SVS 20-39PC+ 20 Hz tune (dB12.2)

[Ilkka]

Manufacturer: SV Sound
Model: 20-39PC+
Provided by: Ate
Manufacturer link: SV Sound
Price: $899

Manufacturer specs:
• 525 watt, built-in amplifier
• 20 Hz extension (variable to 16 or 12Hz)
• +/- 3 dB 20 Hz-100 Hz (20Hz mode)
• 39" tall, 16" in diameter
• Proprietary TC-Sound 12" high output woofer
• Computer Assisted Design (CAD) cylindrical enclosure
• Flush mounted, 525 watt BASH amp (220V. avail)
• Exclusive SVS down-firing woofer with integrated base
• Compliant disk floor mounts, low center of gravity
• "Tri-Power" 3" high-flow ports with custom port block
• Resonance free, protective port grill
• CNC'd, black polymer laminated, 1.5" birch end-caps
• Architectural-grade black fabric exterior

Configuration as tested:
Phase: 0 degrees
Tuning frequency: 20 Hz (no port plugs)
Subsonic filter: 20 Hz
Top grill removed
Orientation: Standard down-firing
This unit has a dB12.2 woofer

[Ilkka]

+/- 3 dB points: 18.5 Hz - 75 Hz

[Ilkka]

[Ilkka]

[Ilkka]

[Ilkka]

Quite a typical SVS frequency response. It too tilts down quite heavily above 50 Hz which can be a problem with higher crossover settings and in rooms with lots of low frequency room gain. The sound becomes too bottom-heavy when the frequency response rises too much toward the low end. -6 dB point at 17.5 Hz is a good thing, but the whole frequency response could be shaped a little bit differently. The crossover works as promised and has a steep enough slope for 2-channel use. The maximum output reaches the 100 dB limit at 20 Hz, but the upper bass (above 50 Hz) output could be a little bit stronger. The power compression grows rather large around the tuning frequency which suggests that the subwoofer is somewhat under ported.

The THD stays reasonably low at all frequencies except below the tuning frequency at around 21 Hz. The group delay grows rather steadily towards the low frequencies, exceeding the 1 cycle limit at 26 Hz. That is a similar performance to all ~20 Hz tuned SVS subwoofers I have tested. The spectral decay graph too shows a typical performance for a ~20 Hz tuned SVS subwoofer; around 160 ms of ringing at those frequencies isn’t that bad.

The cylinder shape of the SVS 20-39PC+ has its supporters but also haters. It is a very light design which can cause some problems during extremely high output, more exactly the cylinder starts to jump up and down. Overall it has a good performance, though same critic applies to it as to most of the other SVS subwoofers. The frequency response could benefit from some shaping, and also the upper bass output could be a little bit higher.

+ High output in 20-40 Hz range
+ Low distortion
+ Very good extension

- Uneven frequency response
- Medium upper bass output
- High power compression around the tuning frequency
- High group delay and slow decay rate at low frequencies