Polk CS400 6 1/2" Sudden Woofer Noise
Hello, Received the CS400 speaker used a few weeks ago. Has been sounding great! All of a sudden noticed the one 61/2" making a slight fuzzy noise. I was playing at a nice volume but certainly nothing abusive. Everything was sounding tight and clean and not nearly in an abusive state. My ears can't stand playing that loud anymore anyway.
Listening to it now and it sounds almost fine but am hearing a slight fuzziness that becomes more apparent at times. Other times I am not even sure there is an issue but it is definitely there. If only listening to dialogue I may not even know it is happening.
Does anyone have any insight or tips to try here or did this speaker need to be replaced? I have never done any speaker repair but am willing to try if the surgery isn't to drastic. I did glue the magnets on my vintage 5jr's
I definitely plead ignorance but from limited things i have tried to gather ...could it be a dust cap that needs re-gluing, or something as simple as that? No clue really so reaching out here for some expert help.
Thanks!
Listening to it now and it sounds almost fine but am hearing a slight fuzziness that becomes more apparent at times. Other times I am not even sure there is an issue but it is definitely there. If only listening to dialogue I may not even know it is happening.
Does anyone have any insight or tips to try here or did this speaker need to be replaced? I have never done any speaker repair but am willing to try if the surgery isn't to drastic. I did glue the magnets on my vintage 5jr's
I definitely plead ignorance but from limited things i have tried to gather ...could it be a dust cap that needs re-gluing, or something as simple as that? No clue really so reaching out here for some expert help.
Thanks!
Comments
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Nobody has any help on this? Could it be a sign of a cap going bad? It actually is not happening right now which is really weird. Think the first thing i will try if it acts up again is to clean the contacts to that speaker with some deoxit and just make sure they are on tight. I was informed that this speaker is indeed a 3 way. Wondered why when I listened with my head in close to center i was hearing more midrange info out of just the one 6 1/2". Thought the other one may be bad too but the right 6 1/2" is just carrying the lower frequencies. Read a post on this forum where someone thought their one speaker was bad on their CS400 because of that difference in tonality. That was so many years ago (2004 i think?) i didn't even bother sharing that info. He probably figured that out. Alright.....rambling to myself it looks like.....hah.
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May have been played hard previously and a blown driver. Have you opened them up and seen the XO or viewed the back of the driver to see if the spider or anything else looks out of place or hot?
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May have been played hard previously and a blown driver. Have you opened them up and seen the XO or viewed the back of the driver to see if the spider or anything else looks out of place or hot?
No I have not done either...yet. Inexplicable to me (and at decent volume) I didn't hear the noise again. This over the last 24 hours. Scared to really turn it up though as i don't want it to reappear. I was adjusting the speaker a lot when i started noticing this. Nothing crazy though. It is a very heavy speaker though for it size. That leads me to believe there may be a bad connection possibly going on somewhere internally. The speaker still sounds fantastic when that noise does not appear.
My first thought was a blown speaker. If it were blown though it would stay sounding blown wouldn't it? It wouldn't all of a sudden sound fine again for awhile would it? That is why i am thinking it may be a bad connection. Or bad seal or air around dust cap somewhere making that fuzzy vibration? But then i have to ask myself....why did that all of sudden disappear for the time being? Guess if it comes back i will have to open it up and check the back of the speaker and the connections.
Also, this speaker just sounds really nice. I am listening to a jazz stream channel on Youtube at the moment. It all sounds so good. The brush work on the snare. The tonality of the piano. The upright bass plucks with the right amount of definition and weight. So when it all is sounding sooooo good and then the one speaker starts to go a little fuzzy out of the blue ....it's like........nooooooooooo! I'm just glad it's back for the time being which lends me to believe all is not lost here with the driver. At least I hope.
Thanks for the reply!! -
Well you mention one thing I over the years have had the (dis)pleasure to experience.....BAD digital recording information. Many times over the years when listening to YouTube stuff I've had all kinds of garbage come through. Have you experienced it with CD,LP's or any other physical media?
That would explain why it all of a sudden gets better. -
Well you mention one thing I over the years have had the (dis)pleasure to experience.....BAD digital recording information. Many times over the years when listening to YouTube stuff I've had all kinds of garbage come through. Have you experienced it with CD,LP's or any other physical media?
That would explain why it all of a sudden gets better.
No i am only set up for streaming. Youtube, Qobuz, Netfliz.....etc. It was definitely only coming out of that one (in question) speaker and none of the others. Never experienced that before in my going on 15+ years of computer audio if that would be the case. There would be distortion from the tweeter and the other driver and it would not be isolated to one driver? This is my brain at work anyway.
Thanks! -
Try rotating the suspect driver 180°
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ken brydson wrote: »Try rotating the suspect driver 180°
Interesting. What will this possibly achieve do you think? And... thanks! -
ken brydson wrote: »Try rotating the suspect driver 180°
Did some more reading on the forums and I did find 2 other members recommending this in regards to the spider and the voice coil. Two separate issues. Letting gravity hopefully remedying the situation was the idea it seemed. Thanks for that recommendation.
Knocking on my head at the moment that it hasn't come back in the last 2 days. Not pushing the speakers right now but do have them at a decent volume and all well. Nervous to ROCK them though. I wonder if me moving them slightly with the speaker cables attached may have done something to the crossover which i understand is mounted right on the speaker terminals plate? If it happens again, will first try the 180 degree spin, clean the leads, then remount. Thanks! -
ken brydson wrote: »Try rotating the suspect driver 180°
Interesting. What will this possibly achieve do you think? And... thanks!
some of the old RT line the rubber surround would get weak on one side. Rotating made a difference. Go ahead laugh
It actually works. This was a Polk recommendation from way back. -
ken brydson wrote: »Try rotating the suspect driver 180°
Interesting. What will this possibly achieve do you think? And... thanks!
some of the old RT line the rubber surround would get weak on one side. Rotating made a difference. Go ahead laugh It actually works. This was a Polk recommendation from way back.
This will be the first thing I try if it starts acting up again! Thanks! -
ken brydson wrote: »Try rotating the suspect driver 180°
Interesting. What will this possibly achieve do you think? And... thanks!
some of the old RT line the rubber surround would get weak on one side. Rotating made a difference. Go ahead laugh It actually works. This was a Polk recommendation from way back.
Which also begs me to ask...is there anyway to apply something to make sure the rubber surrounds don't do this as a precautionary? -
ken brydson wrote: »Try rotating the suspect driver 180°
Interesting. What will this possibly achieve do you think? And... thanks!
some of the old RT line the rubber surround would get weak on one side. Rotating made a difference. Go ahead laugh It actually works. This was a Polk recommendation from way back.
Which also begs me to ask...is there anyway to apply something to make sure the rubber surrounds don't do this as a precautionary?
No -
ken brydson wrote: »Try rotating the suspect driver 180°
Interesting. What will this possibly achieve do you think? And... thanks!
some of the old RT line the rubber surround would get weak on one side. Rotating made a difference. Go ahead laugh It actually works. This was a Polk recommendation from way back.
Which also begs me to ask...is there anyway to apply something to make sure the rubber surrounds don't do this as a precautionary?
No
Ok...thanks! -
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IIRC, you are using two CS400’s?
If there is a problem, you can also get replacement woofers on eBay (get the part number on the back of the woofer) or buy any CS400, RT55, or RT800 on craigslist etc. Any of those will have the same woofers.Alea jacta est! -
boston1450 wrote: »Open It Up
That will happen when it starts happening again -
IIRC, you are using two CS400’s?
If there is a problem, you can also get replacement woofers on eBay (get the part number on the back of the woofer) or buy any CS400, RT55, or RT800 on craigslist etc. Any of those will have the same woofers.
Thanks! I already did look on Ebay. I only saw 2 MW7018's for sale. One was brand new but looks kind of rusty like it was stored in a bad area. The other one says fully functional but had has this description:
"Used, expect sign of light scratches on the edges. Speaker Cone, Surround, Spider and voice coils are good shape - No visible cracks and dents.
The Voice coil sat on the right on the middle of woofer. No scuffing sound created when it pushed - in/out test.
Working and Cosmetic Condition."
What does "The Voice coil sat on the right on the middle woofer." mean exactly? Does that sound right or does it sound like something is out of place but still functional? That's what it sounds like to me but absolutely not sure. -
IIRC, you are using two CS400’s?
If there is a problem, you can also get replacement woofers on eBay (get the part number on the back of the woofer) or buy any CS400, RT55, or RT800 on craigslist etc. Any of those will have the same woofers.
Also...I saw the woofers used in the RT55's are the MW7017's and not sure that would be a direct replacement with the MW7018's? I'm guessing probably not....? Different crossover spec? Pleading total ignorance here once again! -
IIRC, you are using two CS400’s?
If there is a problem, you can also get replacement woofers on eBay (get the part number on the back of the woofer) or buy any CS400, RT55, or RT800 on craigslist etc. Any of those will have the same woofers.
I forgot to respond to the first part of your reply. Yes i actually am using 2. Someone local to me was selling a pair of them for $100 so I grabbed them a few weeks ago. I am actually listening to them near field and they sound absolutely incredible this way. I have them upside down on their sides so the tweeter is closer to my ears on the stands i have. Tweeter to tweeter they are a few inches over 5' apart. Have them slightly angled in at me and the far back corners are about 1.5' from the front wall.
The fuzzy sound hasn't returned since last Sunday. I was driving them harder that day. Hopefully if i keep them at a lower volume this won't return. I am tempted to purchase a replacement woofer however just to have as a spare since they are out of production. One seller on Ebay i just saw today has 84 new ones in stock. Would be about $45 including shipping. These speakers sound so good I think it may be good to have a backup on hand! The tweeters though.....haven't seen ANY of those available unfortunately. -
Honestly, I can only tell you what I saw myself, and from memory, the CS400 used the same drivers as the RT55 and RT800, but I could be wrong. I owned all 3 (still have RT55 and RT800 in storage).Alea jacta est!
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Honestly, I can only tell you what I saw myself, and from memory, the CS400 used the same drivers as the RT55 and RT800, but I could be wrong. I owned all 3 (still have RT55 and RT800 in storage).
Thanks. Well I ordered a MW7018 new from the person selling them on Ebay. He guaranteed me there was no rust on them and that was just the camera shots. He has excellent feedback so went with it. Did a quick search and from what I have seen the RT55 replacement is the MW7017. I wonder if they are interchangeable? My guess is there is just something a little different and that the crossover is utilized differently. If you search the MW7017 both RT55 and RT800 come up but nothing listed for CS400. Only thing i see listed for the 7018 is the CS400. Didn't want to take the chance and just ordered the one that is listed as verified by the seller. -
Did you pull the suspect woofer out and check for a loose spot on the spider also when you flipped it?.Most people just listen to music and watch movies. I EXPERIENCE them.
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Did you pull the suspect woofer out and check for a loose spot on the spider also when you flipped it?.
So far the issue only surfaced that one Sunday a week ago and a bit that Monday. I was playing a little louder than i normally do that day, but since then, and at moderate volumes, the issue has not reappeared. I am in no hurry to open it up until it does it again. I was reading about old glue no longer holding the spider? Is this what you are referring to? I am really rather ignorant about speakers other than listening to them.
A few days prior to it making the bad sound, I had removed the original brass jumper plates, and installed better quality jumpers. The speaker in question was playing fine for days until it wasn't. So i checked to make sure everything was tight and in place back there. It certainly appeared to be but maybe something wasn't touching something right. Maybe it was only that. I certainly am hoping so. Every time i go to nudge the volume a little bit more i cross my fingers. So far so good. These speakers sound phenomenal and couldn't be any happier with them. Like i had mentioned in this thread. Just hope there is no sudden tweeter failure because there ain't no replacements available it looks like. Ugh! Thanks -
I understand your reluctance to remove any woofer. Especially since the speaker sounds good again.
When a speaker makes weird sounds, a removal and look around, the problem will sometimes be easily visible.
There's the problem. 
I have a friend who had a Paradigm speaker that was making weird sounds when the volume was turned up. I asked him to bring the woofer over. A week or two later he brings it over. Yup. Half of the cone had come loose from the spider. I have Aileene's glue and it works great for that.
Unfortunately, he had gone online and bought a replacement woofer though. I forget how much he paid but he'll have a spare if he ever needs one.
I've found a couple of Polk woofers where the spider had come unglued from the frame a cople of inches or less. Aileene's Glue to the rescue too.
I have seen Port Tubes come unglued and they make a strange sound too. Aileene's fixed them too.
It just takes about 5 minutes to unscrew a woofer and have a look-see. Maybe longer for a 12" woofer or the likes. It's a good feeling to know a few minutes and a 7.00 bottle of glue is all that might be needed.
Most people just listen to music and watch movies. I EXPERIENCE them. -
I understand your reluctance to remove any woofer. Especially since the speaker sounds good again.
When a speaker makes weird sounds, a removal and look around, the problem will sometimes be easily visible. There's the problem.
I have a friend who had a Paradigm speaker that was making weird sounds when the volume was turned up. I asked him to bring the woofer over. A week or two later he brings it over. Yup. Half of the cone had come loose from the spider. I have Aileene's glue and it works great for that.
Unfortunately, he had gone online and bought a replacement woofer though. I forget how much he paid but he'll have a spare if he ever needs one.
I've found a couple of Polk woofers where the spider had come unglued from the frame a cople of inches or less. Aileene's Glue to the rescue too.
I have seen Port Tubes come unglued and they make a strange sound too. Aileene's fixed them too.
It just takes about 5 minutes to unscrew a woofer and have a look-see. Maybe longer for a 12" woofer or the likes. It's a good feeling to know a few minutes and a 7.00 bottle of glue is all that might be needed.
Thanks Tony! Sorry for the late reply. Have been busy lately and finally logging in after several days.
I definitely won't be removing the woofer unless it starts acting up again. That being said it is certainly good to know that maybe some simple gluing may be all that is needed. I have read a few people mention the spider becoming unglued so that could be what's happening there. If I have to open her up that will be one of the first things i look for. Also will keep the Aileene's Glue bookmarked. I am not familiar with that product. Once again....thanks so much for that information and taking the time. Much appreciated!! -
I understand your reluctance to remove any woofer. Especially since the speaker sounds good again.
When a speaker makes weird sounds, a removal and look around, the problem will sometimes be easily visible. There's the problem.
I have a friend who had a Paradigm speaker that was making weird sounds when the volume was turned up. I asked him to bring the woofer over. A week or two later he brings it over. Yup. Half of the cone had come loose from the spider. I have Aileene's glue and it works great for that.
Unfortunately, he had gone online and bought a replacement woofer though. I forget how much he paid but he'll have a spare if he ever needs one.
I've found a couple of Polk woofers where the spider had come unglued from the frame a cople of inches or less. Aileene's Glue to the rescue too.
I have seen Port Tubes come unglued and they make a strange sound too. Aileene's fixed them too.
It just takes about 5 minutes to unscrew a woofer and have a look-see. Maybe longer for a 12" woofer or the likes. It's a good feeling to know a few minutes and a 7.00 bottle of glue is all that might be needed.
Thanks Tony! Sorry for the late reply but have been busy the last several days and just logging in today for the first time since.
I did receive a replacement woofer and it is brand new and in great looking shape. At higher volume i do occasionally hear the unwanted sound but it doesn't sound as bad as it did the one day. Not by a long shot. Really subtle. When it gets egregious I will definitely open it up and take a look at the spider first thing. Will bookmark Aileene's glue. Thanks for your help and taking the time! Much appreciated! -
No problem.
I hope you do see a reason for it acting up once in a while. maybe there's a wire hanging down and at loud volumes, the woofer's excursion hits it.
Good luck.Most people just listen to music and watch movies. I EXPERIENCE them. -
No problem.
I hope you do see a reason for it acting up once in a while. maybe there's a wire hanging down and at loud volumes, the woofer's excursion hits it.
Good luck.
Yeah something like that could be it. Thank you! Definitely worth getting right and staying right because these speakers sound really good. Without question replaced my 5jr's i had in this positioning. They sounded really good too but these are giving more spaciousness and layering. Pretty remarkable speaker. Doubt to many people are doing what i have going on here. 2 CS400's near field....hah. Low level listening is just phenomenal.
