152FIND

ENCLOSURE RECOMMENDATIONS: 152FINDX8-115
Driver: 152FINDX8-115 (152FIND) — 15" ferrite pro mid-bass woofer, 8 ohm
Key T/S: Fs=44Hz, Qts=0.37, Qes=0.38, Qms=13.0, Vas=128.5L, Sens=99.03dB
Power: AES 800W / Cont 1600W / Peak 3200W
Xmax=4.45mm (linear), Xmech=14.45mm, Xprot=15mm
Sd=829.6cm², Bl=18.3T·m, Le=0.98mH, Re=4.8Ω
Voice coil: 76mm (3"), CCAW winding, Polyimide former (280°C rated)
Cone: carbon fiber loaded REDCATT paper pulp, environmentally treated
Spider: Nomex (double silicone sealed)
Surround: fabric triple roll constant geometry
Depth: 137mm | Baffle cutout: 360mm | Ferrite motor

ENCLOSURE TYPE RATIONALE:
  Qts=0.37 falls within the standard professional woofer range for vented
  (bass reflex) alignment. The 152FIND operates as a pro mid-bass woofer
  covering approximately 40–1000 Hz — not as a dedicated subwoofer — so
  enclosure tuning priorities favour midbass impact and output efficiency
  over maximum low-frequency extension. The very high Qms=13.0 indicates
  near-lossless suspension mechanics; essentially all mechanical damping
  is delivered by the motor (Qes=0.38) and amplifier source impedance.
  VENTED enclosures are the primary recommendation. Sealed enclosures are
  omitted as the Butterworth sealed alignment at Qts=0.37 would require
  approximately 98L and produce fc≈84Hz — impractical and inefficient for
  a 15-inch pro woofer in full-range PA duty.

DISPLACEMENT:
  Vd = Sd × Xmax = 829.6 cm² × 0.445 cm = 369.2 cm³ (peak, one-way)

WEATHERIZATION:
  The carbon fiber loaded REDCATT paper pulp cone and dust cap are treated
  against humidity and harsh environments. Metal basket parts are coated
  for weather protection. The double silicone sealed Nomex spider resists
  moisture ingress. Suitable for permanent indoor and semi-outdoor PA
  installations; not rated for direct rain exposure without additional
  enclosure sealing at the basket surround joint.
VENTED (BASS REFLEX) ALIGNMENTS
Ports: 100mm diameter round tube (Ap=7.854×10⁻³ m²)
       OR 250×80mm slot port (Ap=2.000×10⁻² m²)
Port velocity limit (pro PA): ≤22 m/s
Port velocity limit (install): ≤17 m/s
ALIGNMENT A — COMPACT TOURING (45 L net internal)
  Box volume:        45 L (net internal)
  Tuning freq (Fb): 65 Hz
  Round port:        100mm dia × 123mm long
    Port velocity:   19.2 m/s (peak, at Xmax)
  Slot port:         250×80mm × 313mm long
    Port velocity:    7.5 m/s (peak, at Xmax)
  System f-3dB:      ~63 Hz
  HP filter:         50 Hz, 24 dB/oct DSP (mandatory)
  Max SPL (800W, 1m): ~128 dB
  Application:       Compact two-way touring PA cabinet, 15" woofer section
                     of portable line array, club PA top box, high-SPL
                     stage monitor (wedge or column format).
  Notes: The highest-output compact alignment. At 63 Hz -3dB the driver
         delivers maximum sensitivity and cone control across the 65 Hz–1 kHz
         midbass band — the core working range for a 15" two-way PA woofer.
         The 45 L net volume is compatible with compact trapezoidal touring
         enclosure formats of approximately 500×500×240mm external. With
         Qts=0.37, cone excursion rises steeply below Fb; the 50 Hz HP filter
         is essential at full programme power. The round port velocity of
         19.2 m/s is acceptable for touring PA; the 250×80mm slot port is
         strongly preferred in any permanently installed application to remain
         within the 17 m/s install limit.
ALIGNMENT B — STANDARD PA (70 L net internal)
  Box volume:        70 L (net internal)
  Tuning freq (Fb): 55 Hz
  Round port:        100mm dia × 111mm long
    Port velocity:   16.3 m/s (peak, at Xmax)
  Slot port:         250×80mm × 282mm long
    Port velocity:    6.4 m/s (peak, at Xmax)
  System f-3dB:      ~53 Hz
  HP filter:         40 Hz, 24 dB/oct DSP (mandatory)
  Max SPL (800W, 1m): ~128 dB
  Application:       General-purpose two-way PA cabinet, installed main
                     speaker (theatre, stadium, house of worship), flyable
                     touring enclosure, outdoor installation.
  Notes: The recommended all-purpose alignment. At 53 Hz -3dB the system
         covers bass guitar, kick drum, and the full vocal and instrument
         range from a single enclosure. The 70 L cabinet is compatible with
         standard 15" professional two-way formats at approximately 560×510×290mm
         external. Port velocities are well within both PA and installation
         limits on both port types. The short 111mm round port can be fitted
         in any panel orientation; the 282mm slot port can span the full
         internal width of the cabinet and double as structural bracing.
         With 99.03 dB sensitivity and 800 W AES, this alignment delivers
         system SPL competitive with dual-12" designs from a single-15" cabinet.
ALIGNMENT C — EXTENDED LF (100 L net internal)
  Box volume:        100 L (net internal)
  Tuning freq (Fb): 48 Hz
  Round port:        100mm dia × 102mm long
    Port velocity:   14.2 m/s (peak, at Xmax)
  Slot port:         250×80mm × 259mm long
    Port velocity:    5.6 m/s (peak, at Xmax)
  System f-3dB:      ~46 Hz
  HP filter:         35 Hz, 24 dB/oct DSP (mandatory)
  Max SPL (800W, 1m): ~128 dB
  Application:       Two-way bass/mid-bass cabinet with extended LF,
                     cinema main LF section, installed music system main
                     speaker, large indoor PA at moderate throw distances.
  Notes: The most extended bass alignment. At 46 Hz -3dB the 152FIND
         reproduces bass guitar open E (41Hz) and the lower range of kick
         drum and piano with full SPL capability. This cabinet size of
         approximately 600×550×360mm external approaches the larger end of
         standard 15" two-way PA formats; internal bracing is recommended
         at this volume. Port lengths are the shortest of the three
         alignments — a counter-intuitive result of the larger Vb more than
         compensating for the lower Fb — making both round and slot ports
         particularly straightforward to implement. Slot port velocity of
         5.6 m/s is exceptionally low, making this alignment suitable for
         audiophile-level installation environments where port noise must be
         completely inaudible.
SYSTEM SUMMARY TABLE
  | Alignment   | Volume  | Fb    | f-3dB | Round Port        | Slot Port         | HP     |
  |-------------|---------|-------|-------|-------------------|-------------------|--------|
  | A Compact   | 45 L    | 65 Hz | ~63Hz | 100mm × 123mm     | 250×80mm × 313mm  | 50 Hz  |
  |             |         |       |       | v=19.2 m/s        | v=7.5 m/s         |        |
  | B Standard  | 70 L    | 55 Hz | ~53Hz | 100mm × 111mm     | 250×80mm × 282mm  | 40 Hz  |
  |             |         |       |       | v=16.3 m/s        | v=6.4 m/s         |        |
  | C Extended  | 100 L   | 48 Hz | ~46Hz | 100mm × 102mm     | 250×80mm × 259mm  | 35 Hz  |
  |             |         |       |       | v=14.2 m/s        | v=5.6 m/s         |        |

  Sensitivity:    99.03 dB (1W/1m)
  Max SPL (800W): ~128 dB at 1m
  Impedance:      8 ohm nominal (Re=4.8Ω)
  Voice coil:     76mm (3"), CCAW, Polyimide former (280°C rated)
  Qms:            13.0 (near-lossless suspension — all damping from motor/amp)