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Discussion Starter #1
Is it better to have higher rated RMS on the speakers or the amp (per channel)? From what I read and think I understand, low power causes distortion and that causes speakers to fail, but over powering causes excess heat and can also cause clipping or failure. So should the speakers and amp match in power ratings? That seems hard to do.

i have the RF 400x4 amp (100w per channel RMS), and I’m definitely getting clipping. my Speakers are rated at 80w RMS. I’m also getting distortion.

so any good rules here? I’m either going to get new speakers or a new amp.
 

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What head unit are you running? If stock, that could be your issue. I know the pre-Rushmore (single din) units are horrible. I couldn’t get past 50% volume without terrible clipping.

I have that same amp powering a pair of Audison and a pair of Hertz. I can roll 80 down the interstate and rarely have to past 50% volume. And it sounds great.


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I would rather have an amp that is too powerful. You can always set it according to the speakers rating. That being said, you won’t hurt anything by under powering the speakers. The only time under powering can be an issue is if you try to over drive the amp, ie. clipping/distortion.
 
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Neither one is good. Always want headroom on the amp.
 
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From what I read and think I understand, low power causes distortion and that causes speakers to fail, but over powering causes excess heat and can also cause clipping or failure.
Neither one of those statements are correct. (Over powering is what causes the heat that does burn stuff, but not until an event causes to much power to be used.)

Assuming you have sufficient power to drive the speaker, the only thing low power will cause is low volume. Look at the speaker's efficiency rating and that will give you an idea as to how much power is needed to drive the speaker. I think my Kappa speakers are rated around 2 W for efficiency, so all I need is 2 watts to get sound out of them (might not be to loud though).

To much power is the problem. Peak Power vs RMS Power. In simple terms RMS is the maximum Average power the speaker can handle (or the amp will produce). Average being the operative word; average being a somewhat constant amount. Peak power is your killer. Peak power is a spike. Peak power is the maximum power the amp can produce, momentarily. Push the amp at its peak to long and it will burn up. Hit the speaker with the peak power for to long and it will burn up. How long is to long? I don't know, each unit will be different and depend upon the quality of the components.

Distortion, clipping; they're essentially the same thing and is what will kill your amp and/or speaker because they will drive the power to peak levels. To understand this, I'm hoping you know what a (sine) wave looks like. The top half of a sine wave looks like an upside down letter U. When you get a spike, the power rises so fast, that for a brief period of time, instead of looking like an upside down U it looks like a vertical line, like an I (and the top will be well above the top of the U).

Some equipment will have circuitry that will prevent a signal from going to high (so things don't blow up). This will cause the top of the I to stop going any higher, but will keep it at that limited, high level, as long as the input spike remains. The resulting output looks like a Square, being flat at the top. The signal is "clipped".

Distortion will occur and act pretty much the same way, but doesn't have the "clipping" circuitry. In that case, things might just burn/blow up. Distortion can also come about if the components can't handle the dynamic frequency well enough. In this case things won't blow up, they'll just sound like shit.

The amplifier just makes stuff (signals) bigger. If you feed garbage into the amp, you'll get garbage out of it, as long as it is capable of doing so. Let's say you can adjust the amp between 1 to 10, meaning that's how much the signal will be amplified. Set at 1, you feed 1 in you get 1 out. Set at 10, you feed 1 in you get 10 out. (Don't ever set it to 10.)

The problem, is when you get "that" spike, the amp will make it bigger. If its got the circuitry to prevent itself from blowing up, the amp will keep the output signal at maximum until the input signal goes back down,clipped. (In this case, I'll guess and say maximum is the RMS maximum because that's how the circuit would be designed.) Can your speakers handle that much power? If so, no problem; if not they blow up. Without that type of circuitry, the input spike gets amplified to maximum, in this case Peak Power. If it stays there to long, after blowing up your speakers, the amp blows up.

So, to be safe, you always want your speakers to be able to handle more power than the amp can put out. If your speakers can handle RMS power that is the same number as the Peak power of the amp, you won't have a problem.

Are you any good with math? Mulitply RMS power by 1.414 and that will give you peak power. So you said your amp puts out 100 watts RMS. 100 x 1.414 = 141.4 Watts peak. You want speakers that can handle at least 140 Watts RMS to ensure that the amp can't blow them up.

Prevent clipping by not feeding in to strong of a signal (including the level of the recording). Don't want distortion, get equipment with a better frequency response.
 

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Are you any good with math? Mulitply RMS power by 1.414 and that will give you peak power. So you said your amp puts out 100 watts RMS. 100 x 1.414 = 141.4 Watts peak. You want speakers that can handle at least 140 Watts RMS to ensure that the amp can't blow them up.
You can mostly ignore any peak ratings though. Matching amp RMS to speaker RMS is just fine.
 
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Discussion Starter #7
Ok thanks for the info. So my speakers RMS is 80w, and amp says 100w. That’s why after 50% volume is about max before distortion? Also, does the gain have anything to do with the output amps or power? I think the gain is at about 40%. The Hz is set all the way down at 50hz. So basically no bass will be clipped correct? Thanks.
 

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I would turn on you high pass filter and set it higher than 50Hz. That’s probably one of your issues. I doubt your speakers can handle frequencies that low. You could easily be hearing some speaker popping from too much low frequency. Need to look at the frequency response of your speakers to determine the correct setting but generally around 80-90Hz is a good spot.


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Only speaker that can handle 50 is some subs. Definitely not 6.5 fairing speakers
 
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Ok thanks for the info. So my speakers RMS is 80w, and amp says 100w. That’s why after 50% volume is about max before distortion?
No, the power ratings of the speakers have nothing to do with distortion. Those ratings tell you how much power the speakers can handle or that the amp can produce. Based upon the ratings you've stated, your amp can produce (not necessarily will produce) 100 W, which is 20 W more than your speakers can handle. So you have the possibility of being able to fry your speakers. Let's look at your next question to try and help explain further.
Also, does the gain have anything to do with the output amps or power? I think the gain is at about 40%.
Your 40% gain setting on your amp would be like a 4 setting in my example above. So, under normal conditions you put 1 in and you get 4 out; 10 watts in, 40 watts out. Put 20 watts in, get 80 watts out. (80 watts, isn't that the RMS rating of your speakers? 80 x 1.414 = 114 peak) 30 watts in, 120 watts out. Oops, we just fried the speakers. (Set it to 50%, put 20 watts in, get 100 watts out.)

The output rating of the amp at 100W RMS is the maximum output the amp is able to produce safely, without cooking itself. It has the ability to produce 141.4 watts out maximum.

Distortion happens when the input signal is to large for the amplifier to accurately reproduce. Because it is not an accurate reproduction is why it sounds like shit. It has nothing to do with how much power the speaker can or can not handle. If the speaker has enough power to make sound (using my Kappa's as an example, 2 watts) it will make sound. It will keep making sound (that sounds just like what it was sent, even if its shitty) right up to the point it can no longer handle the power, then it burns up.

You asked about the relation of amps and power. There is a mathematical formula, called Ohm's Law, which describes the relationship. W = I x I x R. (I don't know how to type the mathematical Square.) W = power, measured in Watts. I = current, measured in Amps or milliAmps (mA). R = resistance (or actually in this case, because its AC not DC, Impedance) measured in Ohms.

Do you know how a fuse works? When current flows through wire, because of resistance, it generates heat. If the wire can not dissipate the heat fast enough, it melts. A fuse is designed so that when the specified current is reached, the heat becomes to much and it melts.

The wire in the voice coil of your speaker is physically thin and if it gets to hot, it will melt; just like a fuse.

During the short period of time that the distorted signal goes into the amp, the amp will amplify that distortion, the same as it would the signal, up to its maximum capability (yours 141 W). When this happens, it exceeds the fuse you have, which is rated for 114 W, that you call a speaker. The fuse will melt.

Distortion/Clipping occurs in the Amp or Head unit, not in speakers. If your speakers sound shitty and they are not blowing up, that is not distortion. That would be caused by the frequency curve, or bandwidth, of the speaker not being wide enough to accurately produce the sound; it has nothing to do with power. These are two separate/different issues.

I'm going to guess and say that whatever you are feeding your head unit (mp3, whatever) is recorded at a to high level. The amplifier within the head unit (yes there is one, its what feeds the bigger amp) can't handle the higher input level and is what is causing the distortion when you turn the volume up.
 

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You can mostly ignore any peak ratings though. Matching amp RMS to speaker RMS is just fine.
You're right. However, his amp puts out more power than his speakers can handle and he's talking about distortion, which can drive the power level up to peak.
 

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an extra 20 watts won’t hurt anything. Music is dynamic and wouldn’t play at full power the whole time anyway. There is nothing wrong with using that amp on those speakers.
 

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The gain control on an amp does not equate to wattage produced.



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Gain is a multiplier. The amplifier will multiply (amplify) the input signal by the gain setting, upto its maximum capability if that multiplication exceeds its capacity. Gain is normally measured in deciBels (dB) and is logarithmic not linear. An increase of 3 dB doubles the output. Just trying to keep it simple for those not schooled in mathematics or electronics. Although not entirely accurate; its easier to understand if kept linearly.

As SetoSeyer pointed out music is dynamic and as such is never constant; that's why we talk about averages (RMS = root mean square). The amplifier never actually works at average, it makes use of its entire capability at that particular instant. Take all of those instances, add them together, then divide by the amount of time that has passed and you end up with an average. It just so happens that the average of a Sine wave can be described by the amplitude multiplied by the square root of 2, or 1.414.
 

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Gain is a multiplier. The amplifier will multiply (amplify) the input signal by the gain setting, upto its maximum capability if that multiplication exceeds its capacity. Gain is normally measured in deciBels (dB) and is logarithmic not linear. An increase of 3 dB doubles the output. Just trying to keep it simple for those not schooled in mathematics or electronics. Although not entirely accurate; its easier to understand if kept linearly.

As SetoSeyer pointed out music is dynamic and as such is never constant; that's why we talk about averages (RMS = root mean square). The amplifier never actually works at average, it makes use of its entire capability at that particular instant. Take all of those instances, add them together, then divide by the amount of time that has passed and you end up with an average. It just so happens that the average of a Sine wave can be described by the amplitude multiplied by the square root of 2, or 1.414.
I understand. I worked in car/ home audio for almost a decade. But the gain is used to match the input to the output. When explained as wattage it sounds more like a volume control instead of a gain control. Your 3dB sounds backwards to me. To get a 3dB increase in sound level you have to double the power.


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Y'all lost me at hello. :)
 

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You're right. However, his amp puts out more power than his speakers can handle and he's talking about distortion, which can drive the power level up to peak.
Then you should just get rid of the distortion rather than using a lower powered amp, unless I am not understanding what you are talking about. There isn't any reason that amp, tuned properly, will be an issue with those speakers.
 

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Then you should just get rid of the distortion rather than using a lower powered amp, unless I am not understanding what you are talking about. There isn't any reason that amp, tuned properly, will be an issue with those speakers.
Once again, you are correct. I'm not saying he should get rid of anything. My bike will go over 100 mph, but I've never ridden it that fast. Just because it can, doesn't mean it has to.

If I put tires with a Q speed rating of 100 mph and I never went over 100 mph, I would not have a problem. But what happens if I go faster than 100 mph, because the bike can do it? Will I have a problem? I don't know, it depends on the quality of the tire. Do I want to chance it? Not really.

As you said, he needs to get rid of the distortion. Generally, distortion isn't planned for but it can happen anyway. Its at that time things go screwy and can blow stuff up.

I've just been trying to explain where distortion comes from, because Brianu1's stated causes were completely wrong.

Y'all lost me at hello. :)
Hi.

If anyone wants me to try and explain it differently, to make it easier to understad, I'm willing to do that. Ask and I'll do my best.
 

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Great explanation from the both of you either way. Close to "English as it can be.

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