SVS PB12-NSD Subwoofer Review

SVS PB12-NSD Subwoofer Introduction

Today we will look at the smallest most cost effective vented offering in SVS’s lineup the PB12-NSD which contains a single 12” driver in a vented enclosure with a 400 watt rated amplifier, all for the low price of $769 shipped to your door. These same basic ingredients are also available in a cylinder style enclosure as the PC12-NSD which also happens to be $20 less expensive. SVS has a reputation for building high performance vented subwoofer systems like the recently reviewed PB13-Ultra, which is a very impressive subwoofer, so I was eager to see how their entry level model would perform.

Unpacking and Initial Thoughts

The PB12-NSD arrived via FedEx in an impressively large box. Thankfully the PB12-NSD is only a fraction of the larger PB13-Ultra’s mass. SVS lists the PB12-NSD’s weight as 66lbs dry, so all packed up it is probably right near 80lbs. It’s a large and bulky box but not bad for an average man to handle. Opening the box and removing the PB12-NSD was quick and straightforward involving the usual opening of the top, removal of some of the smaller items on top and then flipping the sub over and lifting the box up and off. Contained within the box are the usual items: the PB12-NSD in its protective bag, the grill also in its own protective bag, the power cord, quick start guide, etc. SVS has opted to offer the owners manuals online for download.

The curved steel grills that SVS supplies are very heavy and attach securely into place. I’ve never seen any others like it and while they are heavy duty they also must cost quite a bit to manufacture. The size of the PB12-NSD once unpacked is on the large side as compared to most powered subwoofers in it’s price bracket, but not excessively so in my opinion. The black finish had a utilitarian, unobtrusive look to it, which I didn’t mind. It was finished well and the rounded corners looked nice but it did have a crease on the bottom where the wrap meets, not that many will be viewing the bottom of your 70lb subwoofer. It won’t win any looks or style contests but it should blend in well in a dark room which is important as you want to focus on the sound and not the equipment producing it. This is the only finish that SVS offers for the PB12-NSD likely because other higher end ones would raise the cost.

Design Overview

The PB12-NSD utilizes a single 12” nominal driver forward firing on the front panel which is vented in the upper right corner via a large 4” diameter port with generous flares on both the inlet and outlet. The enclosure volume and length of port used result in a system tuning of roughly 20Hz. Power and control for the system comes from an SVS proprietary Sledge plate amplifier rated at 400 watts continuous into a nominally 4ohm load.

Removing the SVS PB12-NSD driver from the enclosure revealed it to be a high quality unit especially for this price bracket. It is built upon an open cast aluminum frame to which is attached a moderate sized rubber half roll surround and single Nomex linear spider of what appeared to be roughly 6” diameter with sewn in leads. These items center and control an aluminum cone with a composite dust cap embossed with the SVS logo, connected to a 2” diameter voice coil and former. This moving assembly is controlled by double stacked ferrite slugs of about 5.5” in diameter and probably ¾” thickness each. The pole piece is vented and the back plate is heavily bumped to prevent mechanical bottoming of the former. Additionally SVS’s literature mentions that there is not a single but a pair of aluminum shorting rings in the motor to control inductance and non-linearity. The unit is also listed as being developed with the use of finite element analysis.

SVS PB12-NSD Driver

The Sledge amplifier itself is listed as providing 400 watts continuous into a 4ohm load and as being a class D switch mode type having very high efficiency. This amplifier is a much more stripped down version having the basic gain, phase, auto/on switch and RCA style input and daisy chain connections without all of the extra bells and whistles, like balanced XLR inputs and parametric EQ ability, that were on display with the more powerful unit used in the PB13-Ultra. Otherwise the construction quality seemed to be similar. A couple of small aluminum heat sinks are in evidence but in testing and use the amplifier never got any more than warm to the touch.

Backpanel View of SVS PB-12NSD Sledge Plate Amplifier

The enclosure of the PB12-NSD is constructed of 1” MDF and is covered in a black textured vinyl wrap. The amplifier, port and driver cut-outs are recessed which is always nice. The driver also mounts with threaded screws and inserts. Internally all of the enclosure walls are lined with about 2” of damping material except for the baffle where the port and driver mount and the back panel where the amplifier is. There is a large window brace which also supports the port in the center of the enclosure that reinforces and connects the center of the top, bottom and 2 side panels. Overall the build quality is very good. The materials are high quality, rugged and there is sufficient bracing and damping involved to ensure that the enclosure won’t degrade the sonic signature of the system.

SVS PB12-NSD Inside View

SVS PB12-NSD Subwoofer Listening Session

For all of the listening sessions the PB12-NSD was placed in the front right corner of the room firing into the corner about 8 inches from the walls. This places the subwoofer a little over 4 meters from the primary listening position. I have determined this to be the best available single subwoofer placement in the room for most units. Audyssey was run on the system to allow it to integrate the PB12-NSD, which was then followed by a check and recalibration of the subwoofer and speaker levels prior to the listening sessions. The internal low pass filter was defeated in favor of the internal one inside of the Onkyo PR-SC886P.

CD: Primus - Green Naugahyde 

In order to give the PB12-NSD a chance to strut its stuff with music I selected the newest full length from eclectic funk rockers Primus. As is usual for the group the material on the album ranges from bluegrass, almost folk rock at times, to funk, rock, metal and full out improvisation sessions. The recording is very clean. The drum kit is exceptionally punchy and tightly tuned as usual and the bass guitar ranges from smooth upright bass to electric fuzz distortion, funk slap and anything else you can think of. There isn’t anything really low or particularly taxing here, as usual that will come from the movie demo session, but what there is on the Green Naugahyde album, is an extreme variety of bass tones and textures. The PB12-NSD easily tracked the fundamental changes of the frenetic bass licks while providing a satisfying tromp to the kick drum and floor toms. Les Claypool’s myriad bass runs and tones had significant dynamic pop and clarity. Even when turning the level up to a point that was quite loud the PB12-NSD maintained excellent pitch definition and composure, providing just the right underpinning as needed and when called for. I listened to almost the entire album plus a few other selected tracks from different artists afterwards and the PB12-NSD exhibited a fine performance devoid of any notable deficiencies with all of them.

Blu-ray: X-men – First Class

I selected the Blu-ray disc of the film X-men First Class to evaluate the PB12-NSD’s performance with a powerful, bass heavy surround mix. I’m a fan of all of the X-men films and this one has by far the most demanding audio track for a subwoofer out of the series. At times the bass range dives below 20Hz at very high levels. I knew this would be a tough test for a single PB12-NSD in my large room. I was surprised and impressed during the first Magneto scene at the amount of bass and depth presented without any sign of distress or overload. During down time between major action sequences the bass content of background scores or day to day activity was represented very well. During the much louder action sequences the PB12-NSD did a good job of filling the room with power and depth. Ocassionally on a particularly loud part I would see the limiter light flash. The later parts of the movie and most notably the end battle scene contain prodigious deep reaching bass that will tax any system. The PB12-NSD gave everything it had and despite the limiter indicator lighting up frequently still sounded very good. Judging from this I would say that SVS has done a tremendous job with the system protection circuits. I do not recall hearing any notable port noise during the listening session either. The PB12-NSD could not match the deep bass extension and dynamic output performance that its larger and much more expensive cousin the PB13-Ultra had, but this is unsurprising. It still offered a very solid all around performance with strong deep bass extension. Think of it as a little less than a half of a PB13-Ultra. Normally in a room of this size I would want two units for headroom and response smoothing but even still, a single PB12-NSD performed exceptionally well for a sub in this price class.

SVS PB12-NSD Subwoofer Measurements and Analysis

The SVS PB12-NSD subwoofer was measured outdoors sitting directly on the ground with the M30 microphone placed 2 meters from the front lip of the cabinet with the grill removed. The driver was facing directly toward the microphone. The LFE input was used so that the internal low pass filter was disabled, the phase was set to 0 and the subwoofer volume was set to maximum. All tests were conducted in this configuration, except for those tests purposely conducted to examine the effects of the built in functions or different operational modes.

The overall approach to this testing along with the equipment and software used is outlined in the article here:

Powered Subwoofer Testing Outline and Procedures Overview

SVS PB12-NSD: Effect of Low and High Pass Filter Settings

 Above is the effect of various settings of the low pass on the PB12-NSD’s response. The slope appears to be 12dB/octave and the response matched up well with the indicators on the control dial.

SVS PB12-NSD: Basic Frequency Response as Tested

In the chart above is the basic response of the PB12-NSD as it was tested. The resulting response shape is extremely flat and extended. The response nose dives below 20Hz at what appears to be 48dB an octave indicating the typical bass reflex 4th order roll off below tune combined with a 4^th order rumble filter. SVS rates the response as 18-150Hz+/-3dB. The response as measured came in at 19-275Hz within a 6dB total window. This is a very close match with SVS spec and confirms their rating. Judging from the result here the PB12-NSD could conceivably be crossed over as high as 200Hz if needed and has excellent top end linearity. SVS publishes a measured outdoor ground plane frequency response curve for each of their subwoofers on their website, so it is no surprise that the measured result should come in extremely close to their published measurement. I wish other manufacturers would publish the same sort of data.

SVS PB12-NSD: Waterfall Decay

SVS PB12-NSD: Group Delay

Looking at the PB12-NSD’s response in the time domain we see that it is well behaved until below 30Hz where there is some delayed energy seen centered at the port tuning. This is typical of resonant systems with a steep high pass filter at tuning. The audibility of this at such low frequencies is debatable and the room that the subwoofer is placed in will also contribute quite a bit in this regard. I certainly never heard this in any obvious manner.

SVS PB12-NSD: Long Term Output Compression

The maximum long term output compression test for the PB12-NSD shows that it has respectable but not herculean maximum output, but that it does maintain exceptional bandwidth uniformity. Even up to the point that the limiter is squelching any further output over the entire bandwidth the overall response shape changes very little. There was just a bit of port compression near 20Hz causing a shallow tilt towards the low end. Output below 30Hz is impressive. Taken all together this indicates that the PB12-NSD will not have the radical changes in response shape with increased output level that most other subwoofers in this price bracket will exhibit.

Editorial Note on Output Compression Testing:

This is by far the most demanding measurement type conducted on the subwoofers during our testing and will reveal any issues with overload, port compression, port noise, driver distress, creaks, rattles, buzzes, etc. Additionally the test is conducted outdoors with just the subwoofer operating so there will be no nearby walls or objects to vibrate and no upper frequency content from other speakers in operation. These would normally help to cover up or mask any objectionable noises from the subwoofer in a typical room. Any sort of audible distress or issues with the subwoofer are readily apparent in this environment.

The PB12-NSD itself was very clean during this testing and was lacking in any major distress noises or cabinet issues. The most offensive noises produced were a tinge of wooliness to the very low bass during heavy driver excursion, which is common and usually indicates distortion and or suspension noise, and some port chuffing on only the very highest level sweeps. I doubt that I would have heard any of this with program content in a domestic setting with the rest of the speaker system operating. SVS’s protection settings are very effective and prevent you from either audibly overdriving the PB12-NSD or destroying it.

SVS PB12-NSD: Output Compression Magnitude

Above we have another way of looking at the results from the output compression test. This shows only the amount of compression of the signal that is occurring at each drive level. The PB12-NSD exhibits virtually no compression at the 100dB sweep level. At 105dB some vent compression at 20Hz can be seen but other than that the signal is largely reproduced at 100%. At the 110dB sweep level we can see that the limiting circuit has intervened and is compressing the signal heavily over the entire range so the testing was stopped at this level.

SVS PB12-NSD: Maximum Long Term Output Level

Looking at the maximum long term output achieved by the PB12-NSD it falls in the middle range of all subwoofers tested thus far providing about 105dB or more from 25Hz on up. With an honest 100dB of output or more at 20Hz it offers greater headroom than most comparably priced subwoofers below 30Hz.

SVS PB12-NSD: Total Harmonic Distortion

SVS PB12-NSD: 110dB Sweep Distortion by Component

Evaluating the distortion performance of the PB12-NSD presented above it is apparent that this is a very clean subwoofer. At the highest 110dB sweep level used for the test the THD is below 10% until below 20Hz. On top of that the distortion is composed primarily of the 2^nd and 3^rd harmonics which are the least offensive. Below the 20Hz tuning the distortion rapidly gets out of hand but this is common for resonant systems below tuning. This is a great performance and reinforces my subjective observation that the PB12-NSD sounded very clean even operating at its limits.

SVS PB12-NSD: CEA2010 2 Meter Groundplane RMS Results

SVS PB12-NSD: CEA2010 2 Meter Groundplane RMS Comparison

CEA2010 Results

The results for CEA-2010 short term burst testing place the PB12-NSD in the middle range of all subwoofers tested to date with 105-110dB output between 31.5-125Hz. The strong 16-25Hz output pushes the PB12-NSD closer to the upper tier of subwoofers tested over that range. In room a useful 16Hz is possible and the recorded output of 103.2dB at 20Hz should mean strong headroom down to that range at least. The output was amplifier limited everywhere at 20Hz and above. Again notice how the response shape of the PB12-NSD maintains its same basic shape still.

SVS PB12-NSD Subwoofer Conclusion

In light of the the build and parts quality, the generous 5 year “everything’s covered” warranty, the performance in the objective measurement session, which includes: Outstanding bandwidth uniformity, linear response, low distortion and true 20Hz extension, etc... There is a whole lot to like about the PB12-NSD and relatively few gripes. It is a big subwoofer compared to many of the micro “subs” on the market and some people may not want something this large in their room. Also the matte black finish, while perfectly fine for me, may not appeal to others who may enjoy a more pleasing aesthetic. Also other subwoofers may provide extra bells and whistles lacking from the PB12-NSD such as EQ pre-sets, more connection options, remotes, etc. Otherwise in the aspect of producing bass the PB12-NSD fires on all cylinders and provides a bulletproof, low distortion bottom end. $769 shipped to your door is a bargain price for this kind of all around performance and well within the reach of most audio aficionados, even those with tight budgets. Anyone looking for a new affordable high performance subwoofer (Or perhaps two at this price.), would be remiss not to include the PB12-NSD into their considerations, even if you are not the type who usually buys products internet direct, sight unseen. SVS has done it again.

The SVS PB12-NSD receives the Audioholics Bassoholic Large Room rating, which means that this sub is recommended as maintaining adequate headroom in rooms or spaces of between 3,000 to 5,000 cubic feet and/or for users who usually listen at moderate to high volume levels. For further information in how we make these recommendations see the full article here.

See: Audioholics Subwoofer Room Size Rating Protocol

SVS PB12-NSD Review

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The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

• — Excellent
• — Very Good
• — Good
• — Fair
• — Poor

Metric	Rating
Bass Extension
Bass Accuracy
Build Quality
Fit and Finish
Ergonomics & Usability
Features
Dynamic Range
Performance
Value