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SVS PC13 Ultra

13527 Views 32 Replies 14 Participants Last post by  Jon Liu
Maybe i'm mistaken but as of yet i haven't found a svs pc 13 ultra test/review on this forum which i find very odd so cn anyone point me in the right direction or explain why this is?
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Great write-up Moonfly. I appreciate you taking the time to test both subs individually and then having the guts to write about your findings.
That would have kinda pointless, as my friend and I both new which sub was turned on during the test. Suffice to say the difference was very noticeable to both of us in his room. I do concede it was only 1 room, but 3 AVF members who swapped after reading my write up all agreed.

FYI, the reason for the testing was because of the following.

I had a PB Ultra and was giving setup advice to fellow forum members. Nothing seemed to cure the issues they had with their cylinders and I couldnt replicate them in my room with my box. During this time a friend demo'd my sub as he was buying a new one. He ordered a cylinder because of its smaller footprint. Once his sub arrived he couldnt get it just right and was reporting the issue other members had with chuffing and grill noise. So, I took my laptop down to his house to set his sub up for him. I spent 8 hourse moving the sub around, running graphs, re-running Audyssey on his amp and trying to get it right. I did improve it a vast amount but we still couldnt completely cure the issues and it didnt sound as good as my box did in my room. At the end of that session the only conclusion we came to was that we had to do a direct side by side shootout to rule out the sub design as the issue.

The following week I took my sub to his house and we spent another 6 hours on the shootout. The end of that brought us to the conclusion the design of the box was indeed superior as the differences between his house and mine remained. The box sounded more accurate, articulate and its quality just seemed a step up.

I came to the following conclusions about the box vs cylinder.

The cylinder suffers from artefacts in the audio due to the drivers location to the bass plate. Both subs when driven hard (near the drivers limits) made a kind of clacking sound. On the box you could only hear this when the speakers were disconnected, but the with the cylinder the proximity of the bass plate seemed to amplify this to the point where you could hear it over the main speakers, and at lower volumes. This was never an issue with the box as you could never normally hear it, and the cylinder seemed to make this audible at lower levels that were within normal listening levels.

The driver seems to operate a bit tighter in the box, in that the bass sounds tighter, like the driver can start and stop quicker. On the cylinder it seemed overblown compared to the box, like distortion was creeping in. I guessed a bit at this, but one theory I thought about was that due to the box's design, perhaps there was more pressure inside the box helping with driver accuracy, more in line with how a sealed box would work.

Chuffing came in sooner on the cylinder, and again well within my friends normal listening levels. The box didnt chuff at all, even in 10hz mode, untill I put the sonic boom scene on from Iron man, put the amp at reference level, and upped the bass channel from -6 to +5. This caused the box to finally chuff, but only in 10hz tune. My theory on this is that the ports bend inside the box, and sit a 90 degrees to the back of the driver. In the cylinder they are dead straight and sit face on to the back of the driver. The box also has more wadding inside between the rear of the driver and the port inlet. To me this basically meant the velocity of air in the ports is faster on the cylinder, and this leads to chuffing coming in sooner.

The last issue I found/had, was the grill on the cylinder. Audible noise from the air being forced through the holes in the grill was very apparent from moderate to high levels. This simply never ever happened with the box. One reason for this IMO is the apparent increased air velocity from the ports, but this isnt the main reason. The grill on the cylinder is fixed above the ports in a small area. This area inside the grill and between the ports is a sealed area, so all the air from the ports is forced through the grill. On top of this, the small area and the fact its sealed means the grill resists the air a bit, increasing the pressure and velocity if the air being forced through the grill. On the box, the top of the grill is open so there is no pressure build up, and the grill is larger so there are more holes for the port wind to travel through. This means on the box there is basically never any grill noise at any level that you can hear.

One last advantage of the box we found was with port resonance. We concluded that both sub had the occasional port resonance sound with certain material, but the box seemed to mask it a bit better. I think the fact the driver is sat right over the ports helps mask these sounds, but with the cylinder, the noise seemed a little easier to detect, perhaps because the ports are away from the driver.

To sum up, there are things that are noticeable with both subs but that the box seemed to hide better, but in any case these small issues didnt really give any cause for concern with either design. The main issue was the cylinder seemed boomier, chuffed earlier than the box (and noticeably sooner) and suffered from grill noise caused by the air rushing through the grill holes.

Not all people report the issue though, so we came to the conclusion certain rooms must make the issue more apparent. Perhaps when setting up for reference volumes and flat responses, certain rooms push the sub harder for the same perceived output causing the issues. That said in our side by side test the box performed better, which leads us to conclude the box is still the better of the 2 designs.

As a result I tend to push people to the box if they are choosing between the 2 designs now, but the cylinder is still a great sub that cant be bettered for the money, at least here in the UK. Its not that the cylinder is a bad sub, just that IMHO the box is enough better to justify is higher price tag.

I do have plans to visit another cylinder owner in the near future, one who reports no issues with his cylinder. I'm hoping to find his sub sounds as good as my box, and a final conclusion will be possible from that.

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Thanks for the add'l info-I have two diy sonosubs and the larger one is grill-less. Planning to build two more, also without grills/topplates:yes: Box resonances could indeed affect the sound. I'm a bit skeptical about the port chuffing, or at least why there would be a difference if all other factors are equal. Perhaps the sub could benefit from a greater gap above the baseplate? Let us know how the upcoming comparison goes:T
When I put my ear to the ports the port resonance sound was pretty much the same from both subs, but in the sitting position it it was less apparent with the box. One theory was that the proximity of the driver to the ports somehow helped mask this. The clacking sound from the driver was apparent on both subs as well as high levels, but again it seemed less apparent in the box. This time the theory we had was that the base plate helped amplify the sound. We tested this by holding a floor tile close to the driver on the box and the 2 subs then sounded the same.

A couple people over at the other forum voiced concerns on the proximity of the ports to the rear of the driver on the cylinder as well, with some speculation being that this aided port turbulence compared to the alignment in the box.

I'm not slating the cylinder by any means, I just thing the box is a step up.
Does anyone have a PC13-Ultra for sale? :R
Actually, about 3 went up for sale in the UK forums and my friend returned his after my opinion :(.

TBH, I wouldnt recommend anyone sell their cylinder if they are happy with it, based purely on what I found. All rooms are different, and how a sub reacts in each is different. There are many many happy cylinder owners, so they must work very well in a lot of peoples rooms.
I'm located in Brooklyn, NY. :dumbcrazy:
Hi Guys, the previous pc13 ultra i had when i started this thread i have now sold, i now have a pb 13 ultra and i have to say i prefer the sound of the pb 13 ultra. Supposedly the pc and the pb have near enough the same response on pen and paper yet from my experience of now owning both of them they sound completely different. Apparently the pc version has a slightly higher spl which i'll never know as i haven't maxed out either of them, but the pb version sounds a lot tighter, more controlled, goes lower down in hz and doesn't sound bloated like the pc version. If you haven't listened or compared the two subs then you'll never know the differences but on the flip side i reckon the pc version integrates slightly better when it comes to listening to music and it also seemed more placement friendly in my listening room. I would still like to see a review of the pc13 ultra on this forum and i think its safe to say i'm not standing alone!!!
Well good to know you found what you were looking for, but on paper, the PB13-Ultra beats out the PC-Ultra by about 1-2dB on output alone.

Also, I'm sure you already played with the location of your sub, but that could've attributed to the sound you were getting with the PC-Ultra.

Either way, congrats on the new PB13-Ultra!
I currently have a SVS 20-39PC+. Looking for a bit more bass omph and better integration with music. I find the 20-39 a bit muddy (for lack of a better word) when listening to music. Would the PC Ultra be an improvement in those areas over the 20-39? Due to space limitations, PB13 Ultra wouldn't work for me, thus the consideration of the PC13.
The Ultra driver is far superior to the PC+ variants and will most definitely be a very good upgrade over your current sub, the PB13Ultra is my favourite but if space dictates then the cylinder would be your best bet :T
I agree with John. Ultra drivers have always been a nice improvement over the Plus series drivers. I'm not sure which generation Plus you have, but this current version of the Ultra is in another league in itself. If you are looking for more oomph, believe it will provide it very nicely for you. The Ultra is very musical as well. Hard hitting and fast. One of the nice things, although it doesn't necessarily work for everyone, is the ability to put the sub into 'Sealed' mode to tighten up the bass even further. Of course, this reduces output, but it's worth trying out, if you end up getting the Ultra.
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