# Do the PB13-Ultra or the PC13-Ultra "dance around" on the floor?



## Kain (Mar 2, 2009)

Since I currently do not have a subwoofer, I run my Klipsch RF-7s as Large and the rest of my speakers as Small. At -15 dB on the volume nob, if I play the THX intro at the beginning of the newer _Star Wars_ movies, the woofers on my RF-7s move A LOT. The bass that comes from the RF-7s at these volumes is pretty much subwoofer like. If I watch a bass-heavy movie at -15 dB or higher on the volume nob, my RF-7s start to move around on my tiled floor. My RF-7s weigh 90 pounds each.

Since the PB13-Ultra weighs 155 pounds, I doubt it will move or "dance around" at high volumes. Am I correct? But what about the PC13-Ultra? It also weighs 90 pounds like my main speakers and will it also "dance around" like my RF-7s on my tiled floor?


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## Ed Mullen (Jul 28, 2006)

Kain said:


> Since I currently do not have a subwoofer, I run my Klipsch RF-7s as Large and the rest of my speakers as Small. At -15 dB on the volume nob, if I play the THX intro at the beginning of the newer _Star Wars_ movies, the woofers on my RF-7s move A LOT. The bass that comes from the RF-7s at these volumes is pretty much subwoofer like. If I watch a bass-heavy movie at -15 dB or higher on the volume nob, my RF-7s start to move around on my tiled floor. My RF-7s weigh 90 pounds each.
> 
> Since the PB13-Ultra weighs 155 pounds, I doubt it will move or "dance around" at high volumes. Am I correct? But what about the PC13-Ultra? It also weighs 90 pounds like my main speakers and will it also "dance around" like my RF-7s on my tiled floor?


Since the woofer reactive forces are oriented in the vertical axis in the PC13-Ultra, you might get a bit of base plate hop on a hard tile floor at very high playback levels. 

If this occurs you could use a GRAMMA under the base plate, or you could install the optional 3M half-circle rubber feet. We send even send you extras if needed and basically you populate the bottom of the base plate with them and that will provide a more compliant and damped foor interface than the standard hard rubber discs. 

FWIW, the RF-7 is not considered a full-range speaker (at least not for HT applications), and will sound and perform much better when set to Small with a 40-60 Hz crossover and a subwoofer in the loop.


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## Tonto (Jun 30, 2007)

I've had my PB 13 in the living room for about 2 years sitting on ceramic tile. Yesterday after a buddy & I got back from turkey hunting, I popped in a disc to show him what a sub sounds like. He looked up & said "that thing shakes your whole house"! The point is, with things rattling & shaking as they always do...my sub has always stay'd put. And thats with it sitting straight on the floor. I can't immagine you'll have any issues.


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## bonehead848 (Jan 21, 2007)

155 pounds is huge. I imagine you would have to damage your hearing before you could move that beast.


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## tonyvdb (Sep 5, 2007)

My PB13U sits on a concrete floor with carpet on top and I have had it move around a little bit during some movies but for the most part it has never moved more than an inch or so. The big thing is I cant use it as a table for anything as any items I have ever placed on top of it moves around alot.


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## robbroy (Oct 19, 2006)

tonyvdb said:


> My PB13U sits on a concrete floor with carpet on top and I have had it move around a little bit during some movies but for the most part it has never moved more than an inch or so. The big thing is I cant use it as a table for anything as any items I have ever placed on top of it moves around alot.


Interesting. I have stuff on top of mine and neither has moved at all (I do have thin foam between anything hard that is on top of the sub). I can't even imagine how loud I'd have to go to get one to move (even when I only had one). Mine is also on carpeted concrete slab.

-Robb


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## berty52 (May 20, 2006)

My PC-Ultra used to dance in the first month of use but after I put a rubber mat under it it stayed right at it's place. :clap:


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## Thunderheader (Jan 25, 2009)

I cuurently have 2xpb13-ultras and 1xpc-ultra soon to have one more pc-ultra and I have never seen any of them move. I have hardwood floors, and with rubber feet that is on the bottom of them they are hard enough to move around as it is.
_Posted via Mobile Device_


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## epereira (May 12, 2008)

I have a PC-13 Ultra and have not experienced any hopping around (even at relatively high volumes) though my neighbors have come a-knocking on my door . I have since started using a Auralex SubDude to help dampen the vibrations and have not had a complaint since then.


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## Ray in Kingwood (Jul 16, 2009)

Pardon my total ignorance but what is a GRAMMA??


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## epereira (May 12, 2008)

The GRAMMA is a sound isolation/dampening pad that sits under the subwoofer or amp to dampen the vibrations. More information is available at the Auralex website:

http://www.auralex.com/sound_isolation_gramma/sound_isolation_gramma.asp

"The GRAMMA (Gig and Recording, Amp and Monitor, Modulation Attenuator) is an incredibly effective patented device that's used to float an amp or loudspeaker."


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## Ray in Kingwood (Jul 16, 2009)

Thank you Sir, most appreciated.


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## Ray in Kingwood (Jul 16, 2009)

Now I know


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## eyecatcher127 (May 9, 2006)

Has anyone tried the aualex products in a home with traditional carpet floors? I'm curious if it assists in dampening to hear any more audible clarity. Right now i have the PB 13 ultra sitting right on the carpet floor.


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## recruit (May 9, 2009)

eyecatcher127 said:


> Has anyone tried the aualex products in a home with traditional carpet floors? I'm curious if it assists in dampening to hear any more audible clarity. Right now i have the PB 13 ultra sitting right on the carpet floor.


I have used the Auralex grammas before on carpeted floors and did not see any benefits from having them, I also had some custom made platforms made for the DD series that I owned, but again NO real benefits for my setup, but on solid floors or raised flooring I imagine they would help...


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## eyecatcher127 (May 9, 2006)

Thanks. for the info.


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