F**k Me, Blew 5 sets of 12"s

[project83]

Question- Does having a smaller box then whats recomended for sub make it easier to blow the speakers.

I have MTX X Thunder 600xd amp, pushes 600rms a 2ohms.

I blew 2 Kicker07C124, 4 ohm,150wrms- Amp Gain 1/4 the way up Showing 30 volts on Multimeter

Then Blew 2 Mtx JH4512, 4 ohms,125-250wrms, Amp Gains Lil more than 1/4 45volts on Multimeter

Then 2 MTX Thunder 4500, 4ohms, 225wrms, Gains showing 40 volts on Multimeter.

The only thing I havent changed was the 2 Wedge Truck boxes, about .65 cubic ft. Re dont whole amp kit 4g power wire, 12g speaker wire, Each set was wired parallel for 2 ohm load.

Oh I blew all of these in about a weeks time, Kickers still show signs of life, Distored to all hell but cone still move Mtx 4500 and Mtx Jackhammer 12's the cone is stuck, can push in or pull out, completly siezed. Called MTX and the said it was impossible for my Amp to do that to the jackhammers.

Any Ideas on what could be causing this, Ive been told to much power but was told by MTX to use 50hz tone from tone generator to set gain- they say 30v = 300 Watts.

Im plannin on gettin a Pair of Fosgate Punches and dont wanna blow them too. Any Ideas

[rustyspring03]

where are you showing 30-45v? cars run on 12v so that would be my guess and yes a small box can put more stress therefore blowing the subwoofer

[1/4milecrazy]

to small of a box can do that

[jagblazer01]

Quote: Originally Posted by rustyspring03

where are you showing 30-45v? cars run on 12v so that would be my guess and yes a small box can put more stress therefore blowing the subwoofer

30-45v is the voltage the amp puts out that goes into the sub (i believe its actually AC voltage). my amps are running at 57.5v

[stupid n00b]

have you tried any polyfill?

[1/4milecrazy]

haha fitting name, polyfill decraeses volume so that would only make it worse

[AVNCHRIS]

i would say dont tune by volts. tune by ear. IMO

[Speedy2222]

polyfill makes the box feel bigger... makes the waves take longer to bounce around in the box

[Heathd]

Quote: Originally Posted by AVNCHRIS

i would say dont tune by volts. tune by ear. IMO

[stupid n00b]

Quote: Originally Posted by 1/4milecrazy

haha fitting name, polyfill decraeses volume so that would only make it worse

actually, youre the noob. it would be great if you knew what you were talking about before you opened your mouth.

poly fill makes the box seem larger, becuase it slows down the air waves, nmaking the subthink its in a larger box.

thank you drive through.

[1/4milecrazy]

Quote: Originally Posted by stupid n00b

actually, youre the noob. it would be great if you knew what you were talking about before you opened your mouth.

poly fill makes the box seem larger, becuase it slows down the air waves, nmaking the subthink its in a larger box.

thank you drive through.

ouch you told me huh

ask me if i give a fuck

sorry i was more concerned with learning how to spell than poly filling boxes

dickbag

[oxsign]

Quote: Originally Posted by 1/4milecrazy

haha fitting name, polyfill decraeses volume so that would only make it worse

Wrong.

Quote: Originally Posted by stupid n00b

poly fill makes the box seem larger, becuase it slows down the air waves, making the sub think its in a larger box.

right.

[stupid n00b]

woah, settle down tough guy.

[1/4milecrazy]

im not mad i thought it was funny, i was wrong, i laughed.

you sounded like the tough guy the way you went about explaining. notice other people told me i was wrong without seeming like a douchebag. that is one of the problems with this forum.

[layitout]

i had heard of checking amp power this way my cadence a 7 hc is around 74 volts playing a spl cd. not sure how that rates in power wise

[project83]

Ive tried polyfill shit-Pretty sure thats what help kill the kickers. Ive been told that Im just overpowering the damn things so I think Ima try to get 300-400wrms subs so I can cut out that variable.

Before I put them in tho Ima build me a bigger box. I got 2 bucket seat in Standard Cab s10. So if a bigger wedge box dont help I gonna take out the passager seat and get 15" or 18" Solobaric.

[Tuteuk]

Quote: Originally Posted by project83

Ive tried polyfill shit-Pretty sure thats what help kill the kickers. Ive been told that Im just overpowering the damn things so I think Ima try to get 300-400wrms subs so I can cut out that variable.

Before I put them in tho Ima build me a bigger box. I got 2 bucket seat in Standard Cab s10. So if a bigger wedge box dont help I gonna take out the passager seat and get 15" or 18" Solobaric.

standard cab....15 or 18...This is gotta see..LOLOLOL

[crux131]

I would can the idea of 2 12's if all you can muster is 0.65 cuft a peice. Most 12's on the market really wont perform their best in that small an enclosure.

Have you thought about a single 12" DVC sub in a little over 1 cuft.? I bet that would work pretty well in a standard cab. I bet you would get great response with a single 10" ported as another option.

I don't think the polyfill helped kill the Kickers. I think it was just an improper box coupled with the amount of power being fed to them. I killed a comp 12" the same way, except the box was 2.7 cuft tuned to 33 hz and it was getting 450 watts RMS. Actually sounded good, but was too much power for the sub. It eventually started working intermittently and had some mechanical noise develop. I canned it and moved on.

Good luck with what ever you chose. I would try to run at least a cubic foot of airspace per 12" if you go that route though, and might even add polyfill in varying ammounts until I liked the sound......I say 1 cuft. per 12 because that seems to be a fairly standard box suggestion from many brands. You still want to double check the manufacturers reccomendations of course.

[danssoslow]

A comparatively smaller enclosure will INCREASE the mechanical limits, not decrease it. Adding polyfill or going bigger with the enclosure would decrease the speakers' ability to handle power.

Did the subs die due to mechanical or thermal failures? Are the coils burnt and discolored?

[project83]

I'd say it was thermal failure, when I pulled out the MTX 4500, I grabbed the magnet like a dumbass and screamed like a bitch. I used my laser temp gauge for my nitro R/c car. The magnet was 195.7 degrees. While the sub was hot you could force the cone to move barley, when it cools it it completey stuck, wont move in or out.

Anyone here of HiFonics HFi12D4 12" 600W Dual 4-Ohm Subwoofer

I found them for 58 dollars a pair, Im still wanting atleast 2 sub, if I gotta lose a seat for airspace it really wont bother me, I dont like any of the bastards that want me to give em a ride anyway.

Im gonna do some research and measuring to see what i can fit in there with proper airspace. If the seat must go, it just gives me more room for subs. Might seem a lil retarded but shit there aint shit to do where i live so f*ck it seems like a good idea at the time.

[timtp2004]

Quote: Originally Posted by Tuteuk

standard cab....15 or 18...This is gotta see..LOLOLOL

He said no pass. seat

[Heathd]

There are a lot of problems or reasons why your subs are failing. First off, how much space did you leave for the subs excusion. Im not reading all the B/S in this thread, so I dont know if it was mentioned. If you put your seats right up against the box, that could be reason number 1.

2) While your method of setting the gains is better then what most people do, its still not a gaurantee that your getting them the true rms power.

3) If your buying subs, that when combined, take a total of 600 watts rms, and your amp is putting out 600 watts rms, you could be pushing your amp into clipping. That will do it all by itself.

4) your looking at cheap subs. Sorry, hate to say it, and Im not saying to be a dick either. Kicker doesnt produce anything worth talking about unless your willing to spend some cash. Their entry level stuff is trash, just like the mtx subs you purchased and blew up.

As far as MTX is concerned, you could custom build and tailor an enclosure just for that sub you buy, and it could still blow. Its a crap shoot with them.

RF may have been real big when I was in high school, but I am still not impressed to this day with their products. They are mediocre at best. However, I do know that some time ago, they produced some fantastic amps, but those engineers are long gone and probley opened up their own company.

Dont buy the Hifonics subs, theyre not worth it. I have a hard time taking their amps seriously anymore, and I doubt their subs are worth sneezing at.

[rustyspring03]

it also sounds like you are doing this all with in a short time period meaning that none of these have been broken in properly either.. sounds like you should take some time and do things right

[stupid n00b]

Quote: Originally Posted by Heathd

RF may have been real big when I was in high school, but I am still not impressed to this day with their products.

have you personally tried the t2 subs? thats what I sell the most of at the shop. here, people want brand names. I wouldnt be able to sell DD, ascendant, fi etc. ive had nothing but great results out of the rockford subs/amps.

[DJDAudio]

Hot Sub? All Blown fast,

Sound like you have DC on your outputs.

Check it with a scope if you can.

Some amps will clamp there outputs if DC is present on them to save the speakers.

[DJDAudio]

when a voice coil gets DC voltage, it turns the coil into a heating element, and the coil quickly burns up, causing teh cone to "freeze" in such a manner as you've described

[DJDAudio]

Also a Reading of more then 0.5VDC on the output with no speaker atached indicates the AMP has gone DC and will require Service.

DC Rail voltage on the outputs is real bad!!

[Heathd]

Quote: Originally Posted by stupid n00b

have you personally tried the t2 subs?

Do I want to? No I dont...

Have I heard them? Yes, I have. I dont like RF speakers, I just dont.

[project83]

Tomorro Im headed to Local audi shop where they said the can test my amp to make sure thats not the source of the problem.

As for breaking in the subs, the kickers I had them for about 6 months in my Lincoln and the MTX 4500s I got them from my brother and he's been pounding the crap out of them for almost a year before I got em. The Jackhammers yea, never broke them in.

Im not really looking for top of the line competition subs, just something that sounds good and bang pretty hard. I been thinking of getting some Fosgate P2 or P3's but I dont wanna fry them to cause they cost a lil bit and Im a poor white kid.

The reason I was looking at getting the Hifonics 12s is so I can have some ok'ish subs that I can try out in a new box, then if they surrvive I plan to upgrade.

The amp I have is MTX x Thunder 600xd, Its rated at 325rms at 4 ohm and 600rms at 2 ohms. The tech sheet that came with it say it actually produces 692rms on a 2 ohm load. I push my subs hard but not to distortion.

About the room for excursion they are sitting right behind the seats maybe and inch or 2 from the cone touching the seat, thats with no power going to them so that could be part of the problem.

[dej1001]

The woofers hitting the seats could definitely be a reason you are blowing woofers. Too much power will not blow woofers, distortion will. Not allowing the woofers move freely will cause the voice coils to seize up.

And the people who were responsible for Fosgate amps being so good were the research and design guys who left and created Diamond Audio. Thats why their products are as good as they are.

[98dimebagtime]

Sounds like you might want to try "breaking in" the subs - go easy on them for a while.


You're familiar with distortion, yes?