'Headroom' is a measure of the badness of an amplifier. The bigger the number, the worse the amplifier.

[KSTR]

When did headroom become the same as peak power? Headroom was always how far over nominal level (0VU) a continuous signal could go before clipping, as in mixing consoles with 20db of headroom. It had nothing to do with peaks. And amps (at least pro amps) never had a headroom/peak power rating till the marketers and reviewers got involved

"headroom" is just a bit sloppy language as is, for example "frequency response". Both should always mention the quantity/item they are applied to.
"Peak Power Headroom (pulse power vs. continuous power)" thus would be the more precise term for this topic.
And, to me, it is also quite clear that it depends on the use case which way is deemed better.

 

[Zaphod]

I think "maintaining a peak" is an oxymoron. Peaks are transient (short, like measured in ms short) by nature, if it's not transient, it's not a peak, it's continuous. Uncompressed music is characterized by a really low RMS value with really high peak values that typically only last tens or maybe hundreds of ms. Even compressed music has a really low RMS compared to a sine.

I agree, but, in the case of the Yamaha amplifiers cited, there is no mention of how long the 'dynamic power' levels can be maintained.

 

[HarmonicTHD]

An amplifier with a stiff power supply, when compared with an otherwise identical amplifier with a soft power supply will always measure better and possibly sound better.

No, not always. What if you have a big soft PS vs a small stiff one?

You have to be more specific.

 

[Multicore]

It's easy to get a bit confused by the arguments in this thread. Lemmy try to confirm something. Let's say (using Amir's protocol for testing peak power)

• amp A can deliver 100 W continuous and 100 W peak
• B can deliver 100 W continuous and 150 W peak
• C can deliver 150 W continuous and 150 W peak

Can I then claim that

• B has headroom while amps A and C do not
• B can deliver more power for some signals than A
• C can deliver more power for all signals than A
• C can deliver more power for some signals than B

If I understood that correctly, I don't see how headroom is a measure of badness.

The extent to which headroom is any use (value) depends on the signals you send to the amp and what you think is important.

There's tuba fan on ASR, I forget his handle, but he or she insists that reproducing unattenuated down to the fundamental is important and is willing to pay for it in sound reproduction equipment. Idk what music this tuba fan listens to but let's imagine there are tuba ensembles doing avant garde stuff with sustained loud low notes. This, I imagine, demands lots of continuous power.

For many of the rest of us, a compromise that takes a statistical view of the power needs of our music might make sense. The 16 to 32 Hz octave isn't significant in most of my collection. Similarly, maximum loudness is not something I can put up with for no more than a couple of seconds.

So I don't think headroom is bad. It's just that it's not quite as clear how useful it is since relating continuous and peak power specs to the real world involves assumptions that can be debatable. If this is what Zaphod means then I think that poster could find better words to state that case.

 

[HarmonicTHD]

It's easy to get a bit confused by the arguments in this thread. Lemmy try to confirm something. Let's say (using Amir's protocol for testing peak power)

• amp A can deliver 100 W continuous and 100 W peak
• B can deliver 100 W continuous and 150 W peak
• C can deliver 150 W continuous and 150 W peak

Can I then claim that

• B has headroom while amps A and C do not
• B can deliver more power for some signals than A
• C can deliver more power for all signals than A
• C can deliver more power for some signals than B

If I understood that correctly, I don't see how headroom is a measure of badness.

The extent to which headroom is any use (value) depends on the signals you send to the amp and what you think is important.

There's tuba fan on ASR, I forget his handle, but he or she insists that reproducing unattenuated down to the fundamental is important and is willing to pay for it in sound reproduction equipment. Idk what music this tuba fan listens to but let's imagine there are tuba ensembles doing avant garde stuff with sustained loud low notes. This, I imagine, demands lots of continuous power.

For many of the rest of us, a compromise that takes a statistical view of the power needs of our music might make sense. The 16 to 32 Hz octave isn't significant in most of my collection. Similarly, maximum loudness is not something I can put up with for more than a couple of seconds.

So I don't think headroom is bad. It's just that it's not quite as clear how useful it is since relating continuous and peak power specs to the real world involves assumptions that can be debatable. If this is what Zaphod means then I think that poster could find better words to state that case.

Absolutely correct.

…. And using the OPs favorite example of that organ note and let’s say the organ note requires 120W.

Amp A will clip immediately.
Amp B will clip a fraction of a second later than A.
Amp C will play it without clipping.

 

[MAB]

No not always. What if you have a big soft PS vs a small stiff one. You have to be more specific.

OP has not constructed a completely specified problem statement, like writing an exam question, "Given an object of mass m and radius r, calculate the motion."
Combined with no accurate definitions of things like headroom, stiffness, etc. Plus zero measurements, but I am not clear on how a measurement would help given the underspecified confusion that has been sown.

It's a big experiment in appeals to reason and experience, but nothing to support. Can't even get an answer on always better vs. might be better. This seems another example of the cost-no-object ethos in HiFi.

 

[III-V]

'headroom', 'stiff', 'soft' are not precise technical terms, neither is the 'badness of an amplifier' so this argument is a bit of a fail

 

[HarmonicTHD]

With all the talk of "stiff" and "soft" power supplies in this thread I think maybe I'm just missing some important subtext and this thread isn't about audio at all.

Even if … still headroom is better as the peak will last a tad longer, even if it is a fraction of second. And as they, it might not be perceived but certainly can be measured

 

[kemmler3D]

I agree, but, in the case of the Yamaha amplifiers cited, there is no mention of how long the 'dynamic power' levels can be maintained.

True, I think the duration that power levels are maintained is generally implied as being very brief, but not often made explicit.

 

[Multicore]

It's a big experiment in appeals to reason and experience, but nothing to support. Can't even get an answer on always better vs. might be better. This seems another example of the cost-no-object ethos in HiFi.

Late last year there was a thread talking about the importance of below 40 Hz. I tend to agree with what @Blumlein 88 said about diminishing returns in that area. It's a lot of cost, fuss and stuff. Transparent DACs aren't so expensive, so may as well get one. Far too loud is quite doable too, as I have found. But continuously far too loud -- forget it -- we have neighbors and dogs. So if the ratio of peak to continuous loudness is the measure of badness then I must like badness.

When it comes to the limits of budget, complexity, fuss, ugliness, and all the other ways that aspects of real life collide with the hobby, our pragmatic compromises often turn out to be personal.

 

[voodooless]

True, I think the duration that power levels are maintained is generally implied as being very brief, but not often made explicit.

Wore, even if it’s specified, it’s hard to know what this actually means in practice. Will this mean I can play track xyz maybe a dB louder? Whoopty do!

 

[jooc]

It's easy to get a bit confused by the arguments in this thread. Lemmy try to confirm something. Let's say (using Amir's protocol for testing peak power)

• amp A can deliver 100 W continuous and 100 W peak
• B can deliver 100 W continuous and 150 W peak
• C can deliver 150 W continuous and 150 W peak

.

I think this entire thread boils down to the fact that Zaphod thinks the "C" amplifier above is the best of those three, and that makes the others 'bad', especially B, which is obviously a Gatsby-esqe pretender that wants to walk in the rarified air of real 150wpc amplifiers but doesn't deserve to be there.

edit: I'll not hasten to judge OPs motives and await proof of his curveless amplifier

 

[MAB]

Stiffer bridges are better.
I submit proof.

Even if I won't include a definition of stiff. Even though no bridge is designed to be perfectly stiff. Even though stiffness has additional drawbacks, like cracks and other more pernicious issues with bridges.

 

[radix]

What definition of 'headroom' is Crown Audio using in their calculator below, and is it the same thing the OP is talking about? Is 'peak power' and 'headroom' being treated as the same thing consistently?

View attachment 349415

The crown calculator is just adding the headroom to the listening SPL. So in your example, it is calculating the power for 93 dB SPL. You can verify this by using "90/3" or "93/0" or "87/6" and they should all have the same power.

It is up to you if you use the "required amplifier power" for the continuous rated power or the peak power. I personally always use the continuous rated power of the amp and consider the peak power icing on the cake.

 

[voodooless]

The crown calculator is just adding the headroom to the listening SPL. So in your example, it is calculating the power for 93 dB SPL. You can verify this by using "90/3" or "93/0" or "87/6" and they should all have the same power.

It is up to you if you use the "required amplifier power" for the continuous rated power or the peak power. I personally always use the continuous rated power of the amp and consider the peak power icing on the cake.

The headroom number is basically meant as an input for the crest factor of the music. If you want an average of 80 dB, you’ll have to handle peaks of 90 to 95 dB, depending on track. 15 dB should be a save margin for most content.

This has zero to do with the headroom we’re talking about here though.

 

[Zaphod]

'headroom', 'stiff', 'soft' are not precise technical terms, neither is the 'badness of an amplifier' so this argument is a bit of a fail

My point exactly.

 

[jooc]

The headroom number is basically meant as an input for the crest factor of the music. If you want an average of 80 dB, you’ll have to handle peaks of 90 to 95 dB, depending on track. 15 dB should be a save margin for most content.

This has zero to do with the headroom we’re talking about here though.

That's what I was wondering, but I suspect there are multiple definitions for 'headroom' existing in this same thread

 

[voodooless]

there are multiple definitions for 'headroom' existing in this same thread

Yeah, fun, isn’t it

 

[Sokel]

I agree, but, in the case of the Yamaha amplifiers cited, there is no mention of how long the 'dynamic power' levels can be maintained.

Ok,here's the specs of one the amps that drive my lows about peaks,continuous and time that all the above are maintained very specifically stated (along with the thermals used,etc in another section)




Would you think I should use a precision chronograph while listening?
I consider it a roughly 300 watt per channel amp (Europe here,230V gives the advantage to the specific one) and that's it,that's the number I calculated my needs with.
The bursts/peaks/whatever are just welcome so I can have some peace of mind when playing my (high dynamic range) stuff.

 

[mhardy6647]

Stiffer bridges are better.
I submit proof.

Even if I won't include a definition of stiff. Even though no bridge is designed to be perfectly stiff. Even though stiffness has additional drawbacks, like cracks and other more pernicious issues with bridges.

Controlled resonance is better -- low Q, so to speak.
That said, bridges are kind of like tonearm/cartridge combinations -- it's best to keep Fs away from inconvenient values, too!

This whole thread sort of flummoxes me. If (!!!) an amplifier is capable of delivering adequate power into one's actual loudspeaker load(s) in one's acoustic space with one's preferred program (source material), does it matter if it can do so based on continuous or peak power capability?

I'm thinkin'... nope.