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SD-2 Series

SD-2 10/12 :

The SD-2 woofer was born of the need for a woofer as close to the performance of the SA series as possible but with significantly less mounting depth. We started with the same heavily tested and proven cone, surround, and spider assembly of the SA line. From there an all new motor was engineered using half the magnet height of the SA line combined with a solid back plate. The solid back plate allows the SD-2 line to be mounted directly against the enclosure wall eliminating the need for venting space behind the motor assembly -- this reduces effective depth requirement by another inch! The SD-2 line is still able to effectively vent the voice coil through 16 holes drilled around the basket perimeter as well as a vented voice coil former allowing it to handle it's rated 500-watts RMS with ease without any excessive air noise or thermal compression.

Xmax = 12mm one-way by 70% BL
RMS Power = 500-watts

SD-2 8 :

The SD-2 8" is a very unique driver in our line. It is our first under-hung design; which means the coil is actually shorter than the top plate and remains completely immersed in the magnetic field without varation over most of it's stroke. For the more technical reader you may notice the top plate does not appear to be tall enough to be classified as under-hung. The fact is our deep custom tooled frame, originally developed for the SA-8 v.2, allowed us to tuck most of the top plate up insde the frame to achieve a total top plate thickness of one full inch without adding additional depth to the driver.

What does this mean to you, as the listener? The end result is a significant reduction of BL induced distortion (the #1 cause of distortion in subwoofers). The under-hung design also greatly reduces the variation of inductance over stroke; which is another major cause of loudspeaker distortion. When combined with the proven low distortion spider and surround borrowed from it's big brother the SA-8 v.2 (of course with half the number of spiders) the SD-2 8" is a truly reference level sound quality driver addressing the reduction all three major modes of distortion. Customers all over the world are constantly surprised by the level of ourput and fidelity these drivers provide.

The parameter set has been optimized for very small sealed enclosures ranging from 0.25 to 0.50 cubic feet. This makes the SD-2 8" the best 8" woofer in our line, and the only one I suggest, for sealed enclosures.

Xmax = 14.5mm one-way by 70% BL
RMS Power = 300-watts


SD-2 8 D4

SD-2 10 D2 | D4

SD-2 12 D2 | D4

Fs: 45.2 Hz
Re: 6.03 ohms
Qms: 7.31
Qes: 0.63
Qts: 0.58
Cms: 138 uM/N
Mms: 89 g
BL: 15.55 NA
Vas: 7.74 L
Sens: 82.29 dB 1w/1m
Le: 6.26 mH
RMS: 300 watts

Measurements SD-2 8"
Fs: 36.7 Hz | 39.7 Hz
Re: 4.0 ohms | 8.0 ohms
Qms: 5.51 | 5.45
Qes: 0.48 | 0.56
Qts: 0.45 | 0.52
Cms: 0.10 | 0.09 mm/N
Mms: 184 g | 178 g
BL: 18.7 NA | 24.7 NA
Vas: 15.6 L | 13.8 L
Sens: 83.9 dB | 83.5 1w/1m
Le: 2.69 mH | 4.06 mH
RMS: 500 watts

Measurements SD-2 10"
Fs: 36.8 Hz | 38.8 Hz
Re: 4.0 ohms | 8.0 ohms
Qms: 6.06 | 6.18
Qes: 0.58 | 0.69
Qts: 0.53 | 0.62
Cms: 0.08 | 0.09 mm/N
Mms: 225 g | 195 g
BL: 18.9 NA | 23.5 NA
Vas: 30.2 L | 31.7
Sens: 86.0 dB | 86.1 1w/1m
Le: 2.63 mH | 4.14 mH
RMS: 500 watts

Measurements SD-2 12"

Enclosure Recommendations

SD-2 8

SD-2 10

SD-2 12

Sealed 0.25ft^3 0.5 ft^3 1.0 ft^3
Ported 0.5 ft^3 1.0 ft^3 2.0 ft^3
Displacement 0.07 ft^3 0.08 ft^3 0.10 ft^3
Depth 4.75" 4.75" 5.25"
Outside Diameter 8 3/8" 10 1/2" 12 5/8"
Cut-Out 7 3/8" 9 1/4" 11 1/8"


Box Specs & Cut Sheet

Box designs are done with Google SketchUp. You will need SketchUp to open files properly.
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SD-8 Single Box Design SD-8 Dual Box Design
SD-10 Single Box Design SD-10 Dual Box Design
SD-12 Single Box Design SD-12 Dual Box Design