Blown MM12?

sireeznutz

Hi. Just purchased a MM12 with enclosure. It's been hooked up in my car for about 3 weeks now until it died on me yesterday. It sucks because I don't have my receipt of purchase anymore, and to make things worse I unknowingly voided the warranty when I removed the sub from the enclosure to do a couple of inspections.

I know for sure it isn't a blown channel on my amp, and that indeed it is the MM12 that failed on me. The sub was running on a dedicated sub channel on my MTX 5 channel amp. I don't think the problem could have been excess power. Any gurus out there have any idea why it would have died out with only a few weeks of play?

I was initially impressed by the sound of the speaker, but now this just disappoints me. I'm going to be looking around for a replacement, unless there is indeed away to get Polk to service the speaker for me. In the meantime, I'll be riding around in a treble machine. I guess that goes to say you get what you pay for, as I only spent $99 on the sub with enclosure at a Fry's Electronics store.

On that same note, anybody have any suggestions on my new subwoofer brand? I don't think I can deal with the wait on getting this one fixed/replaced.

Thanks for listening.

A. Newbie

MacLeod

Now thats service! Polk rules!

bknauss

Nah, just Kim... he's the man

sireeznutz

Thanks for the reply. Okay, so I've sent off my sub, but now I'm concerned with having my replacement die on me also. I'm going to run a 5 channel amp configuration with the 5th channel going to the sub.

Please excuse my lack of speaker knowledge, but I know it couldn't have blown from an excess of power from my amp. So is it indeed because I may have had the gain on my amp too high?

I actually am looking for a little more thump and am considering going with a bandpass or ported enclosure instead of the factory sealed box that came with my MM12. I don't yet have the money to purchase a dedicated amp for my sub, so I might go in the direction of efficiency.

What do you think?

exalted512

how much power did you have going to the sub when it blew?
you might have had the gains too high and the amp started clipping and thus the clipping is in fact the culprit of the blown sub
as far as band pass...they sound like ****
youre also not supposed to port momos
and if you take it out of the box its been said that you void your warranty...im not sure if its true or not and i think its a bunch of BS but you might want to check into that before you take it out of the box
-Cody

sireeznutz

Thanks again for the reply. I'm not sure, but I know I did have my gain turned up a little bit. When you say "clipping" do you mean that the sound cuts in and out... if yes, than I didn't really hear any. However that's not to say that that's not what really happened.

I too was concerned with the warranty thing, but I did call a Polk CSR and they advised that it was okay to send the sub back even if I had taken it out of its enclosure.

I'm glad you informed me of the ported box thing. I guess the only real fix to getting that thump I want is to add a dedicated amp then.

exalted512

how much is the channel rated at? (rms)
as far as clipping...its distortion and can be harder to hear in subs
especially if its in your trunk
-Cody

sireeznutz

160 watts rms @ 4 ohm load I believe.

bknauss

Clipping is when the nice curves of the sound wave become too high/low and the tips are cut off (clipped). This has a couple problems:
-Its harder to tell in subs, but the sound is bad... its definitely not the same signal that's being fed to the amp
-With more time at the peak voltage levels, you're helping the coil on the sub heat up, and possibly overheat and die.

Hope that helps.

jakedubb

May I butt in here? When the coil overheats and dies does the sub have any sound at all? My MM10 quit on me today and I'm not sure if it's the sub or an overheated amp. The amp was damn hot to the touch but never went into protection mode.

After letting the amp sit for awhile I turned on the h.u. and still no bass at all:(. The sub did absolutely nothing...

Checked the speaker wires, rca's, fuses and etc. and all was fine. Is my sub toast?

I bought my MM10 (brand new/sealed) from a dealer on Ebay. Will Polk replace the sub if it is indeed blown? I hope so cause 3/4 of my home and car audio is Polk!

sireeznutz

Got my replacement sub pretty quickly. My overall experience with Polk service has been good so far.

My MM12 did come with a factory enclosure, and I did check with a Polk CSR who confirmed that it was okay to open the enclosure and send only the blown sub. I did not have my receipt, however I was also told by the same CSR that a copy of my bank statement, in which the transaction occurred would suffice.

I think you should be okay with your eBay purchase. Maybe a copy of a PayPal transaction statement (if you used it) might work.

With that, I packed only the sub, enclosed a letter and copy of my bank statement, and sent it away. Got my replacement in about a week without any hitches!

The only issue I now have is preventing my new sub from going out on me like the first one did. I re-tuned my system and tweaked the sub frequencies on my amp and all is sounding great. Hopefully it lasts!

bknauss

Originally posted by jakedubb
May I butt in here? When the coil overheats and dies does the sub have any sound at all? My MM10 quit on me today and I'm not sure if it's the sub or an overheated amp. The amp was damn hot to the touch but never went into protection mode.

After letting the amp sit for awhile I turned on the h.u. and still no bass at all:(. The sub did absolutely nothing...

Checked the speaker wires, rca's, fuses and etc. and all was fine. Is my sub toast?

I bought my MM10 (brand new/sealed) from a dealer on Ebay. Will Polk replace the sub if it is indeed blown? I hope so cause 3/4 of my home and car audio is Polk!

Sub is most likely toast. The amp was probably hot as hell because the sub blew... it was sending a LOT of current to the sub.

As for getting a new sub, I believe you need to buy from an authorized dealer to get any protection against failures.

jakedubb

Well I disconnected the MM10 and hooked up an old sub and it was working just fine...Damn! I was hoping it wasn't my momo. I'm gonna be really upset if Polk doesn't do anything about this, receipt or not it shouldn't have blown! I only had 400 watts (RMS) powering this sub @ 4 ohms. I was working the sub hard for about 1/2 an hour and it quit. To me this isn't acceptable. I've had off brand subs in the past that've taken more of a beating and they were 1/2 the price. We'll see what happens...

jakedubb

Polk isn't doing a damn thing about my piece of **** sub...Just a fair warning to any "would be" Polk consumers, buy from an authorized dealer and keep the receipt. It seems that Polk WILL NOT replace a defective product if you don't have a receipt from an authorized dealer. Seems to me that a company that makes a defective product AND IS AWARE OF IT should replace it no questions asked...:mad:

I was told (by Kim) to try talking w/ Gil Palmer and that maybe he'd go ahead and replace it...right! Like I see this ever happening. I will say that if he does ok the replacement Polk will always be my first choice for anything audio:D!

beenthere

Well I don't know any business that warranties a product without a proper sales receipt. Second, if in fact you fried the Sub from cranking the gain too high on the amp causing clipping, Polk isn't responsible for the damage you did to the Sub. That would be improper operation of the speaker, which is your fault, not Polk's. It's not Polk's responsibility to properly install or properly power the Sub. What you're asking is for Polk to pay for your mistake. That's irresponsible and typical of many people in the U.S. today, IMNHO. If you fried it then you should not blame Polk for your mistake.

MacLeod

Polk subs arent very good. I wont buy them cause they are way too tender.

However, Polk cant be responsible if you buy from just anybody. If you buy from some dude who is selling subs out of the trunk of his car behind some alley, Polk cant guarantee that this guy is not selling remanufactured, repaired, defective or outright immitaions. Thats the whole reason behind "Authorized Dealers". If you buy from Sound Domain.com, you know you are buying from someone that Polk is dealing with and is sending fresh products straight from the factory and if youd bought from an authorized dealer instead of some dude on Ebay, you would be enjoying your new sub again within a few days.

jakedubb

Originally posted by beenthere
Well I don't know any business that warranties a product without a proper sales receipt. Second, if in fact you fried the Sub from cranking the gain too high on the amp causing clipping, Polk isn't responsible for the damage you did to the Sub. That would be improper operation of the speaker, which is your fault, not Polk's. It's not Polk's responsibility to properly install or properly power the Sub. What you're asking is for Polk to pay for your mistake. That's irresponsible and typical of many people in the U.S. today, IMNHO. If you fried it then you should not blame Polk for your mistake.

No the sub wasn't blown due to clipping! You may or may not be aware of the time and effort involved in "tuning" in your audio equipment for optimal performance and soundstaging. I assure you that I am fully aware of how to do it properly. I can assure you that the gain was not "turned up too high" it's at a perfect sensitivity level and always has been. The problem is that this so called "championship performance" sub is no better than a dressed up Audiobahn. Polk did the same thing Audiobahn does, they dressed up this sub w/ a fancy enclosure and put out a sub w/ an improper power rating and defective components...

This was not meant to bash Polk or to make myself feel better about killing my sub! Fact is that this has been a well known problem w/ these subs and I haven't seen Polk do much about it. Yes they'll replace the sub if you kept your receipt, but what if you indeed filled out the warranty slip and properly registered your sub? You get nothing but Momo club points (or whatever it's called) toward your next purchase? Polk may or may not replace my sub, big deal. I guess that I just don't understand how a properly tuned, broken in, and non abused sub can take a crap on me this easily...

coldrealms

Jakedubb, one question for you... did you properly break-in your mm10? Polk subs REQUIRE at least 30 hours of break-in before turning up the volume and most of the guru's here suggest a gentle ramping up of power from the 30 hour mark to about 45 hours. (I just talked my local dealer into letting me turn on my sub when he closed at about 300 watts at 1/4 gain for 3 nights in a row to hurry up my break-in.
My only gripe with polk subs is that don't ever, EVER go over the rated RMS power hadling rating...smoke is not something you want to see from your sub, it hurt me more then the sub tho hehehe.

-Phil

jakedubb

Yep I sure did. It wasn't fun either! Talk about a long 40 hrs...

I'm disappointed that I didn't get to at least see the damn thing smoking, I was driving and the sub was in the back of the truck:mad:. Maybe if I would've seen the smoke I wouldn't be so pissed!

exalted512

well...if they dont take it back...you could always light it on fire...:D
ive blown 6 mm124s, dont feel too bad
-Cody

jakedubb

Originally posted by exalted512
well...if they dont take it back...you could always light it on fire...:D
ive blown 6 mm124s, dont feel too bad
-Cody

Holy ****! 6 of them? LOL! Dude your my new hero. What the heck do you have powering them?

jakedubb

It appears that Polk has stepped up to the plate and is replacing my blown sub!!!!! This is what customer service is all about:). When I make a purchase usually I go w/ the company that has performed well for me and who's customer service is helpful and has knowledge on their products. Polk has meet all of my needs!!

THANKS POLK!!

MacLeod

Originally posted by exalted512
well...if they dont take it back...you could always light it on fire...:D
ive blown 6 mm124s, dont feel too bad
-Cody

LOL! That just cracks me up everytime I read it!

MacLeod

Originally posted by jakedubb
It appears that Polk has stepped up to the plate and is replacing my blown sub!!!!! This is what customer service is all about:). When I make a purchase usually I go w/ the company that has performed well for me and who's customer service is helpful and has knowledge on their products. Polk has meet all of my needs!!

THANKS POLK!!

So, 3 posts ago, Polk was the devil.....now they rule?

exalted512

Originally posted by jakedubb
Dude your my new hero.

i get that a lot
the first 4 i was using a rockford fosgatebd1000
the last 2 were off a couple of RF 550S'
-Cody

jakedubb

Originally posted by MacLeod
So, 3 posts ago, Polk was the devil.....now they rule?

Well of course.