Polk CS246i - bass / rattling problems normal?

Discussion in 'Archived Threads 2001-2004' started by Sean Patrick, Jun 17, 2002.

  1. Sean Patrick

    Sean Patrick Supporting Actor

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    i set up my new center channel today (POLK CS245i) with the Avia disc...and with low frequency sweeps, the speaker grills really rattle badly. is this a fluke and a defective speaker, or was this thing not made to be fed LFE? i even took the protective cover off and verified it is the right hand side speaker driver/cover (don't know the terminology!) rattling bad, and there doesn't even seem to be much strong bass anyway coming from it in the first place.

    I compared it to my ancient DCM center, which handled the bass wonderfully (but is not very well shielded)

    thanks
     
  2. Sean Patrick

    Sean Patrick Supporting Actor

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    of course, in the thread title, i meant 245i, not 246i.
     
  3. Keith Mickunas

    Keith Mickunas Cinematographer

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    The lower -3db limit on that speaker is 55Hz, you need to set your center channel on the receiver to small. Many center speakers are not made to handle low frequencies. I haven't used that speaker myself, so I don't know if it should rattle, it could be that its distorting it if you're passing a real low frequency to it.
     
  4. Sean Patrick

    Sean Patrick Supporting Actor

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    so if i set the speaker to small, the LFE will go to my mains, right?

    i guess the solution would be to get a sub but for a couple of reasons i have been using my mains for LFE.

    i was also concerned because the rattling/distortion was only in one of the two speaker grills. i thought maybe this suggested something was wrong.
     
  5. Sean Patrick

    Sean Patrick Supporting Actor

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    one more question - is LFE *never* sent to the center channel speaker, even in 5.1 setups with a sub?
     
  6. Sean Patrick

    Sean Patrick Supporting Actor

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    ok.....i am trying to decide whether to use my old speaker which isn't as well shielded (but sounds 100 times better to me when set to large)...or set my center to small and use the Polk. Will my receiver send MORE LFE to my two mains once i set the center to small?

    i have the old speaker placed in such a way that the distortion to my tv has disappeared.
     
  7. Lee Bailey

    Lee Bailey Second Unit

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    Sean,
    It depends on what your speaker configuration is. If you are running a subwoofer on a dedicated subwoofer output jack, most setups will direct ALL the LFE information to the sub. If you have your center channel set to small, and the front mains set to large, with NO subwoofer, then yes, the LFE information for the center channel will go to the front mains, as well as all the other bass information for the center that is below the crossover setting you have set for the center channel. If you have a sub, and the front mains set to large, the LFE information will still go to the sub, usually along with all the non-LFE bass below the crossover for the center channel. This is all dependant on how your receiver/preamp handles bass management.
     
  8. Sean Patrick

    Sean Patrick Supporting Actor

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    Lee -

    by setting my new center to small, will MORE lfe be going to my left/right speakers than if i was using the old speaker (that handled LFE just fine) set to large?

    and in this setup, i have no Sub.
     
  9. Keith Mickunas

    Keith Mickunas Cinematographer

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    All LFE goes to the sub (or the mains if you have no sub and told your receiver that). LFE is the .1 in 5.1. I don't think any receiver would direct LFE to the center under any circumstances. There's some strangeness to Avia's LFE test. I think its really sending bass signals to the mains, not to the LFE channel. You might want to do some searching on that.

    If you set your center to small, the bass below a certain point, possibly 100Hz but this varies from receiver to receiver, will be routed to the sub (or mains, as above).

    LFE technically will never go to the center. You should only set your center to large if its a full size speaker that can effectively go down low. Most center speakers are too small. If you had a good sub, the most recommended way of hooking things up is to set all speakers to small, so the LFE and the bass goes to the sub. If you don't have a sub, set your center to small, set sub to none, and direct LFE to the mains. This should also direct bass from the center to the mains.

    Your older speaker may have handled the bass better, or it may just have cut it off. What happens when you remove the speaker grill on the polk? Also, does any part of the grill seem broken or anything? I'm guessing distortion is the problem, but I can't be certain.
     
  10. Lee Bailey

    Lee Bailey Second Unit

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  11. Brian Kaz

    Brian Kaz Second Unit

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    I have my cs245i set to large. It has never rattled no matter how hard I pushed it. With sweeps or anything else.
     
  12. Jeremy Anderson

    Jeremy Anderson Screenwriter

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    If you're getting a rattle from the CS245i, you might want to post on the forum at Polk's website and see what their support guys say. I had problems with my old CS175i and Polk's tech support was outstanding, so I'm sure they'll get you fixed up. I have the 245i now and I couldn't be happier (and I've never heard it rattle once).

    Still, you should definitely have it set to SMALL. I'd also recommend getting a good subwoofer that will blend well with your speakers. I have the CS245i with 4 RT25i's coupled with the SVS 20-39CS+/Samson 1000/ART-351 package, and with careful EQ'ing everything blends together seamlessly.
     

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