Problem with PSW-10

Trigger1018

I've had an PSW-10 for about 6 months hooked up via a single cable to my receiver(Pioneer VSX819). Everything has worked fine for 6 months. I just moved my receiver from level of my cabinet to another. Upon plugging everything back in I get a constant hum from the sub. I've searched the web for weeks and have found many things to try and none of them fixed the problem. The only thing that stops the hum is unplugging sub cable from sub. I've tried leaving the sub on with the hum and unplugging cables one at a time and nothing stops the hum. Now to my question is this a problem with ground loop which I have read so much about, problem with the sub, or my receiver? Thanks for any guidance you can provide.

[Deleted User]

Hello,
Welcome to Club Polk. By chance is your sub-cable a coaxial cable or speaker wire?
Regards, Ken

Trigger1018

Kenneth Swauger wrote: »

Hello,
Welcome to Club Polk. By chance is your sub-cable a coaxial cable or speaker wire?
Regards, Ken

I'm pretty sure it's coaxial. I bought a "sub-woofer" cable. Sorry I have just basic knowledge.

[Deleted User]

A ground loop is usually caused by having too many grounds. Prime candidates can be cable TV service and satellite dish receivers. A couple of things to try: does the humming stop if you unplug the sub-cable from the back of the receiver or only when it is unplugged from the back of the sub? Second, if you were to plug either the right or left audio out of a CD/DVD player into the sub-cable is there humming? The goal is to narrow down the situations where there is humming and not.
Ken

gmcman

Do you have the sub cable pushed in all the way?

Sometimes the flutes have a very snug fit and may not be seated. Also, is there anything touching the connection at either end?

If you wiggle the cable before it enters the RCA connector does the hum go away?

Trigger1018

gmcman wrote: »

Do you have the sub cable pushed in all the way?

Sometimes the flutes have a very snug fit and may not be seated. Also, is there anything touching the connection at either end?

If you wiggle the cable before it enters the RCA connector does the hum go away?

That is not the problem because I never unplugged it after I got the initial set up. Plus I have unplugged and replugged so many times now its seated. When I unplug the cable the hum stops and pretty much as soon as the male connector touches the female connector it hums. I have an email in to Pioneer hoping they can give me some insight I feel its something wrong with the receiver.

gmcman

I can say I have seen flutes that are so tight they pull part of the connection out.

So the only thing that is different aside from moving everything around, was that you have plugged and unplugged the cable many times, correct?

Did you have the receiver turned off and the subwoofer unplugged when you were making connections?

Trigger1018

gmcman wrote: »

I can say I have seen flutes that are so tight they pull part of the connection out.

So the only thing that is different aside from moving everything around, was that you have plugged and unplugged the cable many times, correct?

Did you have the receiver turned off and the subwoofer unplugged when you were making connections?

Yes i've plugged and unplugged many times testing things after this started. For the second question Orginally yes, now since i've been testing things no.

gmcman

Have you by chance tried a different cable?

Trigger1018

gmcman wrote: »

Have you by chance tried a different cable?

No thats one thing I have not tried. I should just buy a new one and if it does not work take it back.

nguyendot

You have a bad ground or bad ground connection. There are a few things you can try - you can ground the sub to the receiver's ground pin for one. You can get a ground loop isolator for the RCA's as well.

Trigger1018

nguyendot wrote: »

You have a bad ground or bad ground connection. There are a few things you can try - you can ground the sub to the receiver's ground pin for one. You can get a ground loop isolator for the RCA's as well.

I already bought a ground loop isolator, but i'm not sure where about where to plug things in. I bought it this weekend from Radio Shack.

gmcman

The thing about it is.....it was working fine before, without a ground-loop isolator.

Something happened during moving everything around or with the hook/unhook.

Did you zap anything with possibly a static discharge?

Trigger1018

Thats my thing is that it was working fine. I don't think I had any static problems.

jobbs

Hi Ken,

I have this Polk Speaker setup - Fronts RT1000i Center CS400i Rear f/x500i Subwoofer PSW650. Should I setup all these speakers as LARGE on my Yamaha RX-V1065 receiver? Should my LFE be the PSW650 or both the PSW650 and the RT1000i's.

I had the speakers set as LARGE and the PSW650 as the LFE but when I play audio CD's 2.0 the subwoofer is never engaged. I selected SMALL for the front speakers and that fixes the output to the PSW650 issue but essentially there is nothing coming out of the subs in the RT1000i's

Yamaha told me to set the fronts as LARGE and the Sub as (both the PSW650 and RT1000i's). That produces bass from all 3 but I am concerned about phase cancellation and a fairly jagged frequency response if all 3 subs are sending out the same frequencies.

What do you recommend? Thanks

[Deleted User]

Hi Jobbs,
I've always been a fan of using a high pass filter whenever possible. To be honest with you, the real reason for adding a sub-woofer is to be able to reduce bass distortion produced by the main speakers. Most of us wouldn't choose an amplifier if we read that it had 10% distortion, yet most speakers have that much and more low frequency distortion. So, to answer your question, I suggest using the "small" setting (I wish manufacturers would have picked a less threatening term, like "filtered"). This reduces low frequency distortion, improves power handling and works to maximize dynamic range. Let the sub do all the heavy lifting and play with the crossover frequencies offered by the receiver to get smooth blending.
I hope this is helpful!
Cheers, Ken

jobbs

Thanks Ken,

Doesn't this (setting all speaker to small) essentially make the subs in my RT1000i's useless. When I choose SMALL I can't hear much of anything coming out of them. Do you have a recommendation for the crossover frequency since all of my speakers are Polk Audio?

Also for the sub volume control on the RT1000is is there a place to set them so I get a flat curve when using pink noise. I tried to adjust them using pink noise generated from my Yamaha RX-V165 reciver and a radio shack sound meter essentially turning up the sub volume on the RT1000i's until the meter moved. That is where I assume too much bass is coming out. Is this the best way to get a flat response from the RT1000i's.

The Yamaha came with a mic and sets the system up on its own. Of course it set all 5 of my speakers to LARGE and only used the PSW650 for the LFE. Problem is on 2 channel audio CD's the PSW650 never turns on cause stereo never uses the .1 in 5.1. UUUGHHH

[Deleted User]

No problem, Jobbs, glad to be of help. Keep in mind the crossover point is a gradual slope, meaning that there will still be sound produced by the bass section of the RT1000i. I actually had a pair of those speakers for home listening when I worked directly for Polk. I used an RTA analyzer and with the speakers away from walls and corners found the frequency response to be nice and flat with the bass amp's volume control at the 9:00 o'clock position, pointing "west" if we were looking at a compass. At first this might seem as though not much bass is being produced, but our hearing mechanism has a "self calibrating" capability that takes a couple of listening sessions to recalibrate. Very much like a person who has to give up too much salt in their diet, at first there's no flavor, then gradually things begin tasting correct.
I'd suggest 80Hz as a beginning crossover frequency, then try 60Hz, then 100Hz and give yourself time to judge how each change effects the sound. If you start feeling a little bewildered, take a break and then come back to it. This is supposed to be fun, remember!
Cheers, Ken

jobbs

Hello Ken,

Thanks for your quick replies. Your feedback makes great sense. 2 more questions if you don't mind. One that has puzzled me for years.

1. My Yamaha RX-v1065 support bi amping. It has a zone 2 amp that can instead be used as a second amp for the main speakers. Should I bi amp my RT1000i's using the bi-amp feature on my receiver or since the RT1000i's have internal amps for the subs is bi-amping useless in this case? Someone suggested the subwoofer on the RT1000i's draws little power from the receiver because of its internal amp thus making bi amping worthless with the RT1000i's.

2. My second question goes back to the day I bought the RT1000i's. I tried at that time to use the subwoofer line level inputs on the RT1000i's with the Front pre out jacks on an Onkyo TX-DS787 removing the flat metal connecting straps on the RT1000is. Even with the subwoofer volume control on the RT1000i's at maximum I could barely hear any bass. I thought maybe it was just an issue with my receiver so I connected the speakers using regular speaker wire and reconnecting the flat metal connecting straps on the binding posts. The bass was much louder and I had to adjust the sub volume control way back using this connection method.

Last year I got a new Yamaha receiver RX-V1065 and try the same setup using the Front pre-outs with the same outcome - very low bass even with volume on the RT1000i's all the way up. The new Yamaha receiver also has 2 subwoofer outputs so I tried them as well thinking surely this will work. 2 separate RCA cables going from the sub outs on the receiver to the line level ins on the RT1000i's. To my surprise the same problem - Very little bass.

When I put that same subwoofer out line into the LFE/Subwoofer in jack on the PSW650 the bass is at normal levels. Do the line level in's on the RT1000i's requiring a stronger signal than the LFE/Subwoofer in on the PSW650? Or what would cause the bass to be so low when using the line level in's on the RT1000i's?

[Deleted User]

Hello Jobbs,
I'm glad to help out, it's what this forum is intended to do.
1). The RT1000i is already a bi-amped system, meaning one amp (your receiver in this case) is powering the upper section of the speaker and the built-in bass amp is powering the lower section. What you are referring to would be tri-amping, a further division to a third amp. There would need to be three sets of binding posts on the speaker for that.
2). From everything you've described I believe there is a problem with the line level inputs on both of the bass amps of your speakers. The line level inputs should behave similarly to the PSW650, granted with a different sound character, but produce a similar sound volume. The ultimate test would to remove the binding post jumper plates and run a good quality RCA cable from either the right or left audio output of a CD player into the line level inputs on the speaker. Keep the volume all the way down on the speaker's bass amp then with a CD playing turn the volume up slightly on the bass amp. This would be with your main receiver off so you can just hear what the bass section is doing. You should hear bass at just about any volume position above completely off.
Regards, Ken

jobbs

Thanks Ken,

1. Regarding question 1 the RT1000i's have 2 pair of binding posts. 1 for mid/tweeter and the other for bass. You can remove the flat metal connector and plug in the line level input or use 2 separate speaker wires to the 2 sets of binding posts. Sounds like separating the signal for high's and lows using 2 speaker wire runs would not provide a cleaner signal.

2. I plugged in my CD player into the line level inputs and at the 9 oclock position I could barely hear anything. at 12 I could hear bass faintly. at the 3 position I heard bass fairly well but not overly loud and at full volume the bass was basically the same as the 3 oclock position.

So the line level inputs work but don't seem to have the right gain or sensitivity or whatever the correct wording is. Was this a design flaw with Polk? I can imagine both speakers would have this same issue so I assume it was designed this way. Any ideas?

[Deleted User]

Hello,
No, I don't believe anything would be gained by adding additional speaker wires to the upper and lower binding posts. There's something wrong with the line level inputs on the speakers. I'm not sure what Polk could offer, maybe give them a call at 1-800-377-7655 or email to polkcs@polkaudio.com. In all likelihood something was not soldered correctly or a connecting wire is not attached.
Regards, Ken

dorokusai

1. Some folks find a tremendous benefit from bi-wiring, others, not so much. It's a personal experience and based on multiple factors. I only bi-wire because of the deal I found on the cables I use, other than that, I've found no sonic advantage to doing it.

2. It's not a design flaw as the odds of you finding something inherently wrong with a speaker system, 10 years after it was introduced is basically ZERO. The problem simply lies within your pair and the line level inputs as Ken suggested previously. Have you tried another pair of speakers, just out of curiosity? It sounds as if the path from the line level input is missing a jumper to the low end capacitors, and section of the xover that covers that spectrum.

jobbs

The RT1000i's are the only speakers I have with a line level input and a built in sub amp. They work find when I use speaker wire to feed the subs so that is what I will continue to do.

Interestingly enough Polk has one of my RT1000i amps. About 4 months ago is started a loud humming and about a month ago the green light on the RT1000i went out and the sub amp was dead. They are supposed to call me with an estimate to fix in the next day or so. Sad thing is these speakers were in storage for 5 of the 10 years I've had them. Needless to say I think next time I will purchase speakers without a powered sub. My PSW650 sounds much better as a sub anyway.

dorokusai

Yeah, I'm not a fan of self-powered loudspeakers but at that time it was trendy. Good information Jobbs, thanks for the reply. Hopefully you get sorted out and back to business. At least you have an option and can rock out when you need to.

jobbs

Hi Ken,

Here is Polk's official tech support reply to my question. This is ridiculous. How do you get a flat response if what they are saying is true?

Greg-

I apologize but the output voltage isn’t going to be the same when doing line level connections over speaker wire connections. The gain output will always be greater in speaker wire.

Breanna Diaz
polkaudio
Customer Service Representative-Technical Support

[Deleted User]

Hi Jobbs,
I'm sure Breanna thought she was giving accurate information, maybe she didn't quite understand what the situation was. For the line level to not work correctly is a very rare situation for a CS person to deal with. It might be a good idea to telephone again and ask for extension 208, that's Kim's line. I'l send him an email and let him know what the situation is.
Cheers, Ken

ROHfan

Holy cow, take a deep breath, relax, and replace the subwoofer cable, dude.

If you've checked all your connections and they're all good then the next course of action should be to REPLACE the subwoofer coax cable with a brand new one, hopefully not brought from Radio Shack. This eliminated the hum from my system and saved a LOT of headaches.

jobbs

Tried 2 sub cables. both produce low bass output from the RT1000is but lots of output from the PSW650's. Polk has had the amp from the RT1000i for a week. No updates yet.

jobbs

Hi Ken,

On Nov. 1 you wrote the main reason to add a subwoofer is to be able to reduce bass distortion. With that in mind wouldn't it make sense to turn the crossover to 200Hz. That way the bass can handle the entire low range with low distortion and the RT1000is can handle the mid and high frequencies.

gmcman

ROHfan wrote: »

Holy cow, take a deep breath, relax, and replace the subwoofer cable, dude.

I assume you were referring to the OP. This thread was hijacked back at post 15 and took a hard turn, almost seems suspect. Not trying to be negative but someones first post was completely off-subject from the OP.