Spyder STR700 8 175W

8″ subwoofer · 4 Ω · 175 W RMS

Fs 32 HzQts 0.82Vas 2.65 ft³
The published specs don’t add up:

Recommended box

For a sedan, one sub, 175 W. It’s the same math as the designer’s step-by-step mode, where you can fit the box to your space, vehicle and amp and get plans, a cut sheet and DXF.

Sealed

Net volume0.78 ft³ (22 L)
Qtc1.72
Fc67 Hz
F3 (−3 dB, no cabin gain)48 Hz
Example box (outside)10 1/4″ × 10 1/4″ × 19 7/16″
Open sealed box in designer

Ported

Net volume1.31 ft³ (37 L)
Tuning (Fb)50 Hz
Portslot 1 9/16 × 14 5/16″, 14 9/16″ long
Port velocity at 175 W28 ft/s
F3 (−3 dB, no cabin gain)46 Hz
Example box (outside)31 1/2″ × 15 3/4″ × 7 13/16″
Open ported box in designer
203040506080100150200667278849096HzdB
Sealed Ported · SPL in dB at 1 W / 1 m, no cabin gain

Thiele/Small parameters

Fs32 Hz
Qts0.82
Qes1.28
Qms2.28
Vas2.65 ft³
Re3.6 Ω
Sd≈ 33.3 in²
Xmax≈ 0.39″
EBP25 — suits sealed calc.
Sensitivity, 1 W / 1 m84.8 dB calc.

General

Size8″
Voice coils4 Ω
RMS power175 W

Mounting dimensions

Ø8 1/16″cutout Ø7 1/8″mounting depth 3 7/16″magnet Ø4 3/4″
Cutout diameter7 1/8″
Mounting depth3 7/16″
Overall diameter8 1/16″
Magnet diameter4 3/4″

“≈” means the value isn’t in the spec sheet and a typical value for the size is used; “calc.” means it’s calculated from the published parameters. Check the manufacturer’s spec sheet before you build.

Data sources

Other Spyder 8″ models