Saturday, 7 December 2019

Redscape and Creative Super X-Fi Amp: Headphone Virtualization

Thought I'd take a little break this week from all the amplifier discussions recently and post on something rather different!


I enjoy headphone listening... But not as much as actual speakers in an actual room :-). I see headphones more as a tool for detailed listening, and will reach for them out of necessity when I'm on the road or for private listening. Otherwise, I would much prefer to be enjoying the sound from my speakers.

Beyond typical reasons such as comfort (no matter how comfortable, I'm just not a fan of things touching the ears or around the head), a big part of the issue is that headphones have never sounded natural to me. Subjectively, the "inside the head" sound, while I can get used to, just isn't an experience that I find particularly pleasurable. A reason I bought the Sennheiser HD800 a number of years back was because it was said that these headphones were capable of projecting sound so that the experience was more outside the cranium. Alas, if one is expecting any headphone to do this well, there will be inevitable disappointment; unless you're applying some kind of playback processing like crossfeed, the physics will not permit such a thing. As a result, I am intrigued by ways of making that head-fi experience more life-like which is what the products today can potentially do.

Remember that there are recordings out there meant to be heard with headphones - binaural recordings - although these are few compared to the multitude of standard recordings.

A few months ago, in my "SUMMER MUSINGS 2: Multichannel and the audiophile" post, I mentioned that one way to perhaps have some more multichannel material out there is to find ways where these tracks can be used to enhance headphone listening. Already, there are quite a number of multichannel albums around - mostly ripped from old DTS-CDs, DVD-As, SACDs, perhaps Blu-Rays - it would be nice to experience these with headphones as well by essentially converting the sound of multichannel into something binaural that feeds into the headphone playback conveying the sense of space. If one could achieve that experience without needing the space and expense of a multiple-speaker system/room, maybe that would be a way to create demand, by finding some among headphone users.

The Redscape

First up, let's talk about REDSCAPE (US$199 with USB head tracker, US$99 software only, available online, 1 year warranty and 15-day money back). This product is the brainchild of Ryan Redetzke. If you've done any gaming, you'll recognize names like Prey, Fallout 3, Doom (2016), and the Titanfall series; all of which Ryan has had a hand in creating. I mentioned a month back that I missed out on Ryan's display at RMAF 2019 this year. As a result, he got hold of me and sent me the product to evaluate.

As you can see from the picture above of the box, it consists of a few pieces including some elastic fasteners plus a sleeve for connecting the headphone wire with the USB connector to reduce the number of separate wire strands. The hardware "magic" resides in that accelerometer / gyroscope box that is fastened to the headband of your headphone to perform head-tracking, similar to what a VR set-up like the Oculus Rift might do.

Since I didn't have time at first to listen to it, I figured I would connect it up to my son's inexpensive Turtle Beach "gaming" headphone and see what he thought:


No doubt these are far from "high fidelity" headphones. They sound a bit hollow, missing deep or full-bodied bass, but reasonable for gaming and the microphone is fine for chatting with friends online. He had a chance to play with it for a week before I took it back :-).

And here they are attached to my own Sennheiser HD800's on my workstation PC:


As you can see, this photo is just the right earpiece where I run the head tracker box's cable down through. You are free to connect to whichever side works best. To the bottom left of the image, we see where both the USB cable and right headphone cable come together in the sleeve. Online instructions here if you want to check out the details.

Notice the head tracking box attached to the top of the 'phones. The box is light weight so no added discomfort; my son was able to play his games for a couple hours at a time without complaint (this is how much time I let him play on the computer at a time - "screen time" rules in my household). And the USB cable is long enough to not be obstructive.

Let's be honest, this does look geeky :-). My wife asked what that thing sticking out the top of my headphones was the other night... I reminded her that audiophiles are in it for the experience and we are not slaves of fashion. ;-) She somewhat doubted that "slave of fashion" comment since she has seen some of the audiophile literature on expensive speakers and pretty cables over the years.

That's the hardware, but it's really the software side that creates the aural illusion we're after. Redscape installs some Windows (sorry Mac users) DSP software which will create the sound of a virtual space.

What the software will do is create a separate virtual device one would send audio to. The sound data is processed through the DSP and fed to your DAC which you select within the settings. Here's the I/O set-up on the workstation:


As you can see, the software has created an input WASAPI driver called "Redscape Virtual Audio Device" and it will output the processed signal to my "ASUS Xonar Essence One" DAC. As such, the sound quality will be influenced by the DAC used on the computer.

Remember to tell Windows that the Redscape audio device can handle 7.1-channel input; don't forget to do this otherwise everything will be folded down to stereo. Windows is a bit convoluted with all the sound option panels - go to Settings --> "Sound" --> "Sound Control Panel" --> Configure to get this done:




Once you get the basics running with sound and head tracking, you can open up the virtual head model showing the direction your head is facing and see the model move as you tilt and rotate your head. Here's a look at the Redscape control panel with said virtual 3D head:


Notice in this screenshot, the model head is a mirror image of where my head is turned (slightly to the left). Notice too the level meters showing that the Input is 7.1 sound - I took this screenshot playing a Blu-Ray rip of a movie with Dolby TrueHD 7.1 soundtrack going. There are a couple of knobs for the room modeling and volume level of the DSP - make sure the volume level doesn't cause Output clipping. For calibration, you can click on the "CENTER" button or the head model window to let the program know that you're looking straight ahead. I found the head tracking very reliable with little drift over hours of listening so there was no need to recenter much. There are 3 presets available for Game, Movie, and Music listening which will change the "Room" and "Volume" knobs. I tended to prefer the Game preset for all my listening which produces the lowest "Room" effect. The ON/OFF button is convenient when I'm using desktop speakers instead of the headphones.

Have fun with the "Anatomy Customization" panel to play around with "Head Width" and "Ear Size" which is used to customize your HRTF:


There's also an EQ setting - here's the Sennheiser HD800 one:


Something to keep in mind is that Redscape with the realtime head tracking and DSP does take a bit of processing power. The amount is relatively negligible with my AMD Ryzen 9 3900X computer (discussed here, about 3-5% CPU use), but if you have a lower power machine like my son's gaming Intel i5-6500 computer, this will be a bit higher:


Notice the jump in CPU demand with peaks up to ~35% on that i5 when I started playing the 5.1 Vince Gill High Lonesome Sound album (DTS-CD to 5.1 FLAC rip). Though the number looks high with the foobar playback, in practice, I didn't hear any problems or notice any frame rate issues with a few games I tried (like Apex Legends) in 1080P on a 4K monitor with an older model AMD Radeon GPU. Latency was also minimal for me even with these first-person games (I suspect there will be quite a variation depending on the game).

Let's talk about sound quality later after describing the other device I have here...

The Creative Super X-Fi Amp (~US$140 online)

See my comment in "SUMMER MUSINGS 2" about this device. Compared to the Redscape, this looks like a more traditional "USB stick DAC" with a button to turn on/off the virtualization DSP and good sized +/- buttons for volume control.

I think it's good that Creative is pushing the envelope a bit and releasing a number of other products that incorporate this Super X-Fi DSP including the more recent Sound Blaster X3 and some headphones like their Bluetooth wireless SXFI AIR (SXFI AIR C seems to be aimed at gamers) and Outlier Gold earbuds.


The Creative Aurvana SE headphones that came as "bonus" with the package are fair-sounding. I believe they're the same as the Aurvana Live!. My budding music-lover daughter likes them as the earpads are comfortable, they're relatively small, and light; clearly an upgrade from the little Apple EarPods she was using. Compared to higher end headphones or inexpensive but good IEM's, they're a bit midrange-accentuated with constrained dynamics.

I think this review of the Aurvana SE/Live! is a bit generous when it comes to sound quality.

Connected to Huawei P30 Pro phone by USB-C cable. Notice the small green LED above the large round button on the Super X-Fi Amp. This tells us the 3D surround DSP is active.
What is special about this device is of course the DSP capabilities built into it that will take audio and process for playback as if listening to the sound in a multichannel room. While Redscape is Windows-centric, the Creative Super X-Fi Amp pretty much needs an Android device to take pictures of the user's face and earlobes for sound customization. After this process, you can plug the stick into any computer/phone/tablet for listening.

Basically, you download on your Android phone the "SXFI App" (sorry Apple iPhone users), take pictures of your face and ears aligned with the onscreen outline, and the program will do it's thing in customizing a profile for you. The data is processed through Creative's server which saves the profile for retrieval.

Here's an example of the "Head and Ear Mapping" on a willing subject using my son's Samsung Galaxy A8 phone (apparently I was ordering take-out sushi that evening :-):


The Android app is able to update firmware to the Amp, upload Mapping personalizations (Creative - please allow the user to rename the profiles rather than just identified by date!), and allows you to select which headphone you're listening with for specific EQ settings.

Other than the Head Mapping stuff (remember, Android phone needed), much of this can also be done in Windows/MacOS with their "SXFI Control" software. Like with Redscape on the computer, turn on the 7.1 multichannel capability in the OS:


One could select and tweak the EQ for your headphones:



Beyond that, just play some music and enjoy...

Because the Super X-Fi Amp is a DAC, I was able to run a quick measurement to check the fidelity of the device with the DSP turned on and off in RightMark; measured using my RME ADI-2 Pro FS ADC:


And some graphs based on the data:


Interesting, right? The reason I measured these at 24/48 is that this device run at a base 48kHz samplerate. For example, at 96kHz, the measurements showed a steep roll-off at 24kHz indicating that the data was being downsampled. With the 3D DSP turned off (white), we see that the "Velvet Sound" AKM4377 DAC inside does an excellent job with flat frequency response, low noise, impressive THD and excellent IMD+N. (I didn't bother measuring the power output or impedance; I can say that this thing does play quite loud though and Creative rates max power as 370mW into 32Ω.)

With the 3D DSP turned on (red graph), it's no surprise to see that the output has gone through major changes! Frequency response is now far from flat, a combination of the "Head/Ear Mapping" customization and headphone EQ. Crosstalk values have dropped as one would expect with crossfeed applied. And all this nonlinearity will have an impact on the level of distortion calculated whether it be THD or IMD. If I had measured the output of the Redscape, results would probably look something like this as well.

Remember, the intent here is not transparency, this is all for the sake of subjective perception. The hope is that the sound converted through the HRTF being presented to the listener conveys the sense of 3D space, will create the impression of an external soundstage, and in doing so, allows the listener's mind to be immersed in this virtual soundscape...

So how do these devices sound?

Finally, let's talk about the sound quality...

First, realize that this discussion, by necessity must be subjective. It depends very much on whether the Redscape or Creative's DSP are able to blend the channels and process the signal through a HRTF that perceptually matches with how one's ears and brain process sound. I'm guess that for most people, the effect will be good but some will find that the effect falls significantly short of the mark.

For me, I can easily say that the Redscape provided a level of immersion that was better than the Creative Super X-Fi. It sounded less "veiled", a bit smoother, and I liked Redscape's simple but effective "Anatomy Customization" to tweak the sound. The customization allowed me to subjectively "focus" the soundstage image and reduce some of the "hollowness" I often hear in these DSP techniques. The ability to change the virtual room setting also helps easily reduce reverb when not needed.

Although the Super X-Fi's "Head and Ear Mapping" looks cool and fancy, there is no way to fine-tune the effect. Sometimes, especially with simple 2-channel music, vocals can sound a bit over-processed (artificial sounding as if through a low bitrate lossy compression) and there's no way to tweak that sound. I'm curious about the effectiveness of the ear/head "mapping" photographs in actually computing one's customized HRTF; I suspect at best this is just a rough estimate.

The other big factor in the preference for the Redscape is the head tracking capability. Yeah, it's totally geeky, but the psychological effect adds a virtual reality dimension that is very cool. Sometimes the effect is very subtle. A few times while listening to 2-channel music with this on, I've caught myself thinking that I was listening to my desktop speakers in front of me. Because the head is tracked, there is an "anchoring effect" to where the speakers are located as if you're listening in a virtual room. Another testament as to how well this works are the times I've had to take off the headphones to double check if the sound was actually coming from my speakers!

Whether through the Redscape or Creative Super X-Fi, well produced multichannel music sounds great (remember, sadly there are many poorly done multichannel mixes). For example, Roger Waters' Amused To Death (5.1 Blu-Ray rip, 2015) sounds fantastic with the sense of envelopment on the Sennheiser HD800. The sound at times can be positively frightening in realism (eg. the chimps screaming in "What God Wants, Part I"). Remember that the original Amused To Death album is QSound-encoded which doesn't really enhance direct headphone listening.

As expected, another stand-out album is Dark Side...; "Money" (5.1 mix off the 2011 Immersion Box) sounded simply brilliant with both the Creative and Redscape. On a lighter note, I was surprised at how good The Carpenters' Singles 1969-1981 (5.1 SACD, 2004) came across.

Movie multichannel playback was another excellent use for the technology. Especially good when you have the full 7.1 soundtrack. I watched Black Hawk Down with 7.1 Dolby TrueHD decoding the other week on the Redscape; excellent effect and clearly superior to just a usual 2-channel fold down. Explosions, ricocheting bullets, helicopter blades, yelling crowds, etc... Wow. Zombieland (2009) was both frightening with the headphones and hilarious for those who like this kind of stuff :-). Good sound helps enhance emotional response.

Finally, another application one might want to try is gaming. I didn't use the Creative device for this purpose but as I showed above, I had installed the Redscape on my son's gaming machine initially. While the Turtle Beach headphone is far from good fidelity, the surround sound clearly accentuated things like footsteps, gauge distance of sounds, and helped localize voices of opponents and partners in a multiplayer arena. To be honest, neither myself nor my son have adequate gaming skillz to say if the technology would improve our scores :-). My son enjoyed his time with the device and didn't complain of latency issues when playing his usual Counter-Strike, Minecraft, and various others I'm not familiar with.

I had bought the Creative during the summer. And now the experience with the Redscape is certainly compelling enough that I bought the Redscape as well!

Like I said at the start, I'm not one to prefer headphones to speakers. But it's great to see that technologies like these are available for those wanting to give them a try. You might find these solutions to be much preferable to just straight 2-channel headphone playback. Unfortunately, I don't think Creative has any kind of demo available. However, if you're curious about Redscape, check out the demo page. This is a good way to hear for yourself if the DSP sounds good through your computer/DAC/headphones and if the 3D effect is agreeable with your ears/brain.

When I wrote the "SUMMER MUSINGS 2: Multichannel and the Audiophile" article back in July, Dush commented on the open-source project Impulcifer. Check out the Impulcifer Measurement Wiki. Unfortunately, I have not had the time to try this out quite yet but hope to do so in the days ahead as I have some Sound Professionals MS-TFB-2 binaural microphones coming my way with their microphone power supply. Hopefully I'll be able to record some low-noise, good sounding binaural material also.

The ability to provide one's customized HRIR (Head Related Impulse Response) captured with our own heads and pinnae is a way forward to achieving higher quality binaural playback. I heard that at CES2018, the Creative Super X-Fi demo actually measured the HRTF of the audience members; perhaps that's why they blew away a number of tech reviewers? Would be very cool if somehow the advanced user can import personalized data into either the Creative Super X-Fi or Redscape (keeping my fingers crossed :-).

---------------------------

Happy December everyone! It's amazing how quickly the year passes. Music in rotation over the last week includes the indie ska band S.M.A.'s On The Farm (1996, DR11, thanks Allan Folz for the suggestion!). Beck's new album Hyperspace (DR5) sounds decent and I like it when he's not too slow and melancholic across the tracks. This album thankfully doesn't have as much audible distortion as his previous Colors (DR4, 2017) album - yes, mastering quality matters, and it might even play a part in how well music sells.

For the kids in the house, the Frozen II (DR9) soundtrack is sweet :-).

Hope you're all enjoying the season and having a great time with great music...

18 comments:

  1. Hi

    there is another such device from Smyth Research, A8 the old one, and now A16 a new version.
    I should soon get one. Can report then.
    Price is "somewhat higher". I heard A8 and a protoype of A16, absolutely amazing..

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    1. Sounds good Dipolaudio,
      Wow, $4000? That's fancy looking with lots of features...

      Yes, please let me/us know how this works out. Word on the street (net) seems to be that this is quite impressive sounding.

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  2. Very cool Arch! Great explanation of the tech and enjoyed your subjective impressions. Nice to see the balance.

    Many years ago I had the Turtle Beach HPA-2’s which were “discrete” multi-driver 5.1 headphones coupled with a Creative Extigy external processor which allows you to convert a Dolby Digital signal, via optical, into analogue 5.1. Playing Gran Turismo was huge fun to hear cars coming from behind and around you when gaming. No delays, very realistic. Movies sounded great. Unfortunately, busted the phones and could not find a replacement at the time. But looks like now there are options.

    I was initially looking at Creative Super X-FI based on last year’s presentation, but I am liking your description and sonic impressions of Redscape. It will be interesting to see/hear your adventures with Impulcifer as well. We share the same binaural mics and I have found them to be about the most accurate on the market. I would think these would yield the best transfer function, but we will see. Edit Dipoleaudio, Impulcifer uses the same method as Smyth A16.

    Keep the great writings, Arch!
    Mitch

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    1. Thanks for the note Mitch,
      Yeah, looking forward to the binaural mics coming soon and playing with Impulcifer perhaps over the holidays :-).

      Would love to see this headphone virtualization commercial space expand over the years to achieve even better levels of sound quality. Much more exciting than yet another headphone amplifier or yet another expensive pair of headphones ;-).

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  3. I don't always tease my readers with hyperlinks to 23 year old college-rock CDs with 4 figure stamping runs, but when I do, I use discogs. ;) (I kid. I kid.)

    Also available on BandCamp bros. Albeit without the live covers Easter Egg. (If you want more, my DM's are open. :))

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    1. Thanks for the note Allan and the BandCamp link.

      Yeah, to get the full experience, one needs that CD version :-).

      Delete
  4. Really cool tech introduction, Arch. I never knew this stuff existed. Thank you.

    To my mind THIS is where the hobby needs to go. Not, teasing out which is the latest DAC to most faithfully reproduce the 64 bit, 1.21 GHz, DR2 vault re-master from the Carter administration that the streaming services are pushing on the public this month.

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    1. Yes Allan, exactly.

      It's perhaps "inconvenient" for much of the audiophile industry to speak of, but so much of the new products really do not and perhaps even cannot push the envelope on sound quality because we've already surpassed the threshold of human hearing already (speaking to the DACs especially).

      More technologies such as these that definitely will change the sound for specific intentional purposes and which can cater to individual preferences could open new avenues of exploration and excitement in the hobby...

      Delete
    2. I hadn't thought of it exactly this way before, but I think you've hit the nail on the head. The incumbent audiophile co's are mostly hardware guys, but the next logical place to take the hobby is almost entirely in the software domain.

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  5. Hi Arch,
    Fun stuff. Redscape has an online demo that is very impressive, especially at that price. Whether I listen to headphones enough to make it worthwhile is another issue...
    I did notice in my case that while the online demo did create a very believable sense of space, the sound never seems to emanate from in front of me as claimed. It's as if my head just got very large :)
    I'm wondering if others' experiences differ.
    Keep up the interesting work
    Phil

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    1. Thanks for the note Phil,
      I find that it varies for me. Depending on the material and what I dial in with the "Anatomy Customization" menu in Redscape, I can get to the point of hearing and believing that the sound is in front of me.

      That "believing" part is the difficult thing especially when I know that there are these headphones stuck to my ears. This is why I think more accurate incorporation of customized, measured HRIR to one's ear/head is important.

      Will see once I play with Impulcifer :-).

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  6. The Dev on Impulcifer has continued to dramatically improve the application. It's setup process is now easier than ever. There's virtual room correction where you use measurement mics (UMIK-1) to take measurements at exactly where your left and right ear was during the binural measurement. Impulcifer then flattens out the frequency response for each channel and applies whatever room curve you like (Harman's is the one that it ships with).

    Because you get no cross talk, and because your head is always in the sweet spot with earphones the sound you get ends up sounding better than my real system. I've simulated my nice LS50 setup at various seating distances and now travel with that wherever I want. From planes, to airbnbs, to public transport. It's remarkable. I find a nearfield measurement best for tablet/laptop use and midfield for home use with the TV/projector.

    The primary headphones I'm using with Impulcifer are the Bose 700s. That way I get noise cancellation. I've recently been doing a big house refurb - when the jack hammers are going off I don the headphones and can still watch a TV show in perfect surround.

    You can even use IEM's using the authors other project - AutoEQ. IEMs can't be used on the Smyth because you can't get the headphone compensation. But by generating an EQ you can transform whatever over ear headphones you use to the IEM's frequency response. I'm having an amazing time using my Airpods Pro with this. The Airpods Pro have extreme noise cancelling and are so comfortable it's almost like audio-virtual-reality. Part of what loses the illusion that you're listening to speakers is that I can always feel the headband even in ultra comfy open backs. With the airpods I forget I have them in - I can even lay down on my side with them.

    Finally my ultimate use case for Impulcifer is with simulating large viewing angles of an IMAX with an OLED TV. If I sit between 0.7m and 1m away from my 65" OLED it has the same viewing angle as an IMAX theater (70 degrees). Because my theater is a batcave with black velvet curtains on all 4 walls and perfect light control due to a JVC x9000 projector when I sit that close to the OLED it feels huge. Before sound used to be a problem - when sitting so close it's really obvious that the center channel is below the screen. With Impulcifer I'm able to take a measurement with all my speakers in the ideal positions "behind" my OLED. So my OLED becomes accoustically transparent. Combine that with bass transducers you get an increadible experience that far outshines even my 120" JVC x9000.

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    1. Holy smokes Dush...

      Now I'm really looking forward to experimenting with this after that testimony! I didn't know about the Airpod Pro and looking at reviews, it looks like Apple has done a good job; hmmm, might have a look at this product as well!

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    2. I love mine. I've owned every top range ANC headphone/earphone and they are by far the best for noise cancelling for me. I test this with YouTube noise clips played over a 7.2.4 system and go back and forth. The comfort is unreal.

      They do exhibit self noise though so for Impulcifer use in quiet environments I still use the Bose 700. They are the only ANC headphone I've tried that barely has any self noise.

      Had a marathon sesh of viewing on my 65" C9 yesterday, then in the evening when my wife was home switched it up to the 120" JVC with speakers. For single watching sessions I much prefer the OLED with Impulcifer :)

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    3. Wow. I HATE the multiple ways Apple uses to put their customers on an upgrade treadmill, but you have me seriously considering pulling the trigger on pair. Christmas and all... :)

      BTW, I had a buddy (freq traveller, not an audio nut) mention the Bose 700's reset the bar on noise cancelling. True?

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    4. Here's some measurements: https://www.rtings.com/headphones/1-3-1/graph#896/3209/678 of the Bose 700 vs the XM3.

      The Bose 700 doesn't really push isolation on more than anything else. Even their old QC35II. But it does have little to no ear drum suck and a much better transparency mode that minimises occusion effect.

      The measurements are on a dummy head though and dummy heads don't have hair, side burns, glasses, odd shapes etc. For me I've always found the inner ear ones like Air Pods Pro or Sony WI-1000x offer far more isolation in real world usage. ymmv

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  7. I'd love to see you compare these to the built-in Windows Sonic.

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  8. Wondering if you've heard of Hesuvi

    https://sourceforge.net/projects/hesuvi/

    It's got impulse responses from a variety of commercial virtualizations you can try out and they sound drastically different.

    My personal preference is Dolby Headphone, though it does seem to muffle the highs a bit, while Out of Your Head seems a bit too sharp.

    Hesuvi also comes with parametric EQ to compensate for a huge number of headphones.

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