LSi9, intermittent buzzing
bthogan
Posts: 151
Howdy! I have a problem with a refurbished pair of Polk Lsi9s - actually, only one of the speakers - and I'd be happy to hear from a Polk employee, or anyone else, about any possible fix. I expect to send the speaker in for some kind of fix or replacement, but I'd like to get any feedback that I can first. If there's some sort of fix that I can do myself (preferably without voiding warranty), I'd be very happy to hear it.
I got the pair of Polk LSi9s about a month ago; last week, I picked up a used McCormack DNA-1. After a day or so of use with the new amp, I put on the Gas cd, Konigsforst. I noticed that, on the first track ("Eins"), when the beat hit, the top woofer of the left speaker buzzed noticeably. The volume wasn't very high (around 8 o'clock on an Adcom GFP-565 pre). The buzz only occurs on the beat. It's a very bass-heavy track in general, and the beat is fairly deep and hard. It definitely makes the woofer vibrate very heavily. So far, this is the only track where I really notice this, although I thought that I picked up some buzzing on some stuff that I played right afterwards. I tried the track again the next day, and got the buzz-on-beat again.
It doesn't seem like a blown driver; there's no pop, and some other tracks that have some heavy bass sound fine. In fact, other than this track, the speaker seems fine; if the buzz occurs on other things I've listened to, I'm not noticing it. It seems like something may have become loose, or been dislodged, behind the driver, and is being touched by the driver when it vibrates intensely; the driver may just be vibrating so much, on this one track, that it's hitting something that usually goes untouched. The other (right) speaker has no similar defect; it sounds fine.
Like I said, I'm resigned to sending the speaker in, unless there's some sort of warranty-preserving fix that I can do on my end. I tightened screws around the driver frame a bit, but it didn't make a noticeable difference; buzz is still there. I don't want to do anything more drastic, like remove the driver and take a look inside, until I get some reassurance that the warranty would remain intact.
I guess it's conceivable that the problem may be the new (old) McCormack amp; it certainly does give the speakers more power, and more of a work-out, than the GFA-545. There could be some sort of output imbalance, or over-powering, going on; as noted, the other speaker seems fine. I haven't had a chance to put the Adcom back in line and see what happens; I'll give that a shot this evening. Any input from Polk, or other forum members, would be greatly appreciated.
I got the pair of Polk LSi9s about a month ago; last week, I picked up a used McCormack DNA-1. After a day or so of use with the new amp, I put on the Gas cd, Konigsforst. I noticed that, on the first track ("Eins"), when the beat hit, the top woofer of the left speaker buzzed noticeably. The volume wasn't very high (around 8 o'clock on an Adcom GFP-565 pre). The buzz only occurs on the beat. It's a very bass-heavy track in general, and the beat is fairly deep and hard. It definitely makes the woofer vibrate very heavily. So far, this is the only track where I really notice this, although I thought that I picked up some buzzing on some stuff that I played right afterwards. I tried the track again the next day, and got the buzz-on-beat again.
It doesn't seem like a blown driver; there's no pop, and some other tracks that have some heavy bass sound fine. In fact, other than this track, the speaker seems fine; if the buzz occurs on other things I've listened to, I'm not noticing it. It seems like something may have become loose, or been dislodged, behind the driver, and is being touched by the driver when it vibrates intensely; the driver may just be vibrating so much, on this one track, that it's hitting something that usually goes untouched. The other (right) speaker has no similar defect; it sounds fine.
Like I said, I'm resigned to sending the speaker in, unless there's some sort of warranty-preserving fix that I can do on my end. I tightened screws around the driver frame a bit, but it didn't make a noticeable difference; buzz is still there. I don't want to do anything more drastic, like remove the driver and take a look inside, until I get some reassurance that the warranty would remain intact.
I guess it's conceivable that the problem may be the new (old) McCormack amp; it certainly does give the speakers more power, and more of a work-out, than the GFA-545. There could be some sort of output imbalance, or over-powering, going on; as noted, the other speaker seems fine. I haven't had a chance to put the Adcom back in line and see what happens; I'll give that a shot this evening. Any input from Polk, or other forum members, would be greatly appreciated.
Marantz CD6004
Adcom GFP-750
McCormack DNA-1
Polk LSi9s
Signal Cable ICs
Blue Jeans cables
Adcom GFP-750
McCormack DNA-1
Polk LSi9s
Signal Cable ICs
Blue Jeans cables
Post edited by bthogan on
Comments
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Hello bt,
Welcome to the forum. Probably the fist thing to do is exchange the two speakers, left for right. Once done see if the buzzing follows the speaker or remains in the same channel.
Regards, Ken -
Kenneth Swauger wrote: »Hello bt,
Welcome to the forum. Probably the fist thing to do is exchange the two speakers, left for right. Once done see if the buzzing follows the speaker or remains in the same channel.
Regards, Ken
Oy, can't believe I didn't do that yet [facepalm]. I'll do that, along with putting my other amp in-line, later today, and report back. Thanks!Marantz CD6004
Adcom GFP-750
McCormack DNA-1
Polk LSi9s
Signal Cable ICs
Blue Jeans cables -
No problem, let us know what you find.
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Well, that's interesting...I swapped speakers, and it does appear that the buzzing effect is specific to the left channel coming out of the amplifier (and only occurs on that one track). I've contacted the folks at McCormack Audio; I'm sending the amp in for an upgrade, and I've asked them to take a look at the left channel output, as well. Of course, it may just be the recording. We'll see. Either way, as of now, it doesn't appear that the issue is with the speakers.
Just as an aside, does tightening the screws around the driver frames have any effect on my warranty, or is it otherwise not recommended? I expect that it won't affect the warranty; I was wondering if, counterintuitively, a slight looseness might be desirable. My assumption is that anything that permits transfer of vibration away from the driver is undesirable, and so tightening the screws and securing the driver frames would be a good thing; I just want to make sure.
I should say (again) that the buzzing only occurs on one track. Aside from that...well, the speakers sounded good with my Adcom GFA-545, but with the McCormack DNA-1, and about 200 more watts @ 4 ohms per channel, it's like I've got a new pair of speakers. The synergy between the amplifier and the speakers is amazing. I guess for now, the solution is "don't play that song!" Anyway, I appreciate your help, and I'm really glad to know that it doesn't look like I'll have to put either of these in the mail. Thanks again!Marantz CD6004
Adcom GFP-750
McCormack DNA-1
Polk LSi9s
Signal Cable ICs
Blue Jeans cables -
Hello,
I'm glad the problem seems to be somewhat resolved. The thing to do would be to play the same track on another system and see if the same buzzing happens. In all likelihood the problem is a defect in the recording and only being reproduced. Rare, but possible. The McCormack DNA-1 is an excellent sounding amplifier, Steve certainly knows how to make things sound convincing.
Enjoy, Ken
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