Why I Sold the Sennheiser HD 660S2, Then Bought It Again
Buying the same pair of headphones twice probably sounds like a perfect example of the never-ending audiophile chase.
In my case, it was more complicated than that.
I originally bought the Sennheiser HD 660S2 when I was still very new to the headphone hobby. I had come from the Beyerdynamic DT 770 Pro and had spent far too much time reading reviews that made the Sennheiser sound like it would completely transform my listening experience.
I expected an immediate wow factor.
It never arrived.
Why I sold my first pair
The HD 660S2 did not sound bad. It just did not sound spectacular in the way I had imagined.
The soundstage was intimate, the treble was fairly relaxed and the bass did not hit with the exaggerated force I expected from something described as an improved, bassier member of the HD 600 family.
I was also using a Focusrite 2i4 at the time. My equipment was mainly intended for music production, and I had very little experience of comparing dedicated headphone amplifiers, different sound signatures or genuinely high-end headphones.
I assumed the HD 660S2 was not giving me enough for the money, so I sold it.
Looking back, the biggest problem was probably not the headphone.
It was my expectation of what an expensive headphone was supposed to do.
What changed afterwards?
Over the following 18 months, my entire listening setup changed.
I added the HiFiMAN Arya Stealth, FiiO FT1 and several IEMs. My desktop chain became the Topping DX5 II feeding the Topping L50 headphone amplifier and Apos Gremlin tube amplifier.
But more importantly, I gained experience.
I started recognising that soundstage width, bass quantity and immediately obvious detail were only parts of the listening experience. I became more aware of tonal balance, vocal placement, texture, cohesion and how comfortable a headphone was over a complete album.
My musical listening also continued to broaden. Pink Floyd remained one of my main references, but I was spending more time with Pearl Jam, Incubus, Fear Factory, Massive Attack, Daft Punk, soundtracks and music where the midrange and overall presentation mattered just as much as sub-bass or treble detail.
The more headphones I tried, the more I kept thinking about the HD 660S2.
Was I remembering the headphone or chasing the idea of it?
That was the difficult question.
Had my taste genuinely changed, or had I simply started romanticising something after selling it?
The HD 660S2 seemed as though it could fill a gap in my collection. The Arya Stealth already gave me scale, openness and detail. The DT 770 gave me a brighter, more energetic closed-back presentation, while the FT1 offered warmth, bass and ridiculous value for money.
What I did not have was that intimate, vocal-focused and emotionally direct Sennheiser presentation.
Then I found the HD 660S2 brand new for £260.
Naturally, I went back to Reddit and asked: “Am I an idiot for re-buying the Sennheiser HD 660S2?”
Opinions were mixed.
Some people thought it made perfect sense. Others pointed out, quite reasonably, that I had already owned and sold it once. A few suggested alternatives or argued that changing amplifiers would not suddenly turn it into a completely different headphone.
They were right about that last part.
Did the better equipment transform it?
Not completely.
The DX5 II and L50 provide plenty of clean power, while the Gremlin gives me another enjoyable flavour when I want it. The HD 660S2 now has all the headroom it needs, but it has not suddenly developed an Arya-sized soundstage or become a basshead headphone.
A better amplifier did not replace the HD 660S2 with a different headphone.
What changed more dramatically was me.
This time, I was no longer waiting for it to flatten me with bass, throw sounds across an enormous space or reveal details I had never heard before.
I listened to what it was actually doing.
That is when it clicked.
How it sounds to me now.
The HD 660S2 is intimate, smooth and wonderfully cohesive.
Vocals sit close and feel connected to the performance. Guitars have a convincing body, drums sound grounded, and the presentation holds everything together without constantly separating the music into individual technical elements.
Pink Floyd’s The Dark Side of the Moon does not sound as enormous as it does through the Arya Stealth, but it feels focused and connected. Vocals, guitars and effects occupy a smaller space, yet the album still flows naturally from beginning to end.
With Pearl Jam and Incubus, the midrange becomes the main attraction. Vocals and guitars have presence and texture without sounding aggressively pushed forward.
Fear Factory also highlights one of the limitations. The HD 660S2 can sound dense when a mix becomes particularly busy, and it does not provide the same separation or openness as the Arya. However, its smoother presentation makes aggressive music easier to enjoy over longer sessions.
Bass has more depth and substance than I remembered, but it is not the type of exaggerated low end that immediately dominates a demonstration. It supports the music rather than becoming the entire performance.
Treble is similarly restrained. There is enough detail for me, but it is not a bright or sparkling headphone. That relaxed top end is part of why I can listen for hours, although anyone wanting maximum air and excitement may find it too polite.
Why it works alongside the Arya Stealth.
The Arya Stealth and HD 660S2 are not trying to do the same job.
HiFiMAN Arya Stealth
Openness, scale, imaging and detail.
The Arya is the headphone I choose when I want cinematic space, clearly defined layers and the feeling that a recording has expanded beyond my head. Pink Floyd, trance and large soundtracks can sound spectacular through it.
Sennheiser HD 660S2
Intimacy, cohesion, vocals and emotional connection.
The Sennheiser brings the performance closer. It gives up some scale and separation but replaces them with a presentation that feels more compact, natural and personal.
One does not make the other redundant.
The Arya impresses me more quickly. The HD 660S2 quietly keeps me listening.
Comfort and build.
The initial clamp can be fairly strong, but the headphone becomes more comfortable as the headband loosens with use.
The overall design is lightweight, practical and reassuringly familiar. It does not feel luxurious in the way its original retail price might suggest, but it feels like something designed to be worn and maintained for years.
I also experimented with cooling-gel replacement pads, but they made the sound too dark and muddy for me. I returned to the original-style presentation because the pads are a fundamental part of the tuning, not merely a comfort accessory.
What I learned from buying it twice.
The first time, I judged the HD 660S2 against an imaginary version created by reviews, price and inexperience.
The second time, I judged it against the headphones I had actually lived with.
That completely changed how I understood it.
The HD 660S2 is not a headphone I would recommend to someone chasing the widest soundstage, the brightest treble or the most dramatic first impression. At its original price, I can also understand why people question its value.
At £260, however, it made far more sense for me.
It filled a genuine gap between the warmth and bass of my closed-back headphones and the enormous, revealing presentation of the Arya Stealth.
Most importantly, it gave me something I had started to miss.
Final thoughts
Was I an idiot for buying the HD 660S2 again?
Possibly. This hobby has certainly encouraged stranger decisions.
But rebuying it taught me something important: the equipment that impresses you most during a short comparison is not always the equipment you miss after it has gone.
The HD 660S2 did not suddenly become a different headphone. My expectations changed, my experience grew, and I finally understood what it was designed to do.
I sold the first pair because it did not give me the wow factor.
I kept the second pair because I realised the wow factor was never the point.
Have you ever sold a pair of headphones or IEMs, only to realise later that you completely misunderstood what made them special?
