / large Vd / compliant suspension combination makes it
an unconventional choice for very deep reproduction in a 10" format. An active
high-pass filter is non-optional at any alignment.

ZOBEL NETWORK (for passive crossover / impedance stabilization):
  Rz = Re = 5.7Ω
  Cz = Le/Re² = 0.58×10⁻³/5.7² = 17.9 μF
  Place in parallel with driver terminals.
--- SUMMARY---
The 10FHWX8-117D is a 10-inch sub-woofer driver designed for professional bass reflex enclosures, compact touring subwoofers, and high-output installation systems. It operates with 85 dB sensitivity (1W/1m) and delivers a free-air resonance of 24 Hz — unusually low for this cone size — enabling genuine infra-bass extension in a compact format. The driver uses a balanced motor-suspension design with Qts=0.37 that provides good cone control while maintaining usable output across the operating bandwidth. A large volume displacement of 420 cm³ (Sd=346cm² × Xmax=12.15mm) places this driver in the output class of many 12-inch PA woofers.

The motor assembly incorporates an anodized aluminum cone, two aluminum demodulation rings, and a solid copper voice coil winding on an aluminum former. The demodulation rings reduce voice coil inductance to 0.58mH — substantially below the unlinearised value typical for this motor geometry — and suppress flux modulation, yielding very low second and third harmonic distortion across the operating band. The solid copper winding (thermal conductivity ≈ 400 W/(m·K)) sustains the AES 200W power rating with reduced thermal compression compared to aluminium-wound alternatives. An extended under-coil gap in the motor back plate provides unobstructed airflow during rearward excursion, efficiently removing heat from the magnetic gap and contributing to consistent performance under sustained drive. The anodized aluminum cone is rigid, thermally conductive, and corrosion-resistant, operating in piston mode throughout the sub-bass range with no audible cone breakup within the intended passband.

In bass reflex enclosures, the driver performs best in net internal volumes of 50 liters, tuned between 23 and 28 Hz. In the balanced alignment (25 Hz tuning), the system achieves an estimated −3dB point at approximately 23 Hz with a 76mm round port of 370mm length and peak port velocity of 14.7 m/s at full rated excursion — comfortably within hi-fi and installation noise limits. The high-SPL alignment (28 Hz tuning, 306mm port) maximises output and cone control for touring applications; the extended alignment (23 Hz tuning, 465mm port) provides the deepest bass extension and is recommended where infra-bass reproduction and DSP-managed protection are available. The driver is intended for use with high-power amplification (approx. 200W AES / 400W continuous) and requires an active high-pass filter in the 20–25 Hz range depending on alignment, with appropriate excursion limiting below the port tuning frequency.