SVS PB12-Plus/2 20 Hz tune (Plus 12.3)

[Ilkka]

Manufacturer: SVSound
Model: PB12-Plus/2
Provided by: Ilkka
Manufacturer link: SVSound - Box Subwoofers
Price: $1199 (black), $1399 (wood veneer)

Manufacturer specs:
• Twin SVS designed/built custom Plus 12.3 woofers
• SVS designed, full-featured 900 watt BASH ® digital switching amp
• Premium finishes ship with on board Parametric EQ (PEQ)
• Built-in, flush-mount amp configuration
• Down-firing woofers with distinctive SVS integrated base-plate
• Compliant floor mounts, ultra low center of gravity
• Three tuned, patented 4” high-flow flared porting (in and out)
• Assembled and tested by SVS in its Ohio factory
• Extra heavy-duty detachable 8 foot power cord
• 6 wood-finishes
• Selectable 16Hz, 20Hz or 25Hz extension with included port plugs
• Size: 48 cm wide, 67 cm tall and 71 cm deep.
• Weight: 64 kg
• Frequency Response: +/- 3dB to 20hz anechoic
• 3 years warranty

Configuration as tested:
Phase: 0 degrees
Tuning frequency: 20 Hz (one port plug)
Subsonic filter: 20 Hz
Orientation: Standard down-firing, ports facing left
This unit has Plus 12.3 woofers

[Ilkka]

+/- 3 dB points: 20 Hz - 85 Hz

[Ilkka]

[Ilkka]

The frequency response becomes a bit better when plugging one of the ports, although the same mid bass hump can still be seen. Extension goes a full 5 Hz lower as promised. The maximum mid/upper bass output is naturally compromised when compared to the 25 Hz tune. Compared to the dB12.1 unit, these new woofers gain around 1-2 dB in mid/upper bass range. The new woofers have a lower THD in the upper bass range, although there is a pronounced hump in 30-40 Hz range at higher levels. The narrow THD spike around 30 Hz during the 110 dB sweep was probably caused by soft-bottoming of the driver(s) and a simultaneous limiting by the amp limiter. I suspect that the limiter let the output grow a little bit too high which resulted as a spike in THD. As the 115 dB sweep shows, the limiter worked as it should be during that sweep. I'm quite sure this problem can only occur during extreme testing, not during music or movie listening. Group delay stays below the 1 cycle limit at all frequencies. Spectral decay shows a little bit more ringing around the tuning frequency than with the 25 Hz tune. Spectral contamination test shows high output capability with lower than average overall distortion, very similar to the dB12.1 unit. The overall build quality is top-notch and the wood finish looks gorgeous. With some small modifications this could become a very good subwoofer.

+ Good extension
+ High overall maximum output capability
+ Low overall distortion
+ Overall price/performance ratio
+ Build quality and finish

- Shape of the frequency response
- High deep bass output compression

[Ayreonaut]

I visited the SVS showroom at their Ohio factory last week. I listened to all of their subs from the PB10-NSD to the PB12-Ultra/2. The big ones like the Ultra/2 were literally flapping my pant legs with infrasonic bass. The PB12-Plus/2 is a monster designed to fill a huge room with low, powerful bass. If you have a large room or you "need" 101 dB at 20 Hz (!) then this sub would fit the bill.

My little sealed 10-incher at home is definately faster that this ported beast. (I'm comparing apples to oranges.) A look at the Impulse Response and Spectral Decay above shows that this sub is not well damped in the lowest frequencies, compared to a sealed design. I personally prefer a tightly damped sound, but I don't get this kind of LF output.

[Blaser]

SVS is famous for reproduction of the deepest frequencies with ease... But concerning the PB 12 +/2 with the new driver (plus 12.3) measurements, it seems that the new driver is less capable below 30 Hz, and loses 4-5 db comparing to the old 12.1 driver at 20 Hz (20 Hz tune FR).... IMO, any frequency below 30 Hz is always welcome.... So, what happened???

I posted a link to this at the AVS subwoofer forum and no one there knows or is willing to answer. I am hoping Ilkka will have time to make comments. I am sure he spent plenty of time already.

[JimLely]

blaser wrote:

SVS is famous for reproduction of the deepest frequencies with ease... But concerning the PB 12 +/2 with the new driver (plus 12.3) measurements, it seems that the new driver is less capable below 30 Hz, and loses 4-5 db comparing to the old 12.1 driver at 20 Hz (20 Hz tune FR).... IMO, any frequency below 30 Hz is always welcome.... So, what happened???

As can be seen, the maximum output levels are about the same for the 12.1 and the 12.3. There is a difference in frequency response, but room gain adds as much as 12 dB per octave below 30 Hz and 15dB of boost at very low frequencies. So the award for flattest response (after including room gain) goes to the 12.3.

Hey Ilkka, Ive seen your completed tests for most of the SVS subs. Is there a chance of you doing an A, B, C comparison between the 12.1, 12.2 and 12.3 series drivers? I have seen a bunch of the 12.1 and 12.2 drivers for sale lately and would like to see how they compare. Is it worth while to upgrade (for SVS owners) to the new drivers or is it just marketing? I wouldnt think the lateral (reading how reputable the SVS company is) but some cant tell the difference (ive read). I was also considering trying a DIY sub with the 12.1 or 12.2 and trying to replicate the SVS sound.

[WillyD]

I was also considering trying a DIY sub with the 12.1 or 12.2 and trying to replicate the SVS sound.

Why replicate when you can improve.