# PB13 vs PC13 Ultra



## alexadams77

I ended up getting the PC13 based on the WAF and she loves it I really wanted to get the PB13, but I was wondering how much of a difference is there in sound quality and/or output?


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## avaserfi

From my understanding the sound between the two subs is nearly identical. Their frequency responses will be useful in telling the differences.

Taken from SVS


















As you can see they look nearly identical, but I would say the PB is _slightly_ more linear in the important regions, but again if this is audible is another question.


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## alexadams77

From those graphs, I would have to agree as well. I'm actually wondering if anyone has done any comparisons or put them against each other yet?


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## jerome

A review done in Norway concluded that:
1) Both PC13 and PB13 are better subs than PB12 Plus/2
2) The PC13 is easier to integrate with the room and the rest of the speakers. It's easier to hear where the boxes are located (PB13 in this case)
3) Max SPL is a bit higher for the PB13 than for the PC13. Maybe because it weights more ???


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## mike c

2) The PC13 is easier to integrate with the room and the rest of the speakers. It's easier to hear where the boxes are located (PB13 in this case)

probably because of room interaction, but definitely not an absolute rule for every room

3) Max SPL is a bit higher for the PB13 than for the PC13. Maybe because it weights more ???

because the box has more volume than the cylinder


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## jerome

mike c said:


> 3) Max SPL is a bit higher for the PB13 than for the PC13. Maybe because it weights more ???
> 
> because the box has more volume than the cylinder


Oh, so the size dictates how loud the subwoofer can play? I thought that it was only related to the speaker element(s) and the amplifier :duh:

I learn something every day on this forum ... Thanks Mike !!! :bigsmile:


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## Ed Mullen

As others have alluded, the PB13-Ultra is tuned a few Hz deeper than the PC-Ultra and also has more internal enclosure volume. As such, it has somewhat higher maximum output capability at the very deepest frequencies. With that said, subjectively they perform very similarly on source material as the Norway comparo pointed out.

The PCU is obviously easier to physically integrate into a smaller room - being lighter, easier to move, and having a much smaller footprint. Also, the minor output/extension deficit of the PCU tends to be offset in a smaller room, which will have more boundary reinforcement and earlier onset of room gain.


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## alexadams77

I'm just curious as the PB's ports shoot out at ankle level and the PC shoots straight up. Would that make a difference in the sound at all? To me, I'd think that the ports shooting straight out would be better heard and felt then having the ports shoot straight up.


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## Ed Mullen

alexadams77 said:


> I'm just curious as the PB's ports shoot out at ankle level and the PC shoots straight up. Would that make a difference in the sound at all? To me, I'd think that the ports shooting straight out would be better heard and felt then having the ports shoot straight up.


The ports only function at very deep frequencies (starting below about 28 Hz). The wavelengths at these frequencies are quite long and tend to acoustically load the room similarly regardless of the port orientation differences between the PB13U and the PCU.


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## alexadams77

Thanks for the quick reply Ed, I always thought that the ports were always active.


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## Ed Mullen

alexadams77 said:


> Thanks for the quick reply Ed, I always thought that the ports were always active.


They are tuned to operate over a fairly narrow bandwidth. When operating, they damp cone motion and contribute output at the deepest frequencies.


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## alexadams77

I love my PC13 and the way it performs, I could not be more pleased and get many comments from my friends about it. At times though, I just wonder how much of a difference there'd be compared to the PB13?


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## Kain

avaserfi said:


> From my understanding the sound between the two subs is nearly identical. Their frequency responses will be useful in telling the differences.
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> Taken from SVS
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> As you can see they look nearly identical, but I would say the PB is _slightly_ more linear in the important regions, but again if this is audible is another question.


 Sorry for the old thread bump. However, based on those graphs, doesn't the PB13-Ultra have about twice the output of the PC13-Ultra at 10Hz in 15Hz mode?


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## Ed Mullen

Kain said:


> Sorry for the old thread bump. However, based on those graphs, doesn't the PB13-Ultra have about twice the output of the PC13-Ultra at 10Hz in 15Hz mode?


FR and max output capability are not the same. The PB13-Ultra does have a few Hz more extension in each tune compared to the PC13-Ultra, primarily due to its larger enclosure volume and slightly deeper tune points. But the max output capability of each subwoofer at any given frequency is pretty close, although the box does hold an edge. 

In back to back comparisons, they sound far more similar than different, so I would typically categorize the differences in their objective performance as more measureable than audible.

Naturally, the PC13-Ultra fits into locations where the PB13-Ultra can only dream about, and is perfect for smaller rooms where floor space is at a premium.


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## Kain

I understand that FR and max output capability are not the same. What I was asking was that in 15Hz tune, the PB13-Ultra outputs about 67.5 dB at 10Hz while the PC13-Ultra (while also in 15Hz tune) outputs less than 60 dB at 10Hz (according to the graphs). Doesn't that make the PB13-Ultra slightly more than twice as loud than the PC13-Ultra at 10Hz (while both in 15Hz tune)? Wouldn't this be quite audible?


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## Ed Mullen

Kain said:


> I understand that FR and max output capability are not the same. What I was asking was that in 15Hz tune, the PB13-Ultra outputs about 67.5 dB at 10Hz while the PC13-Ultra (while also in 15Hz tune) outputs less than 60 dB at 10Hz (according to the graphs). Doesn't that make the PB13-Ultra slightly more than twice as loud than the PC13-Ultra at 10Hz (while both in 15Hz tune)? Wouldn't this be quite audible?


Yes, when the drive levels are matched, the PB13-Ultra has a few Hz greater extension in each tune than the PC13-Ultra. 

Whether or not that additional extension is audible depends on the frequency band in question, and the overall playback level. The relative output differences at 10 Hz (in the 15 Hz tune) would be all but inaudible, because the output level at 10 Hz is not significant for either subwoofer, relative to the output at 16-17 Hz just above the tuning knee/corner frequency.

I would be more inclined to look at the relative F3 points for each subwoofer in any given tune, and gauge the audible differences on that criteria instead. So the PB13-Ultra has an F3 of about 14 Hz (relative to the 20 Hz level). And the PC13-Ultra has an F3 of about 16 Hz (relative to the 20 Hz level). You might be able to hear/perceive the PB13-Ultra digging a little deeper on certain source material, like pipe organ for example.


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## Kain

One quick question. On another forum, someone stated that drivers have to be actually designed for a down-firing setup due to the spider design (I'm actually not aware of what a spider design is). Is this true? I know that the PC13-Ultra and the PB13-Ultra use the same drivers without any alteration so I was wondering about this.

Secondly, will there be any driver sag on the PC13-Ultra?


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