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SVS SB12-NSD Subwoofer Review

by October 31, 2006
  • Product Name: SB12-NSD Subwoofer
  • Manufacturer: SVS Sound
  • Performance Rating: StarStarStarStar
  • Value Rating: StarStarStarStar
  • Review Date: October 31, 2006 08:25
  • MSRP: $ 649 each / $1149 pair (Shipping Included)
  • 12” forward firing long throw “NSD” woofer
  • MDF enclosure
  • Curved non-resonant steel mesh grill
  • Amplifier: 400 watts rms (STA-400D Sledge/Class D)
  • Frequency Response: 23-270Hz +/-3dB (quasi-anechoic)
  • Finishes: Charcoal black textured vinyl or piano gloss black
  • Dimensions (H/W/D): 14.6” x 14.2” x 14.2”
  • Weight: 35 lbs.
  • Warranty: 5 years (Bumper to bumper)

Driver features

  • FEA optimized motor structure
  • Rubber long throw surround
  • Nomex linear roll spider
  • Aluminum cone with composite dust cap
  • Powder coated die-cast aluminum frame
  • Integrated tinsel leads
  • Dual shorting rings and pole piece extenders
  • Double stacked ferrite magnets
  • 2” diameter voice coil with high temperature former materials
  • Vented pole piece
  • Bumped back plate

Amplifier: Inputs/Outputs/Controls

  • Gain control
  • Variable phase 0-180deg
  • Adjustable low pass filter with disable setting (30-150Hz/Disabled)
  • Stereo line-level RCA I/O connections
  • Unfiltered (for daisy-chain) and 80 Hz high pass filtered line level RCA outputs
  • Detachable power cord with main power switch and fuse
  • RoHS compliant, lead-free construction and world-wide safety certifications        
  • Auto-On / On switch with "green" standby mode
  • Customized EQ and DSP limiter settings specifically for the SB12-NSD
  • Limiter LED


  • Diminutive form factor + light weight allows plenty of placement options
  • Impeccable design execution and optimization
  • Unflappable operation at the limit
  • Exceptional warranty term


  • Basic connections and controls only
  • Best suited to smaller spaces and/or moderate playback levels


SVS SB12-NSD Subwoofer Review Introduction

The SB12-NSB12-NSD top.JPGSD is the smallest subwoofer available in the broad lineup offered by SVS and is a sealed design using the same 12” driver and Sledge amplifier used in the recently reviewed PB12-NSD, but with some tweaks to the limiter and DSP in the amplifier that optimize it for the smaller sealed enclosure. The SB12-NSD also happens to be the most frugal way to own one of SVS’s current offerings with an as delivered price of $649. Purchasing a pair together nets you a nice discount and a total cost of $1149 shipped for 2 units. Having recently reviewed both SVS’s top of the line PB13-Ultra and their entry level bass reflex offering the PB12-NSD and been thoroughly impressed with the quality and preformance of both units, I was anxious to sample their entry level sealed alignment subwoofer to say the least..

Unpacking and Initial Thoughts

After having numerous 100, 200 and yes even 300+ lb subwoofers delivered to my home over the past couple of years my lower back heaved a big sigh of relief when the pint sized box containing the SB12-NSD arrived with a shipping weight of less than 50lbs. Yet despite the light weight and compact box the SB12-NSD’s packaging was robust, well thought out and should protect the unit from everything other than a catastrophic mishap during shipping. Unpacking was a simple matter of a few minutes of time and easily accomplished by one person of even limited physicality. Contained within the box are the usual items: the SB12-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 instead of providing a paper copy.

Once unboxed and revealed in all its glory the SB12-NSD is a very compact unit amounting to what is basically a 14” cube, not counting the signature SVS curved steel grille which does add about 2” to the overall depth. While not the absolute smallest unit I have reviewed, it is close. Additionally the weight of the SB12-NSD is only 35lbs so unpacking and moving it into position are a piece of cake. The finish on the review unit was SVS’s basic charcoal black vinyl which has a dark matte look with just a little texture to it. It is a clean but functional looking finish that disappears into a dimly lit room easily. The SB12-NSD is also available in a piano gloss black finish for a $30 up charge for those that want a little more pizzazz in the looks department. With its diminutive size, the curved grille attached and the slight rounding to the cabinet corners the SB12-NSD should rate high on the S.A.F. (Spousal Acceptance Factor) scale. I liked its modern yet functional look as did a few of my friends that I showed it to. The fit, finish and parts quality of the SB12-NSD appeared commensurate with what I have come to expect from SVS. In other words excellent.

Design Overview

The SB12-NSD is a sealed system utilizing a single 12” nominal driver forward firing on the front panel. Power and control for the system comes from an SVS proprietary Sledge plate amplifier rated at 400 watts continuous into a nominally 4ohm load. This is the same amplifier used with the previously reviewed PB12-NSD but with the DSP and protection settings optimized for the SB12-NSD instead.

Removing the SB12-NSD driver from the enclosure revealed it to be identical to the 12” driver used in the PB12-NSD which as mentioned in that models earlier review, is a high quality drive unit developed using FEA analysis. The driver is built upon a powder coated, open design, cast aluminum frame to which is attached a rubber half roll surround and a moderate diameter Nomex linear spider with sewn in voice coil leads. The cone is a lightweight aluminum with a composite dust cap embossed with the SVS logo. The voice coil is a 2” nominal diameter with a high temperature former material to better cope with high power and the motor system is completed by double stack of ferrite slugs of about 5.5” in diameter and about ¾” thickness each. A vented pole piece and a heavily bumped back plate round out the package and prevent mechanical bottoming of the former. Additionally there are two aluminum shorting rings in the motor to control and lower inductance.

SB12-NSD woof2.JPG     SB12-NSD woof1.JPG

The Sledge amplifier is listed as providing 400 watts continuous and as being a class D switch mode type having very high efficiency. This amplifier is a more stripped down version of the STA-1000D from the PB13-Ultra having the basic: Gain, phase, auto/on switch, RCA style inputs and daisy chain output connections as seen in the PB13-Ultra but without all of the extra bells and whistles like balanced XLR inputs, parametric EQ ability and minus 600 extra watts of muscle. Otherwise the construction quality seemed to be similar. A couple of small aluminum heat sinks are in evidence internally in addition to the heat sinking surface provided by the faceplate but in testing and use the amplifier never got any more than warm to the touch even with long duration test signals indicating that the efficiency is indeed very high.

SB12-NSD back.JPG     SB12-NSD inside1.JPG

The small enclosure of the SB12-NSD is constructed of 1” MDF material and despite lacking any cross panel bracing internally is inert and dead offering no appreciable resonance or vibration during listening, measurement testing or with the highly scientific knuckle rap test. This is due to a couple of things. First the panel material is thick and secondly the interior is generously lined with poly batting on four of the six enclosure panels. Even more important is the simple fact that the panels are very small which makes them very stiff already. Small enclosures with short panels such as this simply do not need heavy internal bracing like larger subwoofers do. This is why you see internal bracing extensively used in the much larger SVS PB13-Ultra and not here.

The black vinyl wrap used on the review unit was applied well and with the subtly rounded corners give the SB12-NSD an understated look. The grille secures firmly to the front of the enclosure with tabs that seem to be a little more durable than the typical fare used on most speaker grilles and the driver and amplifier are both nicely countersunk into their respective panels. The end result is visually pleasing and unobtrusive subwoofer. I can only imagine that the piano gloss finish enhances the visual appeal of the SB12-NSD that much more. The quality of construction, finishing and components is very good for this price bracket.

SVS SB12-NSD Subwoofer Review Listening Tests

For all of the listening sessions the SB12-NSD was placed in the front right corner of the room firing into the corner about 4 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 SB12-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 processor I use.

Blu-ray: Foo Fighters – Live at Wembley Stadium 


After integrating the little SVS into my main system I queued up a couple of favorite music selections from various genres and gave those a listen at moderate volume while I tried to decide on what concert Blu-ray I wanted to enjoy while evaluating the SB12-NSD’s performance. What immediately stuck out to me about the SB12-NSD was that it had a very nice upper register that seemed to blend through the crossover region exceptionally well. Small details and sharp transients falling in this range sounded very crisp and clear, certainly better than many subwoofers which seem to have trouble at the top of their range or through the crossover transition to the mains perhaps due to a limited or rolled off upper end bandwidth. Eventually I decided to watch the Foo Fighters concert recorded live at Wembley stadium in London. Mostly because I am a long time Foo Fighters fan and this concert in particular I have watched numerous occasions so that I am very familiar with it. The SB12-NSD did well right from the start, producing clear bass tones and a punchy kick drum with a smooth blend into the main speakers. On the harder driving songs with Nate Mendel dialing in a brasher bass guitar tone and Taylor Hawkins really laying into the drums the SB12-NSD produced a well defined attack and more output than I had expected when the master volume was increased liberally. Additionally clarity and note definition were well maintained which can be a problem with small subwoofers in big spaces. Often a smaller subwoofer will start to blur notes together or flatten the dynamics once they are required to produce more than moderate output in a big room. Not so with the SB12-NSD. It remained composed and clear. I also caught a few other live concerts while the SB12-NSD was being reviewed including the latest rock n roll hall of fame induction ceremony. While The Beastie Boys did a very entertaining set which I enjoyed, the Red Hot Chili Peppers gave the performance of the night in my mind and also had the best rhythm section if not the best mix too. Flea and Chad Smith are still a potent combination and the SB12-NSD delivered the bottom end of their funk rock delivery in a big way with plenty of pop and thump. I watched this with the master volume cranked up a touch louder than normal and the littlest SVS responded well.

Blu-ray: X-men – First Class


Having turned in a solid performance with both multi-channel and two channel music could the SB12-NSD continue to impress with its handling of the LFE channel during a dynamic and taxing action movie? In order to find out I selected the latest movie from the X-men franchise X-men: First Class. I was impressed with the overall mix and quality of audio present in this movie the very first time I watched it. The LFE channel in particular is used adroitly with good variety in volume, texture and depth. Virtually any scene involving Magneto is guaranteed to have some hefty bass transients. For example near the beginning of the film a young Magneto is forced to use his as yet undeveloped powers or face cruel consequences. This angers young Magneto which results in him smashing file cabinets around the room like tin cans and crushing various metal objects with his mind. During this scene there are very deep and heavy bass transients which are room flexing when reproduced right. Having some familiarity with small subwoofers and big action movie playback in this room I was a little worried how the SB12-NSD would handle this type of material but this proved to be of no concern. Certainly the SB12-NSD could not quite muster the sheer depth and room shaking power that some much larger and more expensive subwoofers have exhibited on these types of scenes but I was rather impressed with how well it did do considering its very compact size and modest cost. The very deepest bass frequencies seemed to be a little bit compressed or absent at times when required at high volume, such as the aforementioned Magneto scene, but otherwise the SB12-NSD put out a surprising amount of bass and seemed to be well in control in the process. At times the amount of bass filling the room was quite impressive for such a small subwoofer. Any scenes having thumping club beats or music in particular were well presented. During the final extended battle scene of the movie there is very heavy and difficult to reproduce bass throughout, once again mostly involving Magneto. While the SB12-NSD could not quite get to the bottommost depths of the content or quake the room as violently as some much larger subwoofers have, it still did pretty well. At no time did I hear bad noises or distress coming from the SB12-NSD and that is always my foremost concern with compact subwoofers being asked to anchor the LFE channel in a large space. SVS again seems to have masterfully executed their protection system because the SB12-NSD must surely have been into the limiter at a few points during playback of Xmen: First Class yet I heard nothing that would clue me into that fact. After this better than expected movie performance I found myself pondering what sort of further improvement adding an additional one, two or even three of the review units siblings might result in.

SVS SB12-NSD Subwoofer Review Measurements and Analysis

The SVS SB12-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

F sb12nsd low pass filter.jpg

SVS SB12-NSD: Effect of Low Pass Filter Settings

Above is the measured effect of various settings of the low pass filter on the SB12-NSD’s response. The roll off exhibits a textbook 12dB/octave slope and the corner in the response matched up well with the indicators on the control dial.

A sb12nsd basic response.jpg

SVS SB12-NSD: Basic Frequency Response as Tested

In the chart above is the basic response measurement of the SB12-NSD as it was tested. SVS claims a frequency response of 23-270Hz +/-3dB in the same type of measurement environment. This measurement actually betters the claimed response by fitting into a 6dB total window size from 21-300Hz. This is a very flat and extended response which indicates that there will be no problems blending the SB12-NSD to even the smallest bass shy speakers. A crossover point of 250Hz or slightly higher would not be out of the question if needed. Looking at the basic response shape another thing that jumps out is that there is obviously some signal processing involved to shape and flatten the SB12-NSD’s response. This is very common with small sealed subwoofers which otherwise would exhibit a shallow roll off starting somewhere above 35-40Hz in most cases. In the case of the SB12-NSD the outdoor response measurement indicates some amount of low frequency boosting and a high pass or rumble filter near 20Hz.

B sb12nsd waterfall.jpg

SVS SB12-NSD: Waterfall Decay

D sb12nsd group delay.jpg

SVS SB12-NSD: Group Delay

Looking at the SB12-NSD’s response in the time domain indicates that there is some delayed energy below 35Hz. This is probably due to the DSP signal manipulation going on inside of the amplifier namely the rumble filter and boost EQ employed as sealed subwoofers usually have very uniform and clean energy decay unless there is some sort of processing of the signal involved. The group delay does break through 1.5 cycles between 20-35Hz but during the listening sessions I never noted any overhang or sense of booming or ringing from the SB12-NSD at all. A little perspective here… In my experience there can be some audible issues that show up as delayed energy in these measurements but in the few cases where it has been clearly audible, the amount has been far above normal and perhaps more importantly also high Q in nature indicating a severe amount of ringing or a resonance of some sort. It has also been higher up in the frequency range. Another thing to keep in mind is that even with a quickly, cleanly decaying subwoofer system once you place it inside of a room the acoustics will wreak havoc with the response including in the time domain. Many times it will completely swamp the subwoofers raw contribution all together.

G sb12nsd long term output compression.jpg

SVS SB12-NSD: Long Term Output Compression

The maximum long term output compression test for the SB12-NSD shows that it maintains good bandwidth uniformity through the 100dB sine sweep but with compression setting in at the higher output levels. The output starts being limited near 25Hz first which indicates that is the likely center of the boost equalization used to extend the response. The boost equalization will chew up driver excursion and amplifier headroom much more quickly than the rest of the response range, so that the system will run into output limitations in the frequency range where the boost is centered first. By the 110dB sweep level the SB12-NSD is clearly out of gas. Running an even hotter 113dB sweep through it confirmed that the limiter was fully engaged at that drive level over almost the entire response range. Overall bandwidth uniformity is still pretty good even after the low bass range compresses though.

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 SB12-NSD was completely unfazed by even the highest level sine wave sweeps and emitted no more than a bit of an over tone to its sound when cone excursions were highest, which was probably excessive harmonic distortion. I’m not sure that I would have noticed it indoors or with masking information from other speakers. For all intensive purposes this test is the subwoofer being thrashed for all it is worth outdoors while you listen for any signs of it crying “uncle”. Subjectively, a bit of extra “warmth” to the lowest frequencies at the absolute maximum drive levels indicates that the protections and limiting circuits are doing their jobs very well. It takes a surprising amount of deep bass distortion for it to become offensive. I also thought that I detected just a hint of cabinet rock at very low frequencies when driven to maximum output which would not be surprising considering the small enclosure and light weight. This can occur with high power subwoofers in lightweight, small enclosures, but is not a serious concern usually. There were no notable noises or issues with the cabinet or amplifier otherwise. As with the other SVS subwoofers tested, the protection and limiting circuits employed in the SB12-NSD are extremely effective at limiting any chance of damage to the unit and preventing offensive overload noises.

H sb12nsd long term output compression magnitude.jpg

SVS SB12-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. This graph clearly shows the EQ boost used to extend the response mentioned previously. It is centered at about 23 or 24Hz. This type of compression behavior is typical of a deep bass boosted sealed subwoofer.

I sb12nsd max long term output.jpg

SVS SB12-NSD: Maximum Long Term Output Level

Looking at the maximum long term output achieved during a sine wave sweep by the SVS SB12-NSD shows that, while it is certainly no SPL juggernaut, it does have generous output capabilities for a sealed subwoofer of its size and cost maintaining a respectable 100dB SPL capability or more from about 30Hz on up and reaching over 91dB at 20Hz.


SVS SB12-NSD: Total Harmonic Distortion


SVS SB12-NSD: 110dB Sweep Distortion by Component

Evaluating the distortion performance of the SB12-NSD shows very low distortion levels above 40Hz never breaking 10% THD even at the highest output levels and well below 5% THD above 50Hz. Below 40Hz the distortion spikes up to a maximum near 23Hz which as mentioned previously is the center of the boost EQ used. This behavior of rising distortion towards the lowest frequencies is typical of a sealed subwoofer alignment where the driver excursion alone produces all of the output. Looking at the harmonic makeup of the distortion shows that it is dominated by the second harmonic above 55Hz where distortion is already very low to begin with. In the deeper bass frequencies the third harmonic dominates which is not unusual for a driver being asked to produce long excursions.


SVS SB12-NSD: CEA2010 2 Meter Groundplane RMS Results


SVS SB12-NSD: CEA2010 2 Meter Groundplane RMS Comparison

CEA2010 Results

The results for CEA-2010 short term burst testing show that the SB12-NSD possesses good peak output capabilities for a subwoofer of its size. Over 101dB is available from the 31.5Hz band on up. 105dB is available above 40Hz and the SB12-NSD manages to muster up almost 92dB at 20Hz with passing distortion results. Not bad at all for a single 12” driver in what amounts to a 14” cube. At 25Hz and above the output is amplifier limited. At 20Hz and below the SB12-NSD can eke out a little more raw output before the limiter clamps down but not without greatly increasing distortion levels.

SVS SB12-NSD Subwoofer Review Conclusion

SVS Grille OffI enjoyed my time spent the SB12-NSD. It has many positive attributes such as the compact form factor, excellent build quality and well rounded performance. The SB12-NSD exhibited excellent pitch definition and neutrality while having enough headroom in the typical kick drum range to provide some fun factor as well. The performance turned in with music in particular I felt was great and along with the measurements taken outdoors indicate that it would make a very effective subwoofer for a nearfield monitor system in a project studio or for smaller spaces. Being a small, lightweight sealed subwoofer you cannot expect the SB12-NSD to bowl you over with pants flapping deep bass output, which it does not. Multiple SB12-NSD’s or perhaps one of SVS’s larger and more expensive vented offerings will be required for that type of powerful deep bass extension. However the SB12-NSD does have a surprising amount of headroom for its size which accompanied by the exceptional limiting employed by SVS allows the SB12-NSD to operate up to the limits of its capabilities even in large rooms without having to worry about damaging it or having your experience degraded by bad overload noises. This was shown during movie nights where the SB12-NSD was clearly a little short on firepower for loud playback in my large 4,000+ cu ft room, yet still managed to provide an engaging and enjoyable experience. Note that if the SB12-NSD (or any other subwoofer) were employed in a smaller system/room than mine, which is rather large and difficult to fill, it would likely take on a much more muscular, powerful character.

At $649 shipped this is SVS’s least expensive and smallest subwoofer, but it still performs in a big way. If you need extra headroom and deep bass output you may want to scratch up an extra $120 and move up to the larger vented PB12-NSD, but many people will have a smaller room or want a smaller form which is easier to fit into their living space and this is where the SB12-NSD excels. The extra cost savings is nice as well. Whenever possible I recommend that at least two subwoofers placed in separate locations be at least considered as in many cases it can help to smooth the overall in room response and increase maximum headroom capability. SVS just so happens to offer a nice discount on a pair of SB12-NSD’s and in my opinion this is where the SB12-NSD would really start to shine. Due to the compact size it should open up more placement options for multiple units than if larger subwoofers were used and in many cases multiple smaller subwoofers can turn in a better overall performance than a single more powerful and expensive unit. Multiple SB12-NSD’s spread out would provide an excellent cost effective bass foundation for a moderate sized room while occupying a minimal amount of space. Highly recommended.

The SVS SB12-NSD receives the Audioholics Bassaholic Medium Room rating, which means that this sub is recommended as maintaining adequate headroom in rooms or spaces of between 1,500 to 3,000 cubic feet and/or for users who usually listen at moderate volume levels. For further information in how we make these recommendations see the full article here.

See: Audioholics Subwoofer Room Size Rating Protocol


SVS SB12-NSD Review

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MSRP: $649 (Shipping Included)

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

  • StarStarStarStarStar — Excellent
  • StarStarStarStar — Very Good
  • StarStarStar — Good
  • StarStar — Fair
  • Star — Poor
Bass ExtensionStarStarStarStar
Bass AccuracyStarStarStarStar
Build QualityStarStarStarStarStar
Fit and FinishStarStarStarStarStar
Ergonomics & UsabilityStarStarStarStarStar
Dynamic RangeStarStarStar
Attached Files