Sennheiser HD 660S2

[Takanaka]

How do you one-up a line of legends?

Some of the most neutral headphones in the world are a tough act to follow.
As far back as the HD 580, high-end Sennheiser headphones have inspired generations with their
balanced, natural reproduction. Recognized as benchmarks for neutral audiophile sound, the HD 600, HD
650, and HD 660S all share visible and audible DNA with the HD 66052. The revised coil of the S2, for
instance, now matches the 300-ohm impedance of the legendary HD 600 & HD 650. This new coil also
provides higher magnetic force and electrical dampening for cleaner impulse response.

The surround is now more compliant, too, dropping the resonant frequency to 70 Hz. Considerable effort
also went into optimizing the airflow around the transducer. There's more sensitivity over the entire
frequency spectrum because the magnet's air gap works more efficiently now. Taken together, these
measures result in even greater precision, speed, and resolution - with double the sound pressure at the
lowest frequencies.

Highlights​

• Open-Back, Dynamic, Over-ear Headphones with High Fidelity sound
• Ultra-light aluminum voice coil with 300Ω impedance for excellent impulse response
• Uniquely powerful vented magnet system for minimized distortion
• Outstanding quality designed in Germany, made in Ireland
• Intimate and precise yet non-fatiguing sound with great timbre and deep, accurate sub bass
• Plush ear cushions and open design for maximum comfort

Specifications​

• Transducer Principle: dynamic, open
• Transducer Size: 38mm
• Frequency Response: 8 Hz - 41,500 Hz
• Impedance: 300 Ω
• Sound Pressure Level (SPL): 104 dB (1V)
• Total Harmonic Distortion (THD): < 0.04% (1 kHz, 100dB)
• Weight: 9.17 oz (260g)
• Magnetic field: 2.5 mT

 

[markanini]

The first HD660 was a bit of a shit show. For all we know it might have been designed for efficiency first, unlike it's predecessors which came out before EU regulations of 0.5v output cap. The new S2 looks half as efficient as it predecessor for what it's worth.

OT: I'm predicting the first people to have the HD 660S2 on hand for measurement are probably jude and resolve which happen to use the 5128 now. So no meaningful comparisons to other measurements initially. I'm not saying it's a ruse, but...

 

[Fregly]

Hopefully Senn gets the graph right on this one, with bass more flat to 20hz and bumps and troughs ironed out, and improved distortion. The 660 is arguably inferior to the cheapy Drop Senns, and overpriced generally.

The ad copy sounds like cranked bass for the mass market though, and "relaxed" sound does not bode well.

 

[enricoclaudio]

Can't wait for measurements to come out. I love my 660s and are by far my favorites headphones. I can wear glasses with them and bass remains the same. Can't say the same with my DCA AEON 2 Noires which I sold because bass drops drastically when wearing glasses. I was going to purchase DCA AEON 2 Open but now I'm going to wait for the 660 S2 measurements and reviews before jumping into new open back headphones.

 

[Takanaka]

 

[markanini]

View attachment 260400

Looks like my prediction was true as far as the measurement rig goes.

 

[enricoclaudio]

Yep, looks like an improved 660s.

 

[ugur38]

They're asking 600 Euros for 3 band filter (1 LS, 1 PK, 1 HS) equalized upgrade. I had hopes when they advertised it with good bass.

 

[usern]

They're asking 600 Euros for 3 band filter (1 LS, 1 PK, 1 HS) equalized upgrade. I had hopes when they advertised it with good bass.

Distortion and max SPL is very important also.

 

[markanini]

https://www.reddit.com/r/headphones/comments/10mo3lz

 

[enricoclaudio]

My 660Ss have the same treble dip around 4700Hz. I EQ them with Roon DSP following Oratory's Harman Curve and they sound amazing. The 660S2s look even better above 3000Hz so EQ should be more doable.

 

[ugur38]

Distortion and max SPL is very important also.

Yeah I hope it has much lower distortion. Especially in bass region.

 

[Biblob]

View attachment 260400

This looks great, might have found a good replacement for my normal HD660S.

BTW, I am too a big fan of Khruangbin. I have this album on vinyl (1 of 3), just to have it displayed in my home!

 

[Tachyon88]

If you have to raise the bass output less with EQ then thats good, but the end results will most likely end up being the same type of HD6series experience and distortion numbers. Love the color scheme though, just my taste.

 

[Fregly]

I don't eq with my old school set up so that treble suck out is a no go for me. Why is it so hard for us to get a completely coherent smooth graph? It seems Mars will get populated before we do.

 

[Dazerdoreal]

- "Sennheiser 660S2"? Are Sennheiser a japanese company now? ;-) Why not just 670..
- I find it kind of funny that they try to imply that the higher impedance is a plus now after they used the 150 Ohm impedance as a big marketing argument for the 660S.
- The core idea seems to be to create a 650 with less upper mids and more bass & treble. Might be close to the 58x then.
- I dont trust these reddit measurements and would not worry too much about them yet. I would be surprised if the dip really is that big.

 

[3125b]

Seems they still miss the accurate treble that makes the 600 and 650 so good. And 600$/€ really is a borderline insult, it's still basically the same headphone you can get for 220$ from drop.

 

[Dazerdoreal]

On the amazon page Sennheiser describes the 660S2 as "relaxed". Looking at the frequency response it is clear what that means.

If you pay attention you see that the graphs are not matched in volume. The 660S2 graph is louder on average so on first glance, it looks like it has "more of everything". But if you raise bass and treble, the mids and upper mids will be relatively quieter (1000-5000hz).

Based on the graph and Crinacles measurements, I vaguely EQd the 660s to that frequency response and volume-matched it. I dont expect harmanesque but rather a "laid-back" sound. (EQd curve)

 

[ku1185]

On the amazon page Sennheiser describes the 660S2 as "relaxed". Looking at the frequency response it is clear what that means.

If you pay attention you see that the graphs are not matched in volume. The 660S2 graph is louder on average so on first glance, it looks like it has "more of everything". But if you raise bass and treble, the mids and upper mids will be relatively quieter (1000-5000hz).

Based on the graph and Crinacles measurements, I vaguely EQd the 660s to that frequency response and volume-matched it. I dont expect harmanesque but rather a "laid-back" sound. (EQd curve)

I'm confused. Is that a measurement of the 660s2? Says 660+eq on the graph itself.

EDIOT: Nevermind, I see that's your EQ.

 

[Dazerdoreal]

I'm confused. Is that a measurement of the 660s2? Says 660+eq on the graph itself.

EDIOT: Nevermind, I see that's your EQ.

I based that EQ on the graph Takanaka posted above.