Authorized Polk Repairs in Calgary

disneyjoe7

I still think the sub is over pushed, what size is the room that you have this sub?

danger boy

what we don't know is what part of the amp is going out? with a little detective work.. i'm sure the answer is right there inside the sub.

TShand

There is power to the surge protector... But nothing to the subwoofer.

Could it be the power cord on the subwoofer? Again, I have other components hooked into the surge protector that are working fine. So if something was happening electrically, would it not affect the other things plugged in as well?

I still don't understand how I can 'push' a subwoofer too hard in two hours. What's the point in having one if I can't just plug it in, fine tune it, and then enjoy it?

I should also note that the FUSES are blown each time this happens. The one that died on Monday - the fuse inside is BLACK. Didn't check the one from last night, but I have a feeling it may be gone too. Perhaps there is nothing wrong with the amps?

Also - the subwoofer was plugged into the EXACT SAME spot for 6 months before this happened the first time.

All I know is this is driving me crazy... I will look into the electricity though - I am sure there's something I can purchase to "check" the outlets and the surge protector.

Thanks for the feedback everyone...

T

disneyjoe7

I can overheat an amp in about 3 mins it shuts down after that. When it does this its HOT as HELL I know it shut down before it would die.

But you say the surge as power but the sub doesn't? Did you try to plug it in the wall without the surge power thing? Just so you know sometimes the surge power can't power some amps or subs.

TShand

I plugged it directly into the wall after it died - and nothing. But the surge protector was still getting power, as other things are also plugged into it and working.

The amp was not hot when it died... At least, when I felt the back of it when it shut down, it didn't feel hot at all.

There was no noise, pop, or any other sound when it goes... There's just bass, and then no bass.

I am going to buy an outlet tester... But again, as other things are plugged into the same outlet, I'm not sure this is the problem.

Maybe I have a subwoofer hating Gremlin???

disneyjoe7

Ok then could it be the receiver it self? If you have pre amp outputs on the receiver, place the sub cable into the L or R front, or the center output jack. Or you could use a Ipod or something with a head phone jack, then place a head phone to RCA plug cable and place one L or R into sub directly. *If done place sub off and at a low volume before turning anything on.

danger boy

did it just blow the fuse or the amp again? to have this happen more than one time after 2 hours points to me as being something other than the amp.. the amp gets power from your surge protector and then into the wall outlet. the only other thing is the subwoofer cable.

TECHNOKID

danger boy wrote: »

did it just blow the fuse or the amp again? to have this happen more than one time after 2 hours points to me as being something other than the amp.. the amp gets power from your surge protector and then into the wall outlet. the only other thing is the subwoofer cable.

I was thinking along the same line. From what he describes, power is good (unless it higher than normal and the sub doesn't like it). Do you have a multimeter or voltage meter to check the actual valur of the voltage? Next is the receiver amp and the cable it self. Try another amp with adifferent cable and if it works, then try your AVR with the new cable. If it still works, you know it is the cable. If it doesn't well, get your AVR checked.

Cheers

TShand

I honestly don't think it's the amp either.

Going to by the little tool to check the electrical outlet - just so I can rule that out.

The cable between the reciever and subwoofer is a Monster Sub Cable, attached to the LFE Out on the back of the AVR, and to the LFE In on the back of the sub. Unfortunately I don't have another sub or cable to try this out with... The whole thing is, the sub no doesn't get any power at all right now... So trying this other stuff doesn't help me much until I have a powered up subwoofer.

Waiting to hear back from Ken and Walter as to what I should do. In the meantime, I'm going to do a little detective work in regards to the electrical situation. Just weird that EVERYTHING is plugged into the surge protector - but nothing else is giving me problems.

disneyjoe7

Does this sub have a switch which is ON / OFF / AUTO and are you using it as AUTO? If no signal due to cable or receiver does the sub go on in the ON position?

Sorry but I wasn't able to get a PDF manual of this sub on-line, too help further.

TShand

Here is the link to the manual on the Polk website:

http://www.polkaudio.com/homeaudio/psw/index.php#manuals

The sub has the switch on the back - I usually turn it to "AUTO" - when there is a signal, the light on the back goes GREEN... When it goes into standby mode the light is RED.

There is no light at all now.

T

TECHNOKID

disneyjoe7 wrote: »

Does this sub have a switch which is ON / OFF / AUTO and are you using it as AUTO? If no signal due to cable or receiver does the sub go on in the ON position?

Sorry but I wasn't able to get a PDF manual of this sub on-line, too help further.

disneyjoe7 has got a poin there as many subwoofers nowadays uses the auto switch to turn the subwoofer off when not receiving any signal. If there is an intermittent problem with your cable, your subwoofer may simply shut down as there isn't any signal going to it. Set your switch to on and see if at least the power come on. If it does while no signal going through the subwoofer, you might want to use a different cable and proceed with testing again.

Cheers

TShand

I've already played with that switch... The sub isn't getting any power... So nothing happens.

No light on the back, means no subwoofer love.

There is no power to the subwoofer - otherwise the little light on the back would be on.

disneyjoe7

How old? Sorry I would not be happy, is it possible to return it for a full refund. I am Polk fan and don't know about this sub line, but can say the DSW line kick a$$.

TShand

The sub was about 1 year old when this first happened.

The guys at Polk have been great - just waiting to hear back from them on this 3rd malfunction.

I'd live to upgrade to the DSW line - but that might be a little much matched with the RM8 speaker series!!!

disneyjoe7

One year old then more issues over and over again. I don't know beginning to think it's a power issue blowing amp / sub up. Have you noticed any lights which get bright or others which get dim at times? Any issues with light blubs blowing (not sure with today’s "Green light" fluorescent things that would show up but...)?

Do you own a power meter? Time to start looking else where first

TShand

No issues with any lights or anything... Which is why this whole thing is really odd. And again - all other components of my home theatre are plugged in same spot... And all of them are fine.

I don't have a power meter... But I am going to buy one of those little power outlet do-hickeys that plug into the outlet... Or is that what you are referring to? I am going to check the outlet itself, and the surge protector.

At any rate, I'm going to do a little investigating this weekend and see what happens.

TECHNOKID

TShand wrote: »

No issues with any lights or anything... Which is why this whole thing is really odd. And again - all other components of my home theatre are plugged in same spot... And all of them are fine.

I don't have a power meter... But I am going to buy one of those little power outlet do-hickeys that plug into the outlet... Or is that what you are referring to? I am going to check the outlet itself, and the surge protector.

At any rate, I'm going to do a little investigating this weekend and see what happens.

Even if everythig else doesn't have any issue it doesn't mean the powered subwoofer isn't more sentive to potential sightly higher voltage tha the other gear. I personally experienced it over the holiday with 2 laptops of the same brand but different power supply. One would get hot, freeze and shut down while the other one would still work perfectly. When the problemed Laptop was brought back hoe, it was tested during an entire evening and the problem never reoccur. Matter of fact, this problem happened 2 years in a row with the same laptop and in the same building. In between, the laptop always functioned without any problems. You have to borrow a multimeter and check what is the actual level of your voltage.

TShand

Here's another update...

Checked the outlets yesterday... With a receptacle tester. Didn't look like there were any problems. I left a clock radio plugged into the same outlet for a few hours... It was fine. Plugged the clock radio into the surge protector overnight... And it was fine.

So I don't think this is a power issue. I understand that a clock radio and a subwoofer are not quite the same... But if there's something wrong electrically, technically it would affect other items plugged into the outlet, right?

Next step is to check my receiver for leaky voltage... But again - I have several components hooked into the receiver via HDMI and component... So one would assume that if that was the problem - other components would be failing too, right?

Also going to pack up the entire sub and ship it off to Polk Canada... Hopefully this all gets figured out. 3 months without a subwoofer sucks.

T

TECHNOKID

Also going to pack up the entire sub and ship it off to Polk Canada... Hopefully this all gets figured out. 3 months without a subwoofer sucks.

I guess this is the best to do, it might be the driver itself who knows. Overall, Polk products last for many years however, like many other good companies a few out of many thousands can slip their QC department, you just have to be patient.

Cheers

danger boy

I would guess that whomever looks at your dead subwoofer should be able to tell how this problem keeps killing your sub.

if you are over driving it.. that should be pretty clear once the amp is opened up. if it's another part that keeps failing, then that would also be clear to me if it's getting a surge in power and thereby killing the amp.. or if a cap or resistor is getting fried each and every time.

for your sake, I hope this is the last time it has to be sent out for repairs. I too would be upset if this keeps happening time and time again.

good luck.

once again... the volume knob on the back of the subwoofer should not go above 12 0'clock. don't push it beyond that or you're asking for trouble.

753951

I've read this thread with interest. Have two questions though:

1. If volume needs to be at 12 o'clock so not to blow sub, why can it be cranked higher? Shouldn't sub safety prevent that to happen?
2. What does size of room have to do with sub blowing? Are you telling me that all things being same, bigger room will cause sub to blow?

disneyjoe7

Bass to fill a room needs to pressured the room to feel it. So size of room, the wattage behind it is a factor in filling bass to a room.

Most amps start to clip and square off the signal so it damage the driver (woofer in this case)


Welcome to the club.

753951

I'm still missing something.

Let's say we have room A and room B. Room B is twice as big as room A.

In room A sub volume is set to 50% (12 o'clock). It nicely pressurizes the room and I cen "feel" it.

Same setting (50%) in room B does not pressurize as much so "feeling" is not so great. But that's it. Less of a "feeling" does not equate to blown driver.

Now, if user wants same "feel" as in room A, and it cranks volume up to 100% to get it, I can see how that can blow sub (even though I'd expect engineers to incorporate safety against it). But that's not because of bigger room. It is because of user action (or design oversight).

Or do subs have "pressure meter" and 50% in room A draws less power from amp than 50% in room B?

TECHNOKID

753951 wrote: »

I'm still missing something.

Let's say we have room A and room B. Room B is twice as big as room A.

In room A sub volume is set to 50% (12 o'clock). It nicely pressurizes the room and I cen "feel" it.

Same setting (50%) in room B does not pressurize as much so "feeling" is not so great. But that's it. Less of a "feeling" does not equate to blown driver.

Now, if user wants same "feel" as in room A, and it cranks volume up to 100% to get it, I can see how that can blow sub (even though I'd expect engineers to incorporate safety against it). But that's not because of bigger room. It is because of user action (or design oversight).

Or do subs have "pressure meter" and 50% in room A draws less power from amp than 50% in room B?

Basically if the subwoofer isn't filling the room, one would tempted to push it harder in order to compensate for the lack. Above 12 o'clock an amp will start to distort and not sounding as good. By doing so, the distortion and potential clipping (as described the analogue wave would then be clipped of its top portion generating distortion, adding undue electrical pressure to the involved components)... clipping is the ennemy of both amps and speakers. Internal componets start to overheat up to a point were they simply blow-up disintegrate from the inside surge.The mention of the room size is to basically point that the room is too large for the subwoofer or the subwoofer is too small for the subwoofer. Sound pressure is how you calibrate your room and like anything else, you do not want your gear to overwork to accomplish the task.

Cheers!

753951

So, as I thought, it's not the room. It's user (but user says "Room made me do it!"). Good enough.

Still, I'd expect decent sub to have safety built in against it. Just like cars have engine rev limitter.

disneyjoe7

753951 wrote: »

Just like cars have engine rev limitter.

Only if it's not in gear, you can still blow it up


And then again I think engines have a rev limiter, just for the transmission.

TECHNOKID

753951 wrote: »

So, as I thought, it's not the room. It's user (but user says "Room made me do it!"). Good enough.

Still, I'd expect decent sub to have safety built in against it. Just like cars have engine rev limitter.

Electronic protection is also an electronic component which is vulnerable to abuse. Get them to overwork and the efficiency isn't there anymore. Protection is mainly there to avoid the worse but damage has already occured. A good example is fuses: People think that when the fuse blows the only thing they have to do is replace the fuse and this is totally wrong. The fuse blew for a good reason and in most cases, damages are already done however, the fuse prevented the entire unit to get damaged while it was limited to a minimum, the damage usually stopped at only a few components and the most important it prevented a fire or other potential damages outside of the unit.

When a home breaker trips, it doesn't stop or prevent overload or short circuit. On the opposite, it trips because of the overload or shorted circuit and its job is to prevent any further damage. Today's AVR and other amps are very sofisticated and will trip circuitry prior to damaging the O/P but ignore this alert and keep trying to use it with the problem that is the cause for that circuitry to activate and it will not take too long for damage to (RE)occur despite the circuitry protection!:eek:$$$$$;)