[Majestyk]

Are you guys actually using Youtube to test your cans or are you just linking examples? The sound coming from Youtube is compressed garbage. Sometimes it's not even the correct pitch.

 

[Outaphase]

For me I'm chasing things that DO show up in recordings, good or poor - like leading-edge impulse aggravation suppresion that seem to be related to unique group delay that shows up in charts for the 660s like they do in my AKG K240's, albeit mine has lower levels of change. See if you can listen to that earlier link to Procul Harum and make it through the song without major fatigue despite the loss in quality.

In fact, the very first time I noticed the 240's suppressing leading edges was with hearing a disconnect between the actual "strike" of a triangle, and only hearing the ring. Kind of good for studio ear protection, and not necessarily full audiophile usage. My hope is that the 660s can do double-duty here for a variety of uses.

From my Dad-Rock collection, cover of Traffic's "John Barleycorn Must Die" from the St. Paul's Church in Covent Garden, London UK. Talk about a home recording, yet it would be interesting if any analytical 660s users detect the loss of the triangle strike (yet still hear the ring) or not especially when you see the visual.

(Link forces/takes you directly to youtube rather than a redirect here)



On an emotional note, rather than analytical - wow! Probably great on any set of cans!

 

[Mike F]

For me its just a mistake from Sonarworks , their 660S graph doesnt make sense just look at the low end graph , everyone with older or newer 660s can hear less mid-high bass compared to 650 . I have send them a message way back and I got no response.

First, I find it highly unlikely that Sonarworks just made a 'mistake' when they measured the HD660S. In fact, given that measuring headphones and producing eq programs that flatten the response of headphones is what they do (and have been doing successfully for quite some time), I find it much more likely that Sennheiser did an early revision which tamed the overly exciting treble response that has been reported by some owners of the very first ones here. Second, Sonarworks are far from the only measurements which show a very similar bass response to the HD650. See below the DIYAH graph where green = HD660S orange = HD650 purple = HD600:-



The fact that there is subjectively less upper-mid bass is due to the fact that the driver is faster and more resolving - especially in that region, not because there is actually less.

Also this Sonarworks true fi that I used on 650 , 660s ,Bose ae2 changed the sound signature in a way that I didnt like it , doesnt feel smooth for me . I guess Sennheiser and Others with more XP know how to tune the Headphones to be more appealing on real life hearing , some say that dips on sound signature are there for a reason. I can understand that its all about taste , personally I didnt like it and unistall it . Most of my headphones are neutral signature so …

The Sonarworks calibrations are not designed to make headphones sound better, they are designed to make them flat. This can be extremely useful for sound professionals because it removes a variable from the process of mixing and mastering, and makes any decent headphone that they have a calibration for equally useful. However, as you've observed, flat doesn't sound nice, and headphone manufactures most certainly do make headphones which have peaks and troughs in the FR for a reason. Yes, they can sound much more realistic than calibrated headphones with a truly flat FR.

 

[Outaphase]

Ok, what does this group-delay chart comparing the 650 to the 660s indicate?

https://www.rtings.com/headphones/1-4/graph#245/4014/816

WHAT are they trying to accomplish in the 660s with those major opposing peaks, and that secondary GD peak in the left ear? Is that an attempt to remove the so-called "veil", or what?

Maybe concentrating on FR is only *part* of the equation..

 

[Asspirin]

Ok, what does this group-delay chart comparing the 650 to the 660s indicate?

https://www.rtings.com/headphones/1-4/graph#245/4014/816

WHAT are they trying to accomplish in the 660s with those major opposing peaks, and that secondary GD peak in the left ear? Is that an attempt to remove the so-called "veil", or what?

Maybe concentrating on FR is only *part* of the equation..

Everything that's "happening" in the graph is happening below 20hz. Regarding the fact that neither the 660 nor the 650 produce impressive levels of sound pressure at these frequency ranges, we're most probably looking at measuring artifacts. Besides, the RTings measurements and especially their interpretations should be taken with a grain of salt.

 

[Mike F]

@Outaphase, your theories about group delay are interesting and I'd like to know more about GD (and your impressions of the HD660S when you get one), but I have to agree with @Asspirin that what ever is going on in the chart you quote is completely inaudible. How it affects anything else I have no idea........

 

[Outaphase]

Yup - basically until I get them on my head, and despite my newfound weak-knowledge about GD, I'd be doing nothing but bench-racing if I went further... I guess stay tuned..

 

[Majestyk]

I just got a pair of these. They are the Ireland version with the 'see through' badge. I thought I read where the ear pads were thicker on the 660's but they are no different then the new ear pads I just got for my 600's. In fact, I was just looking at the Sennheiser store in Germany and they only sell one pad for the HD 600, HD 650, HD 660 S, (etc) headphones.

 

[minty1]

I just got a pair of these. They are the Ireland version with the 'see through' badge. I thought I read where the ear pads were thicker on the 660's but they are no different then the new ear pads I just got for my 600's. In fact, I was just looking at the Sennheiser store in Germany and they only sell one pad for the HD 600, HD 650, HD 660 S, (etc) headphones.

To my knowledge pads have never really changed. The second pair I received had the older model number but the box stated it was built in Romania. It also didn't have the Made in Ireland stamped on the side. But it kept the older style headband with the 3 dot markings on the side. Badge was not see through either but in person it didn't bother me as much as I thought it would. In terms of sound they sound exactly like the original 660S when I compared it to my older set.

 

[Majestyk]

My 660's are actually smoother sounding than my 600's, BUT I don't have a typical headphone amp. I use a vintage receiver with a 220ohm headphone jack. So I usually have different results with headphones. Some are more detailed than what's reported and others are smoother. My 600's are fairly detailed with plenty of bass and soundstage. The 660's are closer to the 650's but have less bass (a little more bass than the 600's) and similar highs but with a little more detail. The 660's have the widest soundstage of the three.

Despite the differences (from what I read in comments and reviews) I'm really digging the sound.

 

[Asspirin]

Are you guys actually using Youtube to test your cans or are you just linking examples? The sound coming from Youtube is compressed garbage. Sometimes it's not even the correct pitch.

Just linking examples. Plethora of streaming services out there, so it makes sense to use universally accessible links. Agree with you on the quality issue.

I just got a pair of these. They are the Ireland version with the 'see through' badge. I thought I read where the ear pads were thicker on the 660's but they are no different then the new ear pads I just got for my 600's. In fact, I was just looking at the Sennheiser store in Germany and they only sell one pad for the HD 600, HD 650, HD 660 S, (etc) headphones.

Sennheiser changed the standard pads with the introduction of the HD660S. They're just offering one kind of replacement pad for the 600 series, so we're all buying the new 660 pads from now on. To my ears, the new pads make the sound a tiny bit "lighter" and more detailed.

 

[Mike F]

To my knowledge pads have never really changed. The second pair I received had the older model number but the box stated it was built in Romania. It also didn't have the Made in Ireland stamped on the side. But it kept the older style headband with the 3 dot markings on the side. Badge was not see through either but in person it didn't bother me as much as I thought it would. In terms of sound they sound exactly like the original 660S when I compared it to my older set.

See @Asspirin post above for the correct info on the pads.

From what I can gather and from my direct experience of four HD660S models the timeline was as follows:-

1./ Original production model. Made in Ireland and had 'Made in Ireland' stamped on inside of headband. Original box with Made in Ireland printed on it. See through Sennheiser 'S' badge.

2./ Same as the above but with solid Sennheiser 'S' badge.

3./ Original model, but production moved to Romania. No 'Made in Ireland' stamp on headband (obviously). Original box but with adhesive sticker saying 'Made in Romania' over the printed 'Made in Ireland' text. Solid 'S' badge.

4./ New model (updated stying) made in Romania. No country of manufacture stamp on headband. New style box (outer sleeve - the actual box is the same) with 'Made in Romania' printed. Solid 'S' badge.

If anyone has any corrections or additions, please inform!

 

[Majestyk]

See @Asspirin post above for the correct info on the pads.

From what I can gather and from my direct experience of four HD660S models the timeline was as follows:-

1./ Original production model. Made in Ireland and had 'Made in Ireland' stamped on inside of headband. Original box with Made in Ireland printed on it. See through Sennheiser 'S' badge.

2./ Same as the above but with solid Sennheiser 'S' badge.

3./ Original model, but production moved to Romania. No 'Made in Ireland' stamp on headband (obviously). Original box but with adhesive sticker saying 'Made in Romania' over the printed 'Made in Ireland' text. Solid 'S' badge.

4./ New model (updated stying) made in Romania. No country of manufacture stamp on headband. New style box (outer sleeve - the actual box is the same) with 'Made in Romania' printed. Solid 'S' badge.

If anyone has any corrections or additions, please inform!

I've been reading (here on this thread) that after the first three months or so Sennheiser changed the sound of the 660's. If true, you could add one more to your list.

 

[Mike F]

I've been reading (here on this thread) that after the first three months or so Sennheiser changed the sound of the 660's. If true, you could add one more to your list.

I personally think that that’s quite probably the case, but unfortunately it's only speculation. The list above is limited to physical changes to the headphones and the box that we know for certain.

 

[Majestyk]

I wonder if it's possible Sennheiser didn't change the drivers at all and merely changed the thickness of the pads. When I recently changed the pads of my 600's the treble was brighter, which sounded a lot better to me. The same could have been done to the 660's, but the reverse.

Here's a quote from a 2017 HD660S article: https://www.innerfidelity.com/content/sennheiser-hd-660-s-over-ear-open-headphones

There has been a slight change to the earpad. From what I can gather the earpads are slightly thicker and have a slightly beveled inside circumference. In this Head-Fi post a Sennheiser representative said is was done to make them feel a little more "roomy and pleasant." I went back and forth between my HD 650 and the HD 660 S and felt indeed there might be a small improvement in comfort, but it is subtle.

Sometimes I see photos of the 660's where I can swear the pads are thicker than other 660's. Then there's the fact that you can only buy one size pad from Sennheiser, for the 6 series. There is no exclusive, thicker pad for the 660 anywhere.