# PC/PB13 Stack or Not?



## alexadams77 (Aug 4, 2007)

I currently have the PC13U and am possibly looking at purchasing a PB13. 

I really don't have the room for another PC13, unless I massively re-arrange my HT/Living Room area. The WAF is another battle that I'll have to deal with as well, so I was wondering if I were to get the PB, would I be able to place my PC13 on top of it?


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## Sonnie (Apr 11, 2006)

I wouldn't see any reason why you couldn't, although you might want to place some sort of protection between the bottom of the PC and the top of the PB.


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## avaserfi (Jul 5, 2007)

There wouldn't be a problem with it, but there really isn't a point in doing that unless you need more output. I would doubt you would need more output with an ultra unless you have a massive room.

The real reason to have multiple subwoofers is for placement in regard to getting a more even bass response. Placing a sub on top of another will not achieve this end but instead just allow for more output.

So the real question is why do you want another Ultra and what are you expecting of it?


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## alexadams77 (Aug 4, 2007)

I am looking for a bit more output and to try and even out a null or two that I have in my room. The reason for asking about stacking is to see if that's an option for the WAF. I have pretty much only two places for the PB and that's under the PC or use it as an end table. I'd rather do the latter, but just incase the wife doesn't approve, I want to know if I could stack them.


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## avaserfi (Jul 5, 2007)

alexadams77 said:


> I am looking for a bit more output and to try and even out a null or two that I have in my room. The reason for asking about stacking is to see if that's an option for the WAF. I have pretty much only two places for the PB and that's under the PC or use it as an end table. I'd rather do the latter, but just incase the wife doesn't approve, I want to know if I could stack them.


The end table situation is more likely to help with nulls especially if the woofers are placed diagonally to each other in opposing phases. I would try and convince the wife subs make perfect end tables and then use REW to set phase and in making slight location adjustments to get more output and fix those nulls as well as any peaks.

Good luck!


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## alexadams77 (Aug 4, 2007)

I think that'd I'd rather use the PB13 as an end table because then the ports will be firing directly in front and across of the main listening position. 

Right now the PC13 is in a very tight corner and i think that's the reason for a small null that I have right now. I'm pretty sure that the end table idea will more then likely get rid of the null, but if she doesn't approve it being there, then I need to know if I had the stacking option.


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## weeZ (Sep 10, 2006)

Duals will even out peaks and minor dips. I've got a fairly flat response in my large room, and love the impact two provides. Didn't really notice how smooth the response was till one of the amps went out and I was left with a single.


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## alexadams77 (Aug 4, 2007)

I think that I'm in need of another subwoofer. Now that I've felt the Bass from the PC13-U, I want more room shaking bass.


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## weeZ (Sep 10, 2006)

What about stack PCs? there used to be a photo floating around of a guy that had stack PC+, I'll have to see if I can find it.


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## weeZ (Sep 10, 2006)

Here it is!
http://www.sweetnancy.com/stackingultras.htm


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## alexadams77 (Aug 4, 2007)

The only thing wrong with stacking two PC's is that my ceiling is only 8" and the sub stands 1' shy of 4". If I re-arrangement my entire HT Room, I would be able to fit another PC, but it would have to pass the WAF first and that's not easy these days.


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## mojomike (Feb 12, 2007)

weeZ said:


> Here it is!
> http://www.sweetnancy.com/stackingultras.htm


That is not exactly what I would call an elegant solution.


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## Ghislain (Apr 19, 2006)

Nope.
Won't show this picture to the misses 
I would simply put them side by side (if I were to deploy two subs).


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## weeZ (Sep 10, 2006)

mojomike said:


> That is not exactly what I would call an elegant solution.



Not something I would do or advocate, but just an example. Would never fly here, that's why I have boxes.


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## thxgoon (Feb 23, 2007)

If I remember right stacking subs like this increases output by 6db. That's pretty significant in the subwoofer world. With the extra headroom you could use a BFD and REW to try and even out the room nulls.


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## weeZ (Sep 10, 2006)

With all this talk of stacking I did a little comparison.




As soon as the scene started the scene (Transformers ch19)I could hear and feel the difference. Low end impact was gone and too much in the middle range.



OK guys, why the decrease of SPL in the low end?

Needless to say I'll be keeping them end to end.


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## thxgoon (Feb 23, 2007)

Did you reverse the phase when you stacked them? The drivers are facing a different direction than when they were end to end. End to end is probably just as effective as stacking. I think the main idea is to get them to work in concert as one sub in one location.


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