- EXTENDED FREQUENCY RESPONSE, high excursion, ultra low THD
- Static demodulation coil, large spider with stitched tinsel wires
- Carbon fiber loaded paper cone
- The 121XR was designed to be simply the best driver for 2-way and multi-way systems on the market, yet this driver will also shine in sub-woofer applications. The combination of our XR patented technology with static shorting coil brings an nonparallel opportunity to the audio designers. The common request for 2-way speakers is “more of everything”. Designers wishes for
- more bass, more mids. Well, there you have it! But not only that. We bring this with clarity in the mid-frequencies and undistorted bass. Our designers were able to achieve THD below 0.5% from 20Hz up to 2.5kHz. There isn’t another driver like this on the market.Motor DesignThe magnetic design incorporates large neodymium magnets placed along the voice coil
- winding, together with the 2nd and static coil placed on the pole piece. This has allowed us to push the cone excursion to 25mm peak to peak, while lowering the inductance. The shorting coil covers the complete main coil excursion. This is also an improvement compared to some previous designs on the market. Unique gap venting ensures good air circulation and greatly improves the reliability of this driver.
General specs Nominal Diameter: 12 in. Rated Impedance: 8 Ohm Power handling AES Power: 500 Watts Program Power: 1,000 Watts Voice Coil Diameter: 2.5 in. Winding wire: Copper Former: kapton Winding height: 18.3 mm T/S Parameters Resonant frequency: 46 Hz Re: 5.6 ohm Qes: 0.42 Qms: 1.56 Qts: 0.33 Vas: 69.1 liters Sd: 531 cm2 Mms: 66.8 grams Bl: 16 Le: 0.16 mH Sensitivity: 95.78 dB Design details Surround Material: Fabric Cone material: Paper Spider: Nomex Plate thickness: 31 mm Peak to peak linear cone Displacement 25.4 mm Overall diameter: 320 mm Bolt circle diameter: 299 mm Baffle cutout dia.: 281 mm Number of mounting holes: 8 Depth (flange to rear): 172.5 mm Net weight: 5.1 kg Ordering codes: 8 ohm version: 121XRX8-352 Recone kits: Download: Spec download 2D drawing 3D model
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PRODUCT CODE: 121XRX8-352
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--- ENCLOSURE RECOMMENDATIONS ---
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ENCLOSURE RECOMMENDATIONS: 121XRX8-352
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Driver: 121XRX8-352 (121XR) — 12" Mid-Woofer
Key T/S: Fs=46.0Hz, Qts=0.33, Vas=69.1L, Sens=95.78dB
Power: AES 500W / Cont 1000W / Peak 2000W
Xmax=6.35mm, Sd=531.0cm², Bl=16.0T·m
RECOMMENDED ENCLOSURE TYPE: Bass Reflex (Vented)
PORT RECOMMENDATION: Round port (100mm diameter) — standard for mid-size professional enclosures; good balance of area and packaging
a) High SPL
Net Volume: 55 liters
Tuning (Fb): 51 Hz
Est. -3dB: 47 Hz
HP Filter: 43 Hz (24dB/oct recommended)
Round Port: 100mm dia × 84mm long
Slot Port: 225mm W × 60mm H × 174mm L
Port Velocity: 13.7 m/s
Notes: Strong mid-bass impact, reduced cone excursion, maximum output
b) Balanced Response
Net Volume: 65 liters
Tuning (Fb): 45 Hz
Est. -3dB: 38 Hz
HP Filter: 35 Hz (24dB/oct recommended)
Round Port: 100mm dia × 101mm long
Slot Port: 225mm W × 60mm H × 203mm L
Port Velocity: 12.0 m/s
Notes: General-purpose PA/subwoofer, even response, good transient behavior
c) Extended Low Frequency
Net Volume: 80 liters
Tuning (Fb): 39 Hz
Est. -3dB: 33 Hz
HP Filter: 27 Hz (24dB/oct recommended)
Round Port: 100mm dia × 121mm long
Slot Port: 225mm W × 60mm H × 238mm L
Port Velocity: 10.5 m/s
Notes: Deep bass extension, requires proper system protection below tuning
--- Summary ---
The 121XRX8-352 is a 12-inch mid-woofer driver designed for professional 2-way and multi-way systems requiring high sensitivity (96 dB 1W/1m) and controlled low-frequency behavior. 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.
In bass reflex enclosures, the driver performs best in net internal volumes of 55 to 80 liters, tuned between 39 and 51 Hz. This alignment provides a balanced combination of low-frequency extension, cone control around resonance, and efficient port loading. Lower tuning improves deep bass extension but increases excursion below tuning, requiring appropriate high-pass filtering. Higher tuning increases sensitivity and output in the upper bass region while improving mechanical control.
The driver is intended for use with high-power amplification (approx. 500 W AES / 1000 W continuous) and DSP control. A high-pass filter in the range of 27–43 Hz is recommended depending on enclosure tuning, along with proper limiting to manage thermal and mechanical stress. Typical operating bandwidth is 33–2000 Hz, covering bass through upper-mid frequencies for direct integration with a compression driver or tweeter in a two-way or multi-way system.
This design is particularly effective in single or multi-driver bass reflex systems used in professional two-way and multi-way PA systems, powered monitors, and compact bass-reflex enclosures, where extended bandwidth, controlled distortion across the full operating range, and versatile system integration are required.
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