Lsim 705 with knocking noise durring low bass

eclypse · March 2016

Just watched a movie and I was standing near the right lsim 705 and heard some loud high pitches knocking coming from the speaker. So I pull the cover off and see the woofers going nuts durring so I touch them and heard the sound stop. So of course I wait for more low bass passages to figure what's going on and isolate it to the lower subwoofer.

It's a high rattle/knocking only at low bass parts.

Am I screwed?? These are prob 3-4 years old I'm thinking and bought at polks ebay direct store which mentions only 2 year warranty on towers.. will have to find my receipt if I have one which I don't think so. It might of been new insted if that matters but prob not.

So is that noise a sign of trouble as in its blown or is something just loose?

eclypse · March 2016

Oh btw . I don't have a subwoofer.. I have the fronts set at full range.. and have a emotiva xpa-2 runing them.. I believe it's rated at 250 watts like the speakers but never go crazy loud on them.

cfrizz · March 2016

It sounds like you are over extending the drivers as they try to keep up with the low bass. It would probably be best if you got a sub and set the speakers to small. Everything has its limits.

eclypse · March 2016

Even though the other left 705 does not do this with its 2 subwoofers?

polk500 · March 2016

Hello,

It may be as simple as something loses inside the cabinet, why don't you pull the woofer and have a look?

Cheers

eclypse · March 2016

polk500 wrote: »

Hello,

It may be as simple as something loses inside the cabinet, why don't you pull the woofer and have a look?

Cheers

I hear ya but feel I might wana call CS first before diving into tearing it apart to void any warranty they may provide.

Thinking possable loose spider as I've read from others.

eclypse · March 2016

Just tested it some more durring fantastic 4 since I know there's a ton of low bass in thst movie (hated that flick). Seems to be coming from the top of the bottom subwoofer so I bet it's the subwoofer spider.

So if one wanted to pull the subwoofer off the 705 I assume the outer rubber gasket pulls away from the inner edge to reveal 4 mounting screws?

jghglofer · March 2016

yes the rubber is just a finish trim for looks. it will come out with ease.
home all is good.

K_M · March 2016

cfrizz wrote: »

It sounds like you are over extending the drivers as they try to keep up with the low bass. It would probably be best if you got a sub and set the speakers to small. Everything has its limits.

+++1!

eclypse · March 2016

The only place I have room for the sub would be in the rear of the room.. I'd ha e to pull the couch off the back wall about 3 feet. Now I don't mind moving the couch out as I've been wanting to as it would be better for sound and we sit 18-20 feet back from the 75" sony 940c flad 4k uhd tv.. and it's mention it's best to sit like 8-12 feet away.

Though with that said, I've had these for nearly 4 years and never had this issue prior and rhe other 705 don't do it and is smooth sounding.

polk500 · March 2016

eclypse wrote: »

The only place I have room for the sub would be in the rear of the room.. I'd ha e to pull the couch off the back wall about 3 feet. Now I don't mind moving the couch out as I've been wanting to as it would be better for sound and we sit 18-20 feet back from the 75" sony 940c flad 4k uhd tv.. and it's mention it's best to sit like 8-12 feet away.

Though with that said, I've had these for nearly 4 years and never had this issue prior and rhe other 705 don't do it and is smooth sounding.

Hello,

Pulling the woofer shouldn't be hard to do, I think jghgolfer is correct it's only 4 screws but I'm not home till tomorrow or I would have a look.

As for viewing the TV I used to sit back 15' from my 65" and when I read ideally you should be 10 to 12' for that size screen I reconfigure our media room so now the sweet spot is 9' back so much better and as a bonus it is also the perfect distance for two channel listening as well.

And if you pick up a sub depending on what one you get it may sound great in the back of the room...

Cheers

jghglofer · March 2016

yes 4 screws holds the woofer in place
and in my 1st post
"hope all is good"

eclypse · March 2016

I borrowed the polk audio PSW404b subwoofer from the basement setup for the time being and damn did it save family movie night!!

Watched San Andreas ultra hd blu ray and damn the low bass obviously was increased! Hehe

Managed to fit it to the right of the front right speaker.

I'll try getting ahold of CS this week and see what can be done for the speaker.

F1nut · March 2016

It sounds like you are over extending the drivers as they try to keep up with the low bass.

This!

Your (most) speakers cannot reproduce the LFE bass found in a lot of movies these days. You're lucky to have made it this far without damage. Get a good sub and set all the speakers to small crossed at 80Hz. That's not a sharp cut off, your speakers will still produce sound below that frequency, just not as much as if run full.

eclypse · March 2016

Just got off the phone with polk customer service and wow! There sending me 2 new subwoofers for my lsim705!!

My warranty period was up and he said your close enough.. hehe (actually like a year out)

Thank you polk audio!

Now thats why I stick with polks! It's all I own for the past 20 something years now!

heiney9 · March 2016

Polk Customer Service it top notch!

H9

dhart86 · March 2016

polk500 wrote: »

Hello,

It may be as simple as something loses inside the cabinet, why don't you pull the woofer and have a look?

Cheers

I remember buying a pair and had a similar problem, so I called Polk Customer service, and like with you, they sent me a replacement woofer.
However, when I went to replace the woofer, I found that some packaging materials had worked it's way inside the cabinet causing a rattling noise from the woofer

eclypse · March 2016

dhart86 wrote: »

polk500 wrote: »

Hello,

It may be as simple as something loses inside the cabinet, why don't you pull the woofer and have a look?

Cheers

I remember buying a pair and had a similar problem, so I called Polk Customer service, and like with you, they sent me a replacement woofer.
However, when I went to replace the woofer, I found that some packaging materials had worked it's way inside the cabinet causing a rattling noise from the woofer

Thanks for the insight. Can't wait to pop it out and see what's wrong with it when I get the replacement in a couple of days.

eclypse · March 2016

Coming already tomorrow!

eclypse · March 2016

There here! Now to pull the old one out and see what's up.

eclypse · March 2016

All good! Was a pain getting the thick rubber gasket off with a plastic spoon. Here I was trying to dig the edge out on the outer edge.. once I tried the innew edge it came right off in a sec as I was able to grab it and pull it off with ease.

Not much to see in there as ea subwoofer the cabnet is sealed around it. Nothing looked loose and could see 0 damage to the woofer itself. Slapped the new one in and tested it out on a movie with low bass and the sub off and smooth!

Gona keep the sub on it for now on as wow.. what a difference with the sub for movies. Hehe

cfrizz · March 2016

eclypse wrote: »

Gona keep the sub on it for now on as wow.. what a difference with the sub for movies. Hehe

For now? Do you really need to learn this lesson a second time to get a clue?

Either keep the sub on it all the time, or get another sub to put on it. But the bottom line is you need the sub.

Your own ears are telling you that it sounds better because it is better, on both movies and music, for your ears and the speakers.

eclypse · March 2016

cfrizz wrote: »

eclypse wrote: »

Gona keep the sub on it for now on as wow.. what a difference with the sub for movies. Hehe

For now? Do you really need to learn this lesson a second time to get a clue?

Either keep the sub on it all the time, or get another sub to put on it. But the bottom line is you need the sub.

Your own ears are telling you that it sounds better because it is better, on both movies and music, for your ears and the speakers.

Learn to read and comprehend.. I said leavening on from now on.

cfrizz · March 2016

Just as soon as you learn to write intelligible sentences. For is not from. If you had written from, there would have been no confusion. And FYI leavening is what causes dough to rise. I believe you meant leaving. But at any rate, I'm glad you got it fixed enjoy your system.

"Gona keep the sub on it for now on as wow.. what a difference with the sub for movies. Hehe"

afterburnt · March 2016

eclypse wrote: »

cfrizz wrote: »

eclypse wrote: »

Gona keep the sub on it for now on as wow.. what a difference with the sub for movies. Hehe

For now? Do you really need to learn this lesson a second time to get a clue?

Either keep the sub on it all the time, or get another sub to put on it. But the bottom line is you need the sub.

Your own ears are telling you that it sounds better because it is better, on both movies and music, for your ears and the speakers.

Learn to read and comprehend.. I said leavening on from now on.

That was rude and funny since it was you that screwed up.

Lsim 705 with knocking noise durring low bass

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