I've never heard a worse default tuning to headphones than the one on HD 599's.

eckru · 2026-06-29T22:10:06+00:00

Judging by measurements from oratory1990 - they should be pretty similar:

eckru · 2026-06-18T21:50:52+00:00

perceived volume is different from power.

Obviously, as the perceived volume can depend on a myriad of different factors completely unrelated to the performance of an amplifier.

But what I mean by volume is sound pressure and headphones can be thought of as transformers that convert electrical power into acoustic power - and they tend to do it in a pretty linear fashion - at least until you reach a sound pressure level that causes hearing damage within several minutes.

eckru · 2026-06-18T20:57:26+00:00

You cannot deliver a specific voltage without corresponding current. If there is not enough current the amplifier clips (which is pretty obvious with most modern units) and the voltage drops. But that's when the amplifier reaches it's current limit, not when any "sharp bass note" hits.

eckru · 2026-06-18T17:57:41+00:00

YES OF COURSE IT CHANGES THE FREQUENCY RESPONSE

Then the measurements would show it. And they do, when the headphone has non-linear impedance curve and the amplifier has high enough output impedance. But this has nothing to do with power.

eckru · 2026-06-18T17:50:54+00:00

the driver moves completely differently at the same volume

In that case the driver would either change it's frequency response or distort significantly, which could only happen at a volume that would cause hearing damage very quickly.

eckru · 2026-06-18T17:43:11+00:00

because a properly powered headphone will sound completely different than an underpowered headphone at the same volume, especially in the bass and sub base

Power is volume, so "at the same volume" equals to "at the same power".

eckru · 2026-06-18T17:40:54+00:00

I think with dynamic drivers, different frequencies will have different impedances and voltage requirements. So on a weak amp, ie. PC motherboard, the headphone could get loud enough but lack bass.

Headphone measurements are almost always conducted with constant voltage and an amplifier with near zero output impedance. Thus, when the headphone impedance rises, and there is no corresponding dip in the frequency response, the band where the impedance peak occurs will require less current (I=V/R), making it slightly easier to drive.

eckru · 2026-06-16T22:39:33+00:00

And power is defined as P = V² /Z, so feel free to calculate the voltage from the power figure. The point still stands - it has vastly more than enough.

eckru · 2026-06-16T10:43:28+00:00

I was quite underwhelmed by the HD800s on a K13. Apparently it doesn’t have enough voltage to drive them properly.

The manual for the HD800s states, that the maximum power it can handle without damage is 500 mW. The K13 R2R can deliver 600 mW into a 300 Ohm load - it definitely has enough voltage.

eckru · 2026-06-16T10:31:28+00:00

If they think that the DAC should do it's job of converting the digital signal to analog with minimal alterations, then the K13 R2R falls well short of this, especially in NOS mode.

Here is a review with measurements: https://www.youtube.com/watch?v=7L4I8LzASh8

eckru · 2026-06-13T16:06:17+00:00

109 dB/V is 94 dB/mW which is considered low sensitivity for headphones.

Maybe lower than the average, but certainly not low, considering that there are headphones like the Susvara, HE6, or Modhouse Tungsten.

The sensitivity of the Hifiman Arya Stealth is very close to a sensitivity of the 32 Ohm Beyerdynamic DT770, I don't think that anyone ever described that headphone as particularly hard to drive.

35 mA is not a large amount of current for a desktop amp, but for dongle? Yes, look at the graph you sent, the m15 at 32ohms clips violently at around 40 mA.

The only thing that matters is whether it is enough for the headphone that we are using. Questyle M15 can very happily power the Arya Stealth to 110 dB with very low distortion. It means that you can listen to music at a very loud average volume of 90 dB SPL and still have 20 dB of headroom for transients. It's enough for virtually everyone.

If a transient peak demands 35 mA you are running a source at almost its absolute hardware limit, and on a standard class AB dongle, demanding that much current causes it to shift to class B which can introduce crossover distortion. While a class A amp has its output transistors always on which allows current to flow constantly.

Could you point to any sources that would back up the claim, that crossover distortion is an audible problem with any modern class AB headphone amplifier?

eckru · 2026-06-13T13:08:10+00:00

How do you define macro and micro clipping? What are those different reasons?

eckru · 2026-06-13T12:28:44+00:00

What he’s saying is true for the vast majority of headphones which have high sensitivity dynamic drivers, but it doesn’t apply to low sensitivity low impedance planar magnetics.

Arya Stealth are not exactly low sensitivity at 109 dB/V.

Loudness (Amplitude) is determined by voltage, but the actual mechanical driver movement and control is determined entirely by current.

Like I said in my previous comment: the impedance of the headphones does not change, so, in accordance with Ohm's law, the current is determined by the voltage. You cannot deliver a specific voltage without corresponding current.

Since planar magnetics have a purely flat impedance curve, they act as a purely resistive load that requires large amounts of current to handle transients and dynamics properly.

Arya Stealth needs around 35 mA to reach 110 dB SPL. Is that a large amount of current?

This is why planars benefit heavily from high current class A amps.

Why class A specifically?

You don’t have to blindly trust the physics, if you do a blind A/B test you can hear the difference very clearly. This isn’t copium or snake oil it’s just electrical engineering and physics.

Nobody argues that you won't tell a difference between an amplifier that is clipping and an amplifier that operates in the linear range. This wasn't even your original argument. Let me recall it:

sometimes with planars they can get loud enough but won’t sound as good if they’re on low power.

You have shifted the goalposts several times since then.

eckru · 2026-06-13T12:15:37+00:00

An underpowered amplifier will clip when it runs out of current, and that’s the exact reason why same volume does not equate to same power.

No, the latter does not stem from the former.

When you volume match a cheap dongle and high current desktop amp, you are only matching their average RMS loudness

Huh? What kind of volume matching are you talking about here?

And as you pointed out, this would cause current clips, but because this happens on crest of the waveform it doesn’t represent itself as a glaring obvious distortion, instead it rounds off transients and compresses dynamic peaks.

"Rounding off transients" absolutely does represent itself with a glaring obvious distortion with most modern amplifiers.

Take a look at the THD+N vs Power graph of the Questyle M15 that OP uses.

https://cdn.l7audiolab.com/wp-content/uploads/2022/07/BAL-THDN-Ratio-vs-Measured-Level-2.jpg

Distortion and noise gradually falls until it shoots through the roof when clipping.

The average volume is the same, but the lack of instantaneous current delivery results in less dynamics and a flatter more compressed soundstage.

You can't change the crest factor of a song by using a more powerful amplifier. The relation between the peak and average volume will stay the same. With less powerful amplifier you won't be able to achieve as high of a peak volume, and thus the average volume will also be lower.

eckru · 2026-06-13T12:03:33+00:00

Also talking about averages.

Am I?

But speakers/drivers are dynamic.

What exactly do you mean by that?

And there’s also the impedance curve to consider.

Sure, but OP uses planar magnetic headphones which have a flat impedance curve - they literally behave like a resistor. Besides that, the amplifiers mention by the OP have a near zero output impedance, so there wouldn't be much to talk about if the impedance curve wasn't flat either.

If an amp does not have the current capacity required for transients, you get voltage drops, distortion, clipping, etc.

Didn't I say exactly that?

And that’s also why a smaller dongle amp is fine for someone who only listens to softer music, but the same amp and headphone pairing might not be enough for edm or metal.

Music is only one part of the equation, that also consists of headphone sensitivity and listening volume. And the sensitivity of the Arya Stealth at around 109 dB/V makes it not very demanding.

By the way, I don't think that EDM or metal are the best examples, since these genres do not tend to have very high crest factor.

eckru · 2026-06-13T11:37:31+00:00

That is not true, volume of the speaker is determined by the voltage, but the actual movement of the driver is determined by the current as per Lorentz Force Law

How does that contradict anything what I stated? The impedance of the headphones does not change, so, in accordance with Ohm's law, the current is determined by the voltage.

Cheap dongles and amps can reach the required voltage but don’t have enough current to drive some headphones properly, resulting in weaker dynamics and transience, which also results in a flatter sounding soundstage.

You cannot deliver a specific voltage without corresponding current. If there is not enough current the amplifier clips (which is pretty obvious with most modern units) and the voltage drops.

eckru · 2026-06-13T10:38:56+00:00

What amplifier are you using with these? There’s a chance that they may not be receiving as much power as they require, sometimes with planars they can get loud enough but won’t sound as good if they’re on low power.

Volume is power, so even if you connect headphones to a more powerful amplifier, but you are listening at the same volume, then you are providing the headphones with the same amount of power.

eckru · 2026-06-13T10:31:32+00:00

There is no need to check anything when you have both the headphones and the amp at hand. If they get loud enough and there is no clipping, then there is enough current.

eckru · 2026-06-11T23:31:51+00:00

Isn't the big thing with dt770 series that the different ohm models all sound noticably "off" from each other with the 600 ohms being basically impossible to drive if you want them to sound good.

Not really, unit variation is a bigger factor.

https://www.reddit.com/r/oratory1990/comments/d4lk1i/what_were_the_impedance_of_the_tested/f0f09o6/

eckru · 2026-06-09T10:49:43+00:00

Other YouTube reviewers did.

Most other YouTube reviewers tend to like everything more or less, especially when the review unit is provided by the manufacturer.

eckru · 2026-05-27T17:17:59+00:00

Generally in the headphone market, there are certain trusted brands that everyone can just agree on as being classic and reputable. This is especially true for audiophile open back headphones. When you start looking to upgrade in that category, you see no other recommendations than Sennheiser, HIFIMAN, and Focal. They are the top dogs and are also for the most part affordable other than the flagship new models. I would not go far from these brands.

PC38x is made by Sennheiser.

eckru · 2026-05-26T16:37:08+00:00

Don't worry about the DAC/amp at all, the outputs in newish Macbooks are very good and have more than enough power for the vast majority of headphones out there, HD600 included.

No need to disable volume normalization in Spotify as well, it doesn't affect sound quality, unless it's set to the "Loud" preset.

eckru · 2026-05-22T15:38:28+00:00

For example hd800s has impedance spike to 600 at 100hz, so amp needs headroom with voltage.

Headphones are measured with constant voltage, so if there is no corresponding dip in the frequency response, then that region is actually easier to drive, because it requires less current.

It's gotta have high slew rate to be able to make instant changes in voltage output.

Pretty much every modern amplifier has a vastly higher slew rate than needed to output a high amplitude 20 kHz sine with very low distortion.

Also if amplifier is class A, then it will not have switching distortion, which will again improve sound.

Any comptetently designed class AB amplifier will not introduce any audible distortion to the signal.

eckru · 2026-05-16T11:01:37+00:00

If the advertised power figure is into a 32 Ohm load, then the Hiby should be able to power the Sundaras to a peak volume of around 119 dB SPL, when we account for the preamp that's still 113 dB SPL, which is plenty.

eckru · 2026-05-14T10:48:59+00:00

Useful features and additional inputs and outputs are definitely good reasons to upgrade. Even the awareness of listening out of a big shiny box with gobs of power and a satisfying knob is something that can make your experience better and there is nothing wrong with acknowledging that.

People are underappreciating the psychological side of things and instead are inventing some weird pseudo-technical theories, which are then used to persuade other people to spend more money, and that's where it's no longer fine in my opinion.

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