OK to go beyond speaker recommended max amp power?

[Norton]

I understand a little about matching amps based on speaker efficiency.  But how meaningful are published passive speaker amp power requirements?  I get it that running a speaker with an underpowered amp can result in problems, but what would the drawbacks  be in the opposite - at domestic vol. levels using an amp that is considerably more powerful than the speakers published max power requirements?  

 

 

 

[mansr]

The speaker rating tells you how much power it can accept without something bad happening. The amp rating tells you how much power it can output without exceeding some distortion level. The actual power output depends on the volume setting. As long as you don't turn it up too loud, the speakers will be fine, even if the amp is capable of frying them at a higher level.

 

If you're not hearing obvious distortion, there's nothing to worry about. That said, running an amp far below its intended level may not give the best performance.

[StreamFidelity]

My Sonus Faber Amati Futura have the following values:

 

Sensitivity: 90dB / 2.83V / m. Nominal impedance: 4 ohms. Rated input power: 30-300W without clipping.

 

They are powered by T + A M10 monos that can provide 1,500W / 2 ohms.

 

The sound is better than with previous amplifiers, although I don't hear louder. I think it's because of the improved power delivery ability: The speakers are simply better under control.

 

However, a volume limit should be activated if possible!

[PAR]

1 hour ago, STC said:

Most listeners average volume in room is usually around 80 to 85dB. At peaks it can go over 100dB.

85dB is very loud listening for "most" at home and is at the safe hearing health limit .  A live full sized symphony orchestra will have maximum peaks of around 96dB in a concert hall playing large works and an average SPL quite a lot below that .  Over 85 dB as an average listening level for a reasonable period is considered as dangerous to hearing by most health authorities. Of course some rock acts will hit exceptional SPLs which is why some performers like Pete Townsend are basically deaf.

 

Frankly I cannot imagine what listening to an average SPL of 85dB at home would be like aside from the bricks through my window from near neighbours.

 

Other than that, good post.

[PAR]

In regard to the first part of your question

2 hours ago, Norton said:

 But how meaningful are published passive speaker amp power requirements?

They are only rough guides and don't have a great deal of precise meaning. Take a typical spec " suitable for amps 10 - 100 watts". It is fairly meaningless. Suitable in what sort of way? Is 10 watts suitable for someone who only listens to solo lute recitals in a small room or is it also suitable for someone with a larger room who wants to play Led Zepplin " turned up loud"? We are not told.

 

It all depends on how you listen.  If your average listening level is, say, 65dB and the speaker draws 5 watts from the amp to /provide this level it doesn't matter if it is a 10 watt amp or a 500 watt amp, they are both providing 5 watts though the latter provides more headroom for peaks.

 

So you can use higher powered amps than in the specification so long as you are not excessive. In any case given the latter then it doesn't matter what amp/speaker combination you have, the chance of creating damage will be there. As you say, by using too small an amp you have the possibility of trying to drive it beyond its capacity in which case it may pass DC and fry your speaker coils. If too big and you try to run it flat out you may exceed the mechanical limits of the drive units. But if you use a large amplifier properly then it will have power in reserve which can give a more satisfactory listening experience.

 

Unfortunately few home speaker manufacturers quote a maximum SPL that the speaker can produce which may be more useful for knowledgable enthusiasts  when used in conjunction with  sensitivity and impedance specs . However that would probably be incomprehensible to average buyers so the manufacturers give an amp power range instead.

 

 

[Jud]

I suppose - though I don't know if this is a practical problem in many if any cases - if you had very efficient speakers, like some horns, you wouldn't want amps so powerful that you'd be limited to a tiny fraction of the travel of any volume control you use.

[4est]

2 hours ago, Jud said:

I suppose - though I don't know if this is a practical problem in many if any cases - if you had very efficient speakers, like some horns, you wouldn't want amps so powerful that you'd be limited to a tiny fraction of the travel of any volume control you use.

Barring complete mismatching as in this example, I do not think too much power is all that dangerous in most circumstances. A clipped amp is more likely to fry something than clean excess power.

[STC]

Most listeners average volume in room is usually around 80 to 85dB. At peaks it can go over 100dB. At 85dB you are hardly going to use more than 5 Watt of the amp power depending on your distance and speakers efficiency. At loud peaks the speakers can demand more than 500W. 
 

Most speakers can take the momentarily surge without any problem. The demo by Harbeth with CH Precision Amp showed that at the peak of electronic music the Amp was reaching more than 700W for the speakers with maximum power handling of 150W. 
 

Ideally, use amp where the max out put is 4 times of the speakers maximum power requirement. This is for very loud playback and music with wide dynamic range. 
 

There is always a danger of accidentally pushing the volume to the max. I control the volume using the DAW slider. If you double click the slider it will reset to the max. Once the accident happened. The whole house shook, I was kind of immobilized for few seconds before rushing to the plugs and quickly turned off. All I have to do was to push the slider down but since it happened unexpectedly I couldn’t think. 
 

It was partly my fault. The rule is to adjust the maximum level using the output but the audiophile in me just wouldn’t want to do that until the bitter lesson. 

[STC]

11 minutes ago, PAR said:

85dB is very loud listening for "most" at home and is at the safe hearing health limit .  A live full sized symphony orchestra will have maximum peaks of around 96dB in a concert hall playing large works and an average SPL quite a lot below that .  Over 85 dB as an average listening level for a reasonable period is considered as dangerous to hearing by most health authorities. Of course some rock acts will hit exceptional SPLs which is why some performers like Pete Townsend are basically deaf.

 

Frankly I cannot imagine what listening to an average SPL of 85dB at home would be like aside from the bricks through my window from near neighbours.

 

Other than that, good post.

Even the piano easily hit more than 85dB. It is just right and justify the loudness level for high end product   

 

Depends on the SPL meter, sometimes we may get wrong measurement. 
 

Hope this helps. 
 

https://www.gcaudio.com/tips-tricks/decibel-loudness-comparison-chart/

[Jud]

I find my usual listening level for rock is in the lower 70dB range.

[Richard Dale]

9 hours ago, Jud said:

I find my usual listening level for rock is in the lower 70dB range.

In my two main systems I listen at quite different levels according to the SPL meter on my Android phone. With the valve amp based system in a smaller room the level is about mid 70s average peaking at 80 or so. While the other system in a larger room with KEF LS50 wireless and subs it is more like 82 dB peaking in the upper 80s. Subjectively the smaller system sounds plenty loud enough, and I’m surprised how much the sound levels which sound about right to me differ by so much.

 

Can anyone recommend a cost effective SPL meter than would be more accurate than a mobile phone?

[cjf]

I use this one and its excellent. Cant say if this considered cost effective or not ($200) but its very accurate and easy to use.

 

 

Whenever possible I try and have an amp that is rated well above even the max rating of the speaker because IME the outcome is usually an effortless and clean sounding pair of speakers up to whatever your loudness threshold may be.

 

With that said, in my current setup and gear, I couldn't afford to buy an Amp of the same quality I have now that puts out a matching or greater number of watts than my speakers are listed to handle (500w). There are certainly plenty of times where I wish I had more wattage but I'm still able to achieve a solid 105db at the listening chair so I fine with that.

[Norton]

Thanks to all for your replies - question answered.  N.