SVS 25-31PC+ 20 Hz tune (dB12.2)

[Ilkka]

Manufacturer: SVSound
Model: 25-31PC+
Provided by: Arttu78
Manufacturer link: SVSound - Cylinder Subwoofers
Price: $775

Manufacturer specs:
Proprietary TC-Sound 12" high output woofer
Computer Assisted Design (CAD) enclosure
Flush-mount, internal 525 watt BASH amp
Exclusive down-firing cylinder design
Compliant floor mounts, low center of gravity
"Tri-Power" 3" High-flow ports with port block
User variable tuning: 25 Hz (stock), 20 and 16 Hz
Resonance free, protective top grill
High-strength polymer wrapped enclosure
CNC'd black laminated, 1.5" birch end-caps
Architectural-grade black fabric exterior
Dimensions: 32" tall, 16" diameter
Weight: 23 kg
+/- 3 dB 25-100 Hz (25 Hz config) quasi-anechoic response (in-room extension will be 3-4 Hz deeper)

Configuration as tested:
Phase: 0 degrees
Tuning frequency: 20 Hz (one port plug)
Subsonic filter: 20 Hz
Orientation: Standard down-firing
This unit has a dB12.2 woofer

[Ilkka]

+/- 3 dB points: 19 Hz - 120 Hz

[Ilkka]

[Ilkka]

The shape of the frequency response becomes a bit better when plugging one of the ports. One gains around 5 Hz in extension due to this operation. Naturally the mid bass output takes around 2 dB hit, and the deep bass output gains by the same amount. Output compression grows larger around the tuning frequency due to lowered port area. The crossover works as promised and has a steep enough slope for 2-channel use. THD stays really low down to 20-23 Hz. Group delay stays below the 1 cycle limit. Spectral decay shows some added ringing around the tuning frequency compared to the 25 Hz tune. Spectral contamination test shows higher than average maximum output with low overall distortion.

+ Good extension
+ High mid bass output
+ Low overall distortion at all output levels
+ Overall price/performance ratio

+/- Look and weight of the cylinder
- Shape of the frequency response
- Somewhat high deep bass group delay and some ringing around the tuning frequency

[stlfdemt]

I wish my wife would let me get a cylinder sub

[drdoan]

Ilkka, great work! These boogers are really amazing when you factor in price. I had a 16-46PCi and loved it. Now I have the PB12-Plus/2 with the new drivers-Love it! Dennis