SVS 20-39PC+ 20 Hz tune (dB12.1)

[Ilkka]

Manufacturer: SV Sound
Model: 20-39PC+
Provided by: geecb
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 dB12.1 woofer

[Ilkka]

+/- 3 dB points: 18 Hz - 75 Hz

[Ilkka]

[Ilkka]

[Ilkka]

[Ilkka]

The older version of the 20-39PC+ shows a little bit worse frequency response that its newer version, though the same tilted down response above 50 Hz can be seen. The maximum output also closely resembles the newer version, though the older one has a slightly stronger lower mid bass output. The power compression grows rather large around the tuning frequency which suggests that the subwoofer is somewhat under ported.

The THD profile differs quite a bit from the newer dB12.2 version; the dB12.1 has quite a lot more THD in the upper bass range (above 50 Hz). The group delay stays low down to 30 Hz but grows rapidly below, exceeding the 1 cycle limit at 27 Hz.

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. Now it is geared towards HT use, and performs best in large rooms with little to no low frequency room gain.

+ High output in 20-40 Hz range
+ Very good extension
+ Low THD at low to medium output levels

- Uneven frequency response
- Medium upper bass output
- High THD at high levels, especially above 40 Hz
- High power compression around the tuning frequency
- High group delay and slow decay rate at low frequencies