LF
Mid-Woofer
8"
8NPM
Code: 8NPMX8-157
Mid-Woofer/8inch/Neo/Paper/200W/8ohm
Key Features
- Hi sensitivity
- Hi power handling
- Designed for applications where are sizable amounts of mid-frequencies required
Quick Specs
Impedance
8 Ω
Program Power
400 W
Sensitivity
96.06 dB
Fs
79.00 Hz
Magnet
Neodymium
Voice Coil
50.8 mm
Design Notes
The 8NPM is a high efficiency, (96dB 1watt / 1 meter) 8-inch mid-woofer with extended mid frequency response and high power handling capability. The 8NPM uses a lightweight half pressed paper cone along with a double roll fabric surround. Spider is made of Nomex material with optimized shape for well controlled pistonic motion. The used high quality components ensure long lasting performance even in high powered applications. The chosen material combination provides remarkable strength, high efficiency and sustained output under extreme conditions.
Power Handling
The voice coil featuring Kapton former material capable of withstanding peak temperatures in excess of 280C, well beyond the thermal requirements of modern audio systems. Former strength provides the ideal transfer of power between the voice coil and the cone assembly and assists in reducing distortion artifacts. By combining this material with state of the art adhesives and our winding voice coil technology, the 8NPM delivers incredibly high performance.
Power Handling
The voice coil featuring Kapton former material capable of withstanding peak temperatures in excess of 280C, well beyond the thermal requirements of modern audio systems. Former strength provides the ideal transfer of power between the voice coil and the cone assembly and assists in reducing distortion artifacts. By combining this material with state of the art adhesives and our winding voice coil technology, the 8NPM delivers incredibly high performance.
Specifications
General Specs
Nominal Diameter
8"
Rated Impedance
8 Ohm
Magnet
Neodymium
Basket Material
Aluminum
Power Handling
AES Power
200 W
Continuous Power
400 W
Peak Power
800 W
Voice Coil
Diameter
50.8 mm
Winding Wire
CCAW
Former
Kapton
Winding Height
15.4 mm
T/S Parameters
Resonant Frequency (Fs)
79.00 Hz
Re
5.40 \u2126
Qes
0.310
Qms
3.85
Qts
0.290
Vas
10.90 liters
Sd
213.80 cm\u00B2
Mms
23.90 grams
Rms
3.10
Cms
0.1700
Bl
14.20 T\u00B7m
Le
0.600 mH
Sensitivity
96.06 dB
Design Details
Surround Material
fabric
Cone/Dome Material
Paper CF
Spider
Nomex
T-Plate
8 mm
Xmax (peak)
3.7 mm
Xmech
11.7 mm
Overall Diameter
209.50 mm
Bolt Circle Diameter
197.50 mm
Baffle Cutout Dia.
185.00 mm
Mounting Holes
8
Depth (flange to rear)
87.30 mm
Net Weight
1.80 kg
Ordering Codes
Product Code
8NPMX8-157
Downloads
Frequency Response & Impedance
2D Drawing
Technical Summary
The 8NPMX8-157 is an 8-inch high-efficiency neodymium mid-woofer designed for professional two-way, multi-way, and line array systems requiring high sensitivity (96 dB 1W/1m), extended mid-frequency response, and sustained high-power operation. It features a 2-inch CCAW voice coil on a Kapton former with peak temperature tolerance exceeding 280°C, a lightweight half-pressed paper cone with a double roll fabric surround, and a Nomex spider with optimized geometry for controlled pistonic motion. With a low Qts of 0.29 and strong neodymium motor (Bl 14.2 T·m), the motor and suspension are optimized to maintain consistent performance at high drive levels, with controlled excursion and reduced thermal compression during long-term operation.
This driver is suitable for both vented (mid-woofer) and sealed (midrange) enclosure configurations depending on the system architecture. In bass reflex enclosures, recommended net internal volumes range from 10 to 14 liters with tuning frequencies between 63 and 82 Hz. Smaller volumes (10–12 liters tuned to 72–82 Hz) prioritize mid-bass output and cabinet compactness for portable 2-way systems and stage monitors, while 14 liters tuned to 63 Hz extends the usable low-frequency response to approximately 54 Hz (–3 dB) for stand-alone applications without dedicated subwoofers. Port velocities remain low (9–12 m/s) across all vented alignments. In sealed enclosures for midrange duty, the driver performs in very compact net internal volumes of 1.0 to 2.2 liters, producing system resonances between 193 and 272 Hz. Smaller sealed volumes (1.0–1.4 liters, Qtc 0.85–1.0) maximize acoustic output in the midrange passband for line array modules and horn-loaded midrange systems, while 2.2 liters yields a Butterworth-class response (Qtc 0.707) with maximally flat amplitude for accuracy-focused applications.
The driver requires active DSP crossover management in both configurations. In vented mid-woofer use, a high-pass filter in the range of 53–72 Hz (24 dB/octave Linkwitz-Riley) is recommended depending on enclosure tuning, with a typical crossover to a high-frequency driver at 1.5–3 kHz. In sealed midrange use, a high-pass filter in the range of 180–350 Hz is recommended depending on enclosure volume and system architecture. In both cases, appropriate limiting is required to manage mechanical stress during sustained operation, though the Kapton former provides exceptional thermal headroom.
This driver is particularly effective in professional touring line arrays, compact 2-way portable loudspeakers, multi-way point-source cabinets, stage monitors, and installation systems where versatility across mid-woofer and midrange roles, high sensitivity, high power handling, and extended mid-frequency performance are priorities. The neodymium motor, Kapton former, and aluminum basket provide consistent, durable performance in demanding professional environments.
This driver is suitable for both vented (mid-woofer) and sealed (midrange) enclosure configurations depending on the system architecture. In bass reflex enclosures, recommended net internal volumes range from 10 to 14 liters with tuning frequencies between 63 and 82 Hz. Smaller volumes (10–12 liters tuned to 72–82 Hz) prioritize mid-bass output and cabinet compactness for portable 2-way systems and stage monitors, while 14 liters tuned to 63 Hz extends the usable low-frequency response to approximately 54 Hz (–3 dB) for stand-alone applications without dedicated subwoofers. Port velocities remain low (9–12 m/s) across all vented alignments. In sealed enclosures for midrange duty, the driver performs in very compact net internal volumes of 1.0 to 2.2 liters, producing system resonances between 193 and 272 Hz. Smaller sealed volumes (1.0–1.4 liters, Qtc 0.85–1.0) maximize acoustic output in the midrange passband for line array modules and horn-loaded midrange systems, while 2.2 liters yields a Butterworth-class response (Qtc 0.707) with maximally flat amplitude for accuracy-focused applications.
The driver requires active DSP crossover management in both configurations. In vented mid-woofer use, a high-pass filter in the range of 53–72 Hz (24 dB/octave Linkwitz-Riley) is recommended depending on enclosure tuning, with a typical crossover to a high-frequency driver at 1.5–3 kHz. In sealed midrange use, a high-pass filter in the range of 180–350 Hz is recommended depending on enclosure volume and system architecture. In both cases, appropriate limiting is required to manage mechanical stress during sustained operation, though the Kapton former provides exceptional thermal headroom.
This driver is particularly effective in professional touring line arrays, compact 2-way portable loudspeakers, multi-way point-source cabinets, stage monitors, and installation systems where versatility across mid-woofer and midrange roles, high sensitivity, high power handling, and extended mid-frequency performance are priorities. The neodymium motor, Kapton former, and aluminum basket provide consistent, durable performance in demanding professional environments.
Enclosure Recommendations
ENCLOSURE RECOMMENDATIONS: 8NPMX8-157
Driver: 8NPMX8-157 (8NPM) — 8" Midrange / Mid-Woofer
Key T/S: Fs=79Hz, Qts=0.29, Vas=10.9L, Sens=96dB 1W/1m
Power: AES 200W / Cont 400W / Peak 800W
Xmax=3.7mm (one-way linear), Xmech=11.7mm (protection at 10.2mm)
Sd=213.8cm², Bl=14.2T·m, Re=5.4Ω, Mms=23.9g
Voice Coil: 2" CCAW on Kapton former (15.4mm winding height)
Magnet: Neodymium | Cone: Half-pressed paper
Surround: Fabric (double roll) | Spider: Nomex (optimized shape)
Basket: Aluminum
NOTE: This driver's low Qts (0.29) and high sensitivity (96 dB)
combined with a strong neodymium motor (Bl=14.2 T·m) make it suitable
for BOTH vented mid-woofer and sealed midrange applications. The Kapton
voice coil former provides peak temperature tolerance in excess of
280°C, well beyond the thermal demands of modern high-power systems.
The Nomex spider with optimized shape ensures well-controlled pistonic
motion across the operating range. Six enclosure alignments are provided
below — three vented (mid-woofer use) and three sealed (midrange use).
MID-WOOFER APPLICATION — Bass Reflex (Vented)
Use case: 2-way and multi-way systems where the 8NPM handles low-
frequency and lower-midrange content, typically crossed over to a
compression driver or tweeter at 1.5–3 kHz. The high sensitivity
(96 dB) makes this driver particularly effective in efficiency-
critical applications.
PORT RECOMMENDATION: Round port (65mm diameter) — standard for
compact 8" bass reflex enclosures. Port velocities are low across
all alignments (9–12 m/s), well within limits for all applications
including studio monitors. No flaring required.
a) VENTED — High SPL
Net Volume: 10 liters
Tuning (Fb): 82 Hz
Est. -3dB: 75 Hz
HP Filter: 72 Hz (24dB/oct LR recommended)
Round Port: 65mm dia × 100mm long
Slot Port: 148mm W × 40mm H × 187mm L
Port Velocity: 12.3 m/s
Notes: Compact alignment with strong mid-bass control and
maximum output per cabinet volume. The higher tuning provides
tight, punchy low end with excellent transient response.
Ideal for compact 2-way tops and stage monitors paired with
subwoofers, where the 96 dB sensitivity maximizes system
headroom from moderate amplifier power.
b) VENTED — Balanced Response
Net Volume: 12 liters
Tuning (Fb): 72 Hz
Est. -3dB: 61 Hz
HP Filter: 62 Hz (24dB/oct LR recommended)
Round Port: 65mm dia × 111mm long
Slot Port: 148mm W × 40mm H × 207mm L
Port Velocity: 10.8 m/s
Notes: General-purpose alignment with even response through
the bass region and good transient behavior. Well-suited for
most 2-way PA tops, multi-way systems, and installation
loudspeakers where the system operates with or without
subwoofer support.
c) VENTED — Extended Low Frequency
Net Volume: 14 liters
Tuning (Fb): 63 Hz
Est. -3dB: 54 Hz
HP Filter: 53 Hz (24dB/oct LR recommended)
Round Port: 65mm dia × 130mm long
Slot Port: 148mm W × 40mm H × 242mm L
Port Velocity: 9.4 m/s
Notes: Maximum low-frequency extension for stand-alone use
without subwoofers. The strong motor maintains tight cone
control even at this lower tuning. Best for applications
where deeper bass reach is required from a single 8" system.
Requires proper high-pass protection below tuning.
MIDRANGE APPLICATION — Sealed
Use case: Line array midrange sections, coaxial cabinets, horn-loaded
midrange systems, or dedicated mid-high enclosures where the 8NPM
handles the midrange band (typically 250–3000 Hz or narrower), with
bass duties handled by separate woofer/subwoofer sections. The high
sensitivity and extended mid-frequency response make this driver
particularly effective where sizable midrange output is required.
d) SEALED — High SPL (Qtc ≈ 1.0)
Net Volume: 1.0 liters
System Resonance (fc): 272 Hz
Qtc: 1.0
Response: Broad gentle lift near fc, maximum midrange output
Crossover HP: 250–350 Hz (24dB/oct LR recommended)
Notes: Very compact sealed chamber for maximum acoustic
output in the midrange passband. The elevated Qtc provides
a gentle broad peak near system resonance that can be
equalized flat via DSP or used as a passband sensitivity
boost. Ideal for high-SPL touring line arrays and horn-
loaded midrange systems where output per driver is the
primary requirement.
e) SEALED — Balanced (Qtc ≈ 0.85)
Net Volume: 1.4 liters
System Resonance (fc): 232 Hz
Qtc: 0.85
Response: Slightly warm, smooth transition through resonance
Crossover HP: 220–300 Hz (24dB/oct LR recommended)
Notes: Good compromise between midrange output and response
flatness. Suitable for most professional midrange applications
including line arrays, point-source cabinets, and stage
monitors. The Kapton former's thermal resilience supports
sustained high-power operation in these compact volumes.
f) SEALED — Butterworth (Qtc ≈ 0.707)
Net Volume: 2.2 liters
System Resonance (fc): 193 Hz
Qtc: 0.707
Response: Maximally flat amplitude, textbook Butterworth alignment
Crossover HP: 180–250 Hz (24dB/oct LR recommended)
Notes: Flattest possible sealed response with lowest system
resonance. Allows a lower crossover frequency and extended
lower-midrange coverage. Best for applications prioritizing
accuracy, smooth crossover integration, and minimal DSP
correction.
THERMAL NOTE: The Kapton voice coil former withstands peak temperatures
exceeding 280°C, providing significant thermal headroom beyond the
demands of modern amplification systems. Combined with the neodymium
motor's direct thermal coupling to the aluminum basket, this allows
sustained high-power operation in both vented and sealed configurations
without thermal compression concerns.
DESIGN NOTE: The Nomex spider with optimized geometry provides
well-controlled pistonic motion across the full excursion range. The
half-pressed paper cone and double roll fabric surround deliver a
lightweight, stiff piston with extended mid-frequency response — a
key requirement in midrange applications where vocal clarity and
presence are critical.
Frequently Asked Questions
- - Hi sensitivity
- - Hi power handling
- - Designed for applications where are sizable amounts of mid-frequencies required
ENCLOSURE RECOMMENDATIONS: 8NPMX8-157 Driver: 8NPMX8-157 (8NPM) — 8" Midrange / Mid-Woofer Key T/S: Fs=79Hz, Qts=0.29, Vas=10.9L, Sens=96dB 1W/1m Power: AES 200W / Cont 400W / Peak 800W Xmax=3.7mm (one-way linear), Xmech=11.7mm (protection at 10.2mm) Sd=213.8cm², Bl=14.2T·m, Re=5.4Ω, Mms=23.9g Voice Coil: 2" CCAW on Kapton former (15.4mm winding height) Magnet: Neodymium | Cone: Half-pressed paper Surround: Fabric (double roll) | Spider: Nomex (optimized shape) Basket: Aluminum NOTE: This driver's low Qts (0.29) and high sensitivity (96 dB) combined with a strong neodymium motor (Bl=14.2 T·m) make it suitable for BOTH vented mid-woofer and sealed midrange applications. The Kapton voice coil former provides peak temperature tolerance in excess of 280°C, well beyond the thermal demands of modern high-power systems. The Nomex spider with optimized shape ensures well-controlled pistonic motion across the operating range. Six enclosure alignments are provided below — three vented (mid-woofer use) and three sealed (midrange use). MID-WOOFER APPLICATION — Bass Reflex (Vented) Use case: 2-way and multi-way systems where the 8NPM handles low- frequency and lower-midrange content, typically crossed over to a compression driver or tweeter at 1.5–3 kHz. The high sensitivity (96 dB) makes this driver particularly effective in efficiency- critical applications. PORT RECOMMENDATION: Round port (65mm diameter) — standard for compact 8" bass reflex enclosures. Port velocities are low across...
The 8NPMX8-157 is an 8-inch high-efficiency neodymium mid-woofer designed for professional two-way, multi-way, and line array systems requiring high sensitivity (96 dB 1W/1m), extended mid-frequency response, and sustained high-power operation. It features a 2-inch CCAW voice coil on a Kapton former with peak temperature tolerance exceeding 280°C, a lightweight half-pressed paper cone with a double roll fabric surround, and a Nomex spider with optimized geometry for controlled pistonic motion. With a low Qts of 0.29 and strong neodymium motor (Bl 14.2 T·m), the motor and suspension are optimized to maintain consistent performance at high drive levels, with controlled excursion and reduced thermal compression during long-term operation.
This driver is suitable for both vented (mid-woofer) and sealed (midrange) enclosure configurations depending on the system architecture. In bass reflex enclosures, recommended net internal volumes range from 10 to 14 liters with tuning frequencies between 63 and 82 Hz. Smaller volumes (10–12 liters tuned to 72–82 Hz) prioritize mid-bass output and cabinet compactness for portable 2-way systems and stage monitors, while 14 liters tuned to 63 Hz extends the usable low-frequency response to approximately 54 Hz (–3 dB) for stand-alone applications without dedicated subwoofers. Port velocities remain low (9–12 m/s) across all vented alignments. In sealed enclosures for midrange duty, the driver performs in very compact net internal volumes of 1.0 to 2.2 liters, producing system resonances between 193 and 272 Hz. Smaller sealed volumes (1.0–1.4 liters, Qtc 0.85–1.0) maximize acoustic output in the midrange passband for line array modules and horn-loaded midrange systems, while 2.2 liters yields a Butterworth-class response (Qtc 0.707) with maximally flat amplitude for accuracy-focused applications.
The driver requires active DSP crossover management in both configurations. In vented mid-woofer use, a high-pass filter in the range of 53–72 Hz (24 dB/octave Linkwitz-Riley) is recommended depending on enclosure tuning, with a typical crossover to a high-frequency driver at 1.5–3 kHz. In sealed midrange use, a high-pass filter in the range of 180–350 Hz is recommended depending on enclosure volume and system architecture. In both cases, appropriate limiting is required to manage mechanical stress during sustained operation, though the Kapton former provides exceptional thermal headroom.
This driver is particularly effective in professional touring line arrays, compact 2-way portable loudspeakers, multi-way point-source cabinets, stage monitors, and installation systems where versatility across mid-woofer and midrange roles, high sensitivity, high power handling, and extended mid-frequency performance are priorities. The neodymium motor, Kapton former, and aluminum basket provide consistent, durable performance in demanding professional environments.
AES Power: 200 W,
Continuous: 400 W,
Peak: 800 W.
Sensitivity: 96.06 dB (1W/1m).
