The one watt lie….

[wmgwizard]

"Headroom" refers to the amplifiers ability to deal with momentary peaks in the signal without clipping.

Bob Carver used to do a demonstration where he shattered a glass in front of the crowd then played back a recording of the "event". He demonstrated that the shattering glass required almost 400 watts of power to accurately reproduce the SPL of the glass shattering.

Imagine listening to a quiet passage of music, your amps humming along at 1-2 watts then suddenly there is a cymbal crash or timpani drum and all the sudden your amp needs 100 watts of instant power for a nanosecond.

Another way to look at it is driving down the freeway at 50mph and 10% throttle, you decide to pass a slower car and push the pedal to 75%, the ability to pass the car using the previously untapped power is "headroom". If you needed 100% throttle to maintain 50mph you would have no headroom.

 

[GChief]

I would very much like to know the high efficiency low wattage match that is working for you. I am stubborn and willing to try other approaches.

My restored/modded Maggie 8802 sounds with a set of K-Horns and Cornwalls. And it plugs along respectfully with some KG4's and the current ADS710's.

 

[WaynerN]

Glad headroom was brought up. The missing part to the equation is the power supply. The power supply should never be taxed. If it is, the signal will become corrupt. Lots of low wattage amps skimp on the power supply, because "thats all they need". I believe this is where the term "headroom" comes from. I might only listen to a watt or 2, but (as others have said), the big crescendo comes along and the power supply can't keep up or deliver the goods. That is why we have big power amps. We do not listen to one tone sine waves, we listen to complex music and it has loud and quiet passages that come cone instantly. Therefore the power supply has to respond in the same way. There have been some fairly good attempts at making "smart" power supplies to respond to such demands, but I'm sure many designers just go big.

All that said, I find an amp with 100wpc is probably good enough for almost all of my musical listening, with one exception, that being any amp connected to my Martin-Logan reQuests. They have a very low impedance (another problem) and need lots of power to drive, let alone handle dynamic swings.

 

[Splatter Pak]

"Headroom" refers to the amplifiers ability to deal with momentary peaks in the signal without clipping.

Bob Carver used to do a demonstration where he shattered a glass in front of the crowd then played back a recording of the "event". He demonstrated that the shattering glass required almost 400 watts of power to accurately reproduce the SPL of the glass shattering.

Imagine listening to a quiet passage of music, your amps humming along at 1-2 watts then suddenly there is a cymbal crash or timpani drum and all the sudden your amp needs 100 watts of instant power for a nanosecond.

Another way to look at it is driving down the freeway at 50mph and 10% throttle, you decide to pass a slower car and push the pedal to 75%, the ability to pass the car using the previously untapped power is "headroom". If you needed 100% throttle to maintain 50mph you would have no headroom.

My Proton AA-1150 can do exactly that, as it has a second power supply for those brief 100% power demands. I actually saw my first AA-1150, rated at 50 wpc, hit 400 watts briefly. The speakers were a little raspy after that, but the amp was fine.

 

[kevintomb]

"Headroom" refers to the amplifiers ability to deal with momentary peaks in the signal without clipping.

Bob Carver used to do a demonstration where he shattered a glass in front of the crowd then played back a recording of the "event". He demonstrated that the shattering glass required almost 400 watts of power to accurately reproduce the SPL of the glass shattering.

Imagine listening to a quiet passage of music, your amps humming along at 1-2 watts then suddenly there is a cymbal crash or timpani drum and all the sudden your amp needs 100 watts of instant power for a nanosecond.

Another way to look at it is driving down the freeway at 50mph and 10% throttle, you decide to pass a slower car and push the pedal to 75%, the ability to pass the car using the previously untapped power is "headroom". If you needed 100% throttle to maintain 50mph you would have no headroom.

Except, quiet listening would not be 1-2 watts. That would actually be quite loud. Quiet listening on my system with 89 db/watt speakers, is more like 1/10 OF a watt.

1-3 watts is fairly loud.

20-50 watts was VERY loud.

 

[Poultrygeist]

These Bottlehead SET mono blocks produce 3.5 watts per channel but that's all any sane person would need to drive 98 db Lowthers. Gobs of headroom as you can reach a satisfying listening level with a tiny fraction of that all important first watt. Lowther claims a driver FR of 30-22000 hz and bass is jaw dropping. Some of you critics haven't experienced combinations like this.

 

[62caddy]

i hear it time and again, 1 watt will get you X number of db’s, and thats all you need.

I’m not talking about SPL. Im talking about the soudn you get.

The low wattage high efficiency philosophy is a lie.

Low wattage amp with a very high efficiency speaker cannot compete with high power amp and very high efficiency speaker.

You may achieve a comparatively supernatural experience, but you will NOT achieve the same sense of scale. You will lose the function of making thin, tinny, lean recordings organic.

You sir, do not know what you're talking about.

 

[Beatnik]

I just enjoy listening to music.

 

[Jeepnmon]

"Headroom" refers to the amplifiers ability to deal with momentary peaks in the signal without clipping.

Bob Carver used to do a demonstration where he shattered a glass in front of the crowd then played back a recording of the "event". He demonstrated that the shattering glass required almost 400 watts of power to accurately reproduce the SPL of the glass shattering.

Imagine listening to a quiet passage of music, your amps humming along at 1-2 watts then suddenly there is a cymbal crash or timpani drum and all the sudden your amp needs 100 watts of instant power for a nanosecond.

Another way to look at it is driving down the freeway at 50mph and 10% throttle, you decide to pass a slower car and push the pedal to 75%, the ability to pass the car using the previously untapped power is "headroom". If you needed 100% throttle to maintain 50mph you would have no headroom.

Great analogy and reminds me of my first car, a '75 Chevy Vega. If I needed or wanted to pass another vehicle on the highway, I had to start the process by accelerating about a mile before the actual pass would succeed. Heaven forbid I had to slow down as the whole process would need to start over

 

[whoaru99]

Frankly, it has the markings of a suboptimal pairing to me, at least in some situations.

The combination, I presume, is the Pass F8 and Devore Gibbon X the OP posted about in a different thread.

1. The Pass F8 is rated 25W @ 8 ohms. Thing is though, output power actually decreases as impedance drops, it's 15W @ 4 ohms.

2a. The Gibbon X sensitivity is above average at ~91dB but, IMO, not really a "high sensitivity" speaker in the big scheme things.

2b. Remember the Pass F8 decreases in power below 8 ohms. The Gibbon X impedance drops below 8 ohms starting around 45Hz and goes down to about 6 ohms in the low bass. The OP mentioned a problem when the bass kicked in, or tried to, anyway.

Regardless that the speaker is a bit above average in sensitivity, one still needs to have an amplifier that can deliver the goods to satisfy the use case. Sounds to me like that isn't the case, at least in some cases here.

 

[62caddy]

Great analogy and reminds me of my first car, a '75 Chevy Vega. If I needed or wanted to pass another vehicle on the highway, I had to start the process by accelerating about a mile before the actual pass would succeed. Heaven forbid I had to slow down as the whole process would need to start over

Automotive analogy does not apply here.

 

[kirk57]

I think the OP is confusing opinion, based upon limited experience, with fact.

 

[wyn palmer]

Glad headroom was brought up. The missing part to the equation is the power supply. The power supply should never be taxed. If it is, the signal will become corrupt. Lots of low wattage amps skimp on the power supply, because "thats all they need". I believe this is where the term "headroom" comes from. I might only listen to a watt or 2, but (as others have said), the big crescendo comes along and the power supply can't keep up or deliver the goods. That is why we have big power amps. We do not listen to one tone sine waves, we listen to complex music and it has loud and quiet passages that come cone instantly. Therefore the power supply has to respond in the same way. There have been some fairly good attempts at making "smart" power supplies to respond to such demands, but I'm sure many designers just go big.

All that said, I find an amp with 100wpc is probably good enough for almost all of my musical listening, with one exception, that being any amp connected to my Martin-Logan reQuests. They have a very low impedance (another problem) and need lots of power to drive, let alone handle dynamic swings.

As you can see from my signature I have ML ESL11As and dual mono Benchmark AHB2 amps. The MLs have a nominal 4ohm impedance but can go as high as several kohms and can drop to about 0.9ohms at about 20kHz. The AHB2s can deliver 39A peak current. There are times when I am listening at realistic levels when the "clipping approaching indicators" flash on the amps. The speakers are 91dB for 2.83v ("1W") so they are moderately efficient. Realistic levels are, for example, the volume at my listening position (9' from the speakers) playing a track from the HSU test CD where there is a point in the recording with a calibrated volume in dB. This level was determined during the recording of the track at a position in the audience in the concert hall. The recording was made without compression...
The playback sounds incredibly dynamic and not unnaturally loud until the crescendos are reached.
This recording explores the sub 1W region and then the >1kW region.
The Benchmarks use multiple dynamically selected switching fully regulated supplies. They also use a complex feedforward/feedback compensation scheme that does not cause the high order distortion (the most audible kind) to increase at low signal levels ("1W") unlike classic class AB output stages with overall negative feedback. They in fact keep essentially constant extraordinarily low distortion levels until just before clipping, and the amps are actually never allowed to clip in use. If true "clipping" is detected (either current or voltage hitting the limit points) the amp shuts down and has to be re-initialized.
So my answer is- why not have both? It takes an exceptional amplifier design to achieve both low and high power linearity. With tube amps and their ilk, you get the former but not the latter. With most SS amps you get the latter but not the former.

 

[Ross6860]

My little 5-watt guitar amp driving a single 12" speaker will blow you out of an average sized bedroom.

I drove my Magnepans with 15 wpc SEP power amp. It was adequate.

I just don't like messing with tubes in audio gear. Personal preference is quiet SS.

 

[reddodge053]

Yep i just turn my ole dial till it sounds good to me,never really pay attn to watts ect. Mostly just the music i enjoy

 

[Beatnik]

If all I listened to was piccolo music one watt might suffice.

 

[GChief]

My 6ish WPC does fine with all my Metal, Stoner Rock, Jazz etc.
I guess I go above 1 watt with it sometimes

 

[Beatnik]

My 6ish WPC does fine with all my Metal, Stoner Rock, Jazz etc.
I guess I go above 1 watt with it sometimes

My 30 wpc ss does fine, but the 300 watt 15 inch sub is a game changer for me. I don't think 6 watts would be the same experience.

 

[RT Fan]

The vast majority of my listening is done at < 1/4 of 1 watt, mostly at IDLE on my power amp. Once in a while we get crazed and crank it up to 1/2 of 1 watt.

 

[6.5CM]

I think the OP is confusing opinion, based upon limited experience, with fact.

Keep kidding yourself. You think a few post over a month lets you know the depth of my experience?

Sure people can get loud at 3.5 watts. How does the sound compare to an amp with more power and of similar build and quality? Less corporeal. Clear, but anemic.

My opinion is formed from years of working in PA sound; hearing other peoples systems, trying many combinations and finally going through a series of changes in my own listening room to try and find the potential of said systems that I had an opportunity of putting together.

Low wattage Ive had the pleasure of experiencing -

Klipsch Cornwalls with SET monos
Tannoys with full Shindo front end
Zu Omen Defs with Amp and Sound SET amp

All the above were beautiful, but only in their low wattage way. Neither speaker had the same authority with standard power amps.

My recent experiments went to low-mid power. Thats over. 10 watts. I had a great match and lots of authority with an Audion Super Sterling KT120 SEP 24 wpc amp and Gibbon X. It seemed to be under ratedS The only issue I had with that system was that the match had a boundary that was too close my average listening level. It would be amazing at one point; and just completely fall apart with a nudge on the gain.

My opinion is my opinion. Dont get your panties in a bunch. If I get my hands of some Avantgardes at a reasonable cost: I likely pursue the philosophy a little further just to how much further there is.