A few screenshots from a deleted thread snowballed into the most convincing Sennheiser leak of the year.
Over a few days, screenshots from a deleted thread turned into a full rumor about a new Sennheiser flagship, the alleged HD900S. These quickly spread into forums with prices, dates, and quotes from audiophile icons that looked real.
However, cracks started to show and the facts surfaced. Here’s everything you need to know about this latest rumor.
The Leaked Specifications
On August 29, 2025, a user named fuyou0623 posted on the Chinese forum erji.net, sharing screenshots from a now-deleted Head-Fi thread titled “Sennheiser 80th Anniversary New Flagship Incoming,” allegedly created by Currawong.
Even after the Head-Fi thread was removed, those screenshots circulated quickly across audiophile forums and Reddit, framing the story as a pending reveal at upcoming IFA Berlin.
Key claims at a glance
- Product: Sennheiser HD900S (claimed codename)
- Reveal: September 5 at IFA Berlin, with a YouTube stream
- Price: $2,999 (US) / €2,799 (EU) / £2,499 (UK)
- Preorders: Open immediately after the keynote at 18:00 CEST
- Shipments: Begin October 14
- Finishes: Matte black and limited “obsidian chrome”
- Limited run: 1,500 chrome units with laser numbering
- Accessories: CH 900S balanced cable (€299); HDV 900 hybrid tube/solid-state desktop amp (€1,499)
Alleged Technical Upgrades and Tuning
According to the leaked screenshots, the HD900S was described as a step forward in both engineering and user comfort. These details remained unverified, but they painted a picture of what Sennheiser’s next flagship could look like.
Driver and motor design
A major upgrade from the claims was a 42mm ring-radiator driver. This driver was said to use a new LCP-carbon hybrid diaphragm, making it 30% lighter than the current model.
Besides that, a redesigned dual-flux ring motor was also mentioned, with the goal of lowering distortion and improving overall efficiency.
Tuning changes
The posts also claimed that the HD900S would also address the most common sound signature complaints about the HD800S.
According to those leaks, listeners could expect:
- Sub-bass extension of ~20–25 Hz with minimal roll-off
- Fix for the ~6 kHz peak and treble rise pushed above ~15 kHz
- THD below 0.02% at 94 dB SPL
Overall design and build
Beyond sound, the design was rumored to prioritize comfort.
The headphones were described as lighter overall with reduced clamping force. New earpads would also combine viscoelastic foam with velour, and the headband would use gel-infused memory foam to minimize pressure points.
However, the exact weight, pad depth, etc, remain unclear.
Industry Figures and Authenticity Questions
Aside from the specs, the ‘leak’ also attributed comments to well-known people, which made the rumor feel convincing at first glance. Names like Jude Mansilla (Head-Fi), Dan Clark (“mrspeakers”), and Resolve from The Headphone Show appeared beside confident-sounding impressions.
For example, Jude Mansilla, who runs Head-Fi, was said to have written about exclusive preview events.
The thread also leaned on an “insider” angle. A German enthusiast posting as “third_eye” was said to have spoken with Sennheiser engineers, and the discussion pointed to Sonova patent DE102023203014A1 (a loudspeaker with a bass resonator) as supporting evidence.
That citation sounded plausible on its face, but it’s circumstantial. Apatent can align with many possible products, and it doesn’t verify that these particular claims were real.
Skepticism built from there.
Community members flagged AI-like phrasing and inconsistencies in the wording of the alleged quotes. And, a deeper Reddit investigation connected the dots back to the Chinese forum post, where the original poster walked back parts of the story, acknowledging that the images were fake and the text might have been AI-generated.
Resolve also eventually appeared in a Head-Fi thread to deny the quotes attributed to him.
Sennheiser’s Official Response
It didn’t take long for Sennheiser to weigh in. Eric Palonen, the company’s PR and Key Influencer Manager, called the posts “faked content” and said the team appreciated the excitement but that the rumors were fabricated.
As of publication, Sennheiser denies the existence of an HD900S flagship and has not announced any new headphone in that class.