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Frozen Woofer, Polk Audio EX693a

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=27431
Printed Date: June 09, 2024 at 8:26 AM


Topic: Frozen Woofer, Polk Audio EX693a

Posted By: yoda888
Subject: Frozen Woofer, Polk Audio EX693a
Date Posted: February 29, 2004 at 1:14 AM

Ok folks, am I screwed here?

Amp:  Alpine 4 Channel
HeadUnit:  Alpine
Speaker:  Polk Audio EX693a

I just installed these tonight.  Unfortunately, one of the woofers is "frozen."  I verified this by just listening to that one speaker.  The highs work fine, but the woofer is "frozen."  I swapped the speaker with the other side that I know works and it's still frozen.  So it's not a connection issue, but a "broken" speaker issue.

Can this be fixed?
Is this a common problem?
Anyone see this before?

Thanks!

PS:  I tried to move the woofer with my hand, and it won't move at all, unlike the other side that moves freely.




Replies:

Posted By: superstreet786
Date Posted: February 29, 2004 at 2:40 AM
I had the same problem with mine... I went to the local car audio shop that always hooks me up and they told me my woofer had been underpowered and its completely dead so ull have to get a new one... luckily mine was covered on warrantee and i got a new one

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---- 1996 Chevy S10 ----
1 Lightning Audio S2.600.2 Amp
2 Lightning Audio 12" Subs
1 Lightning Audio 1 Farad Cap




Posted By: yoda888
Date Posted: February 29, 2004 at 3:17 AM

Great..I dont think mine is under warranty anymore..especially since I never fill out those registration cards.  posted_image

Anyone got a receipt I can borrow? hahaha..

Underpowered? how is that possible?  Do you mean overpowered?  Even that would seem unlikely as the speaker is rated for 100w RMS, and 200w peak.  Figure at 100w RMS you'd be pretty damn deaf with these speakers.





Posted By: Clean Install
Date Posted: February 29, 2004 at 6:18 AM
                                                      posted_image

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If we learn from each success and
each failure, then we can improve ourselves




Posted By: auex
Date Posted: February 29, 2004 at 9:01 AM
Basically you melted the plastic coating on the copper wire in the voice coil. You probably had your gains turned up to high and the amp was distorting.


-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.




Posted By: DYohn
Date Posted: February 29, 2004 at 10:25 AM
Here we go again.  Underpower won't harm a speaker.  Too much power kills speakers, not too little.  If the speaker cone is "frozen" it is, as auex suggested, a fried voice coil and the speaker is gone, probably because your amp is either too big for the speaker or because you were driving it into full-out clipping.  Which amp are you using?   It could maybe be repaired by a competent speaker shop, but the cost will probably be about the same as replacing that particular 6X9. 




Posted By: brad123
Date Posted: February 29, 2004 at 11:18 AM
Also you do not have to fill out the warrenty cards to get warrenty.  A manufacturer can not void a warrenty if it is not bought from an authorized dealer.  It is illegal for them to do that, just let them kno it is illegal and they will fix it no problem.  Hope this all helps.




Posted By: Ravendarat
Date Posted: February 29, 2004 at 8:08 PM
DYohn, Underpowering causes distortion which causes heat which destroys a speaker, so underpower does cause harm to a speaker. I can never understand why this is so hard for people to grasp. If you truly understand how audio systems work than this should be an easy concept for people to understand. If an amplipher is to powerful and the gains are not set responsibly that can also destroy a speaker. Either way can damage a speaker but to say that underpowering cannot is just iggnorant.




Posted By: caraudionut
Date Posted: February 29, 2004 at 8:54 PM

please help me to understand how under powering a speaker can destroy it . I have been building big concert rigs......for along time now as well as involved in car audio.....and this is the first time of have ever heard this argument.  I have built and done componet  level troulbeshooting on amplifiers and other types of audio equipment so im pretty sure that i understand the design.

So please help me to understand this "underpowering"  theory....... im not saying its wrong but i have to have the facts or some better documentation besides just saying that people are ignorant.

MY commment to underpowering causes distortion...this would only happen at high levels with an amp would clip sooner or distort sooner causing damage. .   I can take 5-10 watt all day long on a 200watt and that speaker will probably out live us all....but if i crank that 5-10 watt up     sure it will distort sooner and cause damage before reaching a sutible listening level. If i take a 1000 watt amp on a 200 watt pair of speakers.....this is alot better than the 5-10 watt amp only because i will have alot more amplifier headroom and will reach the limitations of the speakers before the amplifier ( reaches clipping) or headunits reach their level of distortion.....is this what you mean by underpowering???? If so then i totally agree with you and this is the most common of all problems in car audio

Chris





Posted By: auex
Date Posted: February 29, 2004 at 9:04 PM
Underpowering itself does not cause distortion. It is the user of the amp that turns the gain up causes distortion, or turns the volume up too much on the radio causing clipping and distortion. This is less likely for a user to turn the gains up on a more powerful amplifier because it in itself is louder.

-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.




Posted By: caraudionut
Date Posted: February 29, 2004 at 9:09 PM
correct.....i just wasnt sure if this was what he was saying




Posted By: Ravendarat
Date Posted: March 01, 2004 at 11:12 AM
That is exactly what I was getting at. I have made this argument so many times and been down this road all to often that sometimes I forget to make it as clear as it needs to be just because it is already so clear in my head.




Posted By: DYohn
Date Posted: March 01, 2004 at 11:32 AM

Underpowering cannot harm a speaker.  Period.  Now if some idiot user tries to push an amplifier too hard and drives it into clipping, then the effective DC voltage being supplied to a speaker can, indeed, overheat the voice coil and damage it.  But that will happen only in cases where the power rating of the amp is close to or exceeds the rating of the speaker.  Even if an amplifier is in 100% clipped mode producing a straight DC signal, if the current it supplies is less than the current carrying capacity of the voice coil, the speaker will just sit there and get warm.  It is only when an amplifier can produce more current than the voice coil can handle that the amp can damage the speaker.  Period.  There is no other way.  That's how electricity works.

Distortion unto itself is not the problem.  Ask a guitar player what heppens when they send a distorted sound through their amps.  It just sounds distorted.  It is clipping that is dangerous.  That, and overpower.

Underpower = damaged speaker is complete BS.  I have been installing sound systems for more than 30 years.  I am a THX certified installer.  I design sound systems for a living.  In a professional system, loudpeakers are chosen that will handle 3X to 5X the amplifier RMS rating. This is called a safety factor.  It is standard procedure.

A speaker rated at 100 watts RMS will operate just fine on ANY lower power amplifier.  It will FRY if it gets too much more than 100 watts RMS.  This is basic electricity, and basic loudspeaker operating theory.  Anyone who preaches anything else is uninformed and may be simply trying to sell larger amplifiers.





Posted By: DYohn
Date Posted: March 01, 2004 at 11:40 AM
And one other thing, speaking of ignorance.  Input gains do not limit the output power of an amlifier.  They are designed to match the input sensitivity of the amp to the output voltage of whatever is driving them in order to get the best performance from the amp in a given setup.  No matter where a gain is set, the amplifier is still 100% capable of producing how ever much power it can produce.  To think anything else is, as you put it, ignorant.




Posted By: Ravendarat
Date Posted: March 01, 2004 at 4:25 PM
I totally agree about your comment on the gain control. Mabye the best way to treat the underpowering argument is that someone who doesnt know how to properly operate a car stereo would blow their speakers easier with to little power because they would try to get output out of the system that just isnt possible without damaging the speakers. I also would like to appologize for the iggnorant comment. Really bad day of dealing with stupid people, so sorry about that.




Posted By: DYohn
Date Posted: March 01, 2004 at 4:54 PM

No problem, thanks for your comments, and I agree with you. 

I have always thought that the "underpower" myth came about because too many inexperienced (to use a more politically correct term) users purchase subs and amps that are too small for the amount of bass they think they want.  So, after a "standard" setup with their moderatly powered system fails to drive neighborhood gophers out from their burrows, they crank up the gain, drive the amp into clipping, and toast their voice coils.  The smart installer/sales person then says "You underpowered the system and blew your woofers.  You need a bigger amp."  And in effect they are right.  The user had too little power for what they WANTED, and mis-used their system.  So, the idea that is was the "underpower" that caused the damage begins, and grows.

In case you couldn't tell, this is a pet peeve of mine... sorry I jumped down your throat.

David





Posted By: caraudionut
Date Posted: March 01, 2004 at 9:48 PM

no that was exactly my thoughts...but to the in-experienced person or the newbie....reading that first post about "underpowering" was a little missleading....but now it is absolutely clear to all who may read this.

I have always thought that the "underpower" myth came about because too many inexperienced (to use a more politically correct term) users purchase subs and amps that are too small for the amount of bass they think they want.  So, after a "standard" setup with their moderatly powered system fails to drive neighborhood gophers out from their burrows, they crank up the gain, drive the amp into clipping, and toast their voice coils. 

you also forgot all the substandard equipment out there.....with big misleading manufacturer claims like a 2000 watt amp for $19.95........ that alone gets most  "inexperienced" users into a jam

I cant tell you how many amps and drivers i have replaced because of this.....dohhhh






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