Blown subwoofers and I have no idea why?

[gunz4me2 10+ year member]

and my bass EQ on the amp is set at about 3/4 way

That bass boost at 75% is a good way to send a clipped signal to the subs. Excessive clipping turns into heat in the woofer's motor assembly and will kill it just as bad as direct DC current will.

it does not sound distorted at all, it sounds great but that smell continues to come. from every sub and even on the sealed enclosuer sony.

Sadly, most do NOT hear distortion until it reaches close to 10% in the sub bass region whereas others don't notice it until it gets closer to 30%. Regardless, just because there is no audible distortion, your amplifier could still be sending a clipped signal to your subwoofers.

Going further, I believe your pre-fab enclosure IS NOT the right size for ANY 12" subwoofer ported, hence the reason your subs hit the "high notes" and struggle on the low notes. I could be wrong, but that enclosure just looked way too tiny from the photo you posted. Generally a modern day single 12 will need anywhere from 1.5 to 2.5 cubic feet ported with the port tuned between 30 and 35 Hz. If I had to guess, your Fierce Audio enclosure is probably 1 cubic foot tuned in the 40 to 50 Hz region. Truthfully, you would be better off with a 8" or a 10" sub if you must live with a 1 cubic foot ported enclosure.

Until you address your enclosure issue, I am afraid you will not have the deep bass that you crave.

 

[hatedonmostly 5,000+ posts]

If I had to guess, that box is probably around 0.5 after displacements...

 

[gunz4me2 10+ year member]

If I had to guess, that box is probably around 0.5 after displacements...

I was trying to give Fierce Audio the benefit of the doubt, but that enclosure looks TINY from every photo I saw of it online.

 

[hatedonmostly 5,000+ posts]

I was trying to give Fierce Audio the benefit of the doubt, but that enclosure looks TINY from every photo I saw of it online.

I've had some sealed truck boxes for 12's about the same size, that's what I'm basing my estimations off of. Mine were 0.64 sealed gross, after displacements it came out to be about 0.5...

Not trying to correct you but giving my input from personal experience.

 

[alpinetree]

I REALLY appreciate the help and I am very sorry I replied so late.

It does not struggle on low notes, it actually hits them better than highs.

The high notes are able to be felt and sound good and the low notes move everything in the truck. including half full cans of coke... ha ha

The ported box is roughly as wide as two 12" subs and around 5-6 inches deep.

I guess it takes more width into account to make for the room.

I tried some new RCA cables and no improvement.

I am confused how it could be tuned wrong because a professional had tuned it for me?

Unless he was wrong, which could be extremely possible.

As for the LPF mine has the lowest setting of 50. there are no options for 30 or 35 and it is set at about 55-60 atm.

 

[gunz4me2 10+ year member]

I can almost guarantee you that your enclosure is TOO SMALL for a Memphis Power Reference 12" subwoofer. Even the Memphis Car Audio pre-fab ported subwoofer enclosure is 2.16 cubic feet prior to subwoofer displacement. As l4yfr4me stated, your pre-fab enclosure is probably .5 cubic feet with the subwoofer in it. I saw online where Fierce Audio claimed that the enclosure was 1 cubic foot, but I'll only believe that when I see one in person and measure it myself!

ETA: Even the Memphis Car Audio ported pre-fab truck enclosure is 1.87 cubic feet.

 

[alpinetree]

But would the box being small have anything to do with making the coils burn and blow the sub?

I have closed the port and it still made a terrible smell.

 

[sub-FATHER 10+ year member]

you better get a bigger set of subs because you definitely are trying to get more outta the subs than they can handle. if you wanta pound you have to go big.

 

[alpinetree]

The amp is turned down to handle that sub, it's not maxed.

 

[AudioDave]

The smell of burning coil does linger around in the box and within the subwoofer though, so you can do this... take the sub out of the box with it still hooked up and see if the cone moves either in our out when you first turn your stereo on, if it moves without any music playing then it is getting DC from the amp, if that's the case then either the amp is faulty or your headunit's preamp stage is faulty, or the RCA cables are pinched and grounding out somewhere. If it doesn't move then play some music and observe the sub's movement and see if anything erratic shows up.
It ***** because it is much harder to troubleshoot car audio systems especially if it's something strange.

Ya dont test DC or anything like shorts with any speakers ya use a volt meter and save your equipment!@ //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[T3mpest 10+ year member]

The amp is turned down to handle that sub, it's not maxed.

No it's not. You said your bass boost was 3/4 of the way up. 3db's of bass boost requires double the amount of power at that frequency. Usually a 45hz boost is what most amps boost. Let's say your amp is turned low on your gains and without any boost your only sending 100 watts of power to your sub. That's no issue right, after all your subs can handle 100 watts and so can your amp. Now, IDK how many decibels of bass boost your amp can do, probably 12? Well 3/4 on your gain not is probably 9db's of boost, give or take, so let's add that in....

3db's+3db's+3dbs=9db's. Every 3db's is a doubling of power. You WERE running 100 watts, but any time a 45 hz tone or anything near it comes along your actually pushing 8x that amount of power (2x2x2). 100x8=800 watts. When a amp clips it can put out almost 2x it's rated clean power. While your amp can't do 800 it can probably do 700ish clipped since it's good for 350. That's why your blowing sub even with low gain. Also 45hz is a very common tone in rap music, most songs have a strong bass presence there.

Also your box is too small. That's why your having to use bass boost to get good output. You need to turn the bass boost off and reset your gains using a dmm, since you can't seem to hear distortion or know when your over driving your equipment. If that isn't loud enough for you after that, you need to build a box that actually properly fits your subs, that'll give your a bigger SPL boost than clipping your amp lol.

Anyway there is no magic to blowing your coils. If your smoking coils your amp is sending them too much power, period.