[Sigmaaa]

I only tried EQ to better spot the thing that made the 660s different from the hd650, I don't like EQing when listening, it involves too much distortion. Maybe only in the bass, where there's not much detail, but I feel that in the rest of the spectrum adding with eq gives something different than a naturally boosted sound.
If EQ had worked for me, I wouldn't have kept the whole HD6xx series. (after lacking one or 2 of then for some periods). One has mellow rolled off highs and boosted midbass, other has boosted high-midrange and weaker midbass, and the third more present highs and very very little recessed high-mids.

 

[SilverEars]

After trying out several rock tracks, I'm realizing that there is a dip in the 2-3k range making vocals sound distant on some tracks. I'm thinking that HD650 is more forward vocals as there isn't that cut there. In general it does sound a bit dulled except the bump at 5-6k. Definately not neutral(as I thought earlier), but a bit on the dulled side. It does suppress treble energy to a degree. This maybe why dynamics sound compressed. I do think it's similar to HD650 in terms of dulling the treble, but not completely. It has that 2-3k recession, pushes back the vocals, and limits cymbals sound tonality by dropping off after 6k. More treble energy than the HD650, yes, but also HD650 has forward mids I believe in comparison. I'm also sure it's faster driver than the HD650.

No doubt that solderdude's graph represent what I hear.

 

[Sigmaaa]

If you refer to the last graph on this thread, then the hd660s is significantly more present at 7-8kHz than the hd650, despite the dip. Also, the 2-3khz on that graph is the same, 0.5dB difference, but I can hear about 2dB less at 3-4kHz. Most headphones have a recession there, usually even bigger. Well, it differs a bit, but they have one around that area, to minimize ear ringing and echo and to sound less shouty. HD600 is different in this respect, with a 3.5khz peak instead of dip. Some can't stand it, but it doesn't bother me, I prefer it to the hd650-660s midbass boost.
Also, I can hear cymbals pretty clear on 660s compared to 650, a step further would start getting into the Beyer-AKG piercing treble territory.

 

[SilverEars]

This is solderdude's graph of HD660S



HD650 and HD660S

 

[Sigmaaa]

Yes, the various measurements look different. This one doesn't show the 9kHz boost from the previous page, but I can hear it, although it's pretty mild.
That's why I said the measurements are somewhat inconsistent. Beyond 7kHz the measurements are also hard to be precise I guess. This one shows the mild 2dB 3-4kHz reduction, anyway.

 

[franz12]

In the end, I let my hd660s go. It failed to win my head time. In fact, I didn't reach to it at all while I possess..

 

[Mike F]

If you refer to the last graph on this thread, then the hd660s is significantly more present at 7-8kHz than the hd650, despite the dip. Also, the 2-3khz on that graph is the same, 0.5dB difference, but I can hear about 2dB less at 3-4kHz. Most headphones have a recession there, usually even bigger. Well, it differs a bit, but they have one around that area, to minimize ear ringing and echo and to sound less shouty. HD600 is different in this respect, with a 3.5khz peak instead of dip. Some can't stand it, but it doesn't bother me, I prefer it to the hd650-660s midbass boost.
Also, I can hear cymbals pretty clear on 660s compared to 650, a step further would start getting into the Beyer-AKG piercing treble territory.

Sigmaaa, we're exactly opposite in this respect. I totally understand how you could prefer the 600 to the 650, but I'm one of those people who just can't stand the 3.5kHz peak on the 600. I completely recognise the faults of the 650, but to my ears it's a more tonally natural and more pleasant set of faults than the 600's. I'll be interested to see if I think the 660 S is a better set of compromises when I get to hear it.

Nobody has addressed my point that the bass on the 660 S is widely reported to different (better) than the 650 despite the fact that all of the FR graphs show it to be nearly (or actually) identical. What's your take on this?

 

[SilverEars]

Sigmaaa, we're exactly opposite in this respect. I totally understand how you could prefer the 600 to the 650, but I'm one of those people who just can't stand the 3.5kHz peak on the 600. I completely recognise the faults of the 650, but to my ears it's a more tonally natural and more pleasant set of faults than the 600's. I'll be interested to see if I think the 660 S is a better set of compromises when I get to hear it.

Nobody has addressed my point that the bass on the 660 S is widely reported to different (better) than the 650 despite the fact that all of the FR graphs show it to be nearly (or actually) identical. What's your take on this?

It's interesting how people have different sensitivies. 3.5k should be more prominent for our ear sensitivity as well(atleast what Munson & Fletcher illustrates based on their sample size). It's just that the kind of treble 3.5k is more of a thin tonality that wouldn't bother me as well. I think when it gets closer to 5k, I hear tape stripping type sound if prominent, which I don't find that annoying. Now, when we start to get higher, that's where my hot areas are. 6-8k. 7k is the hottest. I like listening to vocals, and if these part are more excessive out of the headphone, it can really ruin the experience. Treble gets thicker, and therefore more scratchy as getting to the 9k. 7k is around the area where the cymbals are, so if emphasized(relatively to the other area to lack meat, particularly in the mids), tonality can sound unnaturally metallic for me.

One thing for sure though, if I hear recession in the upper-mids, sound does become awry or vocals gets pulled back(or even buried, which is the worse case of warm headphone). I also know there are factors beyond what FR chart can tell you like in bass and speed of the driver in general.

I just wonder if others hears the treble the same way that I do.

 

[vaibhavp]

Nobody has addressed my point that the bass on the 660 S is widely reported to different (better) than the 650 despite the fact that all of the FR graphs show it to be nearly (or actually) identical. What's your take on this?

That graph represents relative loudness of different frequency range wrt each other. It has nothing to do with bass quality.

Look at distortion, thd figures to get some idea of bass quality. Even that won't be accurate, rather give you a general idea of performance level.

 

[Mike F]

That graph represents relative loudness of different frequency range wrt each other. It has nothing to do with bass quality.

Look at distortion, thd figures to get some idea of bass quality. Even that won't be accurate, rather give you a general idea of performance level.

Good points (which I was aware of) but I'm surprised that the general impression is that the bass, and more importantly upper - mid bass, is not only better quality but also actually less. It's quite possible though that the impression of more or thicker bass quality on the 650 relative to the 660 S is due to THD. Senn gave the 800 S 'more' bass than the 800 by introducing distortion, after all. Can you easily find THD graphs that would illustrate those differences in the 650 and 660 S?

 

[Anarion]

Speaking of bass distortion, it's going to be interesting how HD 58X Jubilee will compare to HD 660 S. While similar but still different I'd still think that HD 660 S will have quite a bit less distortion than HD 58X Jubilee though (especially considering the volume difference).

 

[SilverEars]

Good points (which I was aware of) but I'm surprised that the general impression is that the bass, and more importantly upper - mid bass, is not only better quality but also actually less. It's quite possible though that the impression of more or thicker bass quality on the 650 relative to the 660 S is due to THD. Senn gave the 800 S 'more' bass than the 800 by introducing distortion, after all. Can you easily find THD graphs that would illustrate those differences in the 650 and 660 S?

HD660S distortion graph according to Innfidelity's are not really all that different from the HD650 or probably generally the siblings. Impulse repose on the HD660S looks to be tighter in response(which is how I hear it as well, it sounds more damped and faster).

The HD6-- series has the typical distortion rise in the bass area

https://www.innerfidelity.com/images/SennheiserHD660S.pdf

 

[pietcux]

Good points (which I was aware of) but I'm surprised that the general impression is that the bass, and more importantly upper - mid bass, is not only better quality but also actually less. It's quite possible though that the impression of more or thicker bass quality on the 650 relative to the 660 S is due to THD. Senn gave the 800 S 'more' bass than the 800 by introducing distortion, after all. Can you easily find THD graphs that would illustrate those differences in the 650 and 660 S?

Hi Mike, the HD800S distortion discussion goes on. @jude is still at it:
https://www.head-fi.org/threads/sen...ost-for-summary.795365/page-226#post-14249682
Please read it before you go on in this direction.

 

[Sigmaaa]

The bass seems a bit faster decaying on the hd660s and the midbass a little bit cleaner, but the slight midbass boost is still there.
The hd700 was the worst in this regard, all I could hear was the midbass hump and the 7khz peak, both kicking my eardrums, very unpleasant combination. I'd have taken the 3.5khz boost any day instead.
In fact, the recording matters a lot, 3.5khz can sound harsh on some busy and heavily distorted guitar tracks. Some have sharp sounds at 7khz and a peak there could be fatat. Some may benefit a lot from the midbass boost, others can overwhelm you.

 

[Mike F]

Hi Mike, the HD800S distortion discussion goes on. @jude is still at it:
https://www.head-fi.org/threads/sen...ost-for-summary.795365/page-226#post-14249682
Please read it before you go on in this direction.

I see what you mean!