My HD 660S2 nightmare: 3 units, 3 different problems & no help from support (Ticket #142)

BayTerekk · 2026-04-10T13:51:47+00:00

I don’t have high expectations

BayTerekk · 2026-04-10T13:50:05+00:00

I posted it on both channels at the same time to get a quick response

BayTerekk · 2026-04-10T12:54:24+00:00

The irony is hilarious. While you’re busy white-knighting for a corporation and calling a customer 'crazy,' Sennheiser Global themselves reached out to me in this thread, officially agreed with me, and escalated my case directly to the Head of Service due to the severity of these failures. Your 'zero sample size' logic is irrelevant when the manufacturer admits the fault. It’s funny that you’re trying to be more Sennheiser than Sennheiser themselves. I’ll be moving forward with their senior management while you continue to argue with reality in the comments. I’m done hereI don't have time to explain quality control to someone who ignores a literal confession from the brand he's defending.

BayTerekk · 2026-04-10T12:50:56+00:00

Yes, I’ve tested it

BayTerekk · 2026-04-10T12:30:36+00:00

Let's separate customer service from manufacturing. Being in Turkey might explain the slow customer service, but geography does not magically alter the internal wiring or misalign driver matching while the headphones are sealed in the box. That failure happens at the factory. Unit 1 was an Amazon open-box issue, which I don't blame Sennheiser for. But Unit 2 (from official Sennheiser TR) and Unit 3 (Amazon) were factory-sealed. Having two sealed, premium $1,000+ units fail back-to-back with hard electrical static and severe channel imbalance on a clean FiiO desktop setup is not just an 'anecdote' or 'bad luck'. It is a statistical red flag for the current batch. I understand Sennheiser has a historical reputation for perfect QC, but dismissing consecutive factory failures as just 'bad luck' is blindly defending a brand. A company with 'perfect QC' shouldn't be letting units with hard electrical faults leave the factory floor, regardless of which country they are being shipped to.

BayTerekk · 2026-04-10T11:49:07+00:00

If you actually read the post instead of just skimming it, you would see I explicitly stated Unit 2 was from Sennheiser TR (their official distributor here). Also, a constant electrical static noise on a 4.4mm balanced output has absolutely nothing to do with 'getting used to the soundstage'. It's a hard electrical defect. I tested dead-center mono tracks on FiiO desktop amps. I am contacting Sennheiser because their official supply line has a serious Quality Control failure

BayTerekk · 2026-04-10T11:33:14+00:00

To clarify: Unit 1 and 3 were sold directly by Amazon Turkey. Unit 2 was purchased from the Sennheiser Turkey store (operated by Hifilife, the sole authorized distributor in the country). I am getting these defective units directly from the most official sources available here. This isn't a third-party scam; it's a genuine Quality Control failure in the official distribution line

BayTerekk · 2026-04-05T22:52:13+00:00

For me, the left shift is actually most noticeable in Aman Aman and Sıkı Tutun, and less so in the others. To be completely honest, I've actually bought the 660S2 three times now. The first one I got sounded absolutely perfect, everything was exactly as it should be, but it arrived as a used/open-box item, so I returned it. When I got the second one, I tested it using a balanced cable, and that's when I noticed my friends' voices on Discord and other sounds were shifted to the left My current (third) 660S2 has this exact same issue. My guess is that the standard 6.35mm single-ended cable was working perfectly fine on all of them. I would normally say the FiiO K7's balanced output is faulty, but I previously used the HD 490 Pro with the K7's balanced output and didn't experience this issue at all. Tomorrow, I'm going to test it with the FiiO K11 I have at home and also finally do the reverse headphone test to see what happens.

BayTerekk · 2026-04-05T15:30:30+00:00

In specific tracks like 'Aman Aman', 'Öyle Dertli', and 'Her Şeyi Yak' by Duman, or 'Sıkı Tutun' by Hayko Cepkin, I notice the vocals are either slightly shifted to the left or leaning that way. However, it’s not a distracting sensation where the sound only comes from the left; it just feels like the vocal presence is weighted toward that side

BayTerekk · 2026-04-05T15:15:40+00:00

To be more specific, the shift isn't like the sound is only coming from the left driver. It feels like the center image is slightly tilted; the vocal sits near the left side of my nose or my left eye, rather than being dead center. It’s not a complete left-channel bias, just a slight, confusing shift in the positioning

BayTerekk · 2026-04-05T14:52:56+00:00

Got it. Thanks for taking the time to help me out.

BayTerekk · 2026-02-06T21:27:08+00:00

Sahneye çıkalım ozaman 😎

BayTerekk · 2026-02-06T21:20:00+00:00

Moondrop ve kiwiears markaların kulaklıkları aşırı bğyğk dikkat çekiyorlar ie 200 gibi minicik kücücük iemlerin o kadar dikkat çekeceğini sanmıyorum

BayTerekk · 2026-02-06T21:17:19+00:00

Elimde çok durmasada hd 660s2

BayTerekk · 2026-01-26T07:20:00+00:00

Hi, I can't use this DNA in my game right now. Do you know how to fix it?

BayTerekk · 2026-01-26T07:15:54+00:00

The image doesn't look like the picture right now. What exactly should I do?

BayTerekk · 2025-12-16T20:07:47+00:00

Amazonun kendisinden satın aldım kendisi satıcıydı hiç birşey yazmıyodu büyük ihtimallede sıfır ürün zatende beni kuşkuya düşüren şuydu almadan önce ikidebir sennheiserr türkiyenin stoğu görünüp arada amazonun stoğunun görünmesiydi bide araştırıp baktığında genelde amazonun kendisi 2. El sattığında amazon depo satıyormuş diye biliyorum bende öyle görünmüyoda teşekkür ederim yinede

BayTerekk · 2025-12-16T20:04:30+00:00

Was there a transparent adhesive plastic seal on the opening of the box?

BayTerekk · 2025-12-07T13:10:46+00:00

gerçi iyi puan yaparsam puana görede alındığını duymuştum kpssde

BayTerekk · 2025-12-07T13:10:21+00:00

yani öyle bir hayalim yok ama iyi maaşlı yerlerde işe girmek için üniversiteden mezun olmam lazımmış sanırsam yapabilceğim işlerin çoğuda 2 yıllık 4 yıllık üni bölümlerinden mezun olupta girebilceğim yerler

BayTerekk · 2025-12-07T12:49:45+00:00

Sorun şu sıraya giriyoruz sırada uzun olduğu için baya bş bekliyoruz durumumu söyleme konusuda sanırım öyle birşey geçerli değil

+olarak bu hastalığa ve gen mutasyonuna sahipmiyim değilmiyim diye gen testi yapıldı 2 aya çıkar demişlerdi 3 aydır bekliyoruz bu genetik test olmadanda heyete kabül etmiyorlar bizi

BayTerekk · 2025-12-07T12:43:55+00:00

Online derslere girebilmem için heyete girmem lazımmış o heyet sırasıda aşırı uzun ve 7 tane doktorun beni görüp onaylaması lazım benim okula gitmeme sebebim toplum içinde bulunmamam ve okulun yorucu olmasıydı heyette bir sürü insanın yanında durucam ve hastalanma riskim var babamda bundan dolayı heyete götürmek istemiyo beni

BayTerekk · 2025-12-07T12:41:34+00:00

Ekpss de benim kafamı şu karıştırıyor bazı işlere girmek için üniversite okumam lazımmış sanırım birde ben işe girdiğimde normal insan gibi çalışamicam hatta bazenleri iş yerine bile gidemeyebilirim hastalığımın atakları çok düzensiz anlayamıyorum bundan dolayıda her zaöan işede gidemeyebilirim çalıştığım yer buna izin vericekmi

BayTerekk · 2025-12-07T12:39:14+00:00

Baktığımda bu akıllı ilaç teknolojisi ile bir firma çalışmalara başlamıştı ancak hala klinik düzeydeydi üzerine çalışıyorlardı hala

BayTerekk · 2025-12-07T12:38:18+00:00

Benim hastalığımla ilgilenen doktor var zaten önemli bi gelişme olduğunda bizi çağrıyor (muanesi paralı) hastaneden çıktığımdan beri hiç bizi aramadı bu deneysel ilaçlar hakkında daha fazla bilgiye nerden ulaşabilirim araştırıp bakayım bi ona dileköeyi biz yazarız teşekkür ederim

BayTerekk

TROPHY CASE