What is clipping?

[Kreshna]

Maximum amplification for me


Really ?

Maximum signal amplification for me is 168 watts and maximum watt imput for my speakers is 400 watts and I enjoy crystal clear sound at any volume level without clipping or increased volume distortion. Fact is, before reading the forums on Audiokarma I didn't even know what clipping was. I figured someone was playing with under powered equipment and I think that is the case. I've been pounding those speakers into the ground since '93 when I bought my speakers and receiver new and haven't had a complaint from either one of them. Just had the receiver cleaned and put on the bench and everything checked out perfect.

Speaker wattage ratings are mostly useless and worthless. Anyone who has been around audio gear for a while knows this. I read (had subscriptions) to all those magazines (Stereo Review, Audio, High Fidelity) that used to be published. I don't remember seeing anything saying that speaker wattage should be double that of the amp or receiver published anywhere.

I concur; whether it clips or not basically depends on three things: a) your speaker's sensitivity, b) your amplifier's power, and c) how loud do you want to hear your music on your listening position. Crown power calculator gives you some idea on how much amplifier's power do you need before you clip, based on your speaker's sensitivity and the desired loudness at your listening position. I hope the OP will find it useful.

EDIT: corrected the linky.

 

[Gibsonian]

http://www.crownaudio.com/how-much-amplifier-power

http://bowersandwilkinsus.custhelp....mplifier-would-you-recommend-for-my-speakers?

http://www.cieri.net/Documenti/JBL/Technical Notes/JBL Technical Note - Vol.1, No.16.pdf

Some references here regarding amplifier power. Perusing these sources, seems they mostly recommend amplifier power to be 1X to 4X the max power rating of the speaker, unless for a distorted instrument application, i.e. electric guitar. Obviously if your SPL requirements are met easily with a lower powered amplifier, then less can work as many here demonstrate.

 

[Kreshna]

Speaker wattage should be double that of the amp or receiver.....

I read that in stereo magazines when I was a kid.

If your amp or receiver has twice the power of your speaker's power handling capacity, and you pump up the volume to the max, then your speakers will be damaged. Not damaged from clipping, of course, but from thermal and/or mechanical stress which is bigger than what the speakers could handle.

The reason speakers survive amplifier whose maximum RMS is larger than the speakers' power handling capacity is because we rarely listen with maxed out volume. I sit about three meters from my JBL 120Ti's, whose sensitivity is 89 dB / 1 watt / 1 meter. I want to listen with 90 dB loudness at my listening position, with 3 dB headroom. Based on Crown power calculator, I'd only need 23 watts of amplifier power. Whether I'm using 75 watts Sansui or 300 watts McIntosh is irrelevant as long as I get the necessary 23 watts for the 90 dB plus 3 dB headroom that I want.

 

[Djcoolray]

If your amp or receiver has twice the power of your speaker's power handling capacity, and you pump up the volume to the max, then your speakers will be damaged. Not damaged from clipping, of course, but from thermal and/or mechanical stress which is bigger than what the speakers could handle.

The reason speakers survive amplifier whose maximum RMS is larger than the speakers' power handling capacity is because we rarely listen with maxed out volume. I sit about three meters from my JBL 120Ti's, whose sensitivity is 89 dB / 1 watt / 1 meter. I want to listen with 90 dB loudness at my listening position, with 3 dB headroom. Based on Crown power calculator, I'd only need 23 watts of amplifier power. Whether I'm using 75 watts Sansui or 300 watts McIntosh is irrelevant as long as I get the necessary 23 watts for the 90 dB plus 3 dB headroom that I want.

I understand what your saying...

It's just that I think from my personal experience that speakers stay in much better condition over time when maximum speaker input wattage is twice that of the amp or receivers maximum wattage out-put. Then if your not pushing the speakers close to maximum capacity your experiencing more clarity without abnormal wear and tear on the speakers. The sensitivity of my speakers is 102db...and a 4% distortion rating.

 

[whoaru99]

As Joe said, speaker wattage ratings are mostly useless.

I agree too, for many consumer offerings.

OTOH, Paradigm seems to have some fairly meaningful specs for what I see re. my Studio 100s.

Pro/surround reinforcement speakers from the likes of JBL have pretty well-qualified specs.

 

[coonmanx]

It's just that I think from my personal experience that speakers stay in much better condition over time when maximum speaker input wattage is twice that of the amp or receivers maximum wattage out-put. Then if your not pushing the speakers close to maximum capacity your experiencing more clarity without abnormal wear and tear on the speakers. The sensitivity of my speakers is 102db...and a 4% distortion rating.

So Djcoolray has very efficient speakers. Hence the reason he doesn't need all of that power. However, throw some speakers with a sensitivity raiting of say 89 db @ 1w/m and the story would be quite different. Hence it is the total setup that matters, just like Kreshna said.

 

[Gibsonian]

CVs ?

 

[Kreshna]

I understand what your saying...

It's just that I think from my personal experience that speakers stay in much better condition over time when maximum speaker input wattage is twice that of the amp or receivers maximum wattage out-put. Then if your not pushing the speakers close to maximum capacity your experiencing more clarity without abnormal wear and tear on the speakers. The sensitivity of my speakers is 102db...and a 4% distortion rating.

How so? If you need, say, 15 watts to achieve the desired loudness at your listening position, then 15 watts is what you need. Whether you're using 100 watts amplifier or 1500 watts amplifier to achieve that is irrelevant. Clipping only happens if you need more power than your amplifier can give.

So Djcoolray has very efficient speakers. Hence the reason he doesn't need all of that power. However, throw some speakers with a sensitivity raiting of say 89 db @ 1w/m and the story would be quite different. Hence it is the total setup that matters, just like Kreshna said.

Indeed. Assuming he sits 3 meters from his loudspeakers, and he wants 90 dB loudness at his listening position, then he only needs one watt to achieve that --and it already takes 3 dB headroom into account. Even if he sits 5 meters away from the speakers, he only needs two watts. He would be fine with 5 watt amplifiers like Nelson Pass' First Watt F2. Then I don't understand why he would ever need as much as twice the power of his speaker's power handling capacity.

As far as I know, loudspeakers are unlike light bulbs. Loudspeakers power rating is not the amount of power the speakers consumes, but the maximum amount of power the speakers can take before they break from thermal and/or mechanical stress.

 

[woodj]

Yup.

 

[whoaru99]

Bear in mind when talking about listening level if you're referring to peak SPL or average SPL. If average SPL then you need to figure in the crest factor of the material, above and beyond the average level. Then, if you want extra "belt and suspenders" beyod that, it would have to added in as well.

So, for sake of discussion, you wanted 90dB average at your listen position and that takes 1 watt. Then say your music has 10dB crest factor (10dB peak to average ratio).

So, you'd need the 1 watt, plus 10dB (10x) so now we're at 11 watts.

Then, if you wanted 3dB more cushion in the amp for that belt and suspenders, you'd double the 11 watts, ending up at 22 watts.

If you were talking 90dB peak at listening position that's a way different situation and would require only the 1 watt in this relative example.

 

[Dr Tinear]

Bear in mind when talking about listening level if you're referring to peak SPL or average SPL. If average SPL then you need to figure in the crest factor of the material, above and beyond the average level. Then, if you want extra "belt and suspenders" beyod that, it would have to added in as well.

So, for sake of discussion, you wanted 90dB average at your listen position and that took 1 watt. Then say your music has 10dB crest factor (10dB peak to average ratio).

So, you'd need the 1 watt, plus 10dB (10x) so now we're at 11 watts. Then, if you wanted 3dB more cushion in the amp, you'd double the 11 watts, ending up at 22 watts.

Your calculations are a little bit off. 10 dB crest factor plus 3 dB safety margin means that a listener whose average listening level was 1 W would need 13 dBW (13 dB above 1 W). +13 dBW = 20 W, not 22.

 

[whoaru99]

I'll have to think about that a bit. Not presently convinced dBW applies directly to what I said. My thought is that dBW is relative to 1W, but that's not necessarily the total power required.

 

[sKiZo]

Worth mentioning, 1-2 watts will give you MOST of what you want to hear, but ... that doesn't take into account instantaneous peak requirements. It may only take one watt to get a cone moving, but many multitudes of that to stop it in that exact moment of time where the music achieves perfection ...

Ohhhhmmmmmmmm .... <G>

Just for shitzengiggles, read the small print on a McIntosh MC2205. Those are "only" rated to 200 watts per channel, but almost hidden top right is a little "400" which indicates it will do at least that to cover those peaks.

** Don't forget post processing - I use both expansion AND bass synthesis here, which really crank up the power requirements.

 

[Dennis Gardner]

I understand what your saying...

It's just that I think from my personal experience that speakers stay in much better condition over time when maximum speaker input wattage is twice that of the amp or receivers maximum wattage out-put. Then if your not pushing the speakers close to maximum capacity your experiencing more clarity without abnormal wear and tear on the speakers. The sensitivity of my speakers is 102db...and a 4% distortion rating.

The most important part that you are neglecting to consider is that you purchased a system larger than needed in the first place. If that system would have been undersized and you were using a 5 watt receiver with 10 watt speakers, you most likely would have reached and exceeded the limits of that system over the last 20 years at some time and distortion would have been heard and that rule would become meaningless. Whether or not it damaged the speakers, would depend on how long the amp was being over driven.

It is when the system reaches its limits that problems occur. If you take your same receiver and speakers outside and try to get 300 watts of power through your 400 watt speakers over a n extended period of time, you will hear distortion and could possibly damage your speakers or your receiver. At that point, the rule is worthless. It all has to do with whether the weakest piece of gear is pushed past its limits.

As long as the limits of gear is not exceeded, good sound should abound. A 4000 watt amp can drive 40 watt speakers all day long with no problems as long as you only need 10-15 watts of power to reach the level you want and the speakers will stay as fresh as if they had been used with a 20 watt amp that you prescribe.

 

[whoaru99]

Just for shitzengiggles, read the small print on a McIntosh MC2205. Those are "only" rated to 200 watts per channel, but almost hidden top right is a little "400" which indicates it will do at least that to cover those peaks.

Every amp that is rated by the RMS method for average power does that.

The crest factor of a sine wave is 3dB, which means the peak is twice the average.

McIntosh publishes 1.5dB, give or take depending on model, headroom for their amps. 1-2dB is a typical number for an amplifier, a few exceptions not withstanding - such as 0dB for some amps having regulated output rails to 6dB or maybe a bit more for amps having loose rails and/or short term rail boost circuits.

 

[sKiZo]

That's where those humongazoid caps come in handy ... reserve power, anyone?

... and worth mentioning, my speakers are only rated at 89db, so they tend to get real hungry, real fast. Still, 70 TUBE watts are more than enough more times than not. This is as high as the main channel tube amp ever goes.

Which BTW is right in the sweet spot for most tube equipment, as the scale is true linear ...

 

[Dr Tinear]

I'll have to think about that a bit. Not presently convinced dBW applies directly to what I said. My thought is that dBW is relative to 1W, but that's not necessarily the total power required.

It does, but only because you picked 1 W as the power level required to give your listener the level he wanted. If it had taken 5 W to get the desired level, the amp power would have been 7 dB (10*log 5) higher. Adding 10 dB for crest factor and 3 dB safety margin would put the amp power at +20 dBW, or 100 W.

I remember reading an article when the CD first came out that examined the issue of crest factor. The author took measurements on a number of recordings and found that some audiophile classical discs had crest factors as high as 17 dB. That's a 50:1 power ratio!

 

[lini]

(...) So, you'd need the 1 watt, plus 10dB (10x) so now we're at 11 watts. (...)

w99, Dr.T: There's the bug - you don't need the 1 W plus another 10 W, but just 10 W (1 W plus the missing 9 W to make it ten times as much...).

Greetings from Munich!

Manfred / lini

 

[whoaru99]

Yeah, that first watt is the one throwing me for a loop in the calculation.

 

[Djcoolray]

The most important part that you are neglecting to consider is that you purchased a system larger than needed in the first place. If that system would have been undersized and you were using a 5 watt receiver with 10 watt speakers, you most likely would have reached and exceeded the limits of that system over the last 20 years at some time and distortion would have been heard and that rule would become meaningless. Whether or not it damaged the speakers, would depend on how long the amp was being over driven.

It is when the system reaches its limits that problems occur. If you take your same receiver and speakers outside and try to get 300 watts of power through your 400 watt speakers over a n extended period of time, you will hear distortion and could possibly damage your speakers or your receiver. At that point, the rule is worthless. It all has to do with whether the weakest piece of gear is pushed past its limits.

As long as the limits of gear is not exceeded, good sound should abound. A 4000 watt amp can drive 40 watt speakers all day long with no problems as long as you only need 10-15 watts of power to reach the level you want and the speakers will stay as fresh as if they had been used with a 20 watt amp that you prescribe.

I get what you are saying....

But with speakers that have a sensitivity of 102db it takes less of a signal to produce the same sound. Then with a low distortion rating of 4% there is less inherent noise to overcome. So, I never have to push the amp past fifty percent output capacity. My system runs cool and I won't have to worry about anything besides eventual recapping.

Just because a large group of people are doing the samething, doesn't mean it's the smart thing to do. Like hooking up a pair of sixty watt speakers up to a hundred watt amp. Then, there is the theory of when speakers actually start to distort a signal that's being fed to them.

See, I've been thumping....or I should say blasting my system for over twenty years. I take my receiver in to be cleaned and put on the bench every five years and the tech says its in perfect condition. I mean, it only makes sense, if a person has to repair something after playing a system loudly for a long period of time that the system is not matched up correctly. If cranking up a system half way causes speakers to be blown over time, the person has the wrong speakers.