How much Power is to much Power

[stephgirl]

I searched the data base but did not find an answer to my question.
How much power is to much power. I always hear some say, Oh that speaker or sub handles that much power but that amp has more power and just turn down the gain little and you will be fine. Headroom is the key. I understand that not having enough power or headroom and that a person may have to get a little more powerful amp. I understand all that but, the opposite side is then, how much power is then is to much. Example is say a sub that may handle 500RMS and the person has a 1000rms amp or more and some have said it will work find just turn down the gain a little and you will be fine. Or say a component speaker or just speaker that may handle 100rms and the person has a 150rms amp or more. Turn down the gain a little and you will be fine. I have even read and heard some say you should match up the power, speaker has 100rms so amp needs to match at 100rms too.
I think you all understand my question. When is to much power to much power. Is there a standard or a say word of thumb and base line that should be followed.

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[THATpurpleKUSH 5,000+ posts]

Too much power is when the subwoofer cannot further mitigate the heat build in the coil and the dust cap gets hot, the voice coil bottoms out and or when the glue on the voice coil begins to break down and cause the coil to fail to stay together.

So basically when the coil reaches its thermal limit or the physical limit of the suspension. The enclosure plays a big role in the limiting point of the suspension.

 

[stephgirl]

Too much power is when the subwoofer cannot further mitigate the heat build in the coil and the dust cap gets hot, the voice coil bottoms out and or when the glue on the voice coil begins to break down and cause the coil to fail to stay together.

So basically when the coil reaches its thermal limit or the physical limit of the suspension. The enclosure plays a big role in the limiting point of the suspension.

I understand that and makes sense. So then how would you determine that? Trial and error? Just add very powerful amp and see if it handles the heat and don't fall apart or blows up. Most can't just keep buying more and more powerful amps till the speaker blows. I'm not just talking about subs here but say a components speaker and regular speakers too. All speakers in general. There has to be a standard or rule of thumb or general rule that may determines it. I understand that some speakers may be able to handle more power then it is rated for but, i don't think you would say have a 75 w speaker and add a 500w amp to it. It may be too much power. Then like i said, some on here on CA chat say oh turn down the gain and you will be fine. But what i'm trying to answer here is what is the rule for too much power for a speaker. Example, So if a speaker spec may say 100w rms and Max 175w would it be safe to say that your amp should not exceed the speakers Max wattage.

Maybe there is just no good answer to this question. So for example when building a system how would you determine then the best size amp to install before the speakers may blow. You just would not say take a pair of Polk MM component speakers and hook up a 1000w amp to them. I would think you would see smoke real quick when you turn it up. So after you adjust the gain properly and stuff what would be the rule of thumb about matching the best power to speaker and what would be too much power. I understand the headroom issue. And i understand that too little power or headroom may not be good. I hope you all understand my question I'm trying to answer here.

 

[THATpurpleKUSH 5,000+ posts]

I understand that and makes sense. So then how would you determine that? Trial and error? Just add very powerful amp and see if it handles the heat and don't fall apart or blows up. Most can't just keep buying more and more powerful amps till the speaker blows. I'm not just talking about subs here but say a components speaker and regular speakers too. All speakers in general. There has to be a standard or rule of thumb or general rule that may determines it. I understand that some speakers may be able to handle more power then it is rated for but, i don't think you would say have a 75 w speaker and add a 500w amp to it. It may be too much power. Then like i said, some on here on CA chat say oh turn down the gain and you will be fine. But what i'm trying to answer here is what is the rule for too much power for a speaker. Example, So if a speaker spec may say 100w rms and Max 175w would it be safe to say that your amp should not exceed the speakers Max wattage.

Maybe there is just no good answer to this question. So for example when building a system how would you determine then the best size amp to install before the speakers may blow. You just would not say take a pair of Polk MM component speakers and hook up a 1000w amp to them. I would think you would see smoke real quick when you turn it up. So after you adjust the gain properly and stuff what would be the rule of thumb about matching the best power to speaker and what would be too much power. I understand the headroom issue. And i understand that too little power or headroom may not be good. I hope you all understand my question I'm trying to answer here.

Impedance rise plays a big part in actual power but you're referring to controlling output voltage with the gain. Keeping the gain low is what gives you headroom. Matching the gain to the input voltage or beyond into clipping is the opposite of having headroom.

 

[JTF Vegas]

have even read and heard some say you should match up the power, speaker has 100rms so amp needs to match at 100rms too.
This seems to be the most responsible application and makes the most sense.

 

[THATpurpleKUSH 5,000+ posts]

An amp rated 2-3x the speaker you are driving is sufficient to provide rated power after impedance rise. Beyond that the amp won't have to work as hard to output the same amount of power as a lesser rated amp aka headroom.

 

[JTF Vegas]

An amp rated 2-3x the speaker you are driving is sufficient to provide rated power after impedance rise. Beyond that the amp won't have to work as hard to output the same amount of power as a lesser rated amp aka headroom.

Would not 2-3× the recommended speaker power overheat the voice coil, or at the very least place unecessary stress on the motor system? Curious.

 

[nauc 10+ year member]

running a 300 watt amp to 100 watt speakers will only hurt the speakers if the amp gain is set too high

its all about voltage. too much, speaker melts

 

[nauc 10+ year member]

check this out

Amplifier Level Setting Guide

Note:The following article describes the Amplifier Level Setting process for most car audio amplifiers, regardless of brand. Specific target voltages for applicable JL Audio amplifiers are included...

jlaudio.zendesk.com

 

[wew lad 5,000+ posts]

When thermal dissipation can't keep up with the power dissipation it's too much power. There are far too many factors to have a one size fits all answer.

For the most part, 2-3x rms <10% thd is the most you'll be able to maintain. Of course you can do much more on sub 10 second burps but that's a different story.

I will say this, provided the sub isn't going into over-extension, you'll never blow a driver if you clamp rms to it and the manufacturer rates it properly. People will talk about having a 10k amp on a 3k sub and the reality is they're only getting 2-3kw after rise.

This is just one of those endless questions you'll never get a satisfying answer to.

 

[THATpurpleKUSH 5,000+ posts]

Would not 2-3× the recommended speaker power overheat the voice coil, or at the very least place unecessary stress on the motor system? Curious.

No because impedance rise raises the actual load anywhere from roughly 1.5-10x nominal

Ex 1:
Sundown E10v3 D4s wired to 1 ohm nominal, RE is .76 for both

Actual load the amp sees is anywhere from 1.2 - 5 ohms

As nominal resistance of the driver goes up impedance peaks get higher. That's why you want to wire as low as possible to get the most power out of the amp.

Ex 2:
JL Audio 15W0 8 ohm SVC with RE of 7.56

11.01 -- 101.3 ohms

The maximas (peak) in the curves represent vent and driver resonances and the minima (valley) represents system resonance of the box.

One is for SPL application, the other is a home theatre application.

 

[JTF Vegas]

Ok but what happens when the amplifier is actually able to unload all of its power as the load goes down? I understand as music is dynamic this would be transient, but I suppose my question is why not stay closer to the speaker manufacturers recommended power specs to always be on the safe side? Curious.

 

[THATpurpleKUSH 5,000+ posts]

Ok but what happens when the amplifier is actually able to unload all of its power as the load goes down? I understand as music is dynamic this would be transient, but I suppose my question is why not stay closer to the speaker manufacturers recommended power specs to always be on the safe side? Curious.

Let's use those Sundowns as an example, rated for 500w rms each. Lets pair them to a 1000w rms amp....using that graph from above the amp will have a load as high as 5 ohms. If the amp is rated 1000/500/250w at 1/2/4 ohms, that puts power as low as 200w when it plays that 5 ohm load.

That particular design probably isn't too good for comparison because its a peaky SPL oriented design with a lot of energy focused to one area of the spectrum, but it's enough to explain what's going on and to choose an amp that is powerful enough for your application.

 

[JTF Vegas]

Understood, but in the above example, what happens at 1 ohm resistance when the amplifier is dumping 1000 watts of energy into a voice coil rated at 500 watts root mean square? Curious.
Am I misunderstanding something? Kindly advise.

 

[wew lad 5,000+ posts]

Understood, but in the above example, what happens at 1 ohm resistance when the amplifier is dumping 1000 watts of energy into a voice coil rated at 500 watts root mean square? Curious.
Am I misunderstanding something? Kindly advise.

With inadequate cooling and too long at that power and it'll damage the driver. Unless the driver is underrated by a large factor.

Drivers are rated with pink noise, not music.