Saturday, December 19, 2015

Sennheiser HD 650 v/s HD 598 Review

I love both HD 650 and HD 598. And I'm here to show you the real picture of both these headphones, and to a lesser extent the HD 800. This is a NO BS comparison cum review and I know Head-Fi is going to screen in agony as I write this.

I have owned and used HD 650 and HD 598 quite a bit. I have also owned and sold HD 439, HDR 180, RS 170, Pioneer SE A-1000, Monster Turbine IEMs, Soundmagic PL50, Soundmagic E80s and numerous others.

I have tried but not owned HD 800, LCD2, K701/702 (not sure which one it was) and HD 518.

Headphone Amps Owned:

Bravo Ocean
Garage1217 Project Ember with numerous tubes/settings (HD 650, HD 598, HD 800)
Asus Essence One Muses Edition (DAC cum AMP) (HD 650, HD 598, HD 800)
Asus Essence STX (HD 650, HD 598)
iPhone 5s/iPad Air/iPad Mini Retina (HD 650, HD 598)
MacBook Air Early 2014 (HD 650, HD 598)

Headphone Amps Tried:

Lehmann BCL

DACs Owned:

Asus Essence STX (HD 650, HD 598)
Asus Essence One Muses Edition (DAC cum AMP) (HD 650, HD 598, HD 800)
iPhone 5s/iPad Air/iPad Mini Retina (HD 650, HD 598)
MacBook Air Early 2014 (HD 650, HD 598)

DACs Tried:

Gamma22 DIY DAC

Busting The Famous HD 650 Myth - Is It Really Hard To Drive?

All that is Audiophile BS!

It isn't hard to drive.

It sounds just fine out of an iPhone or MacBook Air but the volume just isn't there. Also, the inbuilt DAC is as good as it gets. But iDevices don't have the voltage or current to drive a phone like HD 650 sufficiently. So even at low volume there is clipping resulting in audible and measurable issues.

At very low volumes you're okay but there is still clipping as there is no reserve. You definitely don't need to change the DAC.

All you need to do is get a powerful amplifier (read powerful, not expensive): that is powerful and transparent, to provide enough clean power. Something like a Superflux HA3D or Objective2 is more than enough. A FiiO E12 isn't enough and it also colors the sound audibly, so I won't recommend that.

As long as you can a good enough amp that is transparent, a HD 650 will sound as good as it gets. Unless of course you're talking of coloring the sound, tubes, placebo, volume changes, clipping etc.

An Asus STX headphone jack is way more than enough to drive HD 650 to its full potential. An O2/ODAC should audibly be similar as well. And so will other expensive systems like Benchmark 1 and Violectric amps. Everything else is either color/distortion, clipping or plain placebo!

Audiophile AMP Myth Busted!

Audiophiles feel an amp is supposed to change/affect the sound. Wrong!

It is supposed to be a wire with gain, to amplify the signal, i.e. make it louder.

I accept most amps in the market do color the sound, but that isn't what an amp should ideally do. And a lot of non sense out there is plain placebo. Whether you like it or not.

Color = Distortion. Period!

As long as you have the correct amp for a headphone (this isn't synergy but there is a measurable science behind this), and you're not clipping and of course the amp must be audibly transparent, all of those amps will sound the same.

To get the volume equal you need to use a Millimeter. Doing it by ear or by a sound level measuring device is non sense.

As far as the HD 650/600/800 are concerned, all the below amps should sound more or less the same, if not absolutely identical:

Benchmark 1
Vioelectric neutral amps

Although there is more to this than merely output impedance, but a good rule of thumb is that for a dynamic headphone, if your amp's impedance is less than 1/8th that of your phone, you'll be fine.

The STX has an impedance of 10.7 ohm. So phones that are 80-100 ohm or more will be just fine.

HD 598 is 50 ohm I think. So technically there will be a sound signature change with slightly more bass and slightly less treble, and audibly so. But thankfully I have tried a HD 598 with it and it is fabulous indeed. Not as much as the HD 650 of course. :D

O2 and a Benchmark 1 have impedances below 1 ohm. So they can pretty much run any phone out there.

And this rule doesn't apply to planar phones like LCD2.

And then of course there are some exceptions that require too much voltage/current like HE6, K1000 etc.

The STX and O2 are fine for HE6 as far as measurements are concerned. From what I've read by other science people, that is. For K1000 - No!

Transparent = Transparent wrt the audible domain

If two amps are audibly transparent, they will sound the same minus placebo, irrespective of one being better or vice Verma.

If one is colored/warm/bright etc, of course there will be a difference. But a very slight one. These differences get exaggerated out of promotion. Even a colored one may often be difficult to tell apart in a Double A/B Blind Test.

Audiophile DAC Myth Busted!

Transparent = Transparent = iPhone/ ODAC / STX / AEX / MacBook = Same

Colored = Distortion = Slight Difference = Muses/ Android phones (I jus got heard Moto G 2014 though)

Colored DACs may sound slightly different. But that is distortion. Not hi fidelity. That is not how a DAC is supposed to be.

A DAC isn't supposed to have a sound. If it is audibly transparent, it sounds the same. End of story!

An iPhone DAC is good enough for any application in the world. It is that flat and transparent.

HD 650 v/s HD 598

A HD 650 sounds better than a HD 598 even out of a MacBook Air. But the MBA amp isn't powerful enough to do justice to it let alone making it loud enough. It is okay though, but not ideal. But it is 100% transparent and clean.

An STX or O2/ODAC or Superlux HA3D/iPhone is as good as it gets.

Everything else is either placebo or color, and it is mostly placebo.

I have been a victim of this placebo thing for years as well. No more!

If you have enough volume without color/clipping (this is hard to say without measurements) you're doing great!

The HD 598 is great.

But the HD 650 is a small but clearly audible jump across the board. With the only drawback being that it is a bit darker but nevertheless more natural and refined.

The HD 650 is as good as it gets under USD 500-1000 once you take into consideration comfort, warranty, sound etc as well. Of course the LCD2 is a big jump in terms of sound, but the HD 650 is far more neutral (I'll explain soon) than a LCD2 at least, perhaps not in absolute terms. And the LCD2 is a pain to wear.

Under USD 500, HD 650/600 are undisputed kings. Beyond USD 500 it may become debatable. And of course although I have not tried the HD 700, I'm sure it should be a decent jump over the HD 650/600.

Don't compare to phones like K701/702 or DT 880. There is a reason the Sennheiser is more expensive and sought after.

The ear doesn't hear sound like a flat Frequency a Response. So no matter how you find the FR curve of the HD 650, that doesn't make it overly dark. That is probably the curve followed to an extent by the ear as well.

Of course HD 600/700/800 might be a slight touch more neutral, with HD 800 being on the bright side of neutral.

HD 650 is better than HD 598 but only where treble is truly required. HD 598 is livelier and more fun otherwise. And far better to the untrained ear. And I do agree HD 650 is slightly dark, so perhaps not for everyone. But it is possible to get used to it and even enjoy its natural sound.


HD 650 is louder than HD 598 in bass. Both are tight. Pretty tight. HD 598 is a tad tighter. HD 650 is a tad softer. Neither is bass heavy/light. HD 650 is definitely softer and with more rumble I guess.

The tightest I heard the HD 650 was with a Beta22. But it wasn't neutral. It was warm. No doubt. Far from transparent.


HD 598 is mids forward. HD 650 has magical lush mids. Need I say more? Ya, HD 650 is slightly better.


Both are great. In their different ways.

HD 650 v/s HD 800

HD 800 is slightly more detailed, refined and with more treble. But when you compare them side by side.

I compared them with Muses and Project Ember (not STX, just for those naysayers).

They are very close. HD 800 is better. But HD 650 is slightly more natural.

The difference is far less than people make it out to be.

The difference is similar like that of going from a HD 598 to a HD 650. It is there. But not night and day, irrespective of the amp/DAC.

I've even tried a Beta22/Lehmann BCL, just to shut people up. :P

If I had the money, I'd take the HD 800 in a heart beat. But I don't. And the HD 650 is close but not quite there. So it is well worth the price as well.

And although I've not tried it, the HD 800 runs just fine out of a STX. My friend has tried one with a STX and an Essence One and there wasn't much difference unless you try to start nitpicking, and there isn't much difference even then.

A FiiO or iPhone amp is of course not capable of running the HD 800 though, with the exception of FiiO desktop amps perhaps. Won't comment on that though.

But the HD 800 is definitely a superior phone and I'd definitely get it if money wasn't an object. But a HD 650 is a close rival, though in a slightly lower league.

Comparing the below setups:

Asus STX amp and DAC
Uncolored and transparent

Asus Essence One Muses Amp and DAC
Thinner, warmer, slightly looser bass but colored. Slight difference, so some people might prefer this DAC, especially with something like a HD 800

Asus Essence One Muses DAC -> Project Ember
Closer to a STX. Slightly more SS. Perhaps a slight difference. The mids may be a bit lusher and wet. But very close and I didn't do a AB test so I may be talking BS. Very close.

Asus STX DAC -> Project Ember
Again, not sure if there is a difference or not. But definitely not a huge difference.

They are all bloody close!

I wouldn't say they are exactly the same. There are differences. But they are close. And it is definitely not an easy task to rule out one better than the other based on listening, because it is a matter of taste/preference.

But according to measurements and science, STX is flat and transparent. The other setups are not.

So if you want Benchmark level fidelity, go with STX. And I can assure you the difference between those systems, even if very slightly audible, isn't huge. And often/mostly placebo. Just like I was a victim of placebo for years.

Honestly, anything over an O2/ODAC seems non sense to me.

And an STX is just as good for most people I guess, unless you're into low impedance non planar phones or IEMs.

Other Asus products like U3, U7, Muses etc are colored and technically worse.

You're fine with a ST or STX though. Not sure about STX II. Not sure whether the difference is placebo or color. But not heard it. Just read about it.

And I hope you realize non sense about cables, power leads etc is just that, non sense.

Some NO BS links that will probably help you in more research:

1 comment:

Nilson said...

Thank you for the great no-frills review. Also, extra bonus for not spreading out audiophoolish BS. So down-to-earth I'd even go as far as guessing you being a regular at Hydrogen Audio. ;-)