[Dr. Hugo]

I am rather new to this hobby and I am confused about somethings regarding headphone amplification. I am not sure if some of these questions have been answered so even pointing me to another thread would be extremely helpful. Thank you guys so much in advance!

1. What does the "watts" as a measurement of "power" in headphone amplification mean? I've heard many people talking power and how much watts per channel an amplifier has but what does it mean? For example, in Audeze's website, they say that LCD-X, for instance, is best driven by power between 1W and 4 W. What does it mean?

2. In sight of answers to the first question, why does balanced output have more "power" than single-ended? I research a bit about balanced and it doesn't seem to me that the rationale behind it would result in more power. So why do amplifier specs say that balanced have more output power? (one example would be Schiit Jot as indicated in their website).

3. What is the difference in driving dynamic and planar magnetic headphones? People say planar needs "power"(kind of going back to the first question), but why is "power" a more important part when ampllifying a planar? On the other hand, what is the things I should consider if I am picking an amplifier for my dynamic headphones?

4. From what I know, the output impedance of the amplifier should match the impedance of the headphone in the case of a dynamic driver; and OTL tube amp usually doesn't work well with planars. But when I am picking an amplifier for my dynamic and planar magnetic headphones, what else should I take note of?

I know they are long questions and probably take long times to write answers but I greatly appreciate any help form you guys!

 

[theveterans]

1) Those are peak power rating. You will be normally listening far lower than that, but some tracks with great dynamics will need those peak power momentarily.

2) Balanced output on the line level have 2X the signal output compared to single ended on the line level. Thus balanced provides more power than unbalanced (aka single ended).

3) Dynamic is your typical dome speaker diaphragm while planar is a like it says, a thin film of diaphragm that is sensitive to magnetic field changes to produce sound

4) Research about damping power, current driven/voltage driven power output, efficiency in dB/mW and headphone gain.

 

[Music Alchemist]

Check out these links to learn about driving headphones and calculating their power requirements.

http://apexhifi.com/specs.html
http://www.digizoid.com/headphones-power.html

The optimal power requirement figures listed on Audeze's website are deceptive marketing (most likely to sell their amps), not what the headphones actually need or use. The LCD-X (which I did own) is 103 dB/mW @ 20 ohms. (That's high sensitivity and low impedance.) And look how easy it is to drive. Even at 120 dB, it only uses 50 mW. (Not multiple watts.) The $99 Schiit Magni 3 headphone amp can output more than 40 times that much power. Granted, the chart below is just a rough guideline, and the headphones will use more power when there is heavy bass and so on.

It's not that all planar magnetic headphones need more power than all conventional dynamic driver headphones; it's just that some planar magnetics have low sensitivity. Look at the impedance and sensitivity of a headphone (and consult the links above) to get an idea of how hard it is to drive.

Look for an amp that has an output impedance at least eight times lower than the impedance of your headphones. (Most amps will be well under 1 ohm anyway.) Other things to look at are output power at various input impedances, distortion, and features.

P.S. I've seen nearly everything in the Dragon Ball franchise.

 

[PurpleAngel]

I am rather new to this hobby and I am confused about somethings regarding headphone amplification. I am not sure if some of these questions have been answered so even pointing me to another thread would be extremely helpful. Thank you guys so much in advance!
1. What does the "watts" as a measurement of "power" in headphone amplification mean? I've heard many people talking power and how much watts per channel an amplifier has but what does it mean? For example, in Audeze's website, they say that LCD-X, for instance, is best driven by power between 1W and 4 W. What does it mean?
2. In sight of answers to the first question, why does balanced output have more "power" than single-ended? I research a bit about balanced and it doesn't seem to me that the rationale behind it would result in more power. So why do amplifier specs say that balanced have more output power? (one example would be Schiit Jot as indicated in their website).
3. What is the difference in driving dynamic and planar magnetic headphones? People say planar needs "power"(kind of going back to the first question), but why is "power" a more important part when ampllifying a planar? On the other hand, what is the things I should consider if I am picking an amplifier for my dynamic headphones?
4. From what I know, the output impedance of the amplifier should match the impedance of the headphone in the case of a dynamic driver; and OTL tube amp usually doesn't work well with planars. But when I am picking an amplifier for my dynamic and planar magnetic headphones, what else should I take note of?
I know they are long questions and probably take long times to write answers but I greatly appreciate any help form you guys!

I'm not the expert, but here is my two cents.
(1), Watts is used for as a marketing tool, It does not mean you will be outputing quality amplification power.
A good quality 50 watt output amplifier can sound better then then a cheap amplifier that outputs 100 watts.
Think of good quality amplifier power as a Formula One race car (fast and great thru corners), talking about watts is more like a taking about a drag race car (only good for the 1/4 mile and can't turn).

(2) To me balanced output allows you to run longer cables and I guess some portection agains interfearance.
A un-balanced signal is a single channel signal, balanced signal is when the same signal is sent thru two separate channels.
And in the end the two signals are combined(?), to hopefully make one good clean signal(?).

 

[MindsMirror]

1. Watts is the unit for power, just like seconds for time, or meters for length.

2. In a single ended amp, the negative terminal is ground, or zero volts, and the positive terminal is the signal which could be 1V for instance. In a balanced amp, the positive terminal would still be 1V, but instead of being ground, the negative terminal would be -1V. So the difference between the positive and negative terminals is a total of 2V instead of just 1V, meaning the signal is twice as large in the balanced output vs single ended.

3. Planars tend to be less efficient, so they usually need more power. Similarly, a heavy car would need a more powerful engine than a light car, and a large house will need a more powerful heater than a small house. The headphone's sensitivity spec tells you how much power they need, with a higher sensitivity needing less power.

4. Output impedance of the amp does not need to match the headphone impedance. Ideally it should be as low as possible, at least 8 times lower than the impedance of the headphone.

 

[ProtegeManiac]

1. What does the "watts" as a measurement of "power" in headphone amplification mean? I've heard many people talking power and how much watts per channel an amplifier has but what does it mean? For example, in Audeze's website, they say that LCD-X, for instance, is best driven by power between 1W and 4 W. What does it mean?

Not sure how much clearer it has to be other than to add more detail to it. They're basically saying the amplifier you use has to be capable of 1watt or 1000mW at least to be able to drive these without clipping even if you're listening to music that has very wide dynamic peaks, like classical music that can have the loudest notes playing at +30dB over the average. On Class A amps that produce less power (though with lower distortion), that means you're farther off from clipping.

If your amp outputs less than that and you crank it up, you'll clip the signal, ie, the amp can't go any louder even on the peak and you'll hear the signal go awfully wrong.

They recommend up to 4watts or 4000mW because 1) an amp capable of putting out more hurts your wallet more than your headphones, regardless of whether you hurt your ears or not, and 2) it's safer to assume that on most amps, using a lot less than all an amp can spit out means you're also getting a cleaner signal. The higher the output, the more noise and distortion, so use less than that. In a Class A/B amp you're also likely to stay within Class A operation, since it has to get up to a certain output level before it switches over to Class B.

Think of the 4000mW recommendation like how you might not be living in Germany to drive an Audi sedan at 250kph, but a twin turbo V8 still helps you get past that slow big rig in front a lot faster which means safer (ie, you'll get past it before an oncoming car slams onto you, or if you're driving really safely, you're stuck behind that truck until its driver goes for lunch). Unless you get a Tesla Model S which has more torque than an internal combustion engine, in which case, you don't need the twin engine version (although the twin engine version has AWD, so it'll have more grip in rain or snow).

Note also that a speaker amp might not necessarily produce nearly the same amount of power out of its headphone output as its speaker output, nor can the latter spit out the same level of power into an 8ohm speaker as it can to a headphone with a much higher impedance.

2. In sight of answers to the first question, why does balanced output have more "power" than single-ended? I research a bit about balanced and it doesn't seem to me that the rationale behind it would result in more power. So why do amplifier specs say that balanced have more output power? (one example would be Schiit Jot as indicated in their website).

Some amps that do both actually spit out less power when running in balanced mode, like DAPs with both SE and balanced drive, likely because their batteries can't handle it.

If the amp is a dual mono balanced design it's like having a Tesla Model S with two engines and AWD, except in the case of the amp the output is symmetrical, unlike the weaker front engine on the Tesla.

Even without dual mono some balanced circuits can still output more power based on how the power supply is designed. Otherwise you can still have cases where given two different circuits the SE amp can still spit out more power - like the Lyr vs the Jotunheim.

3. What is the difference in driving dynamic and planar magnetic headphones? People say planar needs "power"(kind of going back to the first question), but why is "power" a more important part when ampllifying a planar? On the other hand, what is the things I should consider if I am picking an amplifier for my dynamic headphones?

Planars are less affected by damping factor, ie, barring an output level at higher harmonic distortion, your amp is less likely to colour the sound from one planar to another compared to dynamic drivers. Most common cause is a high output impedance on the amp driving a low impedance headphone.

Most planars tend to have lower sensitivity than many dynamic drivers in their price range, but sensitivity is still sensitivity. Just because planars tend to be at 93dB/1mW or less does not mean no planar can go higher nor will a 93dB/1mW dynamic driver be harder to drive. If anything, if accurate sensitivity ratings at 1khz are the same, the planar would be easier to drive since it's less affected by lower damping factor.

Basically you just have way more audiophile headphones using dynamic drivers with 96dB/1mW sensitivity than planars with comparable sensitivity.

4. From what I know, the output impedance of the amplifier should match the impedance of the headphone in the case of a dynamic driver

They're not supposed to be equal. Very rough estimate to be really safe is maintain an 8:1 load to output impedance ratio. With planars you should follow a higher output impedance on the load but not necessarily that ratio.

Also, given nearly all decent headphone amps right now have an output impedance of 5ohms or lower, this isn't really a problem either way. It's only really a problem with OTL amps plus a few oddballs like the Musical Fidelity headphone amps; and also speaker amps with over 120ohm output impedance on the headphone output.

and OTL tube amp usually doesn't work well with planars. But when I am picking an amplifier for my dynamic and planar magnetic headphones, what else should I take note of?

OTL amps output the most power at 300ohms, and least at 16ohms/32ohms. Planars tend to be closer to 32ohms - LCD-XC at 16ohms, HE400S at 24ohms, HE400i at 35ohms, LCD-2 at 70ohms, etc. Add to that the high output impedance, which, with the exception of the Valhalla2, tends to be higher than the load impedance of planars.

Just get practically any solid state or hybrid amp that outputs around 1000mW. Something like the Asgard2 or, if you can spend a little more, there's the Lyr2.

 

[Music Alchemist]

Not sure how much clearer it has to be other than to add more detail to it. They're basically saying the amplifier you use has to be capable of 1watt or 1000mW at least to be able to drive these without clipping even if you're listening to music that has very wide dynamic peaks, like classical music that can have the loudest notes playing at +30dB over the average. On Class A amps that produce less power (though with lower distortion), that means you're farther off from clipping.

If your amp outputs less than that and you crank it up, you'll clip the signal, ie, the amp can't go any louder even on the peak and you'll hear the signal go awfully wrong.

Except that information on their website is an absolute lie. See my post and chart above. I drove the LCD-X from a Chord Mojo (which can output up to 600 mW at 32 ohms, albeit a bit more at 20 ohms) and did not even come close to pushing its limits. You're not likely to use even 20 mW with the LCD-X.

I calculated approximately how loud the headphones would get if you actually sent 1,000 mW and 4,000 mW (the listed figures on Audeze's site) into them: 133 and 139 dB. That's loud enough to cause extreme hearing damage.

 

[Dr. Hugo]

Planars are less affected by damping factor, ie, barring an output level at higher harmonic distortion, your amp is less likely to colour the sound from one planar to another compared to dynamic drivers. Most common cause is a high output impedance on the amp driving a low impedance headphone.

Can you explained a bit more about damping factor? also, where should I check for the damping factor if I'm looking for an amplifier for my planars? Thanks

 

[Music Alchemist]

Can you explained a bit more about damping factor?

In-depth info here:
https://en.wikipedia.org/wiki/Damping_factor
https://www.innerfidelity.com/conte...-250-ohm-and-dt-880-600-ohm-headphones-page-2
https://www.innerfidelity.com/content/musings-headphone-amplifier-output-impedance

where should I check for the damping factor if I'm looking for an amplifier for my planars?

As recommended before, just make sure the output impedance of the amp is at least eight times lower than the impedance of your headphones. (Most amps have an output impedance of under 1 ohm anyway.) Planar magnetics tend to have a near-flat impedance curve, so they are less affected by all this.

 

[Glmoneydawg]

Went from hd650 to lcd2..lcd2 actually play louder with rudistor nxo3 at same volume setting....impedance would seem to be more important?

 

[Dr. Hugo]

Except that information on their website is an absolute lie. See my post and chart above. I drove the LCD-X from a Chord Mojo (which can output up to 600 mW at 32 ohms, albeit a bit more at 20 ohms) and did not even come close to pushing its limits. You're not likely to use even 20 mW with the LCD-X.

it seems rather absurd that a well-respected company with great reputation like Audeze would say something that is not true in their product description.

 

[Music Alchemist]

it seems rather absurd that a well-respected company with great reputation like Audeze would say something that is not true in their product description.

They did say "optimal" power requirement instead of "minimum" power requirement, so if confronted about this, they may simply say that they recommend a stronger amp even if it's not going to use nearly that much power. I do know that if you boost the bass to extreme levels (we're talking 20 to 50 dB) and play at high volume, even sensitive headphones can use multiple watts, so there are at least some circumstances in which the headphones would use a lot more power than in the calculations above. I just don't think that would happen under normal use.

 

[Dr. Hugo]

One more little question, if my planar (not dynamic) headphones reach listening level before the amplifier is at 2 o'clock, does that mean my planar is already well-driven and more power under the same "cleaniness" or distortion level wouldn't help (although cleaner power might)? In other words, my current amplifier drives my planar well enough for listening level, does that mean it has enough power and, if I ever want to upgrade the amp, I need to look for something with cleaner power instead of more power? Thanks.

 

[Dr. Hugo]

Not sure how much clearer it has to be other than to add more detail to it. They're basically saying the amplifier you use has to be capable of 1watt or 1000mW at least to be able to drive these without clipping even if you're listening to music that has very wide dynamic peaks, like classical music that can have the loudest notes playing at +30dB over the average. On Class A amps that produce less power (though with lower distortion), that means you're farther off from clipping.

If your amp outputs less than that and you crank it up, you'll clip the signal, ie, the amp can't go any louder even on the peak and you'll hear the signal go awfully wrong.

They recommend up to 4watts or 4000mW because 1) an amp capable of putting out more hurts your wallet more than your headphones, regardless of whether you hurt your ears or not, and 2) it's safer to assume that on most amps, using a lot less than all an amp can spit out means you're also getting a cleaner signal. The higher the output, the more noise and distortion, so use less than that. In a Class A/B amp you're also likely to stay within Class A operation, since it has to get up to a certain output level before it switches over to Class B.

Think of the 4000mW recommendation like how you might not be living in Germany to drive an Audi sedan at 250kph, but a twin turbo V8 still helps you get past that slow big rig in front a lot faster which means safer (ie, you'll get past it before an oncoming car slams onto you, or if you're driving really safely, you're stuck behind that truck until its driver goes for lunch). Unless you get a Tesla Model S which has more torque than an internal combustion engine, in which case, you don't need the twin engine version (although the twin engine version has AWD, so it'll have more grip in rain or snow).

Note also that a speaker amp might not necessarily produce nearly the same amount of power out of its headphone output as its speaker output, nor can the latter spit out the same level of power into an 8ohm speaker as it can to a headphone with a much higher impedance.




Some amps that do both actually spit out less power when running in balanced mode, like DAPs with both SE and balanced drive, likely because their batteries can't handle it.

If the amp is a dual mono balanced design it's like having a Tesla Model S with two engines and AWD, except in the case of the amp the output is symmetrical, unlike the weaker front engine on the Tesla.

Even without dual mono some balanced circuits can still output more power based on how the power supply is designed. Otherwise you can still have cases where given two different circuits the SE amp can still spit out more power - like the Lyr vs the Jotunheim.




Planars are less affected by damping factor, ie, barring an output level at higher harmonic distortion, your amp is less likely to colour the sound from one planar to another compared to dynamic drivers. Most common cause is a high output impedance on the amp driving a low impedance headphone.

Most planars tend to have lower sensitivity than many dynamic drivers in their price range, but sensitivity is still sensitivity. Just because planars tend to be at 93dB/1mW or less does not mean no planar can go higher nor will a 93dB/1mW dynamic driver be harder to drive. If anything, if accurate sensitivity ratings at 1khz are the same, the planar would be easier to drive since it's less affected by lower damping factor.

Basically you just have way more audiophile headphones using dynamic drivers with 96dB/1mW sensitivity than planars with comparable sensitivity.





They're not supposed to be equal. Very rough estimate to be really safe is maintain an 8:1 load to output impedance ratio. With planars you should follow a higher output impedance on the load but not necessarily that ratio.

Also, given nearly all decent headphone amps right now have an output impedance of 5ohms or lower, this isn't really a problem either way. It's only really a problem with OTL amps plus a few oddballs like the Musical Fidelity headphone amps; and also speaker amps with over 120ohm output impedance on the headphone output.




OTL amps output the most power at 300ohms, and least at 16ohms/32ohms. Planars tend to be closer to 32ohms - LCD-XC at 16ohms, HE400S at 24ohms, HE400i at 35ohms, LCD-2 at 70ohms, etc. Add to that the high output impedance, which, with the exception of the Valhalla2, tends to be higher than the load impedance of planars.

Just get practically any solid state or hybrid amp that outputs around 1000mW. Something like the Asgard2 or, if you can spend a little more, there's the Lyr2.

Greatly appreciate the long response. I like you car analogy as well.

 

[Music Alchemist]

One more little question, if my planar (not dynamic) headphones reach listening level before the amplifier is at 2 o'clock, does that mean my planar is already well-driven and more power under the same "cleaniness" or distortion level wouldn't help (although cleaner power might)? In other words, my current amplifier drives my planar well enough for listening level, does that mean it has enough power and, if I ever want to upgrade the amp, I need to look for something with cleaner power instead of more power? Thanks.

If it's not clipping, I'd say it's driven fairly well. More power could help, but probably won't. Nicer amps tend to have more power either way.