Too much amp for the speakers?

[jnboone]

Is there a problem if an amp is rated to deliver more power than a speaker is rated to carry? If I'm using speakers (8 ohm speaker rated for 75-200 watts), and they are paired with an amp rated at 300W all channels driven at 8 ohms, Can I turn it up too loud???

 

[markw]

Not if you use your head and turn it down immediately if they start sounding bad. Also, keep drunken and/or stupid friends away from the controls.

 

[MidnightSensi2]

Is there a problem if an amp is rated to deliver more power than a speaker is rated to carry? If I'm using speakers (8 ohm speaker rated for 75-200 watts), and they are paired with an amp rated at 300W all channels driven at 8 ohms, Can I turn it up too loud???

Actually underpowering is generally more dangerous (amp clips, makes a square wave, speakers hate that), but like mark said, you need to watch out for the limits of the speakers.

As you turn it up, once they start to sound strained, you'll want to back off from there. Optionally you can set a limiter (generally receivers have this feature) to prevent an accident.

 

[AcuDefTechGuy]

Like others have said, as long as you don't go crazy on the volume, there is no danger whether your amp is "over" or "under" powered.

But if someone were to accidentally or just went crazy on the volume, yes, it would probably damage your speakers.

I don't think under-power is more dangerous. I think over-power is just as dangerous as under-power if the actual average power to the speaker exceeds the physical and thermal limit over a certain period of time.

The speaker engineer who recommends the power rating believes that range to be the safest for most cases.

So if you were to use an amp of 200WPC, you would be just fine.

If you use a 300WPC amp, you will most likely be just fine too.

Personally, I would feel better taking the engineer's recommendation and go with a 200WPC amp if I wanted an amp. The Denon 4520 (also within the recommended range of power) certainly has enough power for most cases.

 

[j_garcia]

The answer is no, there is no such thing as too much horsepower in a car, too much subwoofer, too much amplifier, and there is no crying in baseball.. Use it wisely and it will be fine.

 

[slipperybidness]

I don't think under-power is more dangerous. I think over-power is just as dangerous as under-power if the actual average power to the speaker exceeds the physical and thermal limit over a certain period of time.

That is indeed the key to the problem.

 

[AcuDefTechGuy]

That is indeed the key to the problem.

The clipping isn't what's damaging the speakers per se.

It is the actual power that damages the speakers, not the clipping.

So if all 300W UNCLIPPED power is going to the speakers and it is exceeding the thermal and physical limit of the speaker, then the speaker will be damaged 100% of the time.

The problem may be knowing the REAL thermal and physical limits. If the speaker is rated for 200W, that may be the limit for the woofers. But the tweeter may be 10W.

But as all of us have said, if the listening volume is sensible and not deafening, there should not be an issue.

 

[flyboylr45]

The clipping isn't what's damaging the speakers per se.

It is the actual power that damages the speakers, not the clipping.

So if all 300W UNCLIPPED power is going to the speakers and it is exceeding the thermal and physical limit of the speaker, then the speaker will be damaged 100% of the time.

The problem may be knowing the REAL thermal and physical limits. If the speaker is rated for 200W, that may be the limit for the woofers. But the tweeter may be 10W.

But as all of us have said, if the listening volume is sensible and not deafening, there should not be an issue.

Interesting. I always wondered what the limits of the tweeter , the midrange and the woofers are in the 802s. You think I need to be careful? I asked B&W and they just gave a minimum watt recommendation. ;-)

 

[markw]

Not so much careful as much as using common sense. Like we said, if it starts to sound funky, turn it down immediately.

But, by that point it will most likely be too loud for comfort for most people.

 

[AcuDefTechGuy]

Interesting. I always wondered what the limits of the tweeter , the midrange and the woofers are in the 802s. You think I need to be careful? I asked B&W and they just gave a minimum watt recommendation. ;-)

Diamond tweeters are extra fragile and extra expensive. I would be extra gentle and extra careful. Treat those diamonds like delicate babies.

Definitely don't try to push them with extreme volume.

 

[Irvrobinson]

The clipping isn't what's damaging the speakers per se.

It is the actual power that damages the speakers, not the clipping.

So if all 300W UNCLIPPED power is going to the speakers and it is exceeding the thermal and physical limit of the speaker, then the speaker will be damaged 100% of the time.

The problem may be knowing the REAL thermal and physical limits. If the speaker is rated for 200W, that may be the limit for the woofers. But the tweeter may be 10W.

But as all of us have said, if the listening volume is sensible and not deafening, there should not be an issue.

And that seems like the basis for why Crown makes such a big deal on their web site and in their owners manuals out of amplifier clipping as a threat to speakers. Yes, it's always power that over-drives speakers, but spectrum matters.

 

[AcuDefTechGuy]

And that seems like the basis for why Crown makes such a big deal on their web site and in their owners manuals out of amplifier clipping as a threat to speakers. Yes, it's always power that over-drives speakers, but spectrum matters.

I think Crown and all amp companies want consumers to buy the biggest and most expensive amps they offer so they can make more money.

I was thinking that if all or most speakers were active/internally powered, all the amp companies would bankrupt.

 

[slipperybidness]

I think Crown and all amp companies want consumers to buy the biggest and most expensive amps they offer so they can make more money.

I was thinking that if all or most speakers were active/internally powered, all the amp companies would bankrupt.

There are also limiters and soft-clipping circuits that can get around this type of problem.

Of course, make a big deal about it so you can market your amps that have built in limiters and soft-clipping.

 

[AcuDefTechGuy]

There are also limiters and soft-clipping circuits that can get around this type of problem.

Of course, make a big deal about it so you can market your amps that have built in limiters and soft-clipping.

Well, but the clipping isn't the real problem. The limiters can prevent the clipping.

But even if the amp has limiters, it won't prevent a 1,000W amp from sending 1,000 Watts of UNCLIPPED power to the speaker, right?

Only we have the ability to control how much power goes to the speaker by turning down the volume.

I think amp companies just love the perpetual myth that clipping blows drivers when in reality, too much power blows drivers due to excessive volume.

 

[slipperybidness]

Well, but the clipping isn't the real problem. The limiters can prevent the clipping.

But even if the amp has limiters, it won't prevent a 1,000W amp from sending 1,000 Watts of UNCLIPPED power to the speaker, right?

Only we have the ability to control how much power goes to the speaker by turning down the volume.

I think amp companies just love the perpetual myth that clipping blows drivers when in reality, too much power blows drivers due to excessive volume.

Clipping is absolutely still part of the problem! You are correct about the average power, buuut........

The average power of a clipped signal will be more than the average power delivered by the same unclipped signal.

graphic of a sine wave:
Measuring the Sine Wave

graphic of sine and square wave
Redirect Notice

So, the Root Cause is too much average power, but the Failure Mode can be a clipped signal (allowing for too much avg power).

 

[AcuDefTechGuy]

Clipping is absolutely still part of the problem! You are correct about the average power, buuut........

The average power of a clipped signal will be more than the average power delivered by the same unclipped signal.

graphic of a sine wave:
Measuring the Sine Wave

graphic of sine and square wave
Redirect Notice

So, the Root Cause is too much average power, but the Failure Mode can be a clipped signal (allowing for too much avg power).

It's definitely multi-factorial. The clipped power (double the rated power) could damage the speaker just as much as too much unclipped power could damage the speaker.

Let's say the limit of the woofer is 200W.

If we use a 50W amp and it clips, 100W of power would reach the woofer. Because this power is way below the limit, it doesn't matter if the signal is clipped. As long as it is below the limit, the woofer will not be damaged even if the signal is clipped.

If we use a 300W amp and the volume is crazy, 300 watts of unclipped power would reach the woofer. Because it exceeds the limit, the woofer would be damaged even if the signal was never clipped.

Now if we use a 150W amp and it clipped, 300 watts of clipped power would reach the woofer and damage the woofer too.

So the limiters can help prevent the clipping, which does help. But it does not prevent excessive unclipped power from reaching the speaker.

IOW, even if the amp has limiters, you could still damage the speakers if you use crazy volume and a powerful amp.

Bottom line, as all of us have said, don't go crazy on the amp or the volume. Most people would consider 200-300W amps as normal. If the speaker is rated for 200W, I don't think it's wrong to use a 200W amp.

If the speaker is rated for 200W max and you use a 300W amp, it is most likely okay too even if it is not "recommended" by the speaker engineer.

If the speaker is rated for 200W, I don't think it is any safer to use a 300W amp than a 200W amp.

So I think the statement "It is safer to use a more powerful amp" is less true.

I think the statement "It is safer to use an amp that is recommended by the speaker engineer" is more true.

Naturally, it is safer to use sensible safe volume period.

 

[slipperybidness]

IOW, even if the amp has limiters, you could still damage the speakers if you use crazy volume and a powerful amp.

Absolutely. The real advantage of the limiters is when they have a light that kicks on to warn you that you are clipping. It could be considered an "idiot light". As in "turn it down you idiot".

 

[AcuDefTechGuy]

Absolutely. The real advantage of the limiters is when they have a light that kicks on to warn you that you are clipping. It could be considered an "idiot light". As in "turn it down you idiot".

LOL. True that.

When I go to live events like wedding receptions and concerts, I try to bring ear plugs just in case.

Got to have good hearing to enjoy my HT system.

 

[PENG]

Clipping is absolutely still part of the problem! You are correct about the average power, buuut........

The average power of a clipped signal will be more than the average power delivered by the same unclipped signal.

graphic of a sine wave:
Measuring the Sine Wave

graphic of sine and square wave
Redirect Notice

So, the Root Cause is too much average power, but the Failure Mode can be a clipped signal (allowing for too much avg power).

I don't disagree, but just keep in mind a few points, like 3 dB often said, can't ignore physics.

- Yes a clipped output signal high frequency harmonic contents and the resulting higher average power (easily seen from the waveforms); and would theoretically be more of a threat to the tweeter or even the mid driver, but to lesser extent.
- It shouldn't make much difference to the bass drivers.
- If an amp is only rated for 50W, just because it starts clipping, it does not mean it suddenly become a 100W amp. In other words, if it is truly rated only 50W average, then above that point, it would likely be clipping and self limiting or shutting down because it won't be able to sustain an overload condition for too long without damaging itself. So again, it would either self liming due to voltage drop, or triggering the build in limiter, or triggering the protective system that shuts itself down. I think that is probably what ADTG has been alluding to, that is, more powerful amps are more of the reason for killing speakers. Underpower (relative to the load/speaker) amps can also cause trouble to tweeters though it should represents a lesser threat especially for owners who has the minimum common sense. Regarding the point that amp manufacturers want to sell amps, that too, is common sense and I have no other comments on that one.

 

[jnboone]

I hear you on drunken and stupid, don't forget my 21,18,16 or 15 year olds even though they HOPEFULLY aren't either of the two you mentioned