Sennheiser HD 660S2 Wired Audiophile Stereo Headphones with Deep Sub Bass, Optimized Surround, Transducer Airflow, Vented Magnet System and Voice Coil – Black

Product Information

So we are talking about a relatively narrow and claustrophobic soundscape with a strong center image but with a very sharp, precise imaging and good depth layering so as not to sound congested or one dimensional. Overall detail and resolution are very good, but the HD 660S2 fall behind some mid-range planar magnetic headphones. Soundstage and imaging The HD650 is modded with the Custom Cans, copper - weight mod that only affects bass technicalities without altering the frequency response.

Sennheiser Emotive bass and powerful range - Sennheiser

The 109 PRO has a real sub-bass extension that doesn't roll-off at all so it sounds deeper and fuller especially with electronic bass tunes and modern music An interesting comparison is that when listening to solo singing voices, like an opera aria, the voice on the 660S2 is projected close to your face and at the center of it, at the front of your nose, when with the 109 PRO it feels as being moved a couple of meters away and at the upper part of your head, at your eyes height. And again, thank you Sennheiser for the 660S2, best gift I’ve received this year outside of my cat bringing me a dead guppy from my fish tank, both were unexpected. The S2 has a balanced, almost linear, lower mid-range that is followed by an emphasized center mid-range while it steers away from the upper mids boosting of the HD650.The S2 has a deeper, richer, more textured bass compared to the 600. The treble is more forward with S2. Smooth forward rather than sparkly. The female vocals of S2 are a little richer and more forward. Everything seems more forward with the S2. But, upon a longer listen it is not that the S2 is more forward. There is a sheen of glass taken away compared to the 600. There is for sure an increase in clarity and dynamics. This adds a richness to the sound. To get the earpieces positioned evenly you need to manipulate the left and right sliders – they’re a little stiff, but once you’ve got them in the right place you’re unlikely to find yourself playing around with the positioning. The transition from low-end to midrange and on to the top of the frequency range is level and even, and there’s more than enough dynamic headroom available to make the distance between very quiet and extremely loud in a piece of music very considerable indeed. The facility the HD 660S2 demonstrate with detail retrieval means that low-level dynamic variations are given full expression too, and the consistent neutrality of the tonal signature of the low frequencies and the midrange makes for a unified, singular presentation. The bass on the 109 PRO will just slightly bleed into the mids but it can't be said that it is overlapping the rest of the frequencies or clouding the mid-range.

Sennheiser HD 660S2 Review - Major HiFi Sennheiser HD 660S2 Review - Major HiFi

As far as unity of presentation, tonal commonality, detail retrieval and outright presence are concerned, the HD 660S2 have no lessons to learn. They’re a big, authoritative and profoundly informative listen, able to organise even the most complex recordings to the point that each individual strand is simple to follow. The HD660S2’s mids are clear from the middle of the mids, like 300hz-ish, all the way up to the 3.5khz area and are linear like the HD560S. They also feature that technical ability of the HD660 that allow you to selectively listen to individual vocalists. As the big focus of this review is on the comparison with the other Sennheiser headphones and the amplifier synergy, we’ll keep this part to the point. Testing was done with a series of amplifiers, using the Musician Audio Aquarius and EarMen ST-AMP as DAC, streaming music from Tidal via ROON on my laptop. For the direct comparisons I used the Cayin Audio HA-3A tube headphone amplifier, as it has an impedance selector, and it allows to connect 2 headphones in balanced mode at the same time. All testing was done in balanced mode, unless specified otherwise. Macrodynamic punch is fairly good, even though these aren’t the last word for overall slam and punch. The big similarity is in the bass. The S2 does have a milder subbass bump of the 600 but has the mid bass jump of the 650. Someone took their time to get this S2 right. They lifted some of the “boringness” of the 600 but kept the tonality and clarity and detail of the 600. They also added to the S2 the midbass bump. Great touch.The transition to the mids is even, the bass doesn't bleed into the region nor sound as overlapping them.