What If You Do Put More Watts Than The Rms Can Handle

[reinke]

i want to put more power to the subs i was just wondering if it would be ok, or would it really hurt the subs, like damage them.

if they were anything but the mtx thunderpros you should be fine. just give them the rms.

[MTX J30]

lol, when i had my mtx 5500's in the truck there 300w rms 600max and i was givein em 500wrms each and they took it like a champ but it was a clean 500w tho, when i had my jlw0 12 in there ina lil ass box on the jl site they say there 175wrms(or max musical power) and i was throin 600rms to it and it was eatin it up like nothin else and never got warm, as long as u have clean power goin a lil bit over rms isn't bad but if its cheap distorted watts ur more than likely to blow em with there givin rms, its better to give a sub its rms and a lil over than to underpower it cause if u underpower ur most likely to get dirty wattage and strain the voice coil to hard makein it try to work with what it has and burn it up, and it goes with what brand they are also, just make sure ur lpf, gain, and bass boost aint set to high or ur get a clipped signal and not know it and fry somethin, anyway good luck with ur stereo man

whats the difference between clean and cheap watts.

[tacomabanga1986]

oh ya, and subs in sealed boxs tend to hold more power than subs in ported boxs, but subs in ported boxs get louder with less power than subs in sealed boxs, and mtx ftmfw! i got 2 mtx 8000 15's in the truck now and there 500wrms 1000max and im only givein em 400wrms each and its love to my ears i cant wait till i get somethin like a rft1000 or 1500 or somethin like that to rly throw some power to em and see what they can do, and mtx are really built tough subs, my buddy did an install ina acura with 4 mtx 8000 12's and 2 mtx 1501d's and with proper electrical(witch he had) those 1501ds could put out 2000w peak@2ohm so those subs was givein prolly 750-1000wrms each and took it like a champ, it just matters if the ppl settin the stuff is doin it right and u dont get heavy on the gain on the amp, just make sure its set right and u can put what u want to em, play around with it a lil, turn gain up till they bottom out then back off it around 1/4 then turn the lpf up till it starts playin mids then back off till it gets low again, then turn up the bass boost a little to get that kick but not to much cause it will start clippin and ur good, its mostly by ear tho

[Namosh]

Here's a pretty good article if you want to read it....Kind of long but pretty informative IMO.

http://www.audiojunkies.com/blog/1306/over...hing-in-between

Overpowering, Underpowering, Distortion, Clipping, and Everything in Between

May 1, 2008 by Neil Middlemiss

- Image: 3D Sound Wave Rendering from FXshare.com

One of the most fundamentally misunderstood concepts in audio is what

happens when we apply power to a speaker. We understand that power is

what makes the magic happen, but so few of us "get" what that power

does. For example, you've probably heard about someone who was

"underpowering" their speaker; what on earth does this mean? You've

probably heard this before and if you haven't it will probably be a

wake-up call: if underpowering really existed, you would be

"underpowering" your speaker every time you turned down the volume.

This is one of many ideas that continues to falsely permeate the audio

industry and, together, we can put an end to it.

So where do these misunderstandings come from? Well, the power concept

is inevitably encountered in two situations: 1) You are looking for a

certain level of output, and 2) You have a speaker that doesn't work

anymore. These two concepts are completely related: if you seek a

certain level of output that requires more power than the driver can

handle, then you're looking at scenario #2.

*Definitions*

To understand the idea behind power, let's define a few things first,

shall we?

/Overpowering/ - Overpowering should be simple to understand: a driver

is being "overpowered" any time it has been damaged. If the driver has

not been damaged, have you really "over" powered it? Logic should say

no. In fact, this is probably a term you can stop using in the future.

/Underpowering/ - As I mentioned above, this is a completely useless

and non-sensical term. If you don't have the output you want to hear

from a speaker, say as much. Again, we should stop using this term.

/Distortion/ - Distortion can come from a lot of sources. In the

simplest sense, distortion is when the output signal differs from the

input signal. For the purpose of this article, we will be looking

primarily at distortion generated by the amplifier and passed to a

speaker. As a secondary form of distortion, we will briefly talk about

driving a speaker into distortion, by which I mean that the speaker has

been driven beyond Xmax. Distortion from your speaker is a whole other

ball of wax and we will only briefly stop here today.

/Clipping/ - Here we will strictly stick to the type of clipping that is

passed from your amplifier to your speaker, and is created by setting

the input sensitivity (read: gain) too high when considering the input

voltage from your source unit (ie. headunit, preamp, etc).

*Clipping and Distortion*

Warning: Much of the following will directly oppose everything you've

ever been told about power, distortion, and clipping. The fact remains

that power is almost completely misunderstood, even by many experts in

the industry.

Let us start the next section by breaking down distortion generated by

the amplifier and clipping, which are really the same thing. As we said

early, distortion occurs when the output signal is different than the

input signal. I will give a very simple example here and introduce you

to a concept that may be new to you.

When we play a signal on your speaker, the resulting sound consists of a

number of frequencies with various amplitudes. If we play a 100 Hz sine

wave through a speaker, then the fundamental frequency is 100 Hz. Now,

we may also see response at other frequencies that are typically a given

order higher than the fundamental. Assuming a fundamental frequency of

100 Hz, we can say that the second harmonic is 200 Hz, the third

harmonic is 300 Hz, the 4th is 400 Hz, and so on. The presence of any

of these additional harmonics is considered distortion as they were not

present in the original signal. Typically, the amplitude of these

harmonics decrease as the harmonic itself increases, ie. second harmonic

distortion is often higher than third, third is higher than fourth, etc.

Clipping is itself a form of distortion. In the above example, we

assumed a 100 Hz signal. However, if we were to increase the gain until

we have fully clipped the signal, the result would be the fundamental

frequency (100 Hz) and its higher order harmonics. If you've ever heard

a speaker reproducing a clipped signal, you probably already know that

is sounds like distortion, but you've probably also been told something

else: that distortion or clipping an amplifier will immediately damage

your speaker. Hold on to your hats: it doesn't! Perhaps a little

further explanation is required?

Here is a picture demonstrating what a sine wave looks like, as well as

a square wave (fully clipped signal), a triangle wave, and a sawtooth wave.

- Image: Wikipedia

That square wave sure looks ugly! More importantly, you should notice

one very important thing, though, when comparing a sine wave and a

square wave: the area under the curve from any point A to any point B

will always be greater with a square wave than with a sine wave. In

other words, a square wave carries more power over a given time. I like

to call it "increased average power over time" because it sounds cooler

that way. Hopefully the visual makes this next sentence understandable

as well: if the amplitude of the signal increases (the power increases)

within a given period of time, then the average power over time has

increased as well.

*How a Speaker is Damaged*

Let's take a moment now to examine why and how speakers are damaged by

power. Essentially, there are two types of failure:

1) Mechanical - This means that the speaker has physically been driven

beyond its limits; usually stuff starts banging together. For example,

a speaker can be mechanically damaged if the former is smashed into the

backplate a time or two. This occurs from applying too much

instantaneous power (read: power at any given moment) in a certain

enclosure. Since excursion (which is how much the coil moves) increases

as frequency decreases, we know that a speaker is more likely to have

over-extended itself at low frequencies. This is increasingly likely if

the enclosure is larger than typical for that subwoofer, or if you are

playing frequencies that fall below the "tuning frequency" of your

vented enclosure.

2) Thermal - Simply put, this happens when more power is dumped into the

voice coil than the coil can handle.

But stop! Thermal damage doesn't just come from too much power. Have

you ever wondered why a speaker can take ungodly amounts of power for a

brief moment without the coil exploding? Well, that's because it is

average power over time that matters. There are many subwoofers that

can take 10 kW or more for a second or two, but not many that can take

it for a full minute. And here we come full circle: whether it is a

sine wave, square wave or any wave in between, the speaker will not be

damaged thermally if the input average power over time is less than the

driver can handle. That's right: a low amplitude clipped signal will

not damage your speaker at all! You can test this for yourself: get a

speaker, hook it up, play a clipped signal, and keep the volume low.

You will not see any damage at all.

*When is it too much? When is it not enough?*

So the natural question arises: what is too much average power over

time? To be honest, it is tough for any layperson to make a good

estimate. Manufacturers typically publish power handling specifications

like "100 Watts RMS," which is misleading because there really is no

such thing as "Watts RMS" (a story for another day, or you can read here).

However, we know that we can apply more or less power if we adjust the

time over which this power is applied accordingly, which is why I

support buying just enough.

Dynamite in a monkey's hand is quite dangerous and too much power in a

novice's hands is equally so (minus the casualties). One has to wonder,

though: what is really gained by exceeding the manufacturer's own

recommendations? Is the associated thermal risk of increasing power

really worth it? The answer is simply no, unless you are chasing tenths

in SPL competitions. When more power is applied to the voice coil, the

voice coil becomes hot (duh!). At a certain point, this heat begins to

increase the resistance of the voice coil to the current flowing through

it. So we add more power, and more power, and more power... and before

you know it, the resistance of the voice coil has increased such that

adding more power will not gain any more output. Better yet is the

nature of the human ear: an increase in sound pressure of 1-3 dB is just

barely audible for most humans. To achieve such an increase, we are

looking at doubling the power we are already applying and, thus, putting

the coil at greater risk of thermal failure.

In the event you can't achieve the output you're looking for within the

manufacturer's recommended power handling specifications, your best

solution is usually to look for a different speaker. Of course,

achieving high-output is an equally complicated concept, but more power

than a speaker is rated for is rarely the solution (and will most

certainly void your warranty).

*Conclusion*

In short, you should now understand that only power can damage a

speaker. There are no mystery clipping gnomes that will kill your

speaker at the first sign of distortion. Furthermore, you should be

aware that power is just a way to get a speaker moving: there is no

underpowering or overpowering, there are just various levels of output

and a damaged speaker. Next week we will look even more closely at some

of these concepts, but please ask questions or correct me if something

is unclear. It is time to stop perpetuating these myths that never seem

to die and a good education is the right battle-axe to wield in this fight.

[tacomabanga1986]

clean watts= is an even musical leval spectrium, like if uve seen an occicope(sp) and watch the line go up and down, when it goes flat on the peaks is a distorted signal, but when its even and smooth thats a clean signal, u can hear distortion tho but dirty watts=someone turnin the gain all the way up ona 200w amp tryin to push a 12'' sub rated at 400rms and when it starts "clipping" it starts sendin 12v surges to the sub and frys it, if anyone else wants to chime in more than welcome

[Torres]

actually...i dont think clipping signals sends 12v surges. power from an amp comes out as AC, power going in is DC...so it'd have to do go through a lot more to convert back into DC. not that an amp WONT send out DC current, but clipping wont do it. and clipping wont hurt a sub either, the heat that the clipping produces is what damages the speakers.

http://www.caraudio.com/forum/showthread.php?t=315581

big thread on clipping power made from an electrical engineer

All that clipping is is the transformation of the signal's waveform from sinusoidal to rectangular. What that means is that if you picture the sine function from 0 to 2pi, instead of a curve, make it 2 right angled boxes with dimensions of pi x 1. The integral of the function aka, the amount under the curve is the amount of power being transferred. As you can imagine, a square wave has more power underneath the curve than a sinusoidal curve does. As a result, a clipped signal CAN send more power to a speaker than normal, but clipping is not the cause of blowing the speaker.

There are only two ways to blow a driver: mechanical failure or thermal failure. The former is due to over excursion of some form from some cause (usually improper enclosure), and the latter is usually from overpowering the speaker. If you feed a Type-R a fully clipped signal from a 300 watt amp, it will not reach thermal failure in the least. It might sound like shit, but it won't cause the speaker to fail. The driver doesn't know what it's being sent, all it does is get fed power and turn that into sound. Whether or not the signal is distorted is irrelevant.