Testamonials:
Below are edited quotes and impressions condensed for easy reading, to be updated monthly.
We are currently at a 100% approval rating for everyone who owns or hears them. All are impressed.
We will be updating this page with latest Impressions first. Testimonies from all buyers and listeners. Real people..
Date/Screen name/Impressions:
June17, 2026:
From "North-Educator-493"
I sent my HD800S 'phones to Vince at Centro-Force and he did the mod.
This may be the best money I've spent on audio in the last 52 years.
The CF mod takes an already good headphone, albeit with real flaws, and brings them to world class.
There's more bass (and it's defined and articulate).
The treble is smoother.
Mids are more "lush".
Also, there's more speed and PRAT.
... Frankly, I was surprised at the difference!
...This mod doesn't affect the ability to EQ, so you can use what you like...
This is one of the best "bang for the buck" audio product I can think of...
The HD800S, while very good before (with real caveats) now becomes truly world class - especially if you use a good tube amp.
This has now become my "end game" headphone....
Very highly recommended!
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May 9, 2023:
From "SpectralMornings"
I recently got the Centro-Force mod. All I can say is that it takes the HD800S 'phones to world class levels. Speed, PRAT, more natural, highs are "tamed" and more accurate, bass is tighter, deeper and more defined. I'm hearing things in familiar songs I haven't heard before.
The mod really opens up the soundstage, especially the depth. Notes emerge in a very natural way from a blacker background. Noticeably more enveloping than stock..
Sound is warm, yet dynamic, with details.
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May 2, 2026:
From "Purk"
...Bass impact and dynamics are better but the standout for me is the spatial cues and stage depth for me. I was able to compare the mod on HD800S anniversary, to my stock HD800S anniversary side by side earlier this year...
.... April 22,2026:
Sounding better from portable DAPs really win me over here... The mods really allow the HD800 to sound great out of my DX260.....
Can't second this enough. Rich, warm, and organic with spherical staging. It sounded great out of my desktop rigs as well... The mod CF really enchanted the spatial depth....
April 20, 2026:
I have a lengthy auditioned earlier this year, and if you value a slightly more robust dynamics, better bass bloom & extension, warmer and smoother treble presentations as well as outstanding depth of staging and spatial cues, then the CF mod is an easily recommend from me. The CF mod also sounds better on portable DAPs as it is less forgiving and sound slightly fuller compared to stock unit....
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April 24, 2026:
From "kingoftown1"
I took a chance and ordered the CF mod, and got around to installing it in my HD800 tonight... I like what I'm hearing so far. My initial impression are same HD800 character, but more natural balance and improved dynamics...
....I do think it's a worthwhile mod compared to sdr, etc.
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April 22, 2026:
From "BaltColts"
I am not a reviewer but this is some of what I sent to Charles after he modded mine... Mids and subbass are noticeably better. It's not a basshead better but it hits the mark. Drumbeats are natural...
Their website said it would be live, dynamic and larger. I totally agree. It's also fast and has good timbre....
I absolutely love what you have done. It is my best set now, for sure....
Everything is balanced and natural. YMMV - Very little, if any EQ, is needed. Personally, I don't need any.
I tried it with various DAPs and headphone amps. Regardless of their power, it works well with all..
It has such a space around each note that I am trying to listen to my music all over again.
... I am 100% satisfied with my mod and totally agree with what others have said. Now that it is being offered as kits makes it even more of a good deal.
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April 22, 2026:
From "joseph69"
I listened to the CF mod at CJNYC '26 in an isolated area outside of the show...
It sounded so rich, full and warm with excellent depth and staging, detail retrieval and realistically smooth highs and beautiful bass texture. With that being said, I was listening to the CF out of a AK3000 DAP and was very, very impressive, so I'm sure hearing the CF out of a dedicated desktop system would be an even bigger scale in sound quality...
I've owned both the 800 & 800s in the past, and if I was still a current owner, I'd already have the CF mod done and be enjoying them even more.
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April 20, 2026:
From "boozebuttons" Co-organized 1st International HF Meet (NY 2006)
"Godfather of Babylon"
I also heard this at CanJam-NY, and agree with ESL1 assessment of the mod...
The mod made the hd800 sound more organic... Even "Drew" from Moon audio heard it and agreed...
I should send my Hd800 to Charles to mod.
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April 20, 2026:
From "ESL-1"
I heard this at the last CanJam-NY, and it sounded quite good and the finish work was excellent.
Sound was dynamic and extremely open and transparent. The designer knows how to extract the most from his work. If I still had my HD800 I probably would've made the leap then and there.
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Apr 4, 2025, (Older prototype version.):
From "Xinran"
...at my friends place and I have to say both of us are super impressed....
The soundstage became wide with a better imaging precision as well as a utopia/final a8000 cleaness that was not there before. Is no longer bright sounding as well.
Overall it turned out great and I will send some pics later.
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Jan 2025 (Original prototype version.):
From "Crandon"
I've listened.... over the last few days. I really like how clean and detailed the highs are...
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Thank you for reading Impressions and we hope you will enjoy this Mod too!
Contact for further info
Contact
whitigir@yahoo.com
ABOUT US:
The Centro-Force name came from our teamwork design. It evolved from the improved center driving forces that enabled a more evolved extension to the rear. AKa, "Centro Force". So our name has a meaning attached to the foundations of this Mod.
We are Enthusiasts and listening to Music is our hobby, chasing what we love. Seeking a "reference" headphone that can "do it all" to reproduce everything in the Recording, as Natural and real as possible, without lacking bass or Musicality.
In our Opinion, a true "Reference" should be as Realistic & Natural as possible. From all our experiences with so many different headphones, Desktop and Portable alike, we opted for the HD800, for how Natural and Neutral it is, over all others. But the HD800/800S are now considered Ancient. We have always wished for a true successor to the 800/800S. How about an upgrade with the Dynamics of a Utopia, the staging of the 800/800S, and the detailing/resolve rivaling any TOTL IEM, for a start?... And so our quest began, and ACHIEVED!
For many years, others have tried to find ways to improve the 800/800s, but our "upgrade" work has never been accomplished before. Our work is not a "tuning mod", but a real performance upgrade. With our collaboration of being "open minded", with an "outside the box" approach, the ultimate goals of bringing the 800/800s to newer Heights were accomplished.
Finally, we arrived at Something that restores real Sub-Bass/Mid Bass, while keeping mids natural and as close to stock as possible, and finally cleaning up the high frequency issues (phase shifts, ringing & other parasitics which introduced harshness). These past issues, annoyances, and distortions that plagued the 800s were resolved (not masked like past tuning solutions), by controlling the "Upper Spectrum", extending its control all the way to 22Khz.
In the end, we have achieved a more correct Bass, natural mids, and airiness, with detailed highs giving clarity without harshness, like never before... A greater soundstage, resolution, Dynamics, and flawless Impulses Responses. No words can express enough of how fruitful the Centro-Force is from the results of our hard work. The one thing we are so sure of is that, if we enjoy it this much, so will you.