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How to tell if my subwoofer is clipping and/or going to overheat?

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So i have a Pioneer GM-D8604 4 channel amplifier. 2 channels are setup to my front component speakers and the other 2 channels are bridged for my subwoofer. heres the specs for my amplifier

  • 4-channel car amplifier
  • 100 watts RMS x 4 at 4 ohms (150 watts RMS x 4 at 2 ohms)
  • 125 watts RMS x 4 at 1 ohm
  • 300 watts RMS x 2 bridged at 4 ohms (250 watts RMS x 2 bridged at 2 ohms)

 

Im almost positive that my subwoofer is bridged at 4 ohms. not sure how to tell exactly? any easy way to check? but also, my subwoofer is meant for 4 ohm. so id assume its been wired properly, since it seems to be working fine.

and my subwoofer is the rockford fosgate P1 punch 12 inch. "Rockford Fosgate P1-1X12 Punch P1 12" ported enclosed subwoofer"

its specs for RMS are "power handling: 50-250 watts RMS"

 

so it seems that the amp is set to be good at 250 RMS and so is the subwoofer. i recently turned the gains on the amplifer for my subwoofer, all the way up. because the subwoofer wasnt playing very loud before. so i also found that fading the speakers to the rear a slight bit, allows for me to turn the volume louder on the headunit, which in turn makes the subwoofer play louder. because without fading to the rear, the front speakers are much louder and it hurts how loud it gets, in order to get the subwoofer loud. cause the rear speakers are still stock speakers, and run off the headunit, so they are lower in volume.

 

im mainly wondering, how can i tell if i am clipping the amp/subwoofer. and how can i tell if its being driven too hard so it may overheat? i think im more worried about clipping the subwoofer/amp.  thanks!

 

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Just turning the gain all the way up is generally not a good idea, unless you have really poor signal voltage to the amp. Use your ears, and sometimes your nose. If you can smell your sub, that's a sign you're getting careless. If you turn the volume up and up then the sound starts to change, that's a sign of distortion(not necessarily clipping). When we are new at this, it is harder to detect distortion.

 

Best way I can think of to try and hear the difference would be as follows. Listen to a familiar song multiple times at a moderate volume level with everything balanced out(not bass heavy, etc.). Just loud enough so you get the full spectrum of the song. Then, once you feel you can listen to the song and predict the little nuances and details start turning it up slowly. Once you start to hear things change(lose small details, tones change, lose clarity) it's time to back off a tad. If you start getting too crazy you end up hearing screeching, buzzing, rattling, etc. from the speakers themselves when you hit their mechanical limits and break things for sure.

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If you turned the gain all the way up your definetly clipping the amp, and sending the sub a distorted signal, which will burn it up. A distorted signal will burn a voice coil faster then over powering a sub with clean power. Just adjust your head unit until you hear distortion, then back it off just a bit, then do the same on the sub amp. It's not gonna do a whole lot, cause, well it's a entry level amp, and sub that's more for just filling in the low's, then moving a lot of air. If you feel you need more bass, just use the amp on your highs and mids only,  and buy a dedicated mono amp for your subs so you can feed them some clean power. And if all that ain't enough, just upgrade subs if you have the funds of course. But definetly don't just turn your gain to 100%, you will fry stuff like that it's just a matter of time. And if you wanna know if a amp or sub is hot, just touch it. You can feel the dust cover on a sub, and tell if it's getting too hot. 

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6 minutes ago, Billy Jack said:

If you turned the gain all the way up your definetly clipping the amp, and sending the sub a distorted signal, which will burn it up. A distorted signal will burn a voice coil faster then over powering a sub with clean power. Just adjust your head unit until you hear distortion, then back it off just a bit, then do the same on the sub amp. It's not gonna do a whole lot, cause, well it's a entry level amp, and sub that's more for just filling in the low's, then moving a lot of air. If you feel you need more bass, just use the amp on your highs and mids only,  and buy a dedicated mono amp for your subs so you can feed them some clean power. And if all that ain't enough, just upgrade subs if you have the funds of course. But definetly don't just turn your gain to 100%, you will fry stuff like that it's just a matter of time. And if you wanna know if a amp or sub is hot, just touch it. You can feel the dust cover on a sub, and tell if it's getting too hot. 

100 watts clipped to hell is still just 100 watts. clipping doesn't kill subs, too much power does. 

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7 hours ago, lithium said:

100 watts clipped to hell is still just 100 watts. clipping doesn't kill subs, too much power does. 

I don't know where you heard clipping doesn't kill subs but that's exactly what kills them. The signal is turned into heat and all that heat will burn your coils. But to much power can also kill them by overdriving them into mechanical failure. 

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9 hours ago, hdrox88 said:

Just turning the gain all the way up is generally not a good idea, unless you have really poor signal voltage to the amp. Use your ears, and sometimes your nose. If you can smell your sub, that's a sign you're getting careless. If you turn the volume up and up then the sound starts to change, that's a sign of distortion(not necessarily clipping). When we are new at this, it is harder to detect distortion.

 

Best way I can think of to try and hear the difference would be as follows. Listen to a familiar song multiple times at a moderate volume level with everything balanced out(not bass heavy, etc.). Just loud enough so you get the full spectrum of the song. Then, once you feel you can listen to the song and predict the little nuances and details start turning it up slowly. Once you start to hear things change(lose small details, tones change, lose clarity) it's time to back off a tad. If you start getting too crazy you end up hearing screeching, buzzing, rattling, etc. from the speakers themselves when you hit their mechanical limits and break things for sure.

yea thanks. i thought turning the gain all the way up was a bad idea. i think ill lower it to around 80% of max? cause the subwoofer seems okay at max gains. but i would then assume its the amplifer that may give out and be damaged? i do want the subwoofer to be louder, but dont want to damage anything.

ok so thanks. you guys think turning gains to around 80% would be much safer and a good idea?

also i have this amp kit KnuKonceptz Kolossus 4 Gauge OFC Amplifier Installation Kit

So, would i just be able to hookup a D mono amplifer just for my subwoofer? and then i should be better off? but i am wondering, i forgot how much power can i use from my amplifiers because ill get electrical issues and need to upgrade the battery? i think i remember hearing around 600 watts RMS until i may risk electrical issues?

So since my 4 channel amp is 100 RMS per channel. or 100 RMS for 2 front channels, and then bridged at 250 for subwoofer. thats around 350 to 400 RMS. But if i disconnect the subwoofer from it, its only 200 RMS. so i should be safe with around a 400 RMS D block mono amplifer?

 

Edited by Florida_Audio

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M5 or someone else who knows this very well, i just read this from another place on internet. curious if its true, or at least somewhat true, or whats your opinion on it!

" Mathmatically speaking even a perfect square wave that no amp can even reproduce is only double power under the curve than a sine wave of the same volume. It's 1.414x the voltage so RMS voltage is double as a sine is .707x it's peak voltage to get an average So 750 watts clipped to the point of impossibility (literal impossiblity since you can't make a real square wave) is only going to give you the heat of about a 1500 watt amplifier."

 

Basically if thats true.... then my amplifer bridged is rated at 250 RMS. My subwoofer is also rated at 250 RMS. and 500 W MAX.

so then if clipped then its should produce the heat of the 500 W MAX. so then the only issue would be if its like nearly always clipping to 500 W MAX and not allowing my subwoofer to cool down? so then the subwoofer seems to be safe. but then my question is what about the amplifier? is the amplifier safe?

Edited by Florida_Audio

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22 minutes ago, Florida_Audio said:

yea thanks. i thought turning the gain all the way up was a bad idea. i think ill lower it to around 80% of max? cause the subwoofer seems okay at max gains. but i would then assume its the amplifer that may give out and be damaged? i do want the subwoofer to be louder, but dont want to damage anything.

ok so thanks. you guys think turning gains to around 80% would be much safer and a good idea?

also i have this amp kit KnuKonceptz Kolossus 4 Gauge OFC Amplifier Installation Kit

So, would i just be able to hookup a D mono amplifer just for my subwoofer? and then i should be better off? but i am wondering, i forgot how much power can i use from my amplifiers because ill get electrical issues and need to upgrade the battery? i think i remember hearing around 600 watts RMS until i may risk electrical issues?

So since my 4 channel amp is 100 RMS per channel. or 100 RMS for 2 front channels, and then bridged at 250 for subwoofer. thats around 350 to 400 RMS. But if i disconnect the subwoofer from it, its only 200 RMS. so i should be safe with around a 400 RMS D block mono amplifer?

 

Just setting the gain at some arbitrary number is the wrong way to go about doing it if you are trying to reset. The gain is used to match the amp to the signal it is seeing from the source(head unit, processor, phone, tablet, etc.)

Think of it like a garden hose with on of those adjustable squeeze handle nozzles on the end. The spigot the hose is connected to is the source and the nozzle is the amp. You turn on the spigot and go to squeeze the handle and just get a mist(gain is too low). You then adjust the nozzle until you get that perfect pressure stream you are looking for(correct gain setting). Have you ever opened that nozzle all the way? That perfect jet stream turns in to a splattering mess and then too much water is flowing through(clipping/overdriving). It's a very rough and general analogy, but hopefully it helps.

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8 minutes ago, Florida_Audio said:

M5 or someone else who knows this very well, i just read this from another place on internet. curious if its true, or at least somewhat true, or whats your opinion on it!

" Mathmatically speaking even a perfect square wave that no amp can even reproduce is only double power under the curve than a sine wave of the same volume. It's 1.414x the voltage so RMS voltage is double as a sine is .707x it's peak voltage to get an average So 750 watts clipped to the point of impossibility (literal impossiblity since you can't make a real square wave) is only going to give you the heat of about a 1500 watt amplifier."

 

Basically if thats true.... then my amplifer bridged is rated at 250 RMS. My subwoofer is also rated at 250 RMS. and 500 W MAX.

so then if clipped then its should produce the heat of the 500 W MAX. so then the only issue would be if its like nearly always clipping to 500 W MAX and not allowing my subwoofer to cool down? so then the subwoofer seems to be safe. but then my question is what about the amplifier? is the amplifier safe?

Yes, that is a very real possibility. It can kill both amp and sub. It also depends on the music you are listening to. If it is a constant heavy bass line then things will heat up quickly. If it is maybe a song with a kick drum being the only real bass signal then it probably wont cause much harm, thermally that is.

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38 minutes ago, lithium said:

reread my post, 100 watts of clipped signal is just that, 100 watts. It doesn't matter what the signal looks like, whether its a perfect sine wave or a square wave, if the power received over a period of time exceeds the thermal capability of the woofer then it dies. Setting gain on the amp will always result in some level of distortion unless you're super conservative (which you should never be).  

No doudt the sub can take it but I bet the amp is about to go poof if the gain is at 100% and sometimes when one goes it can take the other component with it. But yea you don't want to go to far either way like tripling the power to a sub even if it's a clean signal or having a amp rated at 1/2 the subs rms running the gain at wide open is not good either. A perfect scenario is having a amp rated just over the subs rms and turning the gain down a little so the sub gets good clean power and the amp doesn't strain to push it and has plenty of headroom and it also provides more sound quality. 

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2 hours ago, lithium said:

If the amp is distorting due to clipping you can easily hear it. If the sub is reaching thermal or mechanical limit, you can easily hear or smell that as well. No need to get out the calculators here. 

ok thanks. should i try by using a 40 hz test tone? or music to test? or just say whatever, and simply play music while driving and listen then?

im pretty sure that my subwoofer is fine, but somewhat concerned. because the amp is like exactly matched with the RMS of amp to RMS of the subwoofer. and ive heard people sometimes overpower with higher RMS amp to their subwoofer.

 

but i guess then my main concern should be the amplifier pushing more than it can handle and it may die or cause some issue?

although ive heard amplifiers will shut down and go into protection mode before they get damaged?

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1 hour ago, Billy Jack said:

No doudt the sub can take it but I bet the amp is about to go poof if the gain is at 100% and sometimes when one goes it can take the other component with it. But yea you don't want to go to far either way like tripling the power to a sub even if it's a clean signal or having a amp rated at 1/2 the subs rms running the gain at wide open is not good either. A perfect scenario is having a amp rated just over the subs rms and turning the gain down a little so the sub gets good clean power and the amp doesn't strain to push it and has plenty of headroom and it also provides more sound quality. 

gain alone is half the equation, you need to understand what the input is. high gain is appropriate when the signal voltage is low, for example. It doesn't cause the amp to produce more power (its not a volume knob), the function of gain is to level match to the input voltage. 

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1 hour ago, lithium said:

use your ears to set it. using test tones is typically way too conservative and leaves output on the table. 

if you hear distortion or smell glue melting then turn it down. its that simple. the numbers are irrelevant. I wouldn't rely on some protection circuit to save anything. 

ok thanks. i would assume that i would need to be playing music for at least several minutes in order to tell if its heating up like such.

i do appreciate the answer. thank you. but im not sure that is related to my question about possibly damaging the amplifier?

1 hour ago, lithium said:

gain alone is half the equation, you need to understand what the input is. high gain is appropriate when the signal voltage is low, for example. It doesn't cause the amp to produce more power (its not a volume knob), the function of gain is to level match to the input voltage. 

are you talking about the headunit's voltage?

i have the Alpine CDE-164BT. its preamp voltage is 4v.

 

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1 hour ago, lithium said:

gain alone is half the equation, you need to understand what the input is. high gain is appropriate when the signal voltage is low, for example. It doesn't cause the amp to produce more power (its not a volume knob), the function of gain is to level match to the input voltage. 

Yes I know all of this but even at the lowest voltage modern h/u make 100% of the gain is more then likely to much. The only way I have ever seen a amp gain need to be turned wide open is if someone was using like a iPhone or MP3 player hooked directly to there amp never with a head unit even the cheap Walmart ones. That's what I was saying not that the gain ups the wattage everybody knows that or atleast they should. Why do you think I told him to adjust it the exact same way you did. Turn until you hear distortion then back it off a little. That's how it's done if you don't have the proper equipment to do it right and must do it by ear. 

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1 hour ago, Florida_Audio said:

ok thanks. i would assume that i would need to be playing music for at least several minutes in order to tell if its heating up like such.

i do appreciate the answer. thank you. but im not sure that is related to my question about possibly damaging the amplifier?

are you talking about the headunit's voltage?

i have the Alpine CDE-164BT. its preamp voltage is 4v.

 

See ^ 4volt pre-out so 100% gain is more then likely 50% to much. Almost every alpine I have ran I ended up with the gain set about half way up that's where mine is right now and it's been playing for 3 years now with no problems. 

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1 hour ago, Jay-C76 said:

Reading this may help.

thanks

good read, although i dont understand everything there, but still good info

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I know during competition & demos at shows a lot of guys will simple feel the heat coming from around the dust cap area. That accompanied with the smell of hot copper can give you an idea if you are needing to cool things down. That being said, I know at shows one tends to go "balls to the wall" on output but if you experience this during daily driving you may be heading toward mechanical failures.

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1 hour ago, Jay-C76 said:

I know during competition & demos at shows a lot of guys will simple feel the heat coming from around the dust cap area. That accompanied with the smell of hot copper can give you an idea if you are needing to cool things down. That being said, I know at shows one tends to go "balls to the wall" on output but if you experience this during daily driving you may be heading toward mechanical failures.

i am more worried now about clipping my amplifer and damaging my amplifier.

but that wouldnt smoke show any signs of possible overuse or damage until its too late? right? or is there someway to check?

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12 hours ago, Billy Jack said:

I don't know where you heard clipping doesn't kill subs but that's exactly what kills them. The signal is turned into heat and all that heat will burn your coils. But to much power can also kill them by overdriving them into mechanical failure. 

Wow.  Rofl.

Only two things kill subs.  Average power or Instantaneous power.  It is completely irrelevant whether the signal is "clipped' or not.  Absolutely no bearing whatsoever except of course that by the nature of clipping the power is increased.  

Plenty of modern music sounds like clipping anyway...boo :(

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7 hours ago, Billy Jack said:

No doudt the sub can take it but I bet the amp is about to go poof if the gain is at 100% and sometimes when one goes it can take the other component with it. But yea you don't want to go to far either way like tripling the power to a sub even if it's a clean signal or having a amp rated at 1/2 the subs rms running the gain at wide open is not good either. A perfect scenario is having a amp rated just over the subs rms and turning the gain down a little so the sub gets good clean power and the amp doesn't strain to push it and has plenty of headroom and it also provides more sound quality. 

Stop guessing.  You have no faith in NVX but I have one and it is fine at 100% gain.  Absolutely no big deal to it and it won't go poof.  Amusingly it is actually designed to do that.  Bit of thermal noise at 100%, but no ill effect otherwise.

If you have no thermal noise at a gain level there is no reason to run the amp at a lower level.  There can surely be reasons why it makes more sense to run it at a lower level, but as long as the input level is matched to the actual input so that the amplifier stays within its specification and doesn't add noise you are golden.  

Your perfect scenario isn't relevant either, but if you slightly modify what you said it would be fine.  A perfect scenario is having enough power to make your subs do what you need without distorting and/or creating thermal noise.

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31 minutes ago, Florida_Audio said:

i am more worried now about clipping my amplifer and damaging my amplifier.

but that wouldnt smoke show any signs of possible overuse or damage until its too late? right? or is there someway to check?

You should be worried about how it sounds and understanding how to set it up.  Your amp has a gain knob for a reason.  The manufacturer expects input voltages to be able to vary from it's lowest setting to it's highest.  Whichever one is right for your car is fine to use.  This could be at the minimum or the maximum.  Normally it is somewhere in the middle and that can be preferable depending on the equipment, but you can also sure be just fine at either extremes.

All this being said, it sounds to us like the way your gains are set right now have no basis in performance or correctness.   You should surely start listening more closely and make sure they aren't set in a way that adds distortion and/or noise.  If that is the case then you are fine.

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