# Have I damaged my PB13



## Texxen (Dec 20, 2008)

Hi all. I've just received my PB13 last week. What a great masterpiece it is  Last night I was watching Kung Fu Panda on Blu-ray. My gain knob was originally at 12 o'clock position and I upped the gain to about 1 o'clock on the control for this movie (Simply because everyone said this movie has incredible bass). At the infamous Skiddoosh scene in the end, where he gets Tai Long in the Wushu Finger grab, my PB13 made a loud pop. I quickly stopped the movie, opened the grill to check if there was any damage to the cone. The cone looks good and intact. There was also no burnt smell. Was that loud pop is what bottom out means? Have I damaged my PB13 in anyway? Does it take just one bottom out to damage the subwoofer? It could be in my head but I felt that the bass is a bit weaker than normal after that incident. (again, it could just be all in my head since I couldn't get that pop noise out of my mind). How do I check if I have damaged my PB13 in anyway or if everything is just fine & the weaker bass is just all in my head.

Thanks all.


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## croseiv (Nov 9, 2007)

Texxen said:


> Hi all. I've just received my PB13 last week. What a great masterpiece it is  Last night I was watching Kung Fu Panda on Blu-ray. My gain knob was originally at 12 o'clock position and I upped the gain to about 2 o'clock on the control for this movie (Simply because everyone said this movie has incredible bass). At the infamous Skiddoosh scene in the end, where he gets Tai Long in the Wushu Finger grab, my PB13 made a loud pop. I quickly stopped the movie, opened the grill to check if there was any damage to the cone. The cone looks good and intact. There was also no burnt smell. Was that loud pop is what bottom out means? Have I damaged my PB13 in anyway? Does it take just one bottom out to damage the subwoofer? It could be in my head but I felt that the bass is a bit weaker than normal after that incident. (again, it could just be all in my head since I couldn't get that pop noise out of my mind). How do I check if I have damaged my PB13 in anyway or if everything is just fine & the weaker bass is just all in my head.
> 
> Thanks all.


It does seem as though you've pushed your Ultra too hard there. Not entirely sure why you pushed the gain up, but yes, you could have damaged the driver/motor. :sneeky: And yes, that scene will tax a sub...It would be better to ask SVS about the technical specifics of the situatuion, as the Ultra's driver is unique and designed a little differently than a typical speaker. I have read that it can't be bottomed, but you did hit some sort of limit.

What's interesting here is that I am getting ready to watch that very movie!


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## thewire (Jun 28, 2007)

The person that mixed Kung Fu Panda probobly never listened to it with the gain set high as 90% of people that are giving the rave reviews. When a film is mixed there is headroom, and your sub ran out.


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## croseiv (Nov 9, 2007)

thewire said:


> The person that mixed Kung Fu Panda probobly never listened to it with the gain set high as 90% of people that are giving the rave reviews. When a film is mixed there is headroom, and your sub ran out.


I give it rave reveiws and my subs are calibtrated flat with my mains, and my in room frequency response pretty flat in room down to 17-18 Hz. The scene is recorded hot, and the reports coming in from people seem to indicate that.

But with that said, pushing the gain up as such will decrease the headroom available. And we don't even know if the sub was properly calibrated in the 1st place.


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## thewire (Jun 28, 2007)

croseiv said:


> I give it rave reveiws and my subs are calibtrated flat with my mains, and my in room frequency response pretty flat in room down to 17-18 Hz. The scene is recorded hot, and the reports coming in from people seem to indicate that.
> 
> But with that said, pushing the gain up as such will decrease the headroom available. And we don't even know if the sub was properly calibrated in the 1st place.


That is a good point. Maybe my own setup was not properly calibrated when I watched it myself simply because of the bass mangement issues I was having. If the scene is bellow 22Hz, I certainly can't say I have much to reference to the actual calibration being a factor then or now, but a pop noise is usually an indication of headroom problems, as indicated by many who sometimes have eq or other devices in their signal path resulting in this common occurance. A boost in frequency would be taxing in a similar manner, but unless the boost somehow exceeded the allocated headroom (this means your sub could go as high as 16dB - 20dB higher or around this, the gain on the sub must have been to high. This is only pertaining to that the mix was not neccessarily listened to at peaks as high as most seem to be reporting to by the mixer, because I don't think they were pushing thier sub/subs to the limit, as most seem to be. If they were, I don't think the boost would be there. What I noticed myself about the mix is that the other channels were less burdened with bass, and that the LFE was sent most content, which I think adds to some wow factor. Not sure however as I have since changed my setup. 

The point being I was trying to make is that what it comes down to is the mix itself, and how it was intended to be listened to. If the movie does not playback, something is wrong on the consumer end usually. It did sound like he bumped up the level with expectations of it having a better quality, which in all cirumstances will have exactly the oppossite effect.


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## weeZ (Sep 10, 2006)

Did you do a frequency response graph when you did your initial setup/calibration? If so you could do it again to compare and see if what your hearing is for real. How big is your room BTW?


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## croseiv (Nov 9, 2007)

The question of proper calibration is a good one. I can say that my set up has no difficulty with it (granted I'm running dual PB13-Ultras:yay, but at -13 dB below reference, I'm measureing 110 dB at the listening postion on this scene. It's centered at 25 Hz, so corrected it's more like 113 dB or so.


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## Texxen (Dec 20, 2008)

Hi all. I haven't done the Frequency Response graph as I don't have access to a PC with Line Out. However, I did the basic calibration for the speakers and the sub. All speakers are 75dB and PB13 is 78dB at reference level. I usually watch my movie at -10dB below reference. However, when I popped in Kung Fu Panda, the movie's recording level seems to be a little low and I had to turned up the volume to -6dB below reference to get my usual listening level (I also have to do this for most of Paramount Blu-rays eg. Transformers & Iron Man). So in this case, I was watching the movie at -6dB below reference (with the sub gain bumped up a notch :rolleyesno: ).


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## croseiv (Nov 9, 2007)

Texxen said:


> Hi all. I haven't done the Frequency Response graph as I don't have access to a PC with Line Out. However, I did the basic calibration for the speakers and the sub. All speakers are 75dB and PB13 is 78dB at reference level. I usually watch my movie at -10dB below reference. However, when I popped in Kung Fu Panda, the movie's recording level seems to be a little low and I had to turned up the volume to -6dB below reference to get my usual listening level (I also have to do this for most of Paramount Blu-rays eg. Transformers & Iron Man). So in this case, I was watching the movie at -6dB below reference (with the sub gain bumped up a notch :rolleyesno: ).


So if your sub is calibrated at 78 dB, then it's really nearly 6 dB hot realtive to your mains already (if it were at 75 dB it would be about 2-3 db hot at the low frequencies). So you may have been as high as 12 dB hot! That's way too much, and yes it could do some damage.


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## weeZ (Sep 10, 2006)

You don't need a pc to do a graph, just an spl meter, avia disc or similar, pencil and paper. You could have frequency peaks around the level of the scene that caused the pop. I would re-calibrate flat then perform a frequency sweep to see where you have peaks of nulls in your room. A null in the 30-50Hz range would make you turn up the gain to feel more bass.

Have you contacted SVS?


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## croseiv (Nov 9, 2007)

Have you tried recalibrating the sub? While there is a chance it could be damaged, there's also a chance it may not be. The Ultra is built like a tank! My guess is that you will see the popping go away after recalibration. Please let us know your results.

Also, there's been a discussion of this scene over at AVS being very demanding. However, properly calibrated, the Ultra should be up to the task!:jiggy:


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## Ed Mullen (Jul 28, 2006)

You're getting all the right advice, above. At 78 dB (sub) / 75 dB (speakers), your subwoofer was already running about 6 dB hot. The SPL meter reads 2-3 dB LOW on the subwoofer test tone. Then you upped the gain from 12:00 to 1:00 (which will add several dB). As others have suggested, I wouldn't be surprised if the subwoofer was already running 10-12 dB hot at that point.

A 6 dB increase is literally a doubling of the acoustic output, so running the subwoofer 10-12 dB hot is asking it to work 3-4X harder than a properly calibrated subwoofer.

Calibrate the subwoofer to 73-74 dB (C/Slow) and the speakers to 75 dB, and you should be fine at any reasonable playback level. 

You didn't bottom the woofer in the conventional sense, but you did exceed the linear excursion limits of the woofer suspension, and the spider assembly flexed/popped and/or smacked the back of the cone. This will only occur under severe/abusive drive conditions.

A one-time occurence won't hurt the woofer, but if you continue to overdrive the subwoofer in this manner, you could prematurely fatigue the suspension over time. All woofers have a finite lifespan - the Ultra will provide you with many years of high performance audio if properly calibrated and operated within its clean/linear/uncompressed limits.


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## Texxen (Dec 20, 2008)

Thank you to everyone for all the input. I initially did what the manual said, which is to set the sub about 1-3dB higher than the speakers. That was why I set the PB13 to 78dB. There was no mentioning that the SPL reads 2-3 dB low on the subwoofer test tone. I have now re-calibrated the speakers to read 75dB and the PB13 to read 74dB as advised


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## Texxen (Dec 20, 2008)

I forgot to mention that I've also tried to do the Frequency Response Graph after the re-calibration. The line looks ok from 16-40Hz. But after 40Hz, the line starts to nose dive 15-20dB downwards. I have no idea what it means and what to make out of it :reading:. So I guess I'll need more :help:


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## weeZ (Sep 10, 2006)

The drop at 40Hz is called a null, don't know the tech behind it but has something to do with the sound waves canceling each other out. Easiest way to reduce/eliminate it is placement, just moving the sub a few inches can make a huge difference.

I had a nasty null at 50Hz and totally eliminated it by moving both subs to the right 12inches.


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## Ed Mullen (Jul 28, 2006)

Texxen said:


> I forgot to mention that I've also tried to do the Frequency Response Graph after the re-calibration. The line looks ok from 16-40Hz. But after 40Hz, the line starts to nose dive 15-20dB downwards. I have no idea what it means and what to make out of it :reading:. So I guess I'll need more :help:


It could be a null as weeZ suggests, but it could also be the low pass filter engaged. Make sure the low pass filter ("crossover") switch is disabled on the subwoofer. 


What crossover frequency are you running in the AVR? What is your speaker set-up and bass management configuration?


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## Sonnie (Apr 11, 2006)

Texxen said:


> I forgot to mention that I've also tried to do the Frequency Response Graph after the re-calibration. The line looks ok from 16-40Hz. But after 40Hz, the line starts to nose dive 15-20dB downwards. I have no idea what it means and what to make out of it :reading:. So I guess I'll need more :help:


You "tried" to do the graph... sounds like you actually did one. Are you sure you did it right? Can you post the graph here and let us take a peek at it? Thanks!


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## Texxen (Dec 20, 2008)

This is what I did to come up with the graph. I hope it's the correct way of doing it.

- Download the 16-160Hz test tones zip file from this page http://www.hometheatershack.com/for...rea/4930d1194889933-downloads-page-index.html
- Convert them to wave, burn to a CD, and play it on my PS3
- Start the 25Hz tone then adjusting the volume on avr until the SPL reads 75dB at listening position.
- Play individual tone from 16Hz to 160Hz and record the SPL reading.
- Add compensation value to the reading then plot the graph.

Here is the result:









As you can see, from 40Hz onward, the reading just go down and down and never return to 75Hz again. 

Thanks for all the help!


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## croseiv (Nov 9, 2007)

Texxen said:


> Thank you to everyone for all the input. I initially did what the manual said, which is to set the sub about 1-3dB higher than the speakers. That was why I set the PB13 to 78dB. There was no mentioning that the SPL reads 2-3 dB low on the subwoofer test tone. I have now re-calibrated the speakers to read 75dB and the PB13 to read 74dB as advised


You're absolutely right. The manual does state to calibrate the sub 1-3 dB hot.
Maybe it should say if you calibrate flat then you are already as much 3 dB hot...


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## Texxen (Dec 20, 2008)

In the previous graph, I've just realised that the AVR crossover was at 80Hz at the time of measurement. So the data from about 70Hz onwards would not be corrected since most of the sound would be sent to the speakers rather the sub. 

I've now changed the AVR crossover to 200Hz and re-measured the data again. The measurement should now reflect correct values as all the sound should be going to the sub now. Below are the new measurement & graph with AVR crossover set at 200Hz for Nearfield position and Listening position.



*DATA*











*GRAPH* (Purple = nearfield, Green = listening position)


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## Ed Mullen (Jul 28, 2006)

You definitely have a null from 40-70 Hz. To the extent practicable, try different subwoofer locations or even try different listening/measurement locations - you may be able to work around that null.

It wouldn't surprise me if moving the mic forward 2-3 feet results in a considerably smaller null over that same bandwidth.


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## lalakersfan34 (Oct 31, 2007)

I agree with Ed (usually a safe thing to do ). That is a huge null. Try repositioning the subwoofer if you can. You'd be surprised by how much of a difference even moving the sub just a foot or two (or sometimes even a few inches) can make. See if you can get that FR smoothed out. It'll make a huge difference in impact with that 40-70hz range flattened out. Good luck!


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## WudChuk (Nov 29, 2008)

mine popped during the HULK scene with the sonic cannons. and during the scene in WOTW when they got off the fairy boats and the tanks show up on the big hill. this one guy has a bazooka and fires it.

i have a Denon 3808ci and caibrated the sub using the test tones at -10.0db

sub is set using the spl meter at 74.5db and my mains are set at 75.0db 

bass management is set for all speakers small and the sub crossover is disabled using the AVR's crossover set to 80hz.

the sub channel out on the AVR is set to 0.0db and the gain on the back of the sub is at 12 o'clock

during the WOTW scene i was listening at -15.odb on the AVR...

-----

i have only had this problem with these two movies. everything else i have watched "including kung fu panda" has passed with flying colors. this sub puts a grin on my face 95% of the time. especially when you get the good movies with "excelent" sound quality. i am posting this because i feel i am in the same boat and dont want to damage the speaker. when the speaker came in and i set it in it's home my wife took a picture of me hugging it.... :kiss:


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## tonyvdb (Sep 5, 2007)

WudChuk said:


> mine popped during the HULK scene with the sonic cannons. and during the scene in WOTW when they got off the fairy boats and the tanks show up on the big hill. this one guy has a bazooka and fires it.


Yes, Mine also did the same with both movies. My understanding is the the studios goofed and the cause of these are over emphasis on the 5-10Hz range to the point that it is dangerously HOT on the uncompressed soundtrack . I sometime wonder if a subsonic filter needs to be in the loop to avoid this.


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## thewire (Jun 28, 2007)

WudChuk said:


> mine popped during the HULK scene with the sonic cannons. and during the scene in WOTW when they got off the fairy boats and the tanks show up on the big hill. this one guy has a bazooka and fires it.
> 
> i have a Denon 3808ci and caibrated the sub using the test tones at -10.0db
> 
> ...


Denon uses a 75dB test pink noise to set reference level. Your listening a little higher than you think maybe.


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## WmAx (Jan 26, 2008)

For the very problem found to exist here (_unusually high subsonic information recorded into the soundtrack_), I always recommend a subsonic filter to be placed at the appropriate point to prevent over-excursion under port tuning on high power ported systems. I am rather surprised that SVS did not build in such a filter, actually. Owners of this PB13 may want to add a subsonic filter in line between the receiver pre-out and PB13 input if you want to ensure you do not end up causing serious damage to the driver in the future.

-Chris


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## mike c (Apr 25, 2006)

afaik, the ultra (and other svs subs) have subsonic filters. because i once asked svs what frequency i should adjust the subsonic filter on my sms-1 and i was told not to, because it would cascade with the built in filter - so i set the sms-1 to 5hz.


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