Underpowering subs will kill them?

[packerfan 10+ year member]

Ok, so ive been told that when i hooked up my brand new RE8s to my home stereo reciever that they blew becuase they were underpowered. (40ish watts each) and thats why they blew. I personaly thing that underpower wont hurt at all unless the amp is clipped. But sence my living room is right above were my stereo is, i never turn it up past 16/30. So, i dunno, i guess i dont know anything and i blew my subs with 40 watts each playing some rock..... :hilarious

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[Randy Savage 5,000+ posts]

Overpowering is what kills speakers....

It's not a clipped signal either, it's the power increase from a clipped signal that will kill a speaker. Power kills a speaker, that's about it. Not clipping //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I mean, think about it, when you have your system turned down, but are still moving the subs a decent amount, is that not underpowering them? Doesn't blow em though //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif.

 

[B&R Innovation2 10+ year member]

Comeon man you've been around long enough to know that.

 

[packerfan 10+ year member]

Comeon man you've been around long enough to know that.

Yea, i thought i was too //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif ......but im supposably a novice to some others and done know crap..... :thumbsdow I just had to post his to prove someone wrong....I think i have even though i know that didnt blow the subs......but, cant fight with ignorance of some.... //content.invisioncic.com/y282845/emoticons/nono.gif.eca61d170185779e0921b0faa9704973.gif some people just need to pay for there mistakes........ :blow_up:

 

[packerfan 10+ year member]

*Reminder to people that own RE8s, never put a 2500d on a pair....they will blow*

 

[Bavarian3 10+ year member]

*Reminder to people that own RE8s, never put a 2500d on a pair....they will blow*

HAHA nice! how long did they last?

 

[packerfan 10+ year member]

HAHA nice! how long did they last?

I dunno, ask the person that had the 2500 watts on my subs.... //content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif

 

[Mark_ab 5,000+ posts]

Overpowering is what kills speakers....
It's not a clipped signal either, it's the power increase from a clipped signal that will kill a speaker. Power kills a speaker, that's about it. Not clipping //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I mean, think about it, when you have your system turned down, but are still moving the subs a decent amount, is that not underpowering them? Doesn't blow em though //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif.

Heat kills. HEAT. Be specific!

Bastard.

 

[geolemon 10+ year member]

I love you, man... //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

HEAT kills voice coils... that's only ONE way to "blow" a speaker though... //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

OVEREXCURSION is the OTHER way.

And - you can exceed the excursion capabilities of just about any speaker with much less than 'rated' power... given free reign over the design of that enclosure and frequency being played, that is... //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

There's no direct correlation between input power and output level (SPL) or excursion - until you lock yourself into a particular enclosure design. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

In fact you can create greater shifts in SPL capability of the subwoofer system by manipulating the enclosure than you can by manipulating the power going into any particular single sub/enclosure alignment.

 

[audiolife 5,000+ posts]

this has gotten to be like a "guns kill people" type of post ..some say its the guns i say its the people.... lol just perspective from where you look. a clip is a cause ... heat is an effect.. for without the clip there would be no heat unless you are running a jbl crown big boy amp on a funky pup 10" or you are just a volume master

 

[geolemon 10+ year member]

There are many potential causes though.

Clipping might or might not be one of them... //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

You could clip the heck out of an amp, and not cause any heat issues. It depends on how large the resulting effective power going to the subwoofer is.

Think of the "area under the curve" (or over the curve, for the negative halves of the waves //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif):

With a sine wave of a certain amplitude, you have a certain amount of power, based on the area under the curve.

When you begin to clip the wave, inherently the amplitude remains the same - but it starts to widen out, the top being flattened out right at that max-amplitude value, morphing into a square wave, the more you clip the signal.

If you consider one half of a sine wave to be parabolic, and one half of a square wave to be... well, square ...if you calculate the total area under the square (both waves being the same frequency and amplitude), you'll see the square has much more area under it.

If you want to think of it more in terms of duration, it might make more intuitive sense as to why this matters:

A drawing of a sine wave represents time on the X-axis, and amplitude [of it's power] on the Y-axis.

If you follow just the positive half of the wave for purposes of simplification, with a sine wave there's a progressive rise in the amount of current flowing until it momentarily reaches that amplitude peak, and then it progressively decreases again until it gets down to the 0 line again.

With a square wave, it rises sharply to the maximum amplitude level, and stays there for the majority of the duration of the wave, and then sharply drops back down to the 0 line again.

So, with an amplifier that's supposed to put out the sub's rated thermal powerhandling worth of power, when operated properly...

It's easy to see how if you clip it then, you could inadvertantly create MORE RMS power than the amp is supposed to give out - and how the distortion would proportionally increase (and how the sub wouldn't be able to use it to increase it's excursion further //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif) - despite the amplitude of the signal remaining the same. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

But if you have an amplifier that is appropriate for your sub/enclosure mechanical limits, but doesn't make as much power as the sub can handle thermally (something like a Brahma in a decent sealed box with an 800 watt amp on it), you could clip the heck out of the amplifier, and still not reach the thermal limits of the sub.

My point is, it's a potential cause, but not a direct correlation... and it's only one possible cause. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

* Too much clean power can thermal a sub.

* A defective amp could thermal a sub.

* Installing electric heaters inside your box could thermal your sub. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

I just think it's important to look at the symptoms, not the causes, because it's the symptoms you need to avoid, not necessarily the activity that in some cases is a cause.

People often get this confused, and you end up with a bunch of misunderstood or misapplied "rules of thumb" that are out there, when most of the time it's more practical to understand the thing you want to avoid, and let common sense dictate what you should do to avoid it. //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

 

[maniackilla 10+ year member]

i wish i knowed as much as you //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[n2audio 5,000+ posts]

this has gotten to be like a "guns kill people" type of post ..some say its the guns i say its the people....

Guns don't kill people...

People don't kill people...

BULLETS kill people!

//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[TPABlazer 10+ year member]

Aww shit

time to take my space heaters out of my box //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[n2audio 5,000+ posts]

People often get this confused, and you end up with a bunch of misunderstood or misapplied "rules of thumb" that are out there, when most of the time it's more practical to understand the thing you want to avoid, and let common sense dictate what you should do to avoid it. //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

Whatever you say Richard Jr. //content.invisioncic.com/y282845/emoticons/clap.gif.178cba2c538c68e720c727fcb024b19c.gif

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