Amp & Subwoofer Questions...

[Shockwave]

Originally posted by: glen
underpowered amps DO clip
but clipping does not make them more powerful or damaging to speakers

I'm not going to argue this with you. You havent taken the time to look into the Fourier Analysis, which show the adidtion of harmonics. Thus, until YOU can provide ME with something to look into to dispute the common knowledge of clipping increasing power, I have to assume your just doing this to piss me off. Fair enough. Go to the links I provided, look into what I suggested.

He with an open mind doesnt fight, but rather seeks to learn. I provided you with links and asked for something backing your statements. Balls in your court. A simple "Its not true" doesnt cut it.

 

[jteef]

Originally posted by: glen
underpowered amps DO clip
but clipping does not make them more powerful or damaging to speakers

this is not entirely true and therefore a dangerous statement.

Clipping them does make them more powerful, however, with a lot of car audio amps the manufacturers are out to cut costs any way they can so they make the power supplies of their amps weak. Hence, the amp would "try" to make the extra power, but the power supply simply can't keep up, so your statement is true sometimes. There are plenty of amps out there that will deliver the extra power required to fry your speakers.

 

[glen]

Originally posted by: jteef

Originally posted by: glen
underpowered amps DO clip
but clipping does not make them more powerful or damaging to speakers

this is not entirely true and therefore a dangerous statement.

Clipping them does make them more powerful, however, with a lot of car audio amps the manufacturers are out to cut costs any way they can so they make the power supplies of their amps weak. Hence, the amp would "try" to make the extra power, but the power supply simply can't keep up, so your statement is true sometimes. There are plenty of amps out there that will deliver the extra power required to fry your speakers.

No.
It is always true.

 

[jteef]

Originally posted by: glen

Originally posted by: jteef

Originally posted by: glen
underpowered amps DO clip
but clipping does not make them more powerful or damaging to speakers

this is not entirely true and therefore a dangerous statement.

Clipping them does make them more powerful, however, with a lot of car audio amps the manufacturers are out to cut costs any way they can so they make the power supplies of their amps weak. Hence, the amp would "try" to make the extra power, but the power supply simply can't keep up, so your statement is true sometimes. There are plenty of amps out there that will deliver the extra power required to fry your speakers.

No.
It is always true.

care to back that up with paperwork?

 

[Shockwave]

Heres the deal Glen.
I'm taking my pants off and settin my nuts on the table.
I know about 900 million times more about car audio then you. Take my advice, research clipping.

I'm not doing this to be an asshat or start a flame war. Like I said earlier, its better to learn then to fight, but your apparently content to just give us this "Its true, your wrong" crap.

Now, until you back up your statements, I'm going to assume your only here for flame wars, and will disregard any other posts from you that do not contain links or info to support your claims.

 

[thomsbrain]

i play guitar with a "100" watt tube amp that probably peaks somewhere in the neighborhood of 150 watts, while my speaker cabinet can handle around 300 watts. if these were subs, the amp would be considered "underpowered." i dime the volume control into maximum power amp distortion and clipping every single friggin day. tube amp distortion is desirable in the guitar world, and it doesn't hurt speakers in the least. if "clipping" sounds hurt speakers, every single person who plays rock music on their stereo would have blown speakers just from listening to distorted guitars and basses (speakers don't know the difference between a signal distorted in the source and a signal distorted through the amp). in fact, "clipping," which is just distortion, is what happens when an amp has reached it's maximum output and has NO more headroom. When an amp clips, it's reached the end of the line. It won't go any louder, and if your speakers still have headroom, you're cool. Of course, in the subwoofer world, distortion is going to sound like crap, unlike the guitar world. But the speakers won't be damaged by it. They'll simply reproduce a dirty signal, exactly the same as if you were playing a loud recording which contained a purposely distorted signal.

summary: any stereo system amp cranked to the max will sound like microwaved crap, but as long as your speakers have a greater power handling capacity than the amp, you won't damage anything.

 

[thomsbrain]

Originally posted by: Shockwave

Originally posted by: glen
underpowered amps DO clip
but clipping does not make them more powerful or damaging to speakers

I'm not going to argue this with you. You havent taken the time to look into the Fourier Analysis, which show the adidtion of harmonics. Thus, until YOU can provide ME with something to look into to dispute the common knowledge of clipping increasing power, I have to assume your just doing this to piss me off. Fair enough. Go to the links I provided, look into what I suggested.

He with an open mind doesnt fight, but rather seeks to learn. I provided you with links and asked for something backing your statements. Balls in your court. A simple "Its not true" doesnt cut it.

and just how many of those new harmonics will actually be reproduced by subwoofers that don't go any higher than ~250 Hz? according to your logic, if you ran a subwoofer without a crossover, it would be damaged, simply because it would be receiving harmonic frequencies it can't reproduce, which simply isn't true.

case in point: guitar speakers are chosen because they do not have enough frequency response to reproduce all the harmonics of a distorted pre or power amp (they cut off around 6-12kHz). the reason is if you could hear them, it would sound super tinny and terrible. so the speakers are an intregal piece of the EQ chain of electric guitars, and they do so by being fed MASSIVELY clipped signals and the harmonics that accompany such signals. these woofers have no trouble handling these signals every day. a stereo woofer fed such a signal would react no differently.

edit: i should point out that an amp driven to the point of clipping will be in some instants producing it's peak power output, and in others, producing it's maximum continuous output. your speakers of course have to be able to handle those peaks as well as the constant signals. but again, it's not usually a problem. my 100 watt amp can peak at probably 150 watts, but the speakers are good up to 300 constant so it makes no difference. in a sub situation, an 200 watt amp might be able to peak at 400 or even 600 watts, but even that wouldn't approach the constant signal limit of the subs we're talking about. and let's not forget that the speakers themselves ALSO have peak capacities that exceed their constant capacities. the subs we're talking about can handle peaks up to 1,400 watts. so they could handle the clipping peaks of an amp that's fairly powerful. the point is, the type of signal has nothing to do with damaging the speaker, it's just the power of the signal, both on average and in the peaks, and whether or not that is below the rated capacity of the speaker in question. don't forget that the peaks you get with a clipped amp will actually be LESS intense than the peaks you get with an amp that still has headroom, because the clipping amp has less juice left over to blast out those peaks due to already being maxed out on average output. an amp that is feeding 700 average watts (clean) to those subs will be producing peaks MUCH more intense than the peaks of a clipping 200 watt amp, let alone the peaks of a clipping 700 watt amp.

 

[Shockwave]

Your right, a subwoofer doesnt play the higher order harmonics. Its acts like its own crossover. but that doesnt prevent the subwoofer from recieving them. So, those higher harmonics arent played, but rather dissipitaed in the form of heat. And that kills speakers, heat or too much power. The Fourier Analysis is simply to show that higher order harmonics exist in the clipped signal, which while not played, ARE still there and become visible in other ways...ie...heat and more power.

Your amp is 150 watts. Your speakers 300.
150x2 (clipped) = 300. Your fine. Hook that amp up to speakers rated at 150 watts and run the piss out of the amp, till its screamin stop. See how long your speakers last.

 

[jteef]

Originally posted by: thomsbrain
i play guitar with a "100" watt tube amp that probably peaks somewhere in the neighborhood of 150 watts, while my speaker cabinet can handle around 300 watts. if these were subs, the amp would be considered "underpowered." i dime the volume control into maximum power amp distortion and clipping every single friggin day. tube amp distortion is desirable in the guitar world, and it doesn't hurt speakers in the least. if "clipping" sounds hurt speakers, every single person who plays rock music on their stereo would have blown speakers just from listening to distorted guitars and basses (speakers don't know the difference between a signal distorted in the source and a signal distorted through the amp). in fact, "clipping," which is just distortion, is what happens when an amp has reached it's maximum output and has NO more headroom. When an amp clips, it's reached the end of the line. It won't go any louder, and if your speakers still have headroom, you're cool. Of course, in the subwoofer world, distortion is going to sound like crap, unlike the guitar world. But the speakers won't be damaged by it. They'll simply reproduce a dirty signal, exactly the same as if you were playing a loud recording which contained a purposely distorted signal.

summary: any stereo system amp cranked to the max will sound like microwaved crap, but as long as your speakers have a greater power handling capacity than the amp, you won't damage anything.

Your stuff was specifically designed to work under these conditions. If you have, say, an amp that is advertised at 225 average watts into 4 ohms. That is 30Vrms and 7.5Arms. or 42.4V peak and 10.5A peak. Under fully clipped conditions, the amp will be trying to supply the full 42.4V and 10.5A continuously or 450 watts. This can only happen if the power supply or amp protection circuitry is capable of delivering the extra current. If the amp is a traditional design and stable into 2 ohms, its quite possible that it can. The extra 225 watts over an extended period could easily cause failure.

 

[thomsbrain]

Originally posted by: jteef

Originally posted by: thomsbrain
i play guitar with a "100" watt tube amp that probably peaks somewhere in the neighborhood of 150 watts, while my speaker cabinet can handle around 300 watts. if these were subs, the amp would be considered "underpowered." i dime the volume control into maximum power amp distortion and clipping every single friggin day. tube amp distortion is desirable in the guitar world, and it doesn't hurt speakers in the least. if "clipping" sounds hurt speakers, every single person who plays rock music on their stereo would have blown speakers just from listening to distorted guitars and basses (speakers don't know the difference between a signal distorted in the source and a signal distorted through the amp). in fact, "clipping," which is just distortion, is what happens when an amp has reached it's maximum output and has NO more headroom. When an amp clips, it's reached the end of the line. It won't go any louder, and if your speakers still have headroom, you're cool. Of course, in the subwoofer world, distortion is going to sound like crap, unlike the guitar world. But the speakers won't be damaged by it. They'll simply reproduce a dirty signal, exactly the same as if you were playing a loud recording which contained a purposely distorted signal.

summary: any stereo system amp cranked to the max will sound like microwaved crap, but as long as your speakers have a greater power handling capacity than the amp, you won't damage anything.

Your stuff was specifically designed to work under these conditions. If you have, say, an amp that is advertised at 225 average watts into 4 ohms. That is 30Vrms and 7.5Arms. or 42.4V peak and 10.5A peak. Under fully clipped conditions, the amp will be trying to supply the full 42.4V and 10.5A continuously or 450 watts. This can only happen if the power supply or amp protection circuitry is capable of delivering the extra current. If the amp is a traditional design and stable into 2 ohms, its quite possible that it can. The extra 225 watts over an extended period could easily cause failure.

if you looked a guitar speaker, you would laugh at how poorly they are constructed. They have paper cones and magnets that would make even a cheap subs' magnet look like godzilla on steroids. they are hardly specialized for the task of handling massive power loads. in fact, some people go out of their way to get speakers that do an especially poor job of it, because they like the sound of a distorting speaker in addition to the clipping amp.

you just answered yourself in your statement. the whole point is a clipping amp CAN'T produce 450 watts for any extended period of time, or it wouldn't be clipping in the first place. on average, the amp still can't produce any more than it's rated power. the 450 can only happen for a quick burst, and speakers can handle those peaks along with the average power. that's why you see them with two ratings: RMS and peak. clipping doesn't magically suck power from an alternate dimension and make the amp magically able to double it's output for "extended periods of time." clipping is a symptom of an amp being unable to produce any more power for an extended period of time. it's what happens when the amp is trying to make "peak" power for more than the "peak" timeframe. the amp does its peak, then settles back down to it's rated power and just distorts instead of being louder.

 

[chiwawa626]

(not trying to side track this intresting debate but...) Can someone please recomend some economical amps that are cheap yet good quality?

 

[thomsbrain]

Originally posted by: Shockwave


Your amp is 150 watts. Your speakers 300.
150x2 (clipped) = 300. Your fine. Hook that amp up to speakers rated at 150 watts and run the piss out of the amp, till its screamin stop. See how long your speakers last.

One of the most popular guitar setups runs an massively clipping amp that makes 100 watts average into a speaker cabinet that can handle 100 watts average. there are cabinets in use today that have been doing that since the 1960's, when they were built. the ones that didn't survive were the ones that got guitars shoved through the cones or were dropped and broken. the amps most certainly peak above 100 watts, but the speakers have their own peak capacities to handle it. running an "underpowered" amp into the cabinet would simply make it even easier for the speakers to handle the power, not harder. the point is, as long as your speakers can handle both the peaks and average power, you're cool. if the amp makes less than that, then you're even more cool.

it looks like from you people's posts, we can expect an amp to make peaks that are around double the amp's average output. so a 200 watt amp pushed to the max will be making peaks around 400 watts. Tell me how a sub cabinet that can handle 700 watts continuously will be damaged by the occasional burst of 400 watts.

 

[Shockwave]

thosbrain, it wont be. Thats why clipping si funny. An amp rated slightly under what a sub can handle CAN blow the sub if you clip it. An amp grossly underrated can NOT blow it. The thing is, in car audio people dont put 50 watt amps on 1000 watt subs. They might put a 6 or 700 watt amp on that 1000 watt sub, clip it, and then the extra heat and power destroy the sub.
The guitar world and the mobile audio world are two different beasts entirely anyways in terms of how equipment is designed etc. Granted, its the same on the basic levels. We have speakers and amps, but how they are used are very different.

 

[jteef]

Originally posted by: thomsbrain

Originally posted by: jteef

Originally posted by: thomsbrain
i play guitar with a "100" watt tube amp that probably peaks somewhere in the neighborhood of 150 watts, while my speaker cabinet can handle around 300 watts. if these were subs, the amp would be considered "underpowered." i dime the volume control into maximum power amp distortion and clipping every single friggin day. tube amp distortion is desirable in the guitar world, and it doesn't hurt speakers in the least. if "clipping" sounds hurt speakers, every single person who plays rock music on their stereo would have blown speakers just from listening to distorted guitars and basses (speakers don't know the difference between a signal distorted in the source and a signal distorted through the amp). in fact, "clipping," which is just distortion, is what happens when an amp has reached it's maximum output and has NO more headroom. When an amp clips, it's reached the end of the line. It won't go any louder, and if your speakers still have headroom, you're cool. Of course, in the subwoofer world, distortion is going to sound like crap, unlike the guitar world. But the speakers won't be damaged by it. They'll simply reproduce a dirty signal, exactly the same as if you were playing a loud recording which contained a purposely distorted signal.

summary: any stereo system amp cranked to the max will sound like microwaved crap, but as long as your speakers have a greater power handling capacity than the amp, you won't damage anything.

Your stuff was specifically designed to work under these conditions. If you have, say, an amp that is advertised at 225 average watts into 4 ohms. That is 30Vrms and 7.5Arms. or 42.4V peak and 10.5A peak. Under fully clipped conditions, the amp will be trying to supply the full 42.4V and 10.5A continuously or 450 watts. This can only happen if the power supply or amp protection circuitry is capable of delivering the extra current. If the amp is a traditional design and stable into 2 ohms, its quite possible that it can. The extra 225 watts over an extended period could easily cause failure.

if you looked a guitar speaker, you would laugh at how poorly they are constructed. They have paper cones and magnets that would make even a cheap subs' magnet look like godzilla on steroids. they are hardly specialized for the task of handling massive power loads. in fact, some people go out of their way to get speakers that do an especially poor job of it, because they like the sound of a distorting speaker in addition to the clipping amp.

you just answered yourself in your statement. the whole point is a clipping amp CAN'T produce 450 watts for any extended period of time, or it wouldn't be clipping in the first place. on average, the amp still can't produce any more than it's rated power. the 450 can only happen for a quick burst, and speakers can handle those peaks along with the average power. that's why you see them with two ratings: RMS and peak. clipping doesn't magically suck power from an alternate dimension and make the amp magically able to double it's output for "extended periods of time." clipping is a symptom of an amp being unable to produce any more power for an extended period of time. it's what happens when the amp is trying to make "peak" power for more than the "peak" timeframe. the amp does its peak, then settles back down to it's rated power and just distorts instead of being louder.

the paper cones and magnets don't have anything to do with the speakers power handling capabilities. most guitar amps don't make enough power to kill any largish speaker, additionally a lot of them are open in the back further facilitating the cooling. And I dont know where you get that a clipping amp can't produce 450 watts for any extended time, that is just simply wrong. The rest of your post is filled with half truths and assumptions. clipping is an example of an amp being unable to produce any more voltage, not specifically power. There is also no such thing as "peak timeframe" The power supply in the amp does store energy for "bursts" in the form of capacitors. But, as in my example, if the amp was capable of working into a 2 ohm load, then the power supply is going to be sufficiently large that it wont prevent the flow of extra power to the output.

 

[Shockwave]

On a side note, its nice to see a lively debate without too much name calling / flaming.

However, I still hold that an clipped amp can kill a speaker even if the amp is rated at less power then the speaker.

 

[thomsbrain]

yet more thoughts.

...a clipping amp *could* be dangerous if it was capable of producing continous power that met or exceeded the speakers. for instance, you might have a 700 watt amp that peaks at 1,400 watts, but suppose your 700 watt speakers are only actually reliable for peaks around 1,000 watts. then, if you cranked your amp to the max, you could feed the speakers too much juice and fry them.

but if you hook up an "underpowered" amp that only makes 400 watts average/ 800 watts peak, then even if you turned it up full blast, its peaks would still be within the capabilites of the speakers. no harm done, but it wouldn't sound too great.

now, i'm not advocating we all go out and run 10 watt amps, because it would sound like crap. but my point is we COULD, and it wouldn't hurt anything. but if you run a 10,000 watt amp it will damage something. too little power = bad, but not damaging. too much power = bad and damaging.

the other reason why you might not want way too little power is those big subs have a lot of mass and air to move around, so they might not be very efficient, and they might be tuned to only be accurate when they're being pushed hard. so, you might need a fair amount of juice to get one sounding as it was meant to sound. but again, you won't be hurting anything.

 

[Shockwave]

Therein is the key...

"now, i'm not advocating we all go out and run 10 watt amps, because it would sound like crap. but my point is we COULD, and it wouldn't hurt anything. but if you run a 10,000 watt amp it will damage something. too little power = bad, but not damaging. too much power = bad and damaging."

Too much power = bad. Clippin and distortion by itself doesnt hurt speakers. A speaker wont know if your feeding it a clean signal or a clipped signal. it WILL see the extra power in the clipped signal however. Its the extra power that kills the speaker. And I agree with you, if your amp is sufficently underpowered, it wont blow the speaker no matter how bad it clips. But, as I said, most people in mobile audio dont run 100 watt amps on 1000 watt subs. You usually try to get as much power as you can afford. So, its not uncommon to see amps that produce *almost* enough power to meet the speakers powerhandling. Then, people get wild on the gains and boosts and next thing you know the amp is clipping and producing far more power then the speaker can handle.
So technically no, clipping doesnt blow speakers. And I havent tried to imply that or say that. My case is that the extra power found in a clipped signal *can* be enough to blow the speaker *if* the amp's RMS power rating is close to the speakers (Or more then half, depending how long we run a clipped signal)

 

[thomsbrain]

Originally posted by: jteef

Originally posted by: thomsbrain

Originally posted by: jteef

Originally posted by: thomsbrain
i play guitar with a "100" watt tube amp that probably peaks somewhere in the neighborhood of 150 watts, while my speaker cabinet can handle around 300 watts. if these were subs, the amp would be considered "underpowered." i dime the volume control into maximum power amp distortion and clipping every single friggin day. tube amp distortion is desirable in the guitar world, and it doesn't hurt speakers in the least. if "clipping" sounds hurt speakers, every single person who plays rock music on their stereo would have blown speakers just from listening to distorted guitars and basses (speakers don't know the difference between a signal distorted in the source and a signal distorted through the amp). in fact, "clipping," which is just distortion, is what happens when an amp has reached it's maximum output and has NO more headroom. When an amp clips, it's reached the end of the line. It won't go any louder, and if your speakers still have headroom, you're cool. Of course, in the subwoofer world, distortion is going to sound like crap, unlike the guitar world. But the speakers won't be damaged by it. They'll simply reproduce a dirty signal, exactly the same as if you were playing a loud recording which contained a purposely distorted signal.

summary: any stereo system amp cranked to the max will sound like microwaved crap, but as long as your speakers have a greater power handling capacity than the amp, you won't damage anything.

Your stuff was specifically designed to work under these conditions. If you have, say, an amp that is advertised at 225 average watts into 4 ohms. That is 30Vrms and 7.5Arms. or 42.4V peak and 10.5A peak. Under fully clipped conditions, the amp will be trying to supply the full 42.4V and 10.5A continuously or 450 watts. This can only happen if the power supply or amp protection circuitry is capable of delivering the extra current. If the amp is a traditional design and stable into 2 ohms, its quite possible that it can. The extra 225 watts over an extended period could easily cause failure.

if you looked a guitar speaker, you would laugh at how poorly they are constructed. They have paper cones and magnets that would make even a cheap subs' magnet look like godzilla on steroids. they are hardly specialized for the task of handling massive power loads. in fact, some people go out of their way to get speakers that do an especially poor job of it, because they like the sound of a distorting speaker in addition to the clipping amp.

you just answered yourself in your statement. the whole point is a clipping amp CAN'T produce 450 watts for any extended period of time, or it wouldn't be clipping in the first place. on average, the amp still can't produce any more than it's rated power. the 450 can only happen for a quick burst, and speakers can handle those peaks along with the average power. that's why you see them with two ratings: RMS and peak. clipping doesn't magically suck power from an alternate dimension and make the amp magically able to double it's output for "extended periods of time." clipping is a symptom of an amp being unable to produce any more power for an extended period of time. it's what happens when the amp is trying to make "peak" power for more than the "peak" timeframe. the amp does its peak, then settles back down to it's rated power and just distorts instead of being louder.

the paper cones and magnets don't have anything to do with the speakers power handling capabilities. most guitar amps don't make enough power to kill any largish speaker, additionally a lot of them are open in the back further facilitating the cooling. And I dont know where you get that a clipping amp can't produce 450 watts for any extended time, that is just simply wrong. The rest of your post is filled with half truths and assumptions. clipping is an example of an amp being unable to produce any more voltage, not specifically power. There is also no such thing as "peak timeframe" The power supply in the amp does store energy for "bursts" in the form of capacitors. But, as in my example, if the amp was capable of working into a 2 ohm load, then the power supply is going to be sufficiently large that it wont prevent the flow of extra power to the output.

actually, in my 100 watts into 100 watts example, the cabinets are closed. the speakers have no way to cool themselves, but they hold up just fine despite being originally designed for the crummy stereo speakers of the 50's and 60's. you gotta realize, people like these speakers because they are so crappy. if anything, they do a far worse job at handling lots of power than a modern subwoofer, which is highly specialized, has a giant magnet to dissapate heat, and has benefited from decades of research.

if the amp could produce 450 watts for an extended period of time, it would be rated as being able to produce 450 watts, not 225. why do you think they make the distinction between peak and average? the "peak timeframe" (admittedly a made-up term because i don't know the real one) would be the time it takes for the capicitors to discharge. those capacitors are there to help extend the clean headroom of the amp. once you start exhausting those caps, you're going to get distortion, and the peaks of the amp are going to drop. assuming an amp and speaker are equally rated, while the caps were discharging, the speaker was unable to produce more volume, and transfered it to heat, but pretty soon the caps are empty and the speaker is free to cool down. if the speaker can't cool down fast enough between those bursts, it frys, obviously. but that has nothing to do with the fact that the amp was distorting between those clean peaks. in fact, it was the clean headroom that killed the speaker. if the amp was less powerful, the speaker would have lived.

if you take any amp and use it to exceed the capabilities of the speaker, you'll fry it. we all agree on that. and, i think we can all agree that the peaks of an amp that on paper looks like it would be ok could still exceed the peak capacity of a speaker and fry it. so from a psychological standpoint, a person who doesn't know what he's doing might be more likely to fry his speaker with an amp he THINKS is underpowered because he thinks he can turn his amp up all the way and still be fine. but my point is obviously the amp ISN'T underpowered if it can fry a speaker. it wasn't the distortion that killed his speaker, it was that his amp was too powerful, even if on paper it appeared not to be. the peaks that killed his speakers would have been there regardless of whether or not the amp was clipping, because the amp only wanted to peak because the music peaked. with an "equally" powered amp, those peaks would have been even stronger. the distortion didn't make the amp louder, it was just too loud to begin with. if anything, the distortion protected the speaker by reducing the peaks. distortion has the effect of compressing the dynamic range of a signal (compression means it reduces the peaks, even when the term is applied in the recording industry), not expanding it.

 

[thomsbrain]

i think we're arguing the same point but from different angles... more coming up in an edit of this post.

edit:
ok, so we're all cool on distortion not inherently damaging speakers. we're all cool on it being the power of the amp that damages the speaker.

so here's my angle. i don't want you guys to be confused and think that because an amp is clipping, it is making more power than a more powerful amp that is not clipping. example: if you have a 700 watt amp cranked to the max, it will NOT be driving the speakers harder than a 1400 watt amp turned up half way. in fact, because the clipping is a symptom of depleted caps, its musical peaks will be less intense than the 1400 amp that still has tons of clean headroom. if someone was forcing me to run one of these setups through a 700 watt speaker setup, i'd choose the clipping 700 watt amp in a heartbeat.

obviously, both are no good. but the point is, buying a more powerful amp is only wasting money to increase the risk of accidentally blowing your speakers because you turned it up too much. no matter whether or not you clip the amp, a less powerful amp poses less risk to your speakers then a clean amp pushing the same average power. basically, the speakers are going to blow at the same final heat/volume regardless of what kind of amp you drive them with, and an underpowered amp is less likely to be able to deliver that volume, and clipping has nothing to do with it. it wasn't that the amp was rated below capacity, it was that the listener turned it up too damn loud. if anything, it means the amp's rating was conservative.

next post, where things get really interesting, and where you guys' own points become valid.

 

[Shockwave]

Well, we agree on distortion in and of itself not blowing speakers.
However, I would agrue that either or 700 watt or 1400 watt amp has the *potential* to blow the speakers just as easily. But, the 700 watter would be more likely IF we factor in user error. The guy with the 700 watt amp would turn his gains up more to compensate for less power, cause the amp to clip, thus our sub sees more power and pow. Speaker blows cause amp clipped producing as much power as our 1400 watter.

 

[jteef]

The amp may very well be "rated" at 450 watts for other loads, but it is only advertised at 225 into 4 ohms. And thats what you'd expect to get when you connect a 4 ohm load. Also, I'm well aware of the design considerations involved with pro audio and guitar amps. the point remains that 100 - 200 watts is not a lot of power for any old 10-15" speaker to dissipate, and the guy who designed it knew that. A quick look at musiciansfriend shows that there are very few amps/cabinets that exceed 100watts per speaker. The duty cycle of somebody playing guitar is probably a lot less than what you'd get from a heavily clipped rap beat, too.

Anyways, the main point of the exercise is that you can buy an amp that is advertised as producing less power than your particular speaker may dissipate, and still blow it with careless volume control, and that this can be fairly common. no, you aren't going to blow an infinity perfect with a 100 watt amp, but if you've got a 300 watt amp and are careless with your volume control for extended periods of time, then yes it could easily malfunction.

 

[thomsbrain]

sorry, this one's really long (again), but i think it clears things up for both sides of our little debate.

ok, i got to thinking about "gain" and how that could play a role in blowing your speaker. here's the deal. increasing the gain on an amp increases the volume of the entire dynamic range until the amp starts to clip, at which point the peaks begin to be cut off. if you keep cranking the gain, your peaks do not change volume, but the lowest part of the dynamic range becomes louder, while the middle part starts to become the "peaks" in addition to the original peaks. Think of the signal going into the gain stage as a piece of paper hitting the ceiling of your room. as you push it harder and harder into the ceiling, it starts to smash up, and more and more of the paper it at the highest level. the more paper is at the highest level, the more distortion.

ok, so that's our conceptual model of how gain stages work. you can apply that to power amps for both home and cars, and also for the pre and power amps in guitar amps (doing that in the preamp is how we get guitar distortion at lower levels these days).

the following is an example where a clipping amp will blow our speaker, but it is not an example that shows that clipping was the CAUSE of the blown speaker.

now, assume we are already at the very brink of overheating our subwoofer. we're really rocking out, and we've got the gain cranked way up. our amp is distorting like a mother, but we don't care cause we're totally ghetto. as we crank the gain up, more and more of the signal is being sent to the speakers as maximum output (not as peak, but as maximum continuous). when the gain gets really high, nearly ALL of the signal is sent as maximum output, which means the speakers are being subjected to the amp's maximum continuous capacity nearly all the time. if the speakers were overrated in capacity (i think we could assume this given the industry), then by feeding them this constant signal that exceeds their capacity, they will overheat and poop out. by having the gain really high, we ensured that the amp sent a really loud signal all the time, instead of the usual crests and falls in level. so if the speaker was overrated a little, or wasn't cooled properly, then a clipping amp could result in speaker failure, not because of the peaks (there weren't any, the caps were drained) or because or the type of signal or the harmonics, but because it was sending it too loud of a signal for too long. it is in this fashion that an amp that slightly exceeds the *real-world* capacity of a speaker would blow it. the point here is if the clipping amp killed the speaker, then the speaker wasn't rated accurately. that doesn't change the fact that Joe Blow hooked his 700 watt amp up to his 1000 watt speaker, dimed the gain, and it blew. It just means Joe Blow's "1000 watt" sub was actually only good for less than 700 watts continuously, or that the amp company was very conservative in their power ratings for the amp (less likely, why in the world would they want to do that?).

it's worth pointing out that if the amp hadn't clipped, it would have been even worse. by allowing "the top of our paper to go above the ceiling," we would have simply ensured even quicker failure of the speaker (remember that although we now would be feeding it a wider dynamic range, that range would be going to the same lows, but much higher highs, producing way more heat). clipping actually prolonged the life of our speaker. so if you hear your amp clipping, that's definetely a warning that you're feeding a crapload of power to the speaker and you should back off. the fact that your "underpowered" amp clipped is what just saved you from buying a new speaker.

now for the reason someone might think that because their amp clipped, it got louder, and thus would complain to the world that their clipping amp was the CAUSE of their blown speaker: as we noted above, distortion has the effect, in addition to adding harmonics to a signal, of compressing the signal. compression is a mental trick that makes you think things are louder when they really aren't. by putting a limit on the highest of the dynamic range, you are free to increase the level of the lows without actually making the signal any louder. people do this in the recording industry all the time. most pop records are majorly compressed (you can do this without distorting). that way the album can seem really loud while not exceeding the limits of the CD. radio stations compress their signals even further, so that you can hear the quiet parts of the music better when you're driving. the music seems louder, but the peaks stay the same. as noted above, in a subwoofer situation, as the amp begins to clip, the music will seem to get louder while the peaks stay the same. Joe Blow thinks that the clipping made his amp louder when really he was just hearing the compression effect that distortion has. if his amp hadn't clipped, it would also have seemed louder, but it would have also seemed punchier in addition to just being loud, and it would have blown his speakers before he even knew anything was wrong. but Joe's amp clipped, and eventually his speakers still blew, so without any real knowledge about the cause of this effect, he blamed it on the clipping and not on the fact that he was misinformed about the capacities of the speaker and was simply turning it up too loud.

 

[thomsbrain]

yet another post.

let's compare two amps. one is 1400 watts and one is only 700 watts. if we turn the gain on our 700 watt amp up to right below the cusp of distortion, then turn the 1400 watt amp to match it in terms of the bottom of the dynamic range, you will be feeding the exact same signal to the speakers. more gain doesn't compress until you actually start distorting, you see. we'll assume any volume changes up to this point were made at a rate so that the volumes always matched. if you continue to turn the amps up at the same rates as before, both amps will continue to send greater average signals, but the 1400 watt amp's average will start to become higher than the 700 watt's average. as you turn them higher and higher, this effect will become more pronounced. the 700 watt's volume will trail off as it starts to distort, while the 1400 will keep going louder and louder. when you reach the end of the line for the 700 watt amp, the 1400 watt amp will be making way more average power, even though you were turning the knobs at the same rate as before, when the volumes used to match. if you've got speakers that can handle 700 watts in the real world, the 1400 watter will have blown them already, and the 700 watt amp would be pretty risky.


if you added a 500 watt amp into this mix, it would be able to play at maximum gain all day long into those speakers. wouldn't sound too hot, but you wouldn't endanger anything. underpowered amps are perfectly safe, but only if you have accurate information about the real capabilites of the speakers, and the real continuous output of the amp. otherwise it's not really underpowered, you just thought it was because the speaker company lied about the speaker.

the key here is more gain doesn't change anything until you reach the end of the line on your underpowered amp. at that point, you're already louder with your powered amp, so the relative level of gain between amps has no signifigant importance in the risk of blowing a speaker. compared to a powerful amp, your underpowered amp isn't more risky simply because you are using more gain, it's exactly the same, and it become LESS risky as the amp starts to clip.

 

[Shockwave]

Dude. Cliff notes. please.

Anyways, the gain knob may very well do two different (although related) things betwene a guitar amp and a car amp. I have no idea how that guitar stuff really works, and I'm not comfortable trying to go out on a limb. But in the mobile audio world, turning your gains up to where the amp clips will cause the amp to produce up to twice the rated RMS power of the amp. Thus, our 700 watt amp *could* be called a 1400 watt at full clipping. Thats why even subs that are rated accurately can be blown by an amp with less RMS that clips. Assume our 1000 watt speaker is a good name speaker and can handle that 1000 watts, we get a 700 watt RMS amp, clip it hard, and suddenly our 1000 watt sub is seeing 1400 watts of heat and power to deal with. Its just more then it can handle. Buyt, a 200 watt amp fully clipped giving 400 watts...Our 1000 watt speaker doesnt care. It doesnt see clipping and distorion, it sees power and heat. And 400 watts isnt enough to mechanically or thermally hurt a 1000 watt speaker. 1400 is another matter.

Either way, you can run ANY amp to ANY speaker in the world, provided you know how to adjust the settings to match and can tell when something in the chain is starting to complain and having problems so you can take actions to prevent damage...ie...turn it down. But, thats never any fun is it

 

[thomsbrain]

I just don't see how the amp is magically going to suddenly double it's output when it starts to distort. That certainly doesn't happen with any amp I've ever seen, including home audio amps, pro audio amps, solid state guitar amps, and tube amps. Don't forget that the entire reason the amp is clipping is because it can't make any more power. If the amp could magically produce double the output, it wouldn't be clipping in the first place. You're confusing the maximum peaks of an amp (which would likely only be attained when the amp is cranked way up near clipping) with clipping itself. Yeah, an amp that's cranked may be peaking at it's maximum peak of double the normal output. But it can't sustain those peaks, and that's why it starts clipping. The clipping is your audio cue that the amp is NOT producing those maximum peaks properly anymore. A clipping sound is proof that the amp is not producing 1400 watt peaks. A heavily clipped 700 watt amp is producing an average of 700 watts, no more. If it gets a little break to charge the caps, then it might be able to hit you with another 1400 watt peak, but pretty soon you'll be right back down to the 700 watts the amp can actually produce on a constant basis.

As for gain stages, they work exactly the same with any type of amplifer. Guitar amps often have more sensitive gain stages so that you reach clipping really fast, but the basic principle is the same. In fact, a solid state guitar amp literally uses the same parts as any other audio amp. You're just changing the sensitivity of the amp. As it gets more sensitive, it gets louder, until you start to clip, at which point you DO NOT PRODUCE MORE POWER, you simply get a more saturated distortion. Most people who don't deal with distortion on purpose don't realize this because they avoid distortion and the equipment they use is designed to avoid it, too. But I deal with it every day on both solid state and tube equipment. As you turn up the gain on an amp, you reach the point of clipping. Beyond that, the amp doesn't get any louder. On any amp I use, there is no difference in volume between around 3 or 4 to 10. The sound gets more distorted, but it doesn't get louder.