SVS PB16-Ultra Ported Subwoofer Review

[gene]

SVS just put the rest of the subwoofer ID market in checkmate with their new 16-Ultra series subwoofer which come in sealed and ported models. SVS has touted their new 16-Ultra series as the most advanced subwoofers in the world, so we were very excited to have SVS send us their new ported super-sub for review to confirm, the PB16-Ultra. The PB16-Ultra sports a 16" driver with an 8" voice coil powered by a 1500 watts (continuous) amplification.

Will this sub bust our Extreme Bassaholics rating? Read on to find out.

Read: SVS PB16-Ultra Ported Subwoofer Review

 

[KEW]

The frequency response graphs of the modes of the PB16-Ultra demonstrate it to be a very accurate subwoofer. One difference between our findings and SVS’s specs occurs in the high end, where SVS’s claims a +/- 3 dB point out to 280 Hz in the ported modes. We see a big drop right after 200 Hz, but that can hardly be a point of complaint for a subwoofer, since that is already an above-average high-end extension that isn’t likely to be taken advantage of as it is.

It looks like it is, in actuality, down 12dB at 280Hz!
While I'd agree that would not typically be a concern for a subwoofer, I do believe it is a valid complaint about a subwoofer that claims to be -3dB at 280Hz. Did you contact SVS to discuss this?
I don't know why they would consider this spec desirable enough to misrepresent it and with their technical rep's experience, it seems like they should be interested in resolving this (change their published specification).

 

[shadyJ]

It looks like it is, in actuality, down 12dB at 280Hz!
While I'd agree that would not typically be a concern for a subwoofer, I do believe it is a valid complaint about a subwoofer that claims to be -3dB at 280Hz. Did you contact SVS to discuss this?
I don't know why they would consider this spec desirable enough to misrepresent it and with their technical rep's experience, it seems like they should be interested in resolving this (change their published specification).

That is a response they may well have measured. That might have been the response from a different DSP setting or firmware version, or it may have been a consequence of the measurement method that they employed for that particular set. Slight changes in the measuring process can lead to some unexpected results. Either way, subwoofer behavior at such high frequencies are rather unimportant.

 

[Irvrobinson]

If you look at the Velodyne DD18 Plus review from five years ago, it has similar frequency response characteristics. In my system it is irrelevant, by over an octave.

 

[gene]

It's inconsequential if you're running speakers that have substantial output down to 80Hz. But if you're trying to mate to a small pair of satellite speakers, go for the SB16-Ultra as it will have more output at 80Hz and above.

 

[nickboros]

Nice review. I noticed one typo though. On the long term output compression figures the Caption says that these are sweeps for the Hsu subwoofer that was recently reviewed.

 

[shadyJ]

Nice review. I noticed one typo though. On the long term output compression figures the Caption says that these are sweeps for the Hsu subwoofer that was recently reviewed.

Oops! good catch. For formatting consistency I copied and pasted certain parts of that review for the structure since both subs have three modes of operation, and looks like I forgot to change the name there.

 

[mthomas47]

I enjoyed the review. It was very thorough and seemed quite objective. I am a little confused about one aspect of the measurements, though. Is your testing methodology the same as Josh Ricci's? I remember that he is also testing at 2 meters ground plane, but are there other differences?

The reason I ask is because I have both the PB13 and the PB16, and the 16 seems to have audibly deeper extension than the 13. That is consistent with SVS's claimed performance for the sub, which indicates a one port tune of 13Hz (not 17Hz) +/- 3db. It is confusing to me that the 16 would have 4db more output at 16Hz (comparing Data-Bass numbers for the PB13 in one-port mode) but have almost identical performance at 12.5Hz.

I know that, in addition to claiming more low-end extension on the SVS website, and in thread posts, that was a specific design goal for the new PB16. The disparity in your tested performance and theirs at 280Hz seems essentially irrelevant to me, as you suggested. But, the disparity in performance below 16Hz is far more significant in my view, and more difficult to understand, given the larger cabinet, driver, excursion, port tune, etc. compared to the PB13. It also seems inconsistent with the observed performance that PB16 owners, including myself, are reporting.

Is this an issue that you were aware of and can comment on? Again, I am extremely surprised that you measured the PB16 (with a reported 13Hz port tune) at only 89.1db at 12.5Hz, when the PB13 (with a 15Hz port tune) measured 89.3db. Is this a difference in testing methodology between you and Data-Bass, and/or SVS?

Thanks for any clarification on this issue. I have three of the new PB16's (that I upgraded from 13's) in a large room, along with a nearfield PB13, that I kept. Even nearfield for increased tactile response, and level matched with the 16's, my 13 does not go quite as deep as the 16's, so this is something I would like to understand better.

Regards,
Mike

 

[shadyJ]

Hello mthomas,

three PB16s in one room! Good lord, that is a beast of a system! To answer some of your questions:

I tried to emulate Josh's measurement methodology as closely as possible, since he really sets the gold standard for subwoofer measurements and reviews. He has given me a ton of advice and assistance in this, and, as a result, my own measurements of a same model sub that he measured average less than a one dB difference. Josh is a great guy and has been tremendously helpful!

As for the measurement as 12.5 Hz, what tells part of the story of what is occurring can be gleaned in this image in the 12.5 Hz panel. The third harmonic is a very heavy presence at both 10 and 12.5 Hz at all but the lowest drive levels seen there. I can only speculate about the cause. First we have to keep in mind that 12.5 Hz is below the intended range of operation for the PB16 in its ported modes, so trying to get monster 12.5 Hz output from it is, in a sense, misusing it. 12.5 Hz is well below tuning, I am not sure what we should really expect from that point except for port noise. The driver is only being controlled by the limiter at that point since there is no more backspring pressure, so it is no wonder there is a lot of distortion. That being said, the other ported subwoofers I have tested did have a greater ratio of fundamental-to-distortion at these super low frequencies. The only other subwoofer I have seen with this constant presence of odd-order harmonic distortion in these low frequencies was the Hsu ULS-15 mk1, which also used a underhung driver, so it may have something to do with the way underhung topology reacts to these extreme deep frequencies? That is just wild speculation though.

Something we should keep in mind is when we talk about hearing deep bass such as 12.5 Hz, what is it that we think we are hearing? We need over 100 dB just to sense 12 Hz at all! And even then we can not discern pitch at such deep frequencies, and sound at these frequencies is just perceived as discontinuous noise. If you blast a 12.5 Hz tone on either the PB13 or PB16, you will definitely hear something, but that something is not 12.5 Hz, it is the harmonics of 12.5 Hz and perhaps port turbulence.

Something else to note about Ricci's results with the PB13 is that while he could only measure a passing burst at 89 dB at 12.5 Hz, he could achieve 97.4 dB without any distortion thresholds. From this, I would guess he was seeing the same kind of behavior that I was; lots of 3rd harmonic distortion even at modestly high drive levels, as I speculated before, perhaps an attribute of underhung topologies since the PB13 uses an underhung motor as well. Similarly, disregarding thresholds, I was able to get a 103.0 dB peak reading (100 dB RMS), so the PB16 is definitely capable of moving more air.

The short version is I think what you are experiencing is overall greater sound pressure levels in really deep bass frequencies, but not the fundamentals so much. Even the third harmonic of 12.5 Hz (37.5 Hz) is still a very deep tone and is certainly in a range where human pitch discrimination is not great. Hopefully that gives you a little bit of insight on what you are experiencing.

 

[mthomas47]

Hello mthomas,

three PB16s in one room! Good lord, that is a beast of a system! To answer some of your questions:

I tried to emulate Josh's measurement methodology as closely as possible, since he really sets the gold standard for subwoofer measurements and reviews. He has given me a ton of advice and assistance in this, and, as a result, my own measurements of a same model sub that he measured average less than a one dB difference. Josh is a great guy and has been tremendously helpful!

As for the measurement as 12.5 Hz, what tells part of the story of what is occurring can be gleaned in this image in the 12.5 Hz panel. The third harmonic is a very heavy presence at both 10 and 12.5 Hz at all but the lowest drive levels seen there. I can only speculate about the cause. First we have to keep in mind that 12.5 Hz is below the intended range of operation for the PB16 in its ported modes, so trying to get monster 12.5 Hz output from it is, in a sense, misusing it. 12.5 Hz is well below tuning, I am not sure what we should really expect from that point except for port noise. The driver is only being controlled by the limiter at that point since there is no more backspring pressure, so it is no wonder there is a lot of distortion. That being said, the other ported subwoofers I have tested did have a greater ratio of fundamental-to-distortion at these super low frequencies. The only other subwoofer I have seen with this constant presence of odd-order harmonic distortion in these low frequencies was the Hsu ULS-15 mk1, which also used a underhung driver, so it may have something to do with the way underhung topology reacts to these extreme deep frequencies? That is just wild speculation though.

Something we should keep in mind is when we talk about hearing deep bass such as 12.5 Hz, what is it that we think we are hearing? We need over 100 dB just to sense 12 Hz at all! And even then we can not discern pitch at such deep frequencies, and sound at these frequencies is just perceived as discontinuous noise. If you blast a 12.5 Hz tone on either the PB13 or PB16, you will definitely hear something, but that something is not 12.5 Hz, it is the harmonics of 12.5 Hz and perhaps port turbulence.

Something else to note about Ricci's results with the PB13 is that while he could only measure a passing burst at 89 dB at 12.5 Hz, he could achieve 97.4 dB without any distortion thresholds. From this, I would guess he was seeing the same kind of behavior that I was; lots of 3rd harmonic distortion even at modestly high drive levels, as I speculated before, perhaps an attribute of underhung topologies since the PB13 uses an underhung motor as well. Similarly, disregarding thresholds, I was able to get a 103.0 dB peak reading (100 dB RMS), so the PB16 is definitely capable of moving more air.

The short version is I think what you are experiencing is overall greater sound pressure levels in really deep bass frequencies, but not the fundamentals so much. Even the third harmonic of 12.5 Hz (37.5 Hz) is still a very deep tone and is certainly in a range where human pitch discrimination is not great. Hopefully that gives you a little bit of insight on what you are experiencing.

Thanks for the response and I appreciate the explanation. It is a pretty cool system, but it's also a big room and on a concrete pad, so the four subs give me both good ULF and good bass envelopment. I thought that you were using a very similar methodology to the one Josh uses. I know from other articles that you have collaborated.

I think you may have missed one thing that I said, and for confirmation of this you might want to look at the SVS website, or talk to Ed Mullen. I may be mistaken, but I believe that in the one port mode (which requires both a port plug and the Extended tuning mode in the control panel) the port tune is 13Hz quasi-anechoic. So, 12.5Hz is actually not well below the port tune. You listed 17Hz as the low port tune in your review, but even the PB13 has a 15Hz port tune, and the PB16 was specifically designed to be lower.

There is no question that the PB16 plays lower frequencies than the PB13. Too many knowledgeable owners besides myself, who have both, have confirmed that. And, that is consistent with SVS's specific design intent from the larger driver, cabinet, amp, and DSP. It was never intended to be just about more SPL, and lower distortion, but about lower extension as well. And, the sub was specifically designed to produce it in the Extended Mode, which is a 13Hz port tune. Is it possible that you tested with one port plugged in Standard Mode? I mean no disrespect by the question. I actually didn't find that particular aspect of the controls extremely intuitive.

Regards,
Mike

 

[shadyJ]

Yes, I set the amp to 'extended' and I plugged a port. If you look at the frequencies responses from the PB16 product page, they largely match what I measured, except I did get a bit more port output, so what I measured might even be a bit more extended than what they present. The +/- 3 dB points that SVS states are not the tuning frequencies, they mostly just mean that the sub will be down by 6 dB at that point from its highest frequency. I can't tell you the exact tuning frequency from looking at a graph, but it doesn't look like 13 Hz. Anyway, the graphs will tell you a lot more about their behavior than a dB window.

I am not so sure that the PB16 was designed to play lower frequencies than the PB13, I think that it was more designed to play low frequencies better than the PB13, which it very much does. When I compare the frequency response graphs of both subs, they are very much alike, and I don't see the PB16 digging significantly deeper. I think the driver would be unloading by 12.5 Hz, and that would at least partly explain the distortion at that point. The good news is the driver is well protected from bottoming out. The ports look too large in diameter for such a deep tuning point anyway. You would lose a lot more than what you would gain with such a deep tuning point. If you plugged two ports, you might lower the acoustic tuning to around that point. The limiter will still be rolling off the low end there, but I think you would definitely have an effect on the response, and you might be able to mitigate the limiter's effect on the nominal response by using the parametric EQ. But of course, the single open port would chuff very easily if the sub were pushed hard at all. You might try an in-room measurement to see what happens, if only to see the base response.

 

[Ed Mullen]

Hi Mike -

The actual system tuning frequencies of the PB13-Ultra and PB16-Ultra are quite close in the Standard and Extended modes (all ports open and one port plugged, respectively).

The PB16-Ultra does dig slightly deeper in each tune, mostly due to our ability to customize the parameters of the high pass filter to shape the corner/knee of the response and the roll-off slope just below tuning.

We employ a sophisticated multi-band limiter and one of the bands is specifically for ULFs. We wanted the subwoofer to be well behaved at 10-12.5 Hz (which is definitely below Extended tuning from a fractional octave standpoint), so that's what you're seeing at those measurement frequencies with respect to CEA-2010 output. Controlling overdrive artifacts at those ULFs is more important to the subjective user experience than trying to eek out another 1-2 dB more output.

 

[mthomas47]

Hi Mike -

The actual system tuning frequencies of the PB13-Ultra and PB16-Ultra are quite close in the Standard and Extended modes (all ports open and one port plugged, respectively).

The PB16-Ultra does dig slightly deeper in each tune, mostly due to our ability to customize the parameters of the high pass filter to shape the corner/knee of the response and the roll-off slope just below tuning.

We employ a sophisticated multi-band limiter and one of the bands is specifically for ULFs. We wanted the subwoofer to be well behaved at 10-12.5 Hz (which is definitely below Extended tuning from a fractional octave standpoint), so that's what you're seeing at those measurement frequencies with respect to CEA-2010 output. Controlling overdrive artifacts at those ULFs is more important to the subjective user experience than trying to eek out another 1-2 dB more output.

Hi Ed,

Thanks for the response! That helps to clarify things. I do feel that I am hearing/feeling the PB16 go a little lower than the PB13, although I am aware that is subjective. Some of that may be the extra 4db at 16Hz, which is not inconsequential. And, I have a tangential room mode at just a hair under 15Hz which probably contributes too. I like the fact that the 16's can play low with less distortion. In any event, the 16 Ultra is a very fine sub.

Regards,
Mike

 

[Ed Mullen]

Hi Mike -

There is no question that subjectively, the PB16-Ultra 'sounds deeper' than the PB13-Ultra. The PB16-Ultra has considerably higher dynamic output capability, lower distortion, and it does indeed extend slightly deeper in each tune. And all three of those factors will influence your subjective impressions of deep extension.

 

[mthomas47]

Thanks again, Ed!

 

[dmusoke]

Thanks for the review of the PB16...so when will you review and post the SB16?

I have one concern here, and that is the phase delay response graph. The PB16, in sealed mode, should have a much less than 1-cycle delay at all frequencies like the PB13 does in sealed mode. But this isn't the case here as it seems the PB16 gets 'unhinged' at 30Hz and under.

The fact that the phase delay response of the PB13 ( in all modes) is much superior to that of the PB16 concerns me. Something's going on here that I hope you can some light on.

Do you know why this happens and could it be an issue?

Thanks,
-David

 

[shadyJ]

Hello David,

It would be great to review the SB16, but for myself, I will not be able to review subwoofers until the spring, sadly, so if that does happen, it won't be for awhile.

As for the group delay, I am guessing that the higher levels of delay in the PB16 are probably mostly due to the subsonic filters used to protect the driver. The nonstandard driver designs and somewhat larger enclosure might also be contributors. But, like is stated in the article, this delay should not concern you, it is far too low in frequency to be offensive or even audible.

 

[Ed Mullen]

The phase changes are due to EQ filters employed to shape the FR response in each tune. The PB16-Ultra in sealed mode has considerably deeper extension and a shallower initial roll-off than the PB13-Ultra in sealed mode.

 

[Eng-399]

Great review as always James! I just got done reading the article this sub is a beast! A lot of guys are going to be really happy with this sub in there room.

 

[Sekosche]

Excellent review! For new buyers, the PB-16 Ultra at $2,500 is a price increase of 25% over the PB-13 Ultra ($2,000), and not 20% as the article mentions. However, factoring in the 5% return customer discount does lower the cost increase to an impressively low 18.75%.