# Overpowering speakers?



## Pillow (Nov 14, 2009)

I have heard mixed views on whether or not it is okay to overpower speakers... Seems like a lot of people do it anyway 

Should I match RMS or Peak W?

Specifically this is for components. I know subs are probably a whole different ball of wax!

Thanks!


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## ChaunB3400 (Dec 12, 2009)

Peak wattage is just a selling point, never go by that...

Go by the rms


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## Oliver (Jun 25, 2007)

....and since rms is made up to [ not real like , voltage, amperes which equal watts ], just hit the components with as much clean power as you can afford { then adjust the gain lower on your amplifier.


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## ChaunB3400 (Dec 12, 2009)

a$$hole said:


> ....and since rms is made up to [ not real like , voltage, amperes which equal watts ], just hit the components with as much clean power as you can afford { then adjust the gain lower on your amplifier.


That works to


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## Dryseals (Sep 7, 2008)

a$$hole said:


> ....and since rms is made up to [ not real like , voltage, amperes which equal watts ], just hit the components with as much clean power as you can afford { then adjust the gain lower on your amplifier.


Funny, I've never heard that before. I've been doing this for 40 years, been a tech for 35 years. The RMS rating is in watts, watts are power, power is heat. The RMS value is the amount of watts the speaker can continously handle without damaging the coil structure. Heat tends to destroy the coil, things melt and seperate when heated for too long.

Peak is for the same heat related problem, but over time also. I've never looked to see what they rate their time over. Most companies in other business use a 20% duty cycle. RMS is a measurement of peak with a standard sinusoidal wave X * 0.707. Music is not sinusoidal wave. Most power protection is measured in time vs power and varies on different current at different points in time.

Here a diagram of a short. For everyday instances we normally do not worry about all the different peaks and time, but in the real world, the amount of time spent in different current draws can be very damaging.

For peak values in a speaker, you would have to ask the company what formula they used to determine peak. Normal peak for a sinusoidal wave is RMS divided by 0.707.


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## ehkewley (Jul 19, 2008)

a$$hole said:


> ....and since rms is made up to [ not real like , voltage, amperes which equal watts ], just hit the components with as much clean power as you can afford { then adjust the gain lower on your amplifier.


Agreed. Plus depending on the component, a highpass filter can allow you to add more power without negative effects.


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## MiniVanMan (Jun 28, 2005)

So, I'm gonna ask, what's the equation for RMS Power?? 

I'm gonna go out on a limb and say there isn't one because RMS Power is an erroneous concept.

You have RMS voltage, and RMS current. If RMS power is a derivative of those two functions, how is it calculated? 

I can find equations for "Average Power". 

Average power is what we should be talking about. However, it's also fairly useless when trying to apply a number to a very dynamic signal like music. 

You don't need as much power as you think, but you usually need a lot more than is advertised.


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## Dryseals (Sep 7, 2008)

MiniVanMan said:


> So, I'm gonna ask, what's the equation for RMS Power??
> 
> I'm gonna go out on a limb and say there isn't one because RMS Power is an erroneous concept.
> 
> ...


Which standard do you want to use, the DIN or ANSI. DIN uses pink noise for a 24 hour period but does not use distortion as part of their calc. ANSI uses thermal power and cannot damage the speaker. Both use the advertized band width of the speaker.

The equation for RMS is root means square and has been used for ages as usable power for a given load. A speaker present two types of load, inductive and resistive.

The power debate started back in the early 1900's. It was standardized in 70's by the FTC for amps. Speakers were by manufacturer specs until 98. So if you want to know how they rated their speaker, you had to ask for the standard they used or calculation.

How is RMS useful? If you use it from a thermal stand point, it's very useful.
A speaker rated at 60 watts RMS with a bandwidth of 70 - 2500. Look at your lower band, that's where the power will be used. If you push 60 watts to it, you know right off the bat that you are at theshhold for damaging it.

And what do most folks do, they buy a 100 watt amp and hook it to the 60 watt speaker and try to push it past the 70hz band, they look at the peak power and think they'll be safe.

If the speaker says 60 watts RMS, then thats the point at which is slides under the wire for thermal damage. At 60 watts you could have 50% distortion, because that's not a measured part of the calc, it's thermal damage.

Subs are by far the best example, 500 watt speaker, geeze I need a 1000 watt amp and what do they call it "headroom".

It should be the other way around 1000 watt speaker and 500 watt amp.


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## Austin (Mar 12, 2009)

^ So your saying i will blow my components that are rated at 50 rms per side when i have an amp that can do 150 rms per component (bi-amping) where the amp is properly adjusted?

Just because we have a 1000 watt amp on a 500 watt sub doesn't mean we have it set to feed it that 1000 watts. Same with my component set up.


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## sam3535 (Jan 21, 2007)

Dryseals said:


> Which standard do you want to use, the DIN or ANSI. DIN uses pink noise for a 24 hour period but does not use distortion as part of their calc. ANSI uses thermal power and cannot damage the speaker. Both use the advertized band width of the speaker.
> 
> The equation for RMS is root means square and has been used for ages as usable power for a given load. A speaker present two types of load, inductive and resistive.
> 
> ...


If your argument holds true, please explain why my tweeters rated for 100 watts have not blow after receiving 150 watts "RMS" for the past six months. Or my midranges rated for *30 watts *receiving the same power, or my midbasses that are receiving twice their "RMS"?

You do realize that you are arguing a point that has been discussed on this forum since 2005, right? MVM and Hic (as well as myself) all realize what RMS for a speaker and from an amp mean. As far as thermal power handling, just like the RMS question; asked and answered in many threads. Speakers in general will lose 90 to 95% of power through heat.


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## MiniVanMan (Jun 28, 2005)

Here's a good read, and a good answer on why "RMS Power" is a rather useless measurement.

epanorama.net/Amplifier power

When calculating "Average Power", I can use an equation that takes into consideration the frequency played, and figure out the power an amplifier can supply into a given load.

Audio power - Wikipedia, the free encyclopedia

Root mean square - Wikipedia, the free encyclopedia 

"RMS Power" assumes a constant load on the amplifier, and with a speaker that just isn't a reality. There also isn't really a recognized equation for RMS Power. It's an assumption based on factors that don't exist in musical reproduction.

We can say that RMS Power = Vrms * Irms, but that once again assumes a purely resistive load which doesn't exist. The real equation we should be using to determine "Average Power" is much more complicated as it takes the time domain into account.


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## Dryseals (Sep 7, 2008)

sam3535 said:


> If your argument holds true, please explain why my tweeters rated for 100 watts have not blow after receiving 150 watts "RMS" for the past six months. Or my midranges rated for *30 watts *receiving the same power, or my midbasses that are receiving twice their "RMS"?
> 
> You do realize that you are arguing a point that has been discussed on this forum since 2005, right? MVM and Hic (as well as myself) all realize what RMS for a speaker and from an amp mean. As far as thermal power handling, just like the RMS question; asked and answered in many threads. Speakers in general will lose 90 to 95% of power through heat.


I guess my first question is how do you know what RMS power you are pushing to your tweeters? Do you have a watt meter on them or are you assuming the power through your equipment?

I find it great that you have discussed the issue here for the last five years. I started in this business when I was 10, I'm now 52. I was in my junior year of highschool when the FTC set the standard for amplifiers on the consumer market, that was 1974.

I explained the RMS standard by two different groups, DIN and ANSI. The original remark was that RMS is useless. I disagree.

I use measurement criteria in my job every day, understanding it and the reference point is the key. What is the RMS value, the point at which the speaker can't take any more.

What does that tell you as far as sound quaility, nothing, it's a power measurement. I even noted that the power measurement took nothing else into consideration for sound quality. It's simply the point at which the speaker will be destroyed.

What does that tell me? If I think I need 100 watts of music power for a system, then I'll use a speaker with 200 watts RMS capabilities. I never blow a speaker and my amp is always happy because the load isn't trying to kill itself.


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## t3sn4f2 (Jan 3, 2007)

Dryseals said:


> Which standard do you want to use, the DIN or ANSI. DIN uses pink noise for a 24 hour period but does not use distortion as part of their calc. ANSI uses thermal power and cannot damage the speaker. Both use the advertized band width of the speaker.
> 
> The equation for RMS is root means square and has been used for ages as usable power for a given load. A speaker present two types of load, inductive and resistive.
> 
> ...


B&C SPEAKERS

"How does B&C calculate their power ratings?
- B&C Speakers specified Nominal Power Handling is measured according to AES2-1984 standard. The transducer under test is driven for a *two hour *period with *pink noise signal*, having a *crest factor of 2 (i.e. 6 dB)* and *filtered to the working range of the transducer itself *(for instance, a 50-500 Hz range is typical for woofer testing). Cone loudspeakers with ferrite magnets are tested in free air, while neodymium magnet speakers are mounted in a box whose characteristics (volume and tuning) are described in their technical specifications. Compression drivers are coupled to their recommended horn. Power is calculated using the *RMS value of applied voltage – averaged over the test period *– and the minimum value of electrical impedance within the working range of the loudspeaker. After the test, the transducer must be in working order, without permanent impact on its technical performance. Due to the transient character of most musical programs, whose crest factor is commonly above 8 - 10 dB, it is customary to specify a “Continuous Program Power Handling”, double the Nominal Power Handling, as a recommended amplifier power in order to fully exploit the thermal and mechanical capabilities of the transducer without any clipping in the amplifier stage. On the contrary, when the amplifier is pushed to its limits and shows frequent saturation, its power specification should be less than the rated Nominal Power Handling of the loudspeaker."

Seas, ScanSpeak, etc........all do it a similar way.


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## savagebee (Sep 12, 2006)

I think the point was that comparing the rms output of an amp and the rms handling of a speaker is very arbitrary, or as some put it, useless.

When will a speaker in a car see a sine wave for extended amounts of time, or pink noise for 24m or even 2, hours? The idea is that since music is dynamic, and not constant, that the speakers can handle well over rms for transient peaks, ala headroom.


Well.. thats how Ive always looked at it.

I have 100wrms on tap for my .75" silk tweets. They probably never see anywhere near that power, but its there. My midbass have 300 watts available, and while I have bottomed them out before Ive never damaged them, and Ive been running them like this for years.

RMS is useful, to me, but as far as picking an amp to power my front stage I get the most power I can afford, then set the gain on my weakest link (midbass) and level match from there. 
Id always rather have more power and not need it, than to need more and not have it.


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## t3sn4f2 (Jan 3, 2007)

savagebee said:


> I think the point was that comparing the rms output of an amp and the rms handling of a speaker is very arbitrary, or as some put it, useless.
> 
> When will a speaker in a car see a sine wave for extended amounts of time, or *pink noise for 24m or even 2, hours*? The idea is that since music is dynamic, and not constant, that the speakers can handle well over rms for transient peaks, ala headroom.
> 
> ...


A sine wave never but pink noise with the crest crest factor I posted is essentially the same as a modern loud music track when it comes to average power over time.


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## savagebee (Sep 12, 2006)

t3sn4f2 said:


> A sine wave never but pink noise with the crest crest factor I posted is essentially the same as a modern loud music track when it comes to average power over time.


okay, Im not too savvy on the science end of this, so it was beyond my knowledge base. But even then, I drive 45 minutes to and from work on a regular basis, and I have a fairly long commute, at 45 minutes. Isnt this a conservative rating? I like my music loud, and I occasionally jam hard, at or close to full tilt on my entire drive, often listening to stuff like pantera, or devil driver, which has tons of transient spikes and is rough on a speaker for a prolonged period (at least i assume it is), and have never had a problem. How often will someone be using a speaker @ full tilt for 2 hours? I feel pretty confident that i wont be matching that level of abuse any time soon, and Im pretty rough on my equipment.


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## kryptekz (Dec 12, 2009)

yeah


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## MiniVanMan (Jun 28, 2005)

t3sn4f2 said:


> Power is calculated using the *RMS value of applied voltage – averaged over the test period *– and the minimum value of electrical impedance within the working range of the loudspeaker.


Exactly.

There are some key points in there. Bolded and underlined as they should be. 

Don't neglect the statement "minimum value of electrical impedance" either.


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## Austin (Mar 12, 2009)

savagebee said:


> Id always rather have more power and not need it, than to need more and not have it.


:2thumbsup: This is the reason we like to get bigger amps than we needs.


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## Oliver (Jun 25, 2007)

Dryseals said:


> I find it great that you have discussed the issue here for the last five years. I started in this business *when I was 10, I'm now 52*.


 42 years later and this is as far as you got ?

Ouch :surprised:


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## bboyvek (Dec 16, 2008)

zoom zoom zoom


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## t3sn4f2 (Jan 3, 2007)

Let's throw power compression into the mix as well........



Abmolech said:


> Let us have look at power compression.
> 
> When current passes through a voice coil (resistor), electrical energy is converted into heat, and dissipated into the surrounding air.
> The rate at which this dissipation occurs is called power and is measured in watts.
> ...


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## Dryseals (Sep 7, 2008)

a$$hole said:


> 42 years later and this is as far as you got ?
> 
> Ouch :surprised:


Yes it is. 

Do you know what pink noise is and why they use it?

I like the line "double the Nominal Power Handling, as a recommended amplifier power in order to fully exploit the thermal and mechanical capabilities of the transducer without any clipping in the amplifier stage"

Why in the world would I want to "fully exploit the thermal and mechanical capabilities of the transducer" ?. As I said earlier, this is for power, the speaker can't show any signs of being destroyed???

Come on, what kind of distortion are you generating when you "fully exploit the thermal and mechanical capabilities of the transducer"

Your pushing the speaker into a range were it cracking up but still holding together. That's insane.

I want the speaker to be in a range of functionality to give me the best sound it can. It'll also extend the life of the speaker and the life of the amp.

If your amp is clipping, it's not built to handle the power you are pushing from it. That's a result of the final power section, normally the slew rate of the final device. If you present the amplifier with a steady state load and it clips, you've got problems with the amp. But if your pushing the that amp into a load that's changing due to hitting it's the loads max, it's not the amp, it's the load. It's a pretty simple concept.

The RMS value of the speaker will tell you how much you can push it. factor that into the power you want to produce. In my 42 years of ignorance, I've never blown an amp or a speaker. But I can come here on a regular basis and see folks asking why such and such blew.

Then I see responses where people tell me there pushing 150 watts to thier 100 watt tweeter and all I can do is laugh. You got something to measure that power to the tweeter, or are you just guessing. Chances are the music content to the tweeter is more along the lines of 20db down from from what being pushed to the woofer, thats why we use pink noise for setting up system. It represents the power required to produce the same sound levels at different frequencies.

But since I'm an old guy and not very good at this kind of thing compared to all the experts that can cut and paste from a web site, I better just take my walker and sit on the front porch and shake my cain at folks as they pass by.


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## freemind (Sep 11, 2008)

I have yet to snap, crackle and pop a set of speakers. 

You just have to use plain old common sense and your ears.

Gain structure is EVERYTHING.


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## sam3535 (Jan 21, 2007)

Dryseals said:


> In my 42 years of ignorance, I've never blown an amp or a speaker. But I can come here on a regular basis and see folks asking why such and such blew.


In 20 years, I have never lost a speaker or amp either. So which of the opposing views is correct? RMS for a speaker or from an amp for me is factored in but at the end of the day is not the end all be all.

I hope when I'm 52 I will be shaking my cane at others also.


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## bboyvek (Dec 16, 2008)

Dryseals said:


> thats why we use pink noise for setting up system. It represents the power required to produce the same sound levels at different frequencies.


Juss about everyone here (including me) uses and rta to set up their systems :laugh::laugh:


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## t3sn4f2 (Jan 3, 2007)

Dryseals said:


> Yes it is.
> 
> Do you know what pink noise is and why they use it?
> 
> ...


Not by anyone that is trying to help you past your ignorance. :laugh:


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## MiniVanMan (Jun 28, 2005)

Dryseals said:


> Yes it is.
> 
> Do you know what pink noise is and why they use it?
> 
> ...


You're completely missing the point of what we're saying. 

First off, the question of what is RMS power hasn't been answered. It's a fuzzy term. Show me an equation for rms power where RMS power isn't more aptly referred to as "average power". 

The fact is that there is very little consistency in how speakers or amplifiers are rated. They can all claim an RMS value because it's fuzzy math, and relatively pointless.

Let's be clear though among all the fuzziness. The enemy is heat. Heat is created by current dissipation across a resistive load. This is true for an amplifier and a loudspeaker. 

So, our argument is the same as yours. We push a known voltage through a resistive load, but increase current. Current turns to heat, efficiency goes down, resistive load goes "poof". We know this.

What I'm asking, and several others is, when rating a speaker, what is RMS power? How does RMS power, which is a misnomer tell us how much heat the motor of a speaker can dissipate? 

I can get more information on how much a speaker can handle current wise by a simple Qes factor than by an RMS power rating.  

Q factor - Wikipedia, the free encyclopedia


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## The J (Oct 27, 2009)

Wow, the debate in this thread has been quite informative! 

I understand the basics of RMS vs. peak values (ie. our 120V outlets in the US are in RMS and are really about 171V peak), but I'm no expert. Until recently I've been confused when a speaker manufacturer states that a speaker's max power is 250W, but it's RMS power is listed as 60W. Why isn't its RMS power ~175W (250W * .7)!? 

So, then, I just assume that "RMS Power" is really a misnomer for "Continuous Power". Is that the case? Is "RMS Power" equal to "Continuous Power" * 0.707? Is "Max Power" measured in RMS Watts or Peak Watts? 

I've thought about this before and subsequently forgot about it a few minutes later.  Though, now that I see this thread I figure I might as well see what others have thought about this.


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## savagebee (Sep 12, 2006)

RMS is a fuzzy rating in itself, MAX or PEAK ratings seem completely arbitrary in most every case.


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## MiniVanMan (Jun 28, 2005)

The J said:


> Wow, the debate in this thread has been quite informative!
> 
> I understand the basics of RMS vs. peak values (ie. our 120V outlets in the US are in RMS and are really about 171V peak), but I'm no expert. Until recently I've been confused when a speaker manufacturer states that a speaker's max power is 250W, but it's RMS power is listed as 60W. Why isn't its RMS power ~175W (250W * .7)!?
> 
> ...


RMS power isn't a misnomer for anything in particular. It's just a misleading term.

Like I said, since heat is the enemy, and current dissipation is what causes heat, then what we really want to know is the amount of current that can be sustained indefinitely given a known voltage. That would be "Average Power".

With an amplifier what current can the power supply handle before the voltage rails sag?

There are just too many variables in play. We have a reactive load, fluctuating current, and fluctuating voltage.


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## Oliver (Jun 25, 2007)

Dryseals,

what's this pink noise ?

http://www.diymobileaudio.com/forum/diy-mobile-audio-sq-forum/566-testing-cds.html



> If you go to www.bcae1.com (basic car audio electronics), there's a link to purchase the site on CD. It's $20 shipped and IMO it's worth it. With the site CD comes a test tone CD that has tones in almost 60 increments from 10hz-20khz, plus sweeps, plus brown noise, pink noise, white noise and a silent track (to listen to your noise floor). All sine waves are 0dB.


We ain't never heard about it around these parts . . . since march of your 48 th enlightening year in car audio



> Richard Clark
> Senior Member
> 
> 
> ...


http://www.audiogroupforum.com/csforum/showthread.php?t=32547&highlight=pink+noise

This is from your 42nd year of life on earth from some feller in one of them Carolina's.

You ever heard of this guy. . . gramps ? ^^^^^


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## Pillow (Nov 14, 2009)

... And I thought this would be a simple question!  Silly me. 

The feedback and information has been great! Keep it comin'


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## keep_hope_alive (Jan 4, 2009)

it would be awesome if you could have an intellectual discussion without childish name calling and immature responses. 

nobody here is "cooler" than anyone else, so get past that and continue as adults. 

"gain structure is everything" - this is summarizing the point that it doesn't matter if i have an amplifier rated for 200 whatever-watts, i can control my volume and my gain and never exceed 20 whatever-watts. agreed?

the concern when powering a speaker with a smaller amp is clipping and distortion when you try to reach "rated" whatever-watt power. planning to get every last watt out of an amplifer is just poor practice (and not a good idea recommending it to kids on a online forum). 

instead, if you buy an amp that is larger than you need you get to operate much lower on the THD curve, as well as help prevent clipping (though you can still clip the source output). 

either way, you can damage a speaker by overpowering it causing excursion beyond mechanical limits, thermal issues, physical failures, etc. so there is no "fail safe" method. 

all power ratings are misleading in some way. for one, time is rarely included. all details of the test conditions would be helpful, but who cares? the average consumer? 

this is a fine discussion. keep to the math and science and it can be educational. don't let this fall to the typical DIYMA bullshyt bantering.


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## The J (Oct 27, 2009)

MiniVanMan said:


> RMS power isn't a misnomer for anything in particular. It's just a misleading term.
> 
> Like I said, since heat is the enemy, and current dissipation is what causes heat, then what we really want to know is the amount of current that can be sustained indefinitely given a known voltage. That would be "Average Power".
> 
> ...


I think I get what you mean for the most part. However, you've piqued my interest, so I'm going to think on paper (...keyboard?) for a bit here. This involves me trying to remember what I learned in my electromagnetism classes, so you might see smoke coming from my ears. 

Just to make sure: is an audio amplifier a constant-voltage (current changes), constant-current (voltage changes) supply, or neither? I would guess it's constant-voltage since, if I remember correctly, it is the presence of current that generates a magnetic field, which drives the speaker. This assumes that the amplifier is able to sustain its voltage at the given current, of course.

Okay, when you say "amount of current that can be sustained indefinitely given a known voltage", do you mean feeding the speaker a signal whose peak amplitude is the desired current (with fixed voltage) across our entire frequency band? This is almost the defintion of white noise, right? To be completely honest, I always just assumed that is how speakers were tested. Is this not how they do it?

So then, we need the speaker manufacturers to tell us more about their testing environment. I notice that amps tell us they can put out 400W with a 13.8V supply, for example, but speakers just say 60W with no other info (at least that's what I see with what little looking-around I've done so far). Since current dissapation causes heat, could we theoretically push 180W through the speaker by cranking up the voltage and keeping the current low enough (sound quality aside)?

I'm just really curious like that, is all!


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## Oliver (Jun 25, 2007)

The J ,

The alternator cannot supply enough voltage and current in some instances.

As you starve the input of the amp, the output drops also.

After time = ? [ months, years, etc..,], the heat produced by loads . . . takes it's toll !

The harder you push something. . . the sooner it fails [ buy more, rinse and repeat ].

An amplifier run at a lower impedance [ subwoofer wired in parallel for 2 ohm or 1 ohm or 0.5 ohm, etc..,], more heat is generated by the electronics in the amp.

Heat takes a toll on all of the items being used, it wears them out.


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## Dryseals (Sep 7, 2008)

The J said:


> I think I get what you mean for the most part. However, you've piqued my interest, so I'm going to think on paper (...keyboard?) for a bit here. This involves me trying to remember what I learned in my electromagnetism classes, so you might see smoke coming from my ears.
> 
> Just to make sure: is an audio amplifier a constant-voltage (current changes), constant-current (voltage changes) supply, or neither? I would guess it's constant-voltage since, if I remember correctly, it is the presence of current that generates a magnetic field, which drives the speaker. This assumes that the amplifier is able to sustain its voltage at the given current, of course.
> 
> ...


Basic amplifier formula P = Vpp2/(8*Rl). To achieve more power to the speaker we have to increase the voltage. So your 13.8 supply gets kicked up in the amp. Simple DC to DC converter.

The issue here is if RMS means anything. Most manufacturers use pink noise, which represents the amount of power across a frequency band to develope the same sound level at all frequencies. So if the manufacturer rates his speaker from 50HZ - 10KHZ at 50 watts, they have ran pink noise to the speaker at that 50 watts for a given period of time with out the speaker being destroyed.

Heat is the killer here. So if I see 50W RMS, that doesn't tell me how much to push the speaker. It tells me that that what it willl take before destruction. Nothing about distortion, distortion could be 50% @ 50 watts.

I use that value as an indictor, I don't want to be anywhere near 50 watts to this speaker. The rule of thumb I learned many years ago from an audio engineer was to go half. Don't tax the speaker any more than you should, it's hard on the speaker and hard on the amp.

Is that a conservative approach? Yes, but when I build a system, I want it to perform and last and most of all sound right. Taxing a system negates all the above. And I don't enjoy buying new equipment to replace things that get destroyed or turning up a system to get good and loud and have it sound like crap.


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## jp88 (Jun 25, 2007)

Dryseals said:


> Heat is the killer here. So if I see 50W RMS, that doesn't tell me how much to push the speaker. It tells me that that what it willl take before destruction. Nothing about distortion, distortion could be 50% @ 50 watts.
> 
> I use that value as an indictor, I don't want to be anywhere near 50 watts to this speaker. The rule of thumb I learned many years ago from an audio engineer was to go half. Don't tax the speaker any more than you should, it's hard on the speaker and hard on the amp.


According to your theory, this speaker from Jl audio linky with a rated continuous power handling of 100 watts. should only be fed with much less than 100 watts. The manufacturer however says the recommended amplifier power is 40-175 watts per Chanel. I do know for a fact that they do just fine with a amp rated at more than 100 watts feeding them. I have also had a customer mess up a pair being fed with 55 watts per channel high passed at 80 hz 12db/oct. The voice coils damaged from heat.

Fact is there is no magic formula to figure out what size amp to run to a speaker. Its partially up to the end user to not abuse them.


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## Oliver (Jun 25, 2007)

Dryseals, I wonder if it is too late for you to help KevinK and MattR [ multiple world championships ]?

These guys don't have the benefit of sage advice


> My plan for the amp upgrade was basically to duplicate each amp for its given driver... so, a bridged 3.0 on each tweeter and a bridged 6.0 on each midrange, mid bass, and subwoofer.


This is currently going on in the build log section, he is going to bridge this to one tweeter


> Mfg Part No. C2K30X
> 
> 
> -Sub-sonic filter for speaker protection
> ...


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## MiniVanMan (Jun 28, 2005)

Dryseals said:


> Basic amplifier formula P = Vpp2/(8*Rl). To achieve more power to the speaker we have to increase the voltage. So your 13.8 supply gets kicked up in the amp. Simple DC to DC converter.
> 
> The issue here is if RMS means anything. Most manufacturers use pink noise, which represents the amount of power across a frequency band to develope the same sound level at all frequencies. So if the manufacturer rates his speaker from 50HZ - 10KHZ at 50 watts, they have ran pink noise to the speaker at that 50 watts for a given period of time with out the speaker being destroyed.
> 
> ...


I get the feeling that you understand the "why" of it all, but not the "what". 

I also think that we all failed to take into consideration one VERY important aspect. When a speaker is tested, is it tested in free air, a baffle, or enclosure? This is important. You say that a speaker is tested utilizing it's advertised frequency response. Well, first off, advertised frequency response is a crock of ****. What's the standard for frequency response? There is none. Many will rate a speaker down to Fs for frequency response, and others will rate it 2x Fs. 2 times Fs will give you much more power handling than at Fs. So, if a crossover is implemented at 2x Fs, I can guarantee you'll get MUCH more power handling from a speaker than if you cross over at Fs. 

Enclosures allow us to get closer to Fs while still controlling excursion. 

So, let's agree to disagree at this point. Your points are valid under some conditions. But, when implemented within a system, understanding the limitations of a driver, goes way beyond just power handling. That's why we use multiple driver systems.


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## Oliver (Jun 25, 2007)

I'd put a component speaker in a super small box and test it at 1,000 Hz, hit that puppy with 50 watts, then I'd sell it to be used IB in a door and tell them it will play at Fs of 43 Hz

I'm going to recommend a sapper helmet , flak vest and riot sheild to Kevink , so he doen't die when his tweeters start shooting out of the A-pillars like a 12 guage 3" magnum


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## sonikaccord (Jun 15, 2008)

Dryseals said:


> Heat is the killer here. So if I see 50W RMS, that doesn't tell me how much to push the speaker. It tells me that that what it willl take before destruction. Nothing about distortion, distortion could be 50% @ 50 watts.
> 
> I use that value as an indictor, I don't want to be anywhere near 50 watts to this speaker. The rule of thumb I learned many years ago from an audio engineer was to go half. Don't tax the speaker any more than you should, it's hard on the speaker and hard on the amp.


Question,

If you have a speaker rated for 50 watts and it starts to distort that badly at that point, couldn't you just increase the xover point/slope to give you more power handling and decreased distortion?


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## keep_hope_alive (Jan 4, 2009)

most of the information presented is technically correct. so neither of you is "wrong" 

you're mainly arguing over a difference in opinion. if your *opinion* is that RMS power is useless, then it's your opinion, no one can tell you you are "wrong". RMS is used in the industry so you can't get away from it. 

[edited due to being useless]

testing conditions are hardly published, so we're basically guessing as to what the actual power handling is anyway. as long as we are careful when tuning, setting levels, and playback we should be just fine. 

overall, this is a fairly informative thread regarding some basic topics.


do you agree that the mfr stated "RMS power" is actually attainable? If so, then that's what really matters when kids are asking questions. I ignore "Peak power" ratings from manufacturers, as there seems to be no way of actually achieving that power safely with, say Boss. 

however, i totally agree that Average power is what i'm actually measuring when my DMM measures RMS voltage.


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## DanMan (Jul 18, 2008)

a$$hole said:


> Dryseals, I wonder if it is too late for you to help KevinK and MattR [ multiple world championships ]?
> 
> These guys don't have the benefit of sage advice
> 
> ...


:lurk:


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## t3sn4f2 (Jan 3, 2007)

keep_hope_alive said:


> most of the information presented is technically correct. so neither of you is "wrong"
> 
> you're mainly arguing over a difference in opinion. if your *opinion* is that RMS power is useless, then it's your opinion, no one can tell you you are "wrong".
> 
> ...


Thats RMS voltage assuming you are using a true RMS meter, the root mean square of the power content of the topor bottom half of the wave. "Average power" is the average of that voltage (peak or RMS however you want to look at it) over time (ie crest factor).










You can't get an average voltage from music from a DMM since the signal is dynamic and not constant like a sine wave and the DMM does not take time into account over a long period to give _an average_.


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## Dryseals (Sep 7, 2008)

jp88 said:


> According to your theory, this speaker from Jl audio linky with a rated continuous power handling of 100 watts. should only be fed with much less than 100 watts. The manufacturer however says the recommended amplifier power is 40-175 watts per Chanel. I do know for a fact that they do just fine with a amp rated at more than 100 watts feeding them. I have also had a customer mess up a pair being fed with 55 watts per channel high passed at 80 hz 12db/oct. The voice coils damaged from heat.
> 
> Fact is there is no magic formula to figure out what size amp to run to a speaker. *Its partially up to the end user to not abuse them*.


Very true.

The speaker you showed has rating to 170 watts. It's marine, so the guy's running it most likely in a boat. 55 watts per channel in a boat in not a lot. My inboard/outboard is not all that quite while crusing. Chances are he ran it pretty load, amplifier clips, more heat, damaged speaker.

Like I said in earlier posts, what's your goal sound level wise. A boat motor db levels are run 88 to 90 db. That's a lot of exhaust noise to 
over come. Just riding in a boat you normally have to yell to be heard. So with a 55 watt per channel amp, your competeing with motor noise. I think the boats going to win.

Knowing that I have to overcome the sound of the boat, my sound level goals are going to be much higher. How many db above the boat motor do I need to go?

At 55 watts he probably hit a sound pressure in a closed room around 107 db, 25 would put him around 104. Is that far enough out there to make the music sound good with a boat motor running in the back ground, I doubt it. We talking open air here, better add some amplifier power to get the levels he wants.

A 200 watt amp is only two sound levels higher, is that going to be enough? It might be, so I'll look for an amp that's 300 watts or more, 400 would be great. But that also means I'll need speakers that can handle that 400 watt amp. Or adjust the gains never to go into that area, hit or miss.

The whole of the conversation was about the usefulness of RMS, some say it doesn't mean anything. I disagree, I use it as a reference for how hard I want to tax the speaker. If folks want to push their systems to the extremes, then so be it. Myself, I want to get the most out of it without having to replace components. So I build by setting a goal, sound level and then select components that can achieve the sound levels without being taxed.


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## Dryseals (Sep 7, 2008)

MiniVanMan said:


> I get the feeling that you understand the "why" of it all, but not the "what".
> 
> I also think that we all failed to take into consideration one VERY important aspect. When a speaker is tested, is it tested in free air, a baffle, or enclosure? This is important. You say that a speaker is tested utilizing it's advertised frequency response. Well, first off, advertised frequency response is a crock of ****. What's the standard for frequency response? There is none. Many will rate a speaker down to Fs for frequency response, and others will rate it 2x Fs. 2 times Fs will give you much more power handling than at Fs. So, if a crossover is implemented at 2x Fs, I can guarantee you'll get MUCH more power handling from a speaker than if you cross over at Fs.
> 
> ...


That's why I've used SoundEasy to test my drivers, so much quicker than what I had to do in the old days. My old test equipment sits gathering dust. I still use the scope from time to time, but the trigger is getting a little flakey.


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## jp88 (Jun 25, 2007)

Dryseals said:


> Very true.
> 
> The speaker you showed has rating to 170 watts. It's marine, so the guy's running it most likely in a boat. 55 watts per channel in a boat in not a lot. My inboard/outboard is not all that quite while crusing. Chances are he ran it pretty load, amplifier clips, more heat, damaged speaker.
> 
> ...


Immaterial as the speaker was blown at the dock with the engines shut down.


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## 3fish (Jul 12, 2009)

*All points well taken*

So I'm driving my 100w RMS speakers with my 100w/channel amp and at higher thresholds I get distortion - my guess would be from my amp, no? So, I now upgrade my amp to 190w/channel amp, and I'm now worried about over driving my speakers.

So if I follow A$$hole how do I adjust correctly to maximize my s/n ratio, performance of my system without blowing my transducers?

All other discusions regarding seting gains have to do with set gain to point where wave form shows clipping.

OK so there's deception and subterfuge in manufacturers ratings. It would seem reasonable to assume that some manufacturers are more reliable testing and reporting partners than others. For example, I would have a hard time believing stats listed for a Sony Explode at Walmart and would have strong confidence in figures reported for, let's say, Focal Utopias. My point being that why could we not, pari passu, use manufacturers specs in setting baseline for our numbers? Seems reasonable to me. Then depending on our sonic goals choose whatever adjustment path meets those goals.


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## Dryseals (Sep 7, 2008)

a$$hole said:


> Dryseals, I wonder if it is too late for you to help KevinK and MattR [ multiple world championships ]?
> 
> These guys don't have the benefit of sage advice
> 
> ...


I find this amusing. You have no knowledge of my background in audio, yet because I called you on the RMS having no value, you want to play games.

I did say I started in this at the age of 10 and now I'm 52. My uncle had a very prosperous recording studio in the 60's. Many of the big stars then recorded in his studio, Frank Sinatra, Sammy Davis to name a few . He passed away in the 80's and now the studio is owned by others. He was an electrical engineer, owned a TV station and a few radio stations along with other investments.

I spent a lot of time learning there at a very young age, audio sparked my interest. These were the days of tubes, but the principals were the same. I watched the studio be rebuilt several times for better sound and learned a lot from those doing it.

I put into practice what I learned from these people. I don't build to be the loudest, I build to have a good clean sound. But over the years I have found that the vast majority of folks do not have a clue, but they sure do like spouting off every chance they get.

I'm going to put you in that category along with the rest. You had an opportunity to present a mature argument, but instead you chose to resort to insults.

There's an old Chinese saying. The person who admits ignorance shows it once; the one who tries to hide it shows it often.

Have a nice day sir.


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## buchaja (Nov 10, 2007)

Dryseals,

Welcome to the forum. I am looking forward to your input. 

And everyone else, for what it's worth, rms is neither made-up nor useless just because we are talking audio signals. 

I don't believe that 150w to your tweeters is doing a thing for you other than making a more expensive amp waste it's capabilities. Headroom? Bunk! I suppose you could strap a jet engine to the back of your VW Beetle and claim you have plenty of reserve power too, you know, just in case you need it. 

I hope you stick around, Dryseals. But, if you don't, say hi to Werewolf when you get to a forum where reason is appreciated. (Did you get that one, A$$hole?)


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## keep_hope_alive (Jan 4, 2009)

t3sn4f2 said:


> You can't get an average voltage from music from a DMM since the signal is dynamic and not constant like a sine wave and the DMM does not take time into account over a long period to give _an average_.



agreed. i wouldn't use music as a source when measuring with a DMM (a True RMS DMM). I only measure with tones and I recognize the difference between a 0 bit tone and music.


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## 89grand (Nov 23, 2006)

buchaja said:


> Dryseals,
> 
> Welcome to the forum. I am looking forward to your input.
> 
> ...


I'm not taking anything away from Dryseals, I don't him, but so far I see nothing to indicate that he is on the same level as werewolf and to suggest so based off his use of the term RMS, which is incorrect by the way, is ludicrous.

It's not really his fault, the term "rms" floats around everywhere, but it makes no sense when discussing audio power. It's been incorrectly used for decades.


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## Dryseals (Sep 7, 2008)

89grand said:


> I'm not taking anything away from Dryseals, I don't him, but so far I see nothing to indicate that he is on the same level as werewolf and to suggest so based off his use of the term RMS, which is incorrect by the way, is ludicrous.
> 
> It's not really his fault, the term "rms" floats around everywhere, but it makes no sense when discussing audio power. It's been incorrectly used for decades.


I'm quite aware of the term RMS and how it can be used and confused. I do not know this person werewolf, but I would enjoy reading some of his info.

The idea of a forum is to exchange ideas, debate some and flatten out some. Sound to one person can be totally opposite to another, we hear with our ears, which are not all perfect. We learn sound and then reproduce it with a system. We tend to want to hear what we heard before or how we think it should sound or the freqs we enjoy the most. Talk to a bass player and he loves the sound, thats why he chose the instrument.

My ears may hear the lower freqs worse than yours, so your system may be flatter in that range. Mine will be peaky down there and I'll love it while you hate it.

My goal has always been to reproduce the sound as clean as I can, and then learn to appreciate what I can hear.

I don't believe in any set rules for sound other than what makes you happy. The rest is all opinion.


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## Pillow (Nov 14, 2009)

>I don't believe in any set rules for sound other than what makes you happy. The rest is all opinion.<

Well said! And I think everyone can agree on that.


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## jp88 (Jun 25, 2007)

buchaja said:


> Dryseals,
> 
> I don't believe that 150w to your tweeters is doing a thing for you other than making a more expensive amp waste it's capabilities. Headroom? Bunk!


A cd has the capability of 96 db of dynamic range. A well recorded well mastered cd will use a good bit of that dynamic range. If a driver is getting 10 watts they will need 100 watts on tap for a 10 db peak.

but of course headroom is completely unnecessary.


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## The J (Oct 27, 2009)

buchaja said:


> I don't believe that 150w to your tweeters is doing a thing for you other than making a more expensive amp waste it's capabilities. Headroom? Bunk! I suppose you could strap a jet engine to the back of your VW Beetle and claim you have plenty of reserve power too, you know, just in case you need it.


It seems like one idea behind "headroom" is that it is easier to dial back power (by lowering gains) if you have too much than it is to add power (buy new amps...?) if you need more. This makes sense, I think, if you tend to upgrade your speakers but keep your amps.




89grand said:


> It's not really his fault, the term "rms" floats around everywhere, but it makes no sense when discussing audio power. It's been incorrectly used for decades.


I think I might have sort of mentioned my confusion before, but is the problem is that it's necessary to qualify "RMS" with something? In other words, wouldn't you need to say "RMS Continuous Power" or "RMS Peak Power" for the term to be used correctly? I ask because I often see "RMS Power" listed for speakers, but it looks like it is being used to mean "Continuous Power."


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## buchaja (Nov 10, 2007)

89grand said:


> I'm not taking anything away from Dryseals, I don't him, but so far I see nothing to indicate that he is on the same level as werewolf and to suggest so based off his use of the term RMS, which is incorrect by the way, is ludicrous.
> 
> It's not really his fault, the term "rms" floats around everywhere, but it makes no sense when discussing audio power. It's been incorrectly used for decades.



I know no one on this forum. I take each poster's level of intelligence, experience and background into consideration as it is revealed to me. So, like you, I look for indications that someone is trustworthy - or full of ********. Dryseals said he has extensive experience with audio. I believe him because: a) I have no reason not to, and b) his posts are well reasoned, rational and sync with my experience. A$$hole might get by some of you by throwing aspersions on the new guy's character, but that's simply because he full of it and can't argue the topic at hand (in this case anyway. I do like many of his posts.)

Now, go back and re-read my post and you will find I made no suggestion Dryseals was on the same level as Werewolf. He revealed himself to be a technician with lots of audio experience. Werewolf, I believe taught engineering at the college level (correct me here, I haven't read him in years), and was the primary reason I joined this forum. I liked his detailed, physics heavy approach.

For what it's worth, I was a technician too. I probably know more about (simple) electronics than 99% of DIYMA members. But, I know little about acoustics, physics etc. I limit my posts to where I think I can be helpful, or where I need to learn. Where I see similarities between Dryseals and Werewolf is in the way they were treated by some here. That's why I said I hope he sticks around. Werewolf left because he got tired of constantly defending himself. I don't blame him for that.



jp88 said:


> A cd has the capability of 96 db of dynamic range. A well recorded well mastered cd will use a good bit of that dynamic range. If a driver is getting 10 watts they will need 100 watts on tap for a 10 db peak.
> 
> but of course headroom is completely unnecessary.



Again, I didn't say that. I like headroom as much as anyone, but I don't think you need much power to get it out of a TWEETER. 

I've been guilty of losing my cool on DIYMA. It's sometimes difficult to not take the bait, but I think I did pretty good in this thread.

You can over power drivers and not blow them, I get that. But you're forgetting that transients are just that: transient. They get loud for a fraction of a second. It doesn't take much power to drive a tweeter to that level for that long.


One other thing. Look at the efficiency ratings for any number of tweeters. It takes ONE watt to drive many of them to 96/97db. I don't believe anyone is sitting in their cars listening to 10 watts continuous RMS power through any modern, reasonably efficient tweeter.


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## MiniVanMan (Jun 28, 2005)

buchaja said:


> I hope you stick around, Dryseals. But, if you don't, say hi to Werewolf when you get to a forum where reason is appreciated. (Did you get that one, A$$hole?)





werewolf said:


> agreed ... it seems to me that the original post is confusing _crest factor_ with _dynamic range_  two very, VERY different things. Crest factor, as stated correctly in _this_ post, is the ratio of peak-to-average power.
> 
> By the way ... we all know that the term "rms power" is meaningless, right?
> 
> The terms "rms voltage" and "rms current" do, however, have real meaning. They are used in the calculation of _average_ ... NOT _rms_ ... power


From this thread. Since you want to throw his name around. 

http://www.diymobileaudio.com/forum/diyma-tutorials/18660-abmolech-talks-power-speakers.html


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## buchaja (Nov 10, 2007)

OK. Before I get shouted down here, I just took my own advice and reviewed a few tweeters on Madisound's website. 

I'll be... I overstated the efficiencies. They commonly fall between 89 and 92db/w/m. And the Scan Airspeaks were apparently tested for 100 hours at 160w RMS without falling apart. **** that's a lot of power.

Let's back this airspeak down and see how much power they take to get LOUD:

They are 92db/m/w rated. So, sitting about three feet away you'll get 92 decibels out of them with one watt. Double power for 3 more db's: 2w=95db, again, and 4w=97db. 8 watts and your getting 100dbs, 16 watts for 103db, 32=105, 64=108, 128=111db.

And you can squeeze a little more out of them without damage. 

Anyone have a link to a loudness/hearing damage chart?


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## buchaja (Nov 10, 2007)

MiniVanMan said:


> From this thread. Since you want to throw his name around.
> 
> http://www.diymobileaudio.com/forum/diyma-tutorials/18660-abmolech-talks-power-speakers.html


From that thread ^^^^^



npdang said:


> Let me add to this. Most 6.5" drivers you see will quite easily fail both thermally and mechanically with a continuous 100w power. Depending on both the length of time driven, and the frequency.
> 
> Dynamic range is great, but bear in mind some if not many people can't hear a difference between a compressed/clipped dynamic peak and one that isn't because it's such a brief period of time. Also, many amps are capable of significantly higher burst levels than their cont. power rating. And lastly, music is generally so compressed these days you don't need an amp capable of such a wide dynamic range.
> 
> Imho, you can certainly do fine with 50-75 wpc amp on your fronstage... provided your drivers arent buried in the car, you have loud environmental noise, or you have hearing damage/grossly inefficient drivers.





It's late. I'll read that entire thread tomorrow. 

But for now, I didn't throw Werewolf's name around because I thought it made me sound smarter. I did it because I saw the same old juvenile responses to Dryseal's posts that I saw to his.

I am far from an expert in this field. And I do know that rms is a measure of voltage and current, and the product of those gives you average power. It's just a naming convention, but it is still useful to understand the power handling capabilities of drivers imo.


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## cubdenno (Nov 10, 2007)

buchaja said:


> OK. Before I get shouted down here, I just took my own advice and reviewed a few tweeters on Madisound's website.
> 
> I'll be... I overstated the efficiencies. They commonly fall between 89 and 92db/w/m. And the Scan Airspeaks were apparently tested for 100 hours at 160w RMS without falling apart. **** that's a lot of power.
> 
> ...


Not to get off topic, but I stopped believing that 3db increase with doubling power after I saw my first 150 db car. It didn't make sense considering the 4000 watts of power being used on the single woofer of 85 db "sensitivity".
We forget the high gain environment that is the vehicle.


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## t3sn4f2 (Jan 3, 2007)

http://www.diymobileaudio.com/forum/197855-post30.html



werewolf said:


> And how many think it's a smart move to "limit" speaker power by the clip-level voltage rails of the power amplifier driving it?


You won't here the clip but our speaker will sure appriciate the missing harmonic power at headroom power levels.


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## Oliver (Jun 25, 2007)

bump


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## buchaja (Nov 10, 2007)

Oliver said:


> bump


Sorry I insulted you Oliver. You use to be such an A$$hole.:jester:


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## Oliver (Jun 25, 2007)

buchaja said:


> Sorry I insulted you Oliver. You use to be such an A$$hole.:jester:


:angel::beerchug:


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## Bugstyvy (Jan 16, 2011)

Better to overpower than underpower


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