The Most Excellent Sennheiser Amperior and HD 25-1 II

Killing Classics
You know what I hate? Companies that change products just to have something new to tout. "New!" is such a powerful word. It's better than "Sex" for consumers, PR people, manufacturers, and, yes, journalists ... even I salivate at the thought of "new" headphones from someone like Sennheiser. (Sex is better in private, of course, but problematic to sell.)

For example, a couple of years ago Denon had a great little headphone in the AH-D1001, but they decided they needed something NEW!, so they discontinued it and produced the markedly inferior AH-D1100. (Fortunately, Creative picked up the AH-D1001 design from Fostex and produced the Creative Aurvana Live!, which sounds great, but we're not going to get that lucky all the time.)

Heck, even Sennheiser let the HD 580 die, and the HD 600 is quickly disappearing. Now we have the HD 650, which is arguably not quite as good as the HD 600 and is much more expensive. And if the HD 580 were still in production, it just might be the best sounding full-size, open headphone at around $199. A little more gasoline? I'd love to have my old pair so I could hear it again, but I'm thinking the Beyerdynamic DT-801 of 20 years ago would be better than many of the current offerings.

Alright, I'm whining too much, but it does piss me off. Which is exactly why I'm so stoked Sennheiser decided to yet again breathe more life into the HD 25-1 II and produce the Amperior. Their development team left the good bits alone, and made incremental improvements with razor sharp engineering skills that few other manufaturers in the world possess. I love these headphones!

The Sennheiser Amperior ($349 MSRP) and HD 25-1 II ($199 MSRP)
I've already reviewed the HD 25-1 II, but I think it's important to review the Amperior in context with it's older, but much less expensive brother. I will be skipping some information in this review, so if you're interested in these cans you may also want to read my previous review to complete your reading about this product.

These nearly identical headphones are on-the-ear, sealed headphones, with a split headband. This configuration provides excellent stability on the head, and when positioned properly, deliver a good seal on the ear and good isolation from outside noise. These are both great headphones for DJs, ENG (electronic news gathering), location audio recordists, and any pro audio application where good sound quality, isolation from outside noise, and stability on the head during movement are required. For all but critical listening applications like mixing and mastering, the less expensive HD 25-1 II will easily suffice; for the critical listener, the Amperior is a treat.

What's New in the Amperior
The most obvious differences are the sexy aluminum ear-cups and headband button, and a one-piece cable assembly (the clamp is molded to the cable, see photo next page). From the outside the Amperior's earpiece housing looks like it might just be a stamped part, but crack it open and you'll see it's milled out of a solid piece of aluminum. That's not cheap! Is it more than just cosmetic? Does it really make a difference? I took the headphones apart for a look-see.


In the picture above, we can see that the inside of the blue anodized aluminum Amperior capsule is a machined part, and there are two pockets into which some sound absorbing foam are inserted. The HD 25-1 II capsule housing is an injection molded plastic part with stiffening braces. Other than that, both headphones are very similar. The earpads shown are different, but the HD 25-1 II does come with both earpad types. The driver assemblies look identical but for the markings. The drivers do have different impedances, but measurements show remarkable similarity, so I think they are much the same internally.

The idea of the "stiffness" of the capsule housing itself is very important in the case of these headphones. Let's take a look at why that is so ....

Sennheiser USA
1 Enterprise Drive
Old Lyme, CT 06371
(860) 434-9190

killmurer's picture

From the pictures it seems like it you compared the amperior with velour pads to pleather clad hd 25s? Don't the pads themselves make a big enough difference?

Tyll Hertsens's picture
They'll almost certainly make some difference. I should try to measure it ... but it's late now, and I don't want to think about it. Maybe in the morning I'll reconsider.
kitasaitama's picture

Don't these headphones have something like a bag to take them like DT1350 does? It will be a pity If they don't....

donunus's picture

LOL this would be pretty funny if they sounded almost exactly the same when both are using the velours.

Limp's picture

You know, the 25-1 has a steel cable, while the Amperior got copper.
Sure that's not why you're hearing a difference? ;)

13mh13's picture

$50 more than 1350 ... so are they better, different, etc?

bravo4588's picture

Do you know when they will hit the European market?
And is the Amperior really better than the DT1350? WoW!!

Roy G Biv's picture

The jack on your Otterbox Defender Case is TOO DAMNED SMALL!!

2Twinster's picture

Hey Tyll, can you try the two pieces of damping from the Amperior in the HD25-1 II cups? That could be enough to reduce the backwave reflection.

13mh13's picture

Signs hung around Senn. HQ read: "Kreatshe Demand"

Orig. Sennheiser lab prototype: Aluminium body (like Amperior). Senn. mkting dept. says: Diese will nicht sellung -- zu fukkung teuer. Use plastische kapsule fur now. "Kreatshe Demand". Get mann fukking hooked on model's sound. Dann, few Jahren spater, introdusche NEUE+IMPROVED "Amperior" mit effektiv psychologische kampaign.
Sell lots. Kollect viele Marks. Gehen Sie auus fur Bier.
Next kampaign: HD700

Okay, so I'm a sucker: The IE-80s have metal capsules (over IE-8's plastic) and they are better.

ultrabike's picture

I was seriously considering an HD650, but the prices have gone up dramatically. This deal with the Amperior is not very attractive. It almost seems like Senn wants to pull out a Bose marketing strategy with these prices. I'm eyeing the Denon D2000 and the Beyerdynamics more seriously now... I still have a lot of respect for Senn, but this Amperior + HD650/600 and the HD800 price is IMHO very questionable. Meanwhile you have Skullcandy pushing really hard... Weird... and interesting :)

13mh13's picture

... competition is catching up. And the "Made in Germany" logo splashed on packages and products is ... gettin' old.
Also, 'Amperior' is a weird -- WTFIT!! -- name for a headphone and, style-wise, pretty ugly.

ultrabike's picture

Agreed. I get the Amp part of the name, but what is it? "Did you say I'm-Su-perior or I'm-In-perior?" ... "No man I said Am-perior" (silence) "You are whot?"

Regardless, this reasonably performing headphone could be named Ugly-Duckling, it is the price that is hard to swallow.

13mh13's picture

First, I don't get why Senn changed their naming strategy from -humble acronym-number (HD-650, IE-8) to a 'word-name'. If one just heard 'Amperior' or 'Whatever', one would never think it was a Senn product. IAC ...
Like the case with writing owner's manuals and product literature (and web site write-ups, PDFs, etc.), when it comes to nomenclature ... best either use and or heavily consult with lotsa NATIVE-TONGUE speakers before proceeding further. Esp. when it comes to naming something for such a large worldwide distribution. Otherwise, Arschlochs like me will drill them a new one via insulting-und-embarraßing-as-fukk-to-them forum postings ;)
I think "Amperior" -- whatever-der-fukk it means -- was probab. coined up by Germans THINKING in German.

Great line from Firefox (1982 film):
Dr. Baronovich: You must *think* in Russian. [When discussing with Clint Eastwood charac. about the MiG's thought-controlled weapons system]

endk17's picture

Rather a small and most likely insignificant difference but they actually have a "Made in Ireland" logo.

The Monkey's picture
Agree. Senn's pricing strategy is not to my liking, and I think Senn underestimates the long term damage it will do to its sales and brand. I would love to see an interview with Senn about this, but doubt they would be willing to talk about such things publicly.
donunus's picture

I agree 110% Senn will never really talk about the pricing here. I've seen it before with so many senn products... px100 to px100-II, hd555 to hd558, 595 to 598, 580 to 600 to 650 price hikes with only slight tweaks, cmon. Its a good thing I happen to like their hd6xx sound because if I didn't, they would never get any business from me.

Tyll Hertsens's picture
The root of the headphone pricing issues lies with Monster and dDre's Beat marketing bullshit driving the prices of headphones up with among wanna-be teensters. Sennheiser (and all headphone makers) are riding a gravy train of unbridled demand, at the moment.

I have to review product in the context of the current market, and I thin the Amperior is a top-notch can in it's class and, relative to the competitive products, it's pricing is rational.

That said, most headphones are overpriced at the moment, and it's only pressures from makers like Philips who seem to be bucking the tide, and the consumers coming to their senses that will turn the price inflation down.

I really don't feel like Sennheiser is the bad guy here.

ultrabike's picture

I agree with the idea that Monster is driving the headphone pricing up, and I do not have any respect for Monster at all.

What drove me to write a bit about Senn here is the fact that I really like the sound signature of the HD600. I have the much lower end HD202 and while not exactly audiophile grade, they are fun to listen and I paid $22.20 for them. The HD202 are not fatiguing at all, and from what I've read here and there, the HD600 are also non-fatiguing and a significant step up from the HD202.

The Audeo IEM I have are wonderful, but they can be a little fatiguing, and I do get canal irritation after a while. Comply tips just don't work out for me in terms of SQ.

If I didn't care for Senn products, there would be little for me to complain about their prices. They could sell their cans for $10000 and I wouldn't mind. But I care because I really would like to get my hands on an HD600, and the prices are frustrating.

Not all decent HP manufacturers seem to be jacking up their prices too much: Koss, Grado, Audiotechnica, AKG, and Denon have decent offerings at relatively acceptable prices. So what? Then buy from them and stop ranting about Senn!... Well I did buy some Koss KSC75 for jogging ($16) and they are fantastic. But the reason why I rant is simple: I want the HD600 or like sound signature. And I'm kicking myself because I'm willing to pay < $300 for it, but not the current street price... So I'm naturally frustrated.

Will Senn change their pricing because of me or my ranting? probably not... So suggestions for something of the likes of a HD600 for < $300 might be welcomed :(

gorboman's picture

If your gripe is the plug, then my grip is the price. Sigh... Anyway, since it used a unibody style housing, is it heavy?

ultrabike's picture

Haven't really tried these at all... but for what its worth, aluminum is not heavy.

Negakinu's picture

And I am awesome.

Will now go and damp my HD25-1 in the exact same spot as the Amperior is and replace the cable for a copper one.

ultrabike's picture

You just gave me an I-mperior-ity complex. I'm getting my < $200 HD580 right now!... Oh wait, I can't!... Options man, options: $400 HD600... Whot!?

Tyll Hertsens's picture
You'd be better off, I think, a little epoxy into the wells of the HD 25-1 II to stiffen the plastic. Don't use too much though, as changing the internal volume. Then you could add a little extra foam if you like, but I think it's the stiffening that counts.
alvin's picture

So what's the reason for the steep pricing? Machined aluminum? Added piece of polarizing foam? Velour pads? Uh-huh. The Koss DJ100 is also machined-aluminum and has an overall better-built quality and it costs $79. I'll pass on this. My next DJ headphone will be an Aiaiai TMA-1

This is silly Sennheiser XD

Tyll Hertsens's picture
It's not just the materials used, the DJ100, though decent at its price, doesn't sound nearly as good as the HD25 series.
biseinen's picture

hi tyll,
audiophile on a budget here trying to get the best portable+ cans $400 can buy me to listen to my lossless library of all music genres on my iPhone 4S and do some occasional mixing. after extensive research, including your reviews, i’m particularly torn bet the Senn Amperior and the Grado SR 325is. i’ve always loved the Grado signature but will the iPhone drive them to any high standard? the Amperior on the other hand, have been optimized for portables. also, are they 'reference'/flat sounding enough for mixing? i’m also aware one is isolating, the other open. i prefer the isolation, but only as long as it doesn’t compromise sound quality. fidelity is my priority.

Tyll Hertsens's picture
I'd take the Amperior in a heart beat. It's well known that I'm not a Grado fan,though, so take it with a grain of salt.
biseinen's picture

Noted. I knew about "not a Grado fan" bit. Just never read the reasons why.
Thx much Tyll. I value your opinion and appreciate you taking the time.

Tyll Hertsens's picture
Grados are just too piercing and bright for me.
13mh13's picture

.... I can't belive I'm agreein' with a Shurelover like, you Tyll ;) Shure IEMs and Grados -- I own SE530s, SR325i's and SR80s -- have that "piercing" sound. YUCK. Hence, my 325i's remained unused for a few years ... then, I read on H-F about "burn-in" time being more important for certain cans/manufs/etc. So I got out a new DAP that I had to burn-in anyway (for its OWN sake), plugged the 325's in (2 birds 1 stone deal), and let 'em ALL break for a few WEEKS using XLO's burn-in track, on infinite repeat. Like with AKG 70x, this EXTENDED burn-in -- while not really changing charac sonic signature -- importantly helps in "calming" the Grado's down.
Too bad I can't say the same for Shure BA IEMs :(

woody's picture

Hi Tyll,

Been combing through the site, but cannot find any link for wall of fame. is there a link or section that you have for all of your wall of fame gear? Thanks.

Tyll Hertsens's picture
Yeah, sorry about that, I'm still working on it, finding and reviewing cans that will go up on the wall. The actual Wall of Fame post (or the beginnings of it, though it will be an ongoing effort) should be up within the month.
13mh13's picture

More Malt-o-Meal please
... oops, (wrong commercial)

More burn-in time ... fukkin' please...

I just commented on this issue above. And I know Tyll devoted an article to it.
Henceforth, I highly recommend any "professional" reviewing agency -- like IF, Headfonia, abt, etc. -- to:
(a) burn them in for 100hrs min before testing; (b) note before/after burn-in charcs (e.g., both subj. and obj. Tyll has already outlined the "procedures" for burn-in testing in his topical article.
Let's all follow the new paradigm, shall we?!!

qba3d's picture

Hello, I know ATH are not Your favorite but how would You compare those new Amperiors to es10? I was thinking of getting nice portable headphones and thought of AT but maybe Amperior are better? You said in Your Youtube review that those are thes best portable in its price..

Fantastic review!

donunus's picture

Since the two headphones here weren't really compared using the same pads, I assume they sound practically the same tonalitywise except for the resonance/vibration issue of the cups. Am I right? I guess this would just be similar to a comparison between the sr60 vs the sr60i LOL. Same headphone, different cups but this time with the senns... due to the metal vs plastic being used, one gets to brag about spending $150 more on an uglier looking blue ampherior LOL

Martyn's picture

Hi Tyll,

I recently had to sell my Sennheiser HD25-1 IIs due to sibilance and lack of soundstage. I am not sure if the headphones introduced sibilance or simply exaggerated sibilance present in the recording but the effect was unpleasant and made the headphones fatiguing to use. Please can you advise if the new Amperior headphones provide an improvement in these respects?

I also own Sennheiser IE80 IEMs which seem to have a much wider soundstage than my HD25-1 IIs. Interestingly, the IE80s and Amperiors form part of trend of Sennheiser re-releasing older products whilst publicly denying any sonic improvement.

Many thanks,


Tyll Hertsens's picture
That's been my complaint with the HD 25-1 II in the past. I felt the Amperior has indeed improved some in that regard. I was surprised as measurements don't really indicate to me that would be the case. They sound fairly clear, and just a bit sparkly, maybe.
Louis Tierney's picture

i am stuck between these two headphones and im not sure which one i prefer. for sound and comfort which one would you chose?


hoshyoto's picture

I'm not sure of his preference on the comfort between the two, but he was pretty clear on the sound quality: " The Amperiors are the best sounding supra-aural sealed cans I've heard to date, handily besting the DT1350, V-Moda M-80, and, of course, the HD 25-1 II. I love these headphones."

hoshyoto's picture

Any idea when these will be hitting the stores? Everything I've seen has mentioned March. Have there been any updates on the release date?

HCHybrid's picture

Being a trumpet player, listening to a lot of Trumpet Jazz / Funk on iPhone/iPad,
which of the two (or others) would you recommend? Can't seem to make a choice now... hope you don't mind me asking...

Tyll Hertsens's picture
Because of it's penchant for being a tad strident, I think the Amperior might be a bit rough with a lot of trumpets. In this case, I might go with the DT1350.
HCHybrid's picture

Thanks a million for you quick reply and advice. Very much appreciated and please keep up the great work! Your reviews are true lifesavers in the (hi)fi 'forrest' ;-)

HCHybrid's picture

My goodness Tyll... thanks AGAIN for your great advice!
I've just received the DT1350 and OMG!!! Can't get enough of them!
What a great set of cans for trumpet related Jazz, R&B, Funk, you name it.
They're not even burnt-in yet and I'm already stunned.
Cheers and please keep up the great work!

Tyll Hertsens's picture
Glad you're enjoying them!

(Friggen trumpets can be amazingly piercing.)

akagi's picture

Hi Tyll nice comprehensive review again, thanks for posting this up. Is the soundstage generally similiar to the HD25, I like listening to orchestra and chamber music on the quiet train journeys home.

Oh and another question, is the Amperior Made in Ireland like the HD25?


Tyll Hertsens's picture
MY pair doesn't say "Made in Ireland" like my HD 25-1 II does, but it might be that it's just an early pair. My assumption is that they'd be made in Ireland.

If you have the HD 25, then the Amperior will be a significant improvement. If you have the HD 25-1 II, then it will be a moderate, but audible improvement.

Corpsemaker's picture

Hi Tyll,I've been following your site for eight months now (much praise to your work), and in the past couple of months I saved up some money to get me a quality headphone. What I want out of a headphone is portability combined with real (can be entry level) Hi-fidelity sound, so my question is this : Would you really classify the Amperiors as at least some level Hi-Fi, or should i look for something like Shure SE425, or even SE535? ( I realise that those are completely different types of HP's and i like "Over the ear" HP's a bit more but I like both IEM's and Supra Aural, and can't afford a pair of each :))Please note that i am only asking for your opinion on sound quality, not overall performance :). ( didn't want to sound rude, but English is not my native language)
Any other durable recommendation is welcome up to 500 bucks..

Tyll Hertsens's picture
Yes, I think the sound quality of the Amperior is excellent, and it's very versatile. A very good choice, I think.
Corpsemaker's picture

Thanks, can't wait to get them and give them a spin :D

crazywipe's picture

Hi Tyll Sorry for the OT

I bought the hd 650 primarly because of your recommendation. The price was bigger than the hd 600 (230EUR for the hd 600, 299 EUR for the hd 650) and now I read that you rank the hd 600 better than the hd 650. Do I understood well? Thanks

Tyll Hertsens's picture
Many people do, but I don't. I think they're very close though.
Demi2k's picture

Does these two share the same driver?

Tyll Hertsens's picture
I believe so.
Broadshoulders's picture

Hi Tylll,

Thanks for the article. Just one question. I've just bought some Amperiors and I would love cable like the ones on the picture above. The one that comes with is really short. Is that a custom bought cable. Where could i get one?

OrbitingCow's picture

I must say I heavily disagree that these are better headphones than the DT1350. In your own measurements you can clearly see the midbass hump in these guys. I mean a lot of things are up to taste but the fact that you say they handily best the others is kind of laughable. The DTs are the best headphones in the 300 range I have ever heard and I amp them from home. In all honesty these look like a tacky jogger's pair of buds heavily overpriced even beyond that of the DTs. Anyway, that midbass hump is NOT audiophile quality however you want to put it.

With your DTs it seemed you may have gotten a pair with channel imabalances as well? Mine don't seem to have any problem with that though my right ear is about 1dB more sensitive than my left one. Hard to say as measuring those kinds of things is pretty tough with certain headphones.


Anyway, I enjoy reading your reviews though I don't agree with this one at all in that regard.

dahoo's picture

so bloated and uncontrolled compared to my DT250, HD580 

like muddy water is spilled over my face. 

USAudio's picture

Hi Tyll,

I currently have a new pair of Amperiors I am evaluating.  I really want to like these headphones but sometimes I just find the sound too bright and occasionally piercing, especially as the volume rises.  Do they settle down over time with some break-in or is this just their character to my ears?  Maybe I'm just too treble sensitive as I get older.

I have an older pair of PX-100s that are probably at least 7+ years old and they don't exhibit the same brightness.  They don't have the same bass response or resolution either but IMHO are smoother in the highs, even as the volume goes up.



Elektrospeed's picture

Hi Tyll, I come from the Car Audio world, and have just recently started into the "headphone audiophile" thing, it's interesting how much focus you gave to this review based on the resonance of the cups as the main difference between the hd25's and Amperiors, as this is a VERY important subject in car audio <resonances>. Hell, eliminating resonances in Car Audio is a real PITA, and PITW (pain in the wallet). 

I really hadn't put much tought on it, but it became obvious when you mentioned it. I think it would be a nice experiment to try some "car audio resonance-reducing tricks" into headphone modding.

For instance, you could try sticking small ammounts of "Dynamat" or similar vibration dampers on the inner or outer sides (if you don't mind the ugly looks) of the cups, and listen if it improves overall SQ.

I don't know if this has been tried before, and I would do it myself, but I'm from Guatemala and unfortunately gear is hard (and expensive, mostly imported) to come by, so I rather not mess with my 'phones lol

So it would be a total win if the HD 25-1 ii could be modded into cuasi-amperiors by reducing their cup resonances, don't know if there's a difference in the driver though?

The thing is Dynamat (and similar products) comes packaged in relatively large quantities, so perhaps you could ask a near Audio Shop for some small scraps... oh man that would really be full of win...

punit's picture

Hi Tyll,

Thanks for the review .Are these two headphones below the same ?

I wanted to buy the Amperior. And am getting a good deal on the HD 25 Aluminium. If they are the same then I will buy the HD 25 Aluminium.



Light Summoner's picture

Hi Tyll I was curious what on-ear headphones would you recommend for primarily listening to classical music? I listen a little bit of pop and thats basically it but treble sounding bright and a good 3d and wide soundstage are the key factor's I'm looking into. I just got the Momentum over ears and to be honest I really do not like how the treble is laid back and I think it's not bright and sounds muffled. Im thinking between the MOE, Urbanite on-ear, Beats solo 2, Monster DNA,(hope you review the DNA sometime). These are just headphones I might be considering please recommend any on-ear headphone for my preferences. Thanks!