Hifiman ananda unveiled 500-1000hz peaks

[Maple Nue]

Hi everyone,

I'm a newcomer to the forum, so please excuse any clunky phrasing in my English. I’ve recently been looking into the Hifiman Ananda unveiled and I'm quite interested in its performance characteristics.
While examining available frequency response measurements, I noticed some distinct broad peaks/elevations in the 500Hz to 1000Hz region. It seems many recent Hifiman planar models exhibit similar behavior in this specific range.

So I would like to ask:

1. Root Cause: What is the likely physical origin of these ripples? Could this be attributed to diaphragm breakup (modal resonances) of the ultra-thin membrane, or is it more likely related to internal cup reflections/grille interference?
2. Audibility: For those who have spent time with the Ananda, how audible are these deviations in real-world listening? Does this specific elevation contribute to any perceived "shoutiness," fatigue, or "graininess" in the midrange?

I also have a specific question regarding my HE400se. I’ve noticed a significant channel imbalance in the ultra-high frequencies（>12khz）. Specifically, there is a very sharp, piercing resonance peak between 15.5kHz and 16.1kHz that I can clearly hear during listening.

I've received conflicting feedback on this: some say it's a coupling resonance from my own ear canal, while others (and some AI tools) suggest it's a diaphragm breakup peak.
I’ve heard rumors that even the Ananda Unveiled might suffer from similar consistency issues in the upper treble.

Regardless of the cause, it has been a nightmare to EQ. The "hissing" sound is so narrow and intense that I eventually had to use a high-Q notch filter to cut it out entirely.
If a headphone already has resonance peaks/breakup in the midrange, won't that ruin the smoothness of the high frequencies? If the diaphragm is already breaking up at 500-1000Hz, how can the ultra-high frequencies stay clean?
Has anyone else experienced such sharp, narrow-band resonances in this range? How do you typically manage such annoying treble peaks when they differ so much between the left and right drivers?

Thank you for any advice!

 

[staticV3]

Hi @Maple Nue! Welcome to ASR.

This might give an indication as to where the jagged midrange response comes from:

I experimented with some 1mm crafts felt in front and back of the driver.

So, likely internal reflections.

 

[solderdude]

Fosi i5 has this the worst of all planars I measured.
With and without driver damping:

Not all hifiman have this either.
HE6:

Nor do FiiO planars:

The Avantone Pro Planar has very tiny ripples but over a wide range.

some Audeze also show a little bit of this.
Audeze sine has very little if any:

The small square membrane from the Fostex T50RP series is very thick (basically flexible PCB) and also shows this effect.

It has a lot of damping in front and back and a hole pattern around the magnets and also has this effect.

As to why some have it much worse than others while all of them have a similar construction (magnets with space between them, membrane, magnets with space between them.
On the rear side they are usually quite open and also on the front side where they all have a similar sized 'chamber' around the ear.
The better the driver is visible (more open front and back) the worse the effect is.
It seems that acoustic damping seems to help but what the exact cause is, is not directly clear to me.
It happens with low and higher excursions in the same manner. (Edition XX at different SPL)

 

[DVDdoug]

or is it more likely related to internal cup reflections/grille interference?

That's unlikely since 1kHz has a wavelength of about 1-foot. But I believe reflections are the main cause of higher frequency ripples which seem to be unavoidable.

If a headphone already has resonance peaks/breakup in the midrange, won't that ruin the smoothness of the high frequencies? If the diaphragm is already breaking up at 500-1000Hz, how can the ultra-high frequencies stay clean?

Usually something in one frequency range doesn't affect another frequency range. And most headphones don't "break up" (distort) in the midrange. But you ears can also distort if the sound is loud enough. Distortion in the bass range is more-often a problem, especially if you boost with EQ.

I also have a specific question regarding my HE400se. I’ve noticed a significant channel imbalance in the ultra-high frequencies（>12khz）. Specifically, there is a very sharp, piercing resonance peak between 15.5kHz and 16.1kHz that I can clearly hear during listening.

For the channel imbalance, did you flip them around to make sure it's not your ears?

I've received conflicting feedback on this: some say it's a coupling resonance from my own ear canal,

At those frequencies, that's possible. When Amir measured a pair (reviewed here) he did measure a spike around that range that was higher in one side but he didn't attempt to correct it with EQ. He usually doesn't recommend trying to make "precise" EQ corrections in the higher frequencies (because of ear interaction) bit it's OK to make a broader adjustment to knock-down or boost the highs. Actually... It's OK to do ANYTHING that sounds better to you!

I'm a newcomer to the forum,

Check out:
The Harman Curve
and Understanding Headphone Measurements (video)

 

[Maple Nue]

For the channel imbalance, did you flip them around to make sure it's not your ears?

Hi @DVDdoug, thank you for the suggestions
Apologies for the lack of precision in my initial description. After further testing, here’s what I found: The massive resonance peak at 15.5-16.1kHz is actually quite balanced on both sides. However, I’ve noticed a distinct channel imbalance in other regions—specifically between 13-13.5kHz and above 16.4kHz, where the left channel is consistently louder.

I did perform the 'flip test' as you suggested, and the imbalance definitely follows the headphone drivers, not my ears. I’ve been forced to apply separate EQ filters for the left channel to get a stable center image.

Is this level of frequency-dependent imbalance common for planar drivers?
or... hifiman QC problem, given the HE400se's budget nature

 

[Maple Nue]

Hi @Maple Nue! Welcome to ASR.

This might give an indication as to where the jagged midrange response comes from:


So, likely internal reflections.

Thanks, that makes sense. The felt acts as an acoustic resistor, heavily attenuating those multi-pass reflections while leaving the direct sound mostly intact. Great to see the physical proof!

 

[Maple Nue]

Fosi i5 has this the worst of all planars I measured.
With and without driver damping:

Not all hifiman have this either.
HE6:

Nor do FiiO planars:

The Avantone Pro Planar has very tiny ripples but over a wide range.

some Audeze also show a little bit of this.
Audeze sine has very little if any:

The small square membrane from the Fostex T50RP series is very thick (basically flexible PCB) and also shows this effect.

It has a lot of damping in front and back and a hole pattern around the magnets and also has this effect.

As to why some have it much worse than others while all of them have a similar construction (magnets with space between them, membrane, magnets with space between them.
On the rear side they are usually quite open and also on the front side where they all have a similar sized 'chamber' around the ear.
The better the driver is visible (more open front and back) the worse the effect is.
It seems that acoustic damping seems to help but what the exact cause is, is not directly clear to me.
It happens with low and higher excursions in the same manner. (Edition XX at different SPL)

View attachment 513561

Thank you for the masterclass, Solderdude! The multi-SPL graph is truly eye-opening—it confirms these ripples are a fixed structural signature rather than non-linear artifacts. Your data is incredibly thorough, and I have no further questions. I’ve learned a lot from this thread. Much appreciated!

 

[solderdude]

Hi @DVDdoug, thank you for the suggestions
Apologies for the lack of precision in my initial description. After further testing, here’s what I found: The massive resonance peak at 15.5-16.1kHz is actually quite balanced on both sides. However, I’ve noticed a distinct channel imbalance in other regions—specifically between 13-13.5kHz and above 16.4kHz, where the left channel is consistently louder.

I did perform the 'flip test' as you suggested, and the imbalance definitely follows the headphone drivers, not my ears. I’ve been forced to apply separate EQ filters for the left channel to get a stable center image.

Is this level of frequency-dependent imbalance common for planar drivers?
or... hifiman QC problem, given the HE400se's budget nature

I found channel balance is usually very good for hifiman models as well as most other planars except for Fostex T40/50 series that is usually terrible.

HE400SE:

One should only check imbalance using mono signals and if you find any then you must do 2 more experiments.
1: reverse the left and right cup (so right cup on left ear, etc) and listen if the imbalance shifts to the other ear. (what you already did)
2: headphone normally on the head and put the right plug in the left cup etc. When the balance shifts to the other side it is the amp.
When its always the left ear that's louder it is an ear aspect.

 

[Jiraya369]

Hi everyone,

I'm a newcomer to the forum, so please excuse any clunky phrasing in my English. I’ve recently been looking into the Hifiman Ananda unveiled and I'm quite interested in its performance characteristics.
While examining available frequency response measurements, I noticed some distinct broad peaks/elevations in the 500Hz to 1000Hz region. It seems many recent Hifiman planar models exhibit similar behavior in this specific range.
View attachment 513494
So I would like to ask:

1. Root Cause: What is the likely physical origin of these ripples? Could this be attributed to diaphragm breakup (modal resonances) of the ultra-thin membrane, or is it more likely related to internal cup reflections/grille interference?
2. Audibility: For those who have spent time with the Ananda, how audible are these deviations in real-world listening? Does this specific elevation contribute to any perceived "shoutiness," fatigue, or "graininess" in the midrange?

I also have a specific question regarding my HE400se. I’ve noticed a significant channel imbalance in the ultra-high frequencies（>12khz）. Specifically, there is a very sharp, piercing resonance peak between 15.5kHz and 16.1kHz that I can clearly hear during listening.

I've received conflicting feedback on this: some say it's a coupling resonance from my own ear canal, while others (and some AI tools) suggest it's a diaphragm breakup peak.
I’ve heard rumors that even the Ananda Unveiled might suffer from similar consistency issues in the upper treble.

Regardless of the cause, it has been a nightmare to EQ. The "hissing" sound is so narrow and intense that I eventually had to use a high-Q notch filter to cut it out entirely.
If a headphone already has resonance peaks/breakup in the midrange, won't that ruin the smoothness of the high frequencies? If the diaphragm is already breaking up at 500-1000Hz, how can the ultra-high frequencies stay clean?
Has anyone else experienced such sharp, narrow-band resonances in this range? How do you typically manage such annoying treble peaks when they differ so much between the left and right drivers?

Thank you for any advice!

idk what caused em but i heard the edition xv and it was a really nice sounding headphone.

instead of trying to understand why the midrange oddity happened, just see if it matters or not. The treble peak is the main offender and is the reason why i think the ananda unveiled sucks. You should not look into it at all. Just get the more durable XV as it has no unveiled parts and is actually better tuned.

Another tip, always compensate these graphs, use one constant compensation like diffuse filed +10db tilt or something. Let your brain recalibrate to those for a little while and then you'll be able to read graphs better. Especially if you're not using a simple curve like Harman which is a bit easier to read and judge.

 

[Maple Nue]

I found channel balance is usually very good for hifiman models as well as most other planars except for Fostex T40/50 series that is usually terrible.

HE400SE:

One should only check imbalance using mono signals and if you find any then you must do 2 more experiments.
1: reverse the left and right cup (so right cup on left ear, etc) and listen if the imbalance shifts to the other ear. (what you already did)
2: headphone normally on the head and put the right plug in the left cup etc. When the balance shifts to the other side it is the amp.
When its always the left ear that's louder it is an ear aspect.

I just completed Experiment 2 by swapping the L/R cable plugs at the headphone cups. The result was conclusive: the imbalance stayed with the left driver.

Combined with the 'flip test' I did earlier, this definitively rules out both my hearing and the upstream gear (amp/cables). It's clearly a driver matching issue—specifically a QC outlier on my particular unit, given that your measurements show much better consistency.

It's interesting that such a massive resonance at 15.5kHz can be so well-matched while the adjacent regions are not. I’ll stick with my independent L/R EQ to keep the center image stable.

Thanks again for the diagnostic logic and the reference graphs.

 

[Maple Nue]

idk what caused em but i heard the edition xv and it was a really nice sounding headphone.

instead of trying to understand why the midrange oddity happened, just see if it matters or not. The treble peak is the main offender and is the reason why i think the ananda unveiled sucks. You should not look into it at all. Just get the more durable XV as it has no unveiled parts and is actually better tuned.

Another tip, always compensate these graphs, use one constant compensation like diffuse filed +10db tilt or something. Let your brain recalibrate to those for a little while and then you'll be able to read graphs better. Especially if you're not using a simple curve like Harman which is a bit easier to read and judge.

Got it! I've been using the Tilted DF target for my comparisons, which I find much more revealing than the standard Harman curve and it is indeed my primary EQ target as well.
Regarding the Ananda Unveiled, I had a chance to audition it once. Interestingly, that 8kHz peak seemed almost non-existent on my head—likely a case of individual HRTF where my ear's natural resonance didn't align with the driver's peak.
That said, I'll definitely take your advice and check out the Edition XV next time. It seems like the safer, better-tuned, and more durable bet. Thanks for the heads-up!

 

[Jiraya369]

Got it! I've been using the Tilted DF target for my comparisons, which I find much more revealing than the standard Harman curve and it is indeed my primary EQ target as well.
Regarding the Ananda Unveiled, I had a chance to audition it once. Interestingly, that 8kHz peak seemed almost non-existent on my head—likely a case of individual HRTF where my ear's natural resonance didn't align with the driver's peak.
That said, I'll definitely take your advice and check out the Edition XV next time. It seems like the safer, better-tuned, and more durable bet. Thanks for the heads-up!

get the XV, a DX5 II and if the XV doesnt have balanced cables then a pair of balanced cables

Assuming you dont get hit with poor qc, you can call it your headphone endgame.