Went throu 2 burnt voice coil on the SR124 dvc, SOMEONE HELP!!

jalilig35

I bought 2 12" SR DVC, i wanted to go 2 12's in my trunk but wanted to test out how 1 12" ported will sound, and it sounded amazing, i have the PA1200.1 monoblock amp, the swtich on the amp for the +8db was on and i listen to music which has alot of bass and gain is about 75-85% the box is perfectly built to spec on the polks website. the first sub i played 2 weeks slowly and i started smell smoke and burnt the voice coil, the 2nd sub i played for 4 weeks!!! slowly before i cranked it up and again there was smoke comin out from the back. i got them both warrantied, my installer called polk and polk sayin to turn off the +8db switch off if your listenin to music with bass already in it. then why even have that switch?? does anyone know why this has been happening?? is it the amp??? someone please help srry for the long post.

exalted512

You're overpowering it, plain and simple.

What kind of radio do you have?
-Cody

jalilig35

i have the stock headunit if thats what you were asking, really im overpowering it??? what do i do, turn off the +8db and put gain higher or +8db switch on turn gain lower?

jalilig35

or do i just put in 2 12's?

exalted512

Turn the bass boost off and get another 12 is what I'd start with.

I would also put the bass on the factory radio at either neutral or somewhere below that.
-Cody

MacLeod

Youve got the gain set WAY too high. Youre clipping the hell out of that amp and feeding about 1200 watts to each 700 watt sub. Thatll kill one evertime.

As Cody said, turn the bass boost off and set the gain to NO HIGHER than the halfway point. Mine is set at the 10:00 position and Ive still got it turned down 10 db on my processor!!

jalilig35

exalted512 wrote: »

Turn the bass boost off and get another 12 is what I'd start with.

I would also put the bass on the factory radio at either neutral or somewhere below that.
-Cody

lol i put the bass on my headunit to 4 max is 5, and 50% gain??? thats no bass, and isnt the pa1200.1 made for srs?? i guess i gotta go 2 12's, anyone have good experience with 2 12 sr dvc in a sealed or ported box? my installer talked to polk, polk told him that these subs are alot better in a sealed enclosure, is that true?

jalilig35

MacLeod wrote: »

Youve got the gain set WAY too high. Youre clipping the hell out of that amp and feeding about 1200 watts to each 700 watt sub. Thatll kill one evertime.

As Cody said, turn the bass boost off and set the gain to NO HIGHER than the halfway point. Mine is set at the 10:00 position and Ive still got it turned down 10 db on my processor!!

isnt it for one 12 sr dvc at 2 ohm its 800 watts? and if i go 2 12's its going to bring down to 1 ohm 600 watts each sub?

MacLeod

jalilig35 wrote: »

lol i put the bass on my headunit to 4 max is 5, and 50% gain??? thats no bass, and isnt the pa1200.1 made for srs?? i guess i gotta go 2 12's, anyone have good experience with 2 12 sr dvc in a sealed or ported box? my installer talked to polk, polk told him that these subs are alot better in a sealed enclosure, is that true?

The gain IS NOT a volume control. It simply matched the input of the amp to the output of your head unit so that when your HU volume is at 50% the amp is at 50%. If the gain is set too high, then itll be at 80% when your volume is at 40% so when you turn up the volume to 75%, you just pushed the amp to 110% which cause it to clip which means it sends a signal at 10% distortion at a power limited only by its input voltage which is usually at least DOUBLE its RMS power. Again, I have my single SR12 running with the gain at the 10:00 position and I still have to turn it down 10db on the head unit.

jalilig35

MacLeod wrote: »

The gain IS NOT a volume control. It simply matched the input of the amp to the output of your head unit so that when your HU volume is at 50% the amp is at 50%. If the gain is set too high, then itll be at 80% when your volume is at 40% so when you turn up the volume to 75%, you just pushed the amp to 110% which cause it to clip which means it sends a signal at 10% distortion at a power limited only by its input voltage which is usually at least DOUBLE its RMS power. Again, I have my single SR12 running with the gain at the 10:00 position and I still have to turn it down 10db on the head unit.

ah i see what you mean, u seem to know alot about sr's, is it true these subs preform better in a sealed enclosure rather than a ported? if i plan to go 2 12's should i go sealed or ported? i listen to music that has lots of bass in it, how do i tune the amp to when i put the volume on my hu to 24 max 30 that my sub doesnt blow? just test it out and crank the gain knob down? leave the bass boost off? why is it there in the first place then????

greg2350

Sealed

Toxis

So wait, using a stock HU into a sub amp with a bass boost and 85% gain has so much distortion that 1200w would blow a 700w sub? I will never understand audio...

ben62670

+8db bass boost, and high gain, and you are wondering why they are blowing

black magic

I have both of my SR dvc subs in a sealed enclosure with just over 500 watts going to each woofer. I love the sound and they play pretty loud for my taste.

jalilig35

ben62670 wrote: »

+8db bass boost, and high gain, and you are wondering why they are blowing

never knew these subs couldnt handle it,

ben62670

jalilig35 wrote: »

never knew these subs couldnt handle it,

It's not the subs;) Any sub receiving an overdriven signal will self destruct. Bass boost is for lower listening levels not what the name implies;) A lot of my younger friends like lots of bass boost, and gain. Kill the distortion of the bass boost, and drive it with a clean signal and you will be much better off.
Ben

jalilig35

if i were to go for 2 12's go sealed or ported?

ben62670

Sealed helps, but you control the levels. If you just want loud subs to beat the **** out of why not get some kicker L..'s?
Blow up some kickers. Polk's are way too nice to just abuse.

Jstas

Ummm...I might be wrong but last I checked, the SR's were not recommended for ported enclosures.

exalted512

They have ported box recommendations for the SRs.
www.polkaudio.com/car/toolbox/subboxplans/

I had to look it up because in the manual it said nothing of ported.
-Cody

jalilig35

exalted512 wrote: »

They have ported box recommendations for the SRs.
www.polkaudio.com/car/toolbox/subboxplans/

I had to look it up because in the manual it said nothing of ported.
-Cody

this is exactly what my installer said and its very weird, he called polk polk told him to do a sealed only, the sub is no good in a ported. can anyone confirm this??

ben62670

I would call Polk CS. They are very good. Report back to us.

MacLeod

Stick with sealed - easier to build and sounds better.

And its not the distortion thats melting the voice coils, its the constant 1200 watts thats being fed to them from the amp clipping. He listens to bass heavy music and has the gains and bass boost maxed out. Id say his amp is at balls to the wall with his volume at 25% so when he gets on it the 1200.1 is being supremely driven into clipping which essentially turns it into a 2500.1!! Granted the signal is at about 15% distortion but its not the cause of the problem. Kinda like being shot by a .357. It wasnt the big BANG that put a 4" hole in you, it was that pesky bullet. Same here.

The SR subs are designed to dissipate 700 watt worth of heat with no problem. Having 1200 watts fed to them constantly is WAY over what theyre designed to handle so more heat builds up than the voice coils can dissipate and bada bing, youve got liquid voice coils.

jalilig35

anyone have Polk cs number? A sealed box will not sound as nice as a ported thou

exalted512

better than no sound when you blow the damn things up.

www.polkaudio.com to look up their number.
-Cody

greg2350

polk cs 1-800-377-7655 selaed will sound better

black magic

jalilig35 wrote: »

A sealed box will not sound as nice as a ported thou

Actually its the other way around. I think a sealed enclosure sounds better than a ported one since ported boxes are tuned for a specific frequency and usually don't sound as good when played below it.

jalilig35

wont a ported box have more bass than a sealed box? will 2 12's sealed sound louder in bass than a 1 12' ported?

greg2350

If your going for spl and not sq you should go with the kicker L series.

black magic

greg2350 wrote: »

If your going for spl and not sq you should go with the kicker L series.

I agree. Look into the L5

exalted512

jalilig35 wrote: »

wont a ported box have more bass than a sealed box? will 2 12's sealed sound louder in bass than a 1 12' ported?

So you associate loud as sounding good?
-Cody