I blew my 300.2 Amp!

[Flamekiller20]

i was riding in my car one day listening to some music, when my subs cut out and i smelled something burning. I looked in my back seat and smoke was pouring out of my trunk. I have a 300.2 amp hooked up to 2 12" momo subs (everything i have is the carbon series). i checked all my wires and none of them were touching anything else, no fuses are blown anywhere, and the ground wire is still hooked in good. i didnt have my bass up real loud either. Does anyone have any suggestions as to what may have caused this, or why my fuses didnt blow when they should have? I dont know if it matters or not, but i have no idea if my subs are bridged or not, my friend wired that up, while i was wiring my head unit. Any help would be greatly appreciated.

[neomagus00]

since it's only a 300.2 to 2 12" subs, i'd say that the gain was turned up WAY too high, and the clipping was too much. check the position of the gains knob, if it's beyond say 2 o'clock, that's probably it.

were you in the car for a long time before you noticed the burningness?

[MacLeod]

Jesus Christ dude!! Smoke pouring out of your trunk?!?!? Im not even sure if an amp can put out that kind of smoke!

Check the amps wiring. Make sure that only one sub is hooked up to one channel of the amp. If your friend hooked up both subs bridged (left negative and right positive) then your amp is running at 2 ohms mono which it isnt designed for. Still I cant believe it would put out enough smoke to come bellowing out of your trunk.

Also check the gain and make sure its not turned up any higher than the noon position.

Honestly tho, I kinda think you may have another problem and if it was as much smoke as you say, my guess is a wire is shorting on something somewhere. Thats dangerous. There is no telling how your friend wired the thing up.

If you cant locate the problem I advise taking your car to a local shop (real shop not Circuit City or Best Buy) and tell them your symptoms. They will be able to fix it before your car catches fire!

[neomagus00]

Originally posted by MacLeod
They will be able to fix it before your car catches fire!

yeah, by the way, this isn't a figure of speech, your car really can catch fire and burn to a black rusted shell... to not have that happen, i highly reccommend you (in this order):

a) disconnect the power wire from the battery entirely, and keep your HU off just to be safe.
b) take mac's advice and take it to a shop (this didn't occur to me, but is a wonderful idea).
c) if the shop finds a wiring problem, hunt down your friend and hit him with heavy for putting your life in danger.

oh, and mac - i think the VCs overheated (probably from clipping) and cooked the subs... literally...

[MacLeod]

Yeah but still, would that make enough smoke to come bellowing out of the trunk?!?

Where the hell is Vinnie or Josh? They would know.

I used cheap wire once several years ago and my power wire scraped some insullation off and shorted on some metal under the carper. I wasnt running that many amps but that sure did smoke a lot! Melted the wire pretty fast too!

No more cheap Radio Shack wire for me!

[chakabobo18]

Originally posted by Flamekiller20
i was riding in my car one day listening to some music, when my subs cut out and i smelled something burning. I looked in my back seat and smoke was pouring out of my trunk. I have a 300.2 amp hooked up to 2 12" momo subs (everything i have is the carbon series). i checked all my wires and none of them were touching anything else, no fuses are blown anywhere, and the ground wire is still hooked in good. i didnt have my bass up real loud either. Does anyone have any suggestions as to what may have caused this, or why my fuses didnt blow when they should have? I dont know if it matters or not, but i have no idea if my subs are bridged or not, my friend wired that up, while i was wiring my head unit. Any help would be greatly appreciated.

If you sure you don't have any blown fuses or lose end wires shorting anywhere, it sound like your two subs where wired wrong in the sense that they are asking the amp to output a impedance load that is too low and unstable for the amp. E.g. your two Momo subs are 4 ohms each, if they are wired in a parallel series on the same channel, then they would both be asking for a 2 ohm load from the amp instead of a 4 ohm. Virtually ever amp on the market is stable down to 2 ohms as long you aren't combing two separate channels into one. But when you combine two channels into one, 99% of your 2 and 4 channel amps are only abe to sustain a 4 ohm load when two channels are bridged.

To me it sound like you have a two channel amp, (hint the .2 in the model number of the amp) and your subs are wired in a parallel series. A parallel series in your case, since your subs are single voice coil is when you take both the positive on each sub and plug them into the same positive terminal on one of the two channels of the amp. Then you take the negative on both subs and plug them into the same negative terminal on the other channel of the amp, therefore combining both channels of the amp together. So e.g. on your left channel or channel 1 you might be using only the positive or only the negative and on the other channel, with me be called right channel or channel 2, you would be using the opposite polarity that you are using on the other channel.

I've had a very similar situation with what your experiencing, when I first started fooling with car audio, I had taken two 4 ohm subs and tried to bridged them on a 2 channel amp, that could only sustain a 4 ohm load when bridged. My amp started smoking just like your did, but I don't recall a fuse being blown, I had fried some of the capacitors inside of the amp that supply the power to the subs, because based on the way I wired my subs, the subs were asking the capacitors for more power then they could supply/sustain, eventually frying the capacitors.

Hopefully this helps you out, but if not, send me a email.

[exalted512]

Sounds to me like you wired it to 2 ohms. But what size is your power and speaker wire?
-Cody

[Josh]

Sounds like a burnt voice coil. If you are running two 4 ohm subs bridged down to 2 ohms and then bridged at the amp, the amp is seeing a 1 ohm load. Our amps should immediately go into protection. I have a feeling the subs are running in stereo (2 ch) mode and the gains were set too high. The subs were probably clipping badly, but since they were in you trunk, you couldn't hear it. Also, what kind of box is it? Is it ported or a bandpass. The reason I ask this is that if you have a sealed box, unless the cone catches fire, you're not going to be able to tell that the VC is cooked. If it there is a port, smoke would pour out of it.

[neomagus00]

Originally posted by chakabobo18
wired in a parallel series on the same channel

you said this several times, and for 2 subs, it's just 'parallel'... you can't have the colloquial 'series-parallel' until you have at least 3 VCs.

Originally posted by Josh
Sounds like a burnt voice coil... The subs were probably clipping badly...

woohoo!

[chakabobo18]

Originally posted by neomagus00
you said this several times, and for 2 subs, it's just 'parallel'... you can't have the colloquial 'series-parallel' until you have at least 3 VCs.


woohoo!

First off what is a coollquial? If this isn't no unique kind of sub, then why does it need at least TVC. Only two voice coils are required to wire a sub or pair of subs in a parallel series. It all depends on if the sub(s) is single of dual voice coil.

[fireshoes]

You can wire in series, parallel, and series-parallel, so he is saying your terminology is confusing. You should just say parallel, not parallel series.

[neomagus00]

i said colloquial because i'm not entirely sure that 'series-parallel' is an accepted term like 'series' and 'parallel' are *(if that sentence doesn't make sense, look up colloquial in the dictionary). and you most certainly cannot run series-parallel with only 2 VCs. if you disagree, feel free to show me a wiring diagram that proves me wrong.

[chakabobo18]

Originally posted by neomagus00
i said colloquial because i'm not entirely sure that 'series-parallel' is an accepted term like 'series' and 'parallel' are *(if that sentence doesn't make sense, look up colloquial in the dictionary). and you most certainly cannot run series-parallel with only 2 VCs. if you disagree, feel free to show me a wiring diagram that proves me wrong.

Before I say anymore, fill me in on what series-parallel configuration is as far as wiring is concern. Because it seems to me that your telling me that series-parallel is not series or parallel wiring, it is a wiring of its own. If so then this is definitely news to me.

[Flamekiller20]

Ok, i am going to do my best to answer your questions..when it happened, i drove for about an hour, my car sat for about 4 hours, then i drove for about another 45 minutes befor it happened. i immediatly turned my head unit off. it worked fine for about 6-8 weeks.

my box is a .88 sealed box..it is what was recommended by 3 or 4 car audio sites for these subs

After it happened, and i worked up enough nerve to look at at it (about 3 days later) the power light still came on so there is power getting to the amp, the Thermal light never came on before or after this happened, and the Short/Low Ohm light never came on before or after this happened.
The following settings are the way they were at the time this happened:
Crossover set to the LP position
Freq set at 120
Pre-EQ set on bypass
Input controls set on low
Gain at about the 10:00 position

i just went and looked at how my friend wired my subs and if you go to this page http://www.polkaudio.com/car/amps/diagrams.php he has it wired the same way as the diagram with the big yellow X through it (the first one you come across) the 2 DVC driver parallel/parallel..IT FIGURES!! but why did it work for about 6 weeks and the low ohm light not come on?

hope i helped out a little bit..if you want more info email me at blk84_02@yahoo.com

[neomagus00]

the low ohm light absolutely should have come on, and protection engaged. you should call polk about possibly getting a replacement, you may have a faulty amp, because your settings were all fine (the xover is unusually high, though).

you are feeding the amp from RCA's, yes?

i have the feeling that the amp was just on for too long, and couldn't take it any more.

chakabobo: series-parallel describes a scheme wherein some of the VCs are in series to another, and some are in parallel. this is most simply used in wiring 2 4-ohm DVC subs to 4 ohms; the VCs of each sub are wired in series up to 8 ohms, then the 2 sub-units are wired in parallel to bring it back down to 4. much more complicated setups are, of course, possible.

[MacLeod]

Yes but as Josh pointed out, if its in a sealed box you wouldnt be seeing any smoke! Amps dont smoke that much....do they?

Im sticking by my shorted wire theory for now.

[Flamekiller20]

Alright, i broke down and opened it up.. there is all kinds of **** fried in it..lol
so i think im just gonna buy another one off of ebay

by the way, i looked at how my subs are wired up again, and its not like the DVC parallel/parallel. It has one sub going to one channel and the other sub going to the other. the subs are not hooked together at all..

now comes my next question, what caused this? was it a faulty amp, or did i have a setting too high/low? from what ive read from your posts it sounds like everything was set where it should be, so i am going with the faulty amp theory

[neomagus00]

absolutely... there is nothing on this earth that should fry that amp, it must have been bad... everything else seems to be right.

i'd say call polk about a warranty replacement... except you said 'another one off ebay', which leads me to believe you're slightly screwed when it comes to a replacement. also, you may have gotten screwed on the initial buy... ebay is dangerous. if you paid through paypal, you might be able to take some sort of action, but i'm not familiar enough with it to know for sure.

if that's the case, i'd say bite the bullet and get a real one, from an authorised internet dealer or a local authorised shop and put that in... yay for warranty...

[chakabobo18]

Originally posted by chakabobo18
First off what is a coollquial? If this isn't no unique kind of sub, then why does it need at least TVC. Only two voice coils are required to wire a sub or pair of subs in a parallel series. It all depends on if the sub(s) is single of dual voice coil.

I understand stand the setup perfectly, I just didn't follow the series-parallel, although it makes perfect sense now.

[MacLeod]

If you bought the amp off of Ebay then youve just learned why I flat out refuse and discourage buying from unauthorized dealers. Chances are you got an amp that as been repaired or refurbished or worse, just been patched up and sold.

If you buy another one, get it from Sounddomain.com. They have the cheapest prices and theyre an authorized dealer so you know youre getting a product fresh from the Polk assembly lines with the full warranty and blessing of the benevolent Matt Polk!

If you did buy from an authorized source then either the amp was faulty or (dont want to sound like a broken record here) your wiring may have shorted out. Either way, re-check your wiring if for no other reason than to shut me up about it! :D

[Flamekiller20]

i just wanted to thank you all for your help

[chakabobo18]

Originally posted by MacLeod
If you bought the amp off of Ebay then youve just learned why I flat out refuse and discourage buying from unauthorized dealers. Chances are you got an amp that as been repaired or refurbished or worse, just been patched up and sold.

If you buy another one, get it from Sounddomain.com. They have the cheapest prices and theyre an authorized dealer so you know youre getting a product fresh from the Polk assembly lines with the full warranty and blessing of the benevolent Matt Polk!

If you did buy from an authorized source then either the amp was faulty or (dont want to sound like a broken record here) your wiring may have shorted out. Either way, re-check your wiring if for no other reason than to shut me up about it! :D

I definitely agree with purchasing from Sounddomain.com, although when you click on the icon to view a product, you should check the top of the page to make sure that they state they are authorized to sell that particular product.

[MacLeod]

As far as I know, Sounddomain, like Crutchfield, is authorized delaers for all the brands they sell.

[neomagus00]

Originally posted by Flamekiller20
i just wanted to thank you all for your help

any time

[chakabobo18]

Originally posted by MacLeod
As far as I know, Sounddomain, like Crutchfield, is authorized delaers for all the brands they sell.

Crutchfield doesn't sell anything they aren't authorized to sell, but I've bought products from Sounddomain that they aren't authorized to sell, and if they were, it wasn't displayed on the product page just as they normally do with other products. Check out this links below to see what I mean.

I didn't buy this product, but take a look at this pages:
http://www.cardomain.com/shopbrand/Jensen
www.cardomain.com/shopbrand/Panasonic

I actually bought somethinig from this page:
www.cardomain.com/shoplist~b~Koito~t~Headlight+Replacement+Bulbs

[51Audio.info]

I have this same amp and got it used for installing some subs for a friend. I tossed out a 1200w amp as soon as I heard this amp hooked up to my 15's. Best amp I ever had period