How Much Power Do I Actually Need..(revisited)

[Ajani]

Thanks Gasolin and Davedotco!

It pretty much sounds like using a more powerful amp than required to reach the max output of the speakers, means taking a risk of producing peaks in excess of what the speakers may be able to handle.

 

[Vladimir]

Your typical ferro-fluid cooled dome tweeter can handle 500-600W in transient peaks. The woofers much more.

 

[Ajani]

Your typical ferro-fluid cooled dome tweeter can handle 500-600W in transient peaks. The woofers much more.

OK. So what's the limiting factor? The crossover? A quick look at a few bookshelf speakers show relatively low power handling capacity.

Kef LS50 - 100W

Monitor Audio GX50 - 100W

Revel Perfoma M150 - 120W

B&W 805 D3 - 120W

Spendor D1 - 125W

I'd be hesistant to throw large amounts of power at products when the manufacturers advise against it.

 

[Andrewjvt]

Your typical ferro-fluid cooled dome tweeter can handle 500-600W in transient peaks. The woofers much more.

OK. So what's the limiting factor? The crossover? A quick look at a few bookshelf speakers show relatively low power handling capacity.

Kef LS50 - 100W?

Monitor Audio GX50 - 100W

Revel Perfoma M150 - 120W

B&W 805 D3 - 120W

Spendor D1 - 125W

I'd be hesistant to throw large amounts of power at products when the manufacturers advise against it.

Thats only a guide and you can damge speakers much more easier by an under powered amp than an over powered one (if one exists)

An amp that goes into clipping is what damages the speaker.

All those speakers mentioned in your above post could be driven by my amp thats rated at 250w into 8ohm and i bet they would appreciate the juice but just need to be sensible and not blast the @##$# out of them.

Also if the speaker manufacturer says you need an amp with loads of watts they would sell less.

But as many said already 100w and a decent power supply and componants is more than enough in normal cases.

 

[Ajani]

Your typical ferro-fluid cooled dome tweeter can handle 500-600W in transient peaks. The woofers much more.

OK. So what's the limiting factor? The crossover? A quick look at a few bookshelf speakers show relatively low power handling capacity.

Kef LS50 - 100W

Monitor Audio GX50 - 100W

Revel Perfoma M150 - 120W

B&W 805 D3 - 120W

Spendor D1 - 125W

I'd be hesistant to throw large amounts of power at products when the manufacturers advise against it.

Thats only a guide and you can damge speakers much more easier by an under powered amp than an over powered one (if one exists)

An amp that goes into clipping is what damages the speaker.

All those speakers mentioned in your above post could be driven by my amp thats rated at 250w into 8ohm and i bet they would appreciate the juice but just need to be sensible and not blast the @##$# out of them.

Also if the speaker manufacturer says you need an amp with loads of watts they would sell less.

But as many said already 100w and a decent power supply and componants is more than enough in normal cases.

The manufacturers all put a range - usually from around 20 - 100 Watts. So as long as they don't change the minimum value it wouldn't mean that you need an amp with lots of watts. So they could just as easily state 20 - 200 Watts.

Also, I still wonder how a speaker benefits from a truly high powered amp, if the speaker wasn't designed to produce the kind of SPLs associated with that kind of power.

I just wonder if there really is a point in using really high powered amps for typical HiFi. Most of us probably aren't trying to fill massive rooms with rave level sound, and I expect that those who are would look for speakers designed to really produce high SPLs.

 

[Andrewjvt]

Your typical ferro-fluid cooled dome tweeter can handle 500-600W in transient peaks. The woofers much more.

OK. So what's the limiting factor? The crossover? A quick look at a few bookshelf speakers show relatively low power handling capacity.

Kef LS50 - 100W?

Monitor Audio GX50 - 100W

Revel Perfoma M150 - 120W

B&W 805 D3 - 120W

Spendor D1 - 125W

I'd be hesistant to throw large amounts of power at products when the manufacturers advise against it.

Thats only a guide and you can damge speakers much more easier by an under powered amp than an over powered one (if one exists)

An amp that goes into clipping is what damages the speaker.

All those speakers mentioned in your above post could be driven by my amp thats rated at 250w into 8ohm and i bet they would appreciate the juice but just need to be sensible and not blast the @##$# out of them.

Also if the speaker manufacturer says you need an amp with loads of watts they would sell less.

But as many said already 100w and a decent power supply and componants is more than enough in normal cases.

?

The manufacturers all put a range - usually from around 20 - 100 Watts. So as long as they don't change the minimum value it wouldn't mean that you need an amp with lots of watts. So they could just as easily state 20 - 200 Watts.

?

Also, I still wonder how a speaker benefits from a truly high powered amp, if the speaker wasn't designed to produce the kind of SPLs associated with that kind of power. ?

?

I just wonder if there really is a point in using really high powered amps for typical HiFi. Most of us probably aren't trying to fill massive rooms with rave level sound, and I expect that those who are would look for speakers designed to really produce high SPLs.

?

 

Its not just about volume. Music is dynamic and some music more demanding than others. A powerful amp or an amp with good current delivery is able to deliver this easy. A weaker amp will struggle and not control or grip the speaker driver as well and will not sound clearer or cleaner. An amp not able to handle dynamic shifts can loose grip and cause a boomy bass or grainy highs (example my old k2 did this even though it was rated at 120w)

A good amp to look at with lower power but welding spec current delivery is the abrahamsen intergrated. Its only 70w per channel but has the power supply and internals of a high spec power amp. Now compare these internal parts to its pricewise and power wise competition and tell me which one will drive the speakers better and have the juice to handle the dynamic shifts without losing control?

In the same way a higher powered amp can handle the music easier because of more current available on tap. Its just they can do it without breaking a sweat.

Hope this gets across my point im trying to make.

 

[Vladimir]

Do I need a 300Wpc RMS amp for my hi-fi? Of course not. I don't need big or expensive speakers with flat frequency response and fast transients. I don't need it to listen and enjoy music when a small Denon mini system will do. Hi-Fi is aspirational, we don't need any of it. We want it. We desire and crave that sound we heard at a live event. And if you've been to a symphony, rock concert or even a jazz night club, you should know things are very very loud, detailed and multidimensional. The 60W amp + standmount speakers and budget rubber band turntable simply don't come close to replicate this experience . You can certanly enjoy music on this small scale kit, but it's not really high fidelity. The only difference between splash of water from a glass and a tsunami is scale.

 

[davedotco]

Your typical ferro-fluid cooled dome tweeter can handle 500-600W in transient peaks. The woofers much more.

OK. So what's the limiting factor? The crossover? A quick look at a few bookshelf speakers show relatively low power handling capacity.

Kef LS50 - 100W

Monitor Audio GX50 - 100W

Revel Perfoma M150 - 120W

B&W 805 D3 - 120W

Spendor D1 - 125W

I'd be hesistant to throw large amounts of power at products when the manufacturers advise against it.

Thats only a guide and you can damge speakers much more easier by an under powered amp than an over powered one (if one exists)

An amp that goes into clipping is what damages the speaker.

All those speakers mentioned in your above post could be driven by my amp thats rated at 250w into 8ohm and i bet they would appreciate the juice but just need to be sensible and not blast the @##$# out of them.

Also if the speaker manufacturer says you need an amp with loads of watts they would sell less.

But as many said already 100w and a decent power supply and componants is more than enough in normal cases.

The manufacturers all put a range - usually from around 20 - 100 Watts. So as long as they don't change the minimum value it wouldn't mean that you need an amp with lots of watts. So they could just as easily state 20 - 200 Watts.

Also, I still wonder how a speaker benefits from a truly high powered amp, if the speaker wasn't designed to produce the kind of SPLs associated with that kind of power.

I just wonder if there really is a point in using really high powered amps for typical HiFi. Most of us probably aren't trying to fill massive rooms with rave level sound, and I expect that those who are would look for speakers designed to really produce high SPLs.

I explained this above, it is all to do with the relationship between transient/peak power and human perception.

All but the most ridiculous recordings will have a dynamic range, good recordings of popular music, pop, jazz, will have peaks 10-20dB above average levels, classical often much more.

I explained the relationship between peak and average power, for music with peaks 10dB above average levels, even a 200wpc amplifier driven up to but not into clipping may produce 250+watts peak but this is still only 25 watts average, within the power capabilities of most speakers.

At the other end of the scale, your average 50 wpc budget amplifier will, if it is any good, produce about 70 watts peak, or an average power of 7 watts. However if you have a more dynamic recording with peaks say 20dB above average levels the maximum average power is just 0.7 watts.

These figures are somewhat simplyfied but give you a rough idea what is going on and why more power makes a difference, even at 'sensible' listening levels.

One further thing to bear in mind, perceived loudness is a function of average SPL (power), we do not respond to transients as being loud, we respond to average SPL, so big amplifiers, used correctly, are not really about loudness.

 

[matt49]

For a graphic representation of what Dave's saying, check out this video. The issue at stake is the type of music being played. With say baroque chamber music an output of 10W may be normal even at quite high subjective volumes, but if you're playing e.g. electronic music with heavy bass, you may need 500W to capture the peaks without compression.

 

[Ajani]

Its not just about volume. Music is dynamic and some music more demanding than others. A powerful amp or an amp with good current delivery is able to deliver this easy. A weaker amp will struggle and not control or grip the speaker driver as well and will not sound clearer or cleaner. An amp not able to handle dynamic shifts can loose grip and cause a boomy bass or grainy highs (example my old k2 did this even though it was rated at 120w)

A good amp to look at with lower power but welding spec current delivery is the abrahamsen intergrated. Its only 70w per channel but has the power supply and internals of a high spec power amp. Now compare these internal parts to its pricewise and power wise competition and tell me which one will drive the speakers better and have the juice to handle the dynamic shifts without losing control?

In the same way a higher powered amp can handle the music easier because of more current available on tap. Its just they can do it without breaking a sweat.

Hope this gets across my point im trying to make.

What speakers were you using at the time with the K2s?

 

[Ajani]

Do I need a 300Wpc RMS amp for my hi-fi? Of course not. I don't need big or expensive speakers with flat frequency response and fast transients. I don't need it to listen and enjoy music when a small Denon mini system will do. Hi-Fi is aspirational, we don't need any of it. We want it. We desire and crave that sound we heard at a live event. And if you've been to a symphony, rock concert or even a jazz night club, you should know things are very very loud, detailed and multidimensional. The 60W amp + standmount speakers and budget rubber band turntable simply don't come close to replicate this experience . You can certanly enjoy music on this small scale kit, but it's not really high fidelity. The only difference between splash of water from a glass and a tsunami is scale.

I don't disagree with any of that, but that's not at all what I'm asking. My last 2 amps were 200W & 300W @ 8 ohms respectively and my ideal system would be large towers with brutish monoblocks beating them into submission. So I see the value of a big amp on speakers really able to handle the power, but my concern is whether it's really beneficial to put that kind of power on a pair of tiny standmounts.

I'm still concerned that if I hit a nasty bass peak and actually draw 300 Watts out of the amp, it will do real damage to a tiny pair of standmounts.

For example look at the difference between the power handling requirements for the smallest standmount versus the largest tower in the Revel Performa line

M105 Standmount: 50 - 120 Watts

F208 Tower: 50 - 350 Watts

I get putting a 350 watt amp on the F208, cuz it's clearly designed to handle that level of power. However, I'm not convinced that putting 350 watts on the M105 isn't just potentially dangerous to the little speaker.

 

[Vladimir]

Do I need a 300Wpc RMS amp for my hi-fi? Of course not. I don't need big or expensive speakers with flat frequency response and fast transients. I don't need it to listen and enjoy music when a small Denon mini system will do. Hi-Fi is aspirational, we don't need any of it. We want it. We desire and crave that sound we heard at a live event. And if you've been to a symphony, rock concert or even a jazz night club, you should know things are very very loud, detailed and multidimensional. The 60W amp + standmount speakers and budget rubber band turntable simply don't come close to replicate this experience . You can certanly enjoy music on this small scale kit, but it's not really high fidelity. The only difference between splash of water from a glass and a tsunami is scale.

I don't disagree with any of that, but that's not at all what I'm asking. My last 2 amps were 200W & 300W @ 8 ohms respectively and my ideal system would be large towers with brutish monoblocks beating them into submission. So I see the value of a big amp on speakers really able to handle the power, but my concern is whether it's really beneficial to put that kind of power on a pair of tiny standmounts.

I'm still concerned that if I hit a nasty bass peak and actually draw 300 Watts out of the amp, it will do real damage to a tiny pair of standmounts.

For example look at the difference between the power handling requirements for the smallest standmount versus the largest tower in the Revel Performa line

M105 Standmount: 50 - 120 Watts

F208 Tower: 50 - 350 Watts

I get putting a 350 watt amp on the F208, cuz it's clearly designed to handle that level of power. However, I'm not convinced that putting 350 watts on the M105 isn't just potentially dangerous to the little speaker.

No one said you should be putting continously 350W RMS in a 120W RMS capable speaker. You just have the headroom so transients don't get clipped off. You could also do away with a smaller amp that has a PSU capable of holding good amount of joules. Good example mentioned is the 70Wpc RMS Abrahamsen with its 1,000VA transformer, 12 output devices and 100,000uF capacitor bank. Why did they bother with so much power at bay in a small domestic hi-fi amp? Because music needs it in transient peaks.

 

[GCE]

... Terrible video! Not the best spot for Harbeth ...

For a graphic representation of what Dave's saying, check out this video...

 

[Blacksabbath25]

For a graphic representation of what Dave's saying, check out this video. The issue at stake is the type of music being played. With say baroque chamber music an output of 10W may be normal even at quite high subjective volumes, but if you're playing e.g. electronic music with heavy bass, you may need 500W to capture the peaks without compression.

i thought we had compression on the cd its self and thought you could not uncompress the music on the disc ? so are you saying you get compression twice ?

 

[matt49]

For a graphic representation of what Dave's saying, check out this video. The issue at stake is the type of music being played. With say baroque chamber music an output of 10W may be normal even at quite high subjective volumes, but if you're playing e.g. electronic music with heavy bass, you may need 500W to capture the peaks without compression.

i thought we had compression on the cd its self and thought you could not uncompress the music on the disc ? so are you saying you get compression twice ?

Yes, though ironically the less compressed the music on the CD is, the more likely you are to get compression at the amplification stage (depending of course on how dynamic the music is.)

The idea is simply that music with extreme dynamic peaks will require a lot more power from your amp than you might think; and if the amp doesn't have the necessary power, the peaks will be compressed.

 

[DocG]

For a graphic representation of what Dave's saying, check out this video. The issue at stake is the type of music being played. With say baroque chamber music an output of 10W may be normal even at quite high subjective volumes, but if you're playing e.g. electronic music with heavy bass, you may need 500W to capture the peaks without compression.

Apparently AS learned something in Hilversum. Where the specs for the M40.1 suggest a power handling of >50 W, the M40.2 reads "650 W programme"!

 

[Vladimir]

For a graphic representation of what Dave's saying, check out this video. The issue at stake is the type of music being played. With say baroque chamber music an output of 10W may be normal even at quite high subjective volumes, but if you're playing e.g. electronic music with heavy bass, you may need 500W to capture the peaks without compression.

Apparently AS learned something in Hilversum. Where the specs for the M40.1 suggest a power handling of >50 W, the M40.2 reads "650 W programme"!

He must have gotten sick from customers asking if their expensive <50W amp will do well if they sit close enough to the speakers.

 

[Andrewjvt]

Its not just about volume. Music is dynamic and some music more demanding than others. A powerful amp or an amp with good current delivery is able to deliver this easy. A weaker amp will struggle and not control or grip the speaker driver as well and will not sound clearer or cleaner. An amp not able to handle dynamic shifts can loose grip and cause a boomy bass or grainy highs (example my old k2 did this even though it was rated at 120w)

A good amp to look at with lower power but welding spec current delivery is the abrahamsen intergrated. Its only 70w per channel but has the power supply and internals of a high spec power amp. Now compare these internal parts to its pricewise and power wise competition and tell me which one will drive the speakers better and have the juice to handle the dynamic shifts without losing control?

In the same way a higher powered amp can handle the music easier because of more current available on tap. Its just they can do it without breaking a sweat.

Hope this gets across my point im trying to make.

What speakers were you using at the time with the K2s?

Its same as i have now kef r700s. They are great speakers but now i have a better amp i feel i need speakers in the same class or not as safe like atc 40s or kef ref.

 

[matt49]

For a graphic representation of what Dave's saying, check out this video. The issue at stake is the type of music being played. With say baroque chamber music an output of 10W may be normal even at quite high subjective volumes, but if you're playing e.g. electronic music with heavy bass, you may need 500W to capture the peaks without compression.

Apparently AS learned something in Hilversum. Where the specs for the M40.1 suggest a power handling of >50 W, the M40.2 reads "650 W programme"!

Ah, well spotted. But I note he hasn't had the courage to change this:

"Amp. Suggestion: works with a wide range of amplifiers from 35W/channel."

 

[manicm]

To Ajani, a good example of a stand mount which benefits from more power is the ls50. And just about any b&w speaker.

 

[gasolin]

Quick question for the more technically savvy persons in this thread. I know we always talk about the sensitiivity of the speakers, desired listening volume and room size and even peaks in the music to determine how much power we need. But wouldn't the real limiting factor be the maximum output of the speakers?

For example the KEF LS50 is only 85DB sensitive and the maximum output is 106DB. So based on my simplistic calculations that means you need 128 watts to hit the max output at 106DB. So wouldn't a 128 Watt amp be the max you should throw at the KEF?

they are rated to 100watt s peak power would be 106 db

Many speakers can handle much more power then they are rated to as long as it's 100% clean power (no distrotion) but not with bassy edm,techno (edm techno is very bass heavy so you would reach max limited (amp/speaker) much faster then pop music)

 

[gasolin]

Thanks Gasolin and Davedotco!

It pretty much sounds like using a more powerful amp than required to reach the max output of the speakers, means taking a risk of producing peaks in excess of what the speakers may be able to handle.

NO

Since what destoys speakers more is distortion NOT clean power/watt

 

[gasolin]

Your typical ferro-fluid cooled dome tweeter can handle 500-600W in transient peaks. The woofers much more.

OK. So what's the limiting factor? The crossover? A quick look at a few bookshelf speakers show relatively low power handling capacity.

Kef LS50 - 100W

Monitor Audio GX50 - 100W

Revel Perfoma M150 - 120W

B&W 805 D3 - 120W

Spendor D1 - 125W

I'd be hesistant to throw large amounts of power at products when the manufacturers advise against it.

Thats only a guide and you can damge speakers much more easier by an under powered amp than an over powered one (if one exists)

An amp that goes into clipping is what damages the speaker.

All those speakers mentioned in your above post could be driven by my amp thats rated at 250w into 8ohm and i bet they would appreciate the juice but just need to be sensible and not blast the @##$# out of them.

Also if the speaker manufacturer says you need an amp with loads of watts they would sell less.

But as many said already 100w and a decent power supply and componants is more than enough in normal cases.

The manufacturers all put a range - usually from around 20 - 100 Watts. So as long as they don't change the minimum value it wouldn't mean that you need an amp with lots of watts. So they could just as easily state 20 - 200 Watts.

Also, I still wonder how a speaker benefits from a truly high powered amp, if the speaker wasn't designed to produce the kind of SPLs associated with that kind of power.

I just wonder if there really is a point in using really high powered amps for typical HiFi. Most of us probably aren't trying to fill massive rooms with rave level sound, and I expect that those who are would look for speakers designed to really produce high SPLs.

Macintosh make great amps (more then any brand macintosh is used for high end systems when i watch some hifi video's on youtube) they make a 2000 watt pr channel amp WHY

So you can play as loud as you want to or need to without any distortion before you reach concert levels or you are affraid of damiging your high end speakers,ears

Dymanic headroom

http://www.mcintoshlabs.com/us/products/pages/ProductDetails.aspx?CatId=amplifiers&ProductId=MC2KW

(Must be fun to have HUGE speakers like the best from dynaudio,radhio,B&W,Jbl and such a huge amp as the machintosh and play some pink floyd,gensis,Queen,black sabbath,ac/dc,jimi hendrix or eric clapton mabye som live recording)

 

[gasolin]

For a graphic representation of what Dave's saying, check out this video. The issue at stake is the type of music being played. With say baroque chamber music an output of 10W may be normal even at quite high subjective volumes, but if you're playing e.g. electronic music with heavy bass, you may need 500W to capture the peaks without compression.

Holy crap i need 200watt+ pr channel

 

[gasolin]

Do I need a 300Wpc RMS amp for my hi-fi? Of course not. I don't need big or expensive speakers with flat frequency response and fast transients. I don't need it to listen and enjoy music when a small Denon mini system will do. Hi-Fi is aspirational, we don't need any of it. We want it. We desire and crave that sound we heard at a live event. And if you've been to a symphony, rock concert or even a jazz night club, you should know things are very very loud, detailed and multidimensional. The 60W amp + standmount speakers and budget rubber band turntable simply don't come close to replicate this experience . You can certanly enjoy music on this small scale kit, but it's not really high fidelity. The only difference between splash of water from a glass and a tsunami is scale.

I don't disagree with any of that, but that's not at all what I'm asking. My last 2 amps were 200W & 300W @ 8 ohms respectively and my ideal system would be large towers with brutish monoblocks beating them into submission. So I see the value of a big amp on speakers really able to handle the power, but my concern is whether it's really beneficial to put that kind of power on a pair of tiny standmounts.

I'm still concerned that if I hit a nasty bass peak and actually draw 300 Watts out of the amp, it will do real damage to a tiny pair of standmounts.

For example look at the difference between the power handling requirements for the smallest standmount versus the largest tower in the Revel Performa line

M105 Standmount: 50 - 120 Watts

F208 Tower: 50 - 350 Watts

I get putting a 350 watt amp on the F208, cuz it's clearly designed to handle that level of power. However, I'm not convinced that putting 350 watts on the M105 isn't just potentially dangerous to the little speaker.

No one said you should be putting continously 350W RMS in a 120W RMS capable speaker. You just have the headroom so transients don't get clipped off. You could also do away with a smaller amp that has a PSU capable of holding good amount of joules. Good example mentioned is the 70Wpc RMS Abrahamsen with its 1,000VA transformer, 12 output devices and 100,000uF capacitor bank. Why did they bother with so much power at bay in a small domestic hi-fi amp? Because music needs it in transient peaks.

so nad amps are good? (transient peaks) the smallest nad amp 316BBE 45watt pr channel in 4/8 ohm peaks 90 watt in 8 ohm and 120watt in 4ohm

The bigger nad amps are not that powerfull max peak power in 8 ohm might be 1-2 db higher where the smaller ones is 3db then the continuous power