hardtocope

I'm running a 12" jl audio w3v2 with alpine mono 400 watt amp. I have my sub and amp running off my stock hu. When I adjusted the amp i have the freq a little less then 100, the db at 4 and i have the gain adjusted a knotch less then half way. When i adjust the gain to halfway and the db to 6 my sub is a lot louder but i'm scared I will blow it. What do you guys think? Is it easy to blow out a sub?

BlackSS05

no as long as you do not go more than 3/4 on the knobs.

JRANGER

what are the RMS rating on the sub and amp? What OHM is the sub?

hardtocope

the subs rms ratings are 350 and the sub is 4 ohms wired for 2ohm since my amp is 2 ohms stable.

StinkBOMB

Ohm rating is irrelevant to power handling and knob adjustment. So long as you have the sub wired correctly for the amp that part of it is fine. I'd be weary of turning the base up with that DB knob. You're distorting the signal to push that extra base. It's not good on the sub. You're better off turning the DB down and adjusting the gain to 3/4.

hardtocope

Really? the db is around 4 right now should i turn it down any more? was does the db do exactly?

JRANGER

Ohm rating is related to the output of the amp. Before you rant about the DB knob the power has to be taken into account. If your amp is not pushing over the 350 RMS range then putting the DB up 1/2 way and the gain up past half shouldnt blow your sub. It will distort the signal but if your not turning your radio up all the way it shouldnt be a problem

EmperorJJ1

iTrader: (5)

a 1w clipped signal can destroy a sub(alot of factors apply thou dont get all excited) just to be sure im on the same page as you the db knob is on the amp correct?

sunrise_mj

in simple terms... dont crank on anything stupid... if you hear it distort, turn it down

Bandit2941

1 watt isn't going to kill the sub. Clipping is bad because it makes the amp produce more power then normal in a wave that resembles a square wave, which doesn't allow for normal cooling of the voice coil. But if the clipped signal is well within the sub's power rating it won't kill it.

sunrise_mj

you are incorrect... distortion (audible clipping) kills speakers, not power...
granted, underpowering a woofer is not good either

EmperorJJ1

iTrader: (5)

wrong clipping kills the coil no matter what rating it is.... ever wonder why people bloe speakers all the time with headunits that put out only what 15w maybe 20... i can go to mexico and buy a speaker that can handle 20w for 50 cents

The only reason wattage matters is its the amount of time before the coil will fry... if you do my example of 1w it wont just blow the sub up but it will eventually burn the coil. If you apply 350w of clipped signal it will happen alot faster

hardtocope

what does a clipped signal mean?

Bandit2941

Yes, I know. But the reason that distortion (audible clipping) kills speakers is because the amp sends a clipped signal that is of much higher wattage then the amp is rated for in the first place, and the speaker isn't moving as it would with a normal square wave, so cooling is compromised. The only reason "underpowering" a woofer is bad is because the user usually cranks the gain/volume to compensate for the low volume and sends the amp into clipping, which sends more power to the speaker due to more surface area under the clipped square wave. As the wave resembles more and more of a square wave, the speaker cone doesn't move properly to cool the voice coil.

HOWEVER, a 1 watt clipped signal isn't going to kill a speaker.

Bandit2941

Yes, clipping kills. No, I don't wonder why people blow speakers all the time with headunits that put out 15 watts. They crank the knob, which drives the internal amp into clipping in which the head unit produces much more power then its normal 15 or 20 watts. Then on top of that, the square wave signal doesn't allow the speaker cone to move as usual to cool the voice coil as it should. A normal wave form tells the speaker "move in this much, out this much, etc" which cools the voice coil, but a clipped wave pretty much has the speaker stay STILL for extended periods while feeding it higher wattage then usual.

But in your example 1 watt isn't going to do jack even if it's a constant 1 watt run through the speaker all day long. It's just not enough power to heat anything up or hurt it.

EDIT: Here's a good quote from Mark Zarella over on rec.audio.car:

hardtocope

i have my gain turned up to a knotch less than half way... this way i have good bass that goes with the loudness of my stock speakers. I've turned up the gain to halfway before and it makes the sub perform well but it puts out to much bass for me to enjoy my music.

EmperorJJ1

iTrader: (5)

i agree with you of what clipping is and how it destroys a speaker but the key word in my sentance was can. Yes it would take a really ghetto woofer and it shouldnt burn with that power in a normal setup... but i can bet you that if everything is right 1w will fry a sub. Key concept is cooling. 1w makes heat. when applied to a coil that doesnt cool at all 1w will eventually burn the coil

Bandit2941

Sounds like we're on the same page. I think like you said though it'd have to be a REALLY GHETTO speaker, lol. Voice coils normally get warm as they operate and I just don't think 1 watt is going to heat it up enough to do anything, even applied consistently. Especially if the woofer is one rated for a few hundred RMS. A few hundred RMS going through it even with a non clipped signal will prolly heat the voice coil more then a 1 watt constant.

iamslow

1w will not kill a sub unless it is rated for <1w. I will bet you $5000. A sub does not have brains it can't determine what type of signal it's getting it just responds and reacts to the direction, magnitude, and speed of the current. Clipping doesn't kill speakers. You'd be suprised how many people are sending clipped signals to their speakers all day long and not even know it.

1gmfanatik

Keep in mind, that with you running the sub and amp off of your stock HU, that the sub(s) will sound a bit louder at lower volume but will quiet down as you increase the volume. GM has it set up this way so that the base is cut down to keep from blowing the stock speakers. The subs will cut down slightly as you increase volume but will regain some of that towards maxing out the volume level. My subs are set at a slightly higher Db level on the amp and all, and I adjust the bass levels through the radio.

EmperorJJ1

iTrader: (5)

lol I don’t have 5g to bet and I don’t have the ability to make the perfect conditions needed to do such a thing... reason why I said 1w is to be very clear at what clipping can do to a sub.

I agree with you clipping may not destroy a speaker but whether or not the coil will burn has to do with cooling.... If a sub cant cool itself properly it may eventually fail. Clipped signal increases the power with no such increase in excursion to cool the coil. It all depends on the specific application, sub design, outside temp ect... lol a sub clipping in Canada at -1 degrees F outside with vents for the coil (such as the new re style) will have a lower chance of burning then a sub in a badly designed box that has low excursion, and the coil is completely covered with little way of cooling, in Florida at 115 out in a black car without air conditioning.

But if you want to prove me wrong do this... get a good pair of cheap spare speakers (I say cheap bc it will speed up the process in which the speaker will die)... match it with a amp that puts out the rms value suggested then send it a sine wave within its frequency range but make sure the gain on the amp is set to max, any loud settings or boosters are again maxed, eq settings maxed ect... then play it like that until constant it blows. Then without changing anything at all except putting the second speaker do the same thing but without all the boosters and with a clean signal (same volume setting required)
I can guarantee you the second speaker will outlive the first

If you do the above and find different results then plz post them up and I will shut up. And maybe I’m wrong but you maybe thinking "most of the time people don’t clip speakers that hard" then yes you are right but your going into grey area of how much clipping is actually acceptable by the sub before failure and that varies so diversely that a statement like "clipping doesn’t kill speakers" is false where as something like "clipping can kill speakers but doesn’t always do so" is a lot more correct.

Problem with that is for the noobs you cant set a specific amount of clipping a normal sub can handle because there is no normal sub and there is no amount. So while yes both of our statements could be proven correct and incorrect with the right settings its impossible to explain a lengthy subject like this to someone who doesn’t know much about car audio... so since my statement is a lot more conservative and will save subs/speakers vs. yours which will do the opposite it seems easier to say it in simple conversation. Sry if i mislead you in anyway