Sennheiser HD25 SE – not exactly closed back endgame, except maybe for me

I bought them, I should stop reading this thread . It will be fun to compare my HD25 (with Custom Cans dumping installed) with Amperior. I wonder if I should order the dumping kit for Amperior as well. I will probably keep Amperior and sell HD25. I am still amazed how good they are, iand I never expected on ears cans with passive noise cancellation at this level.

 

Haha, that was you? I dithered, and according to the seller you beat me by mere moments. Congrats!

If you decide on a Custom Cans kit for them, note the language on the website:

"This will fit the HD25, HD25-1, HD25-c, HD25-1 BE, HD25-1 LE and if requested we can do a version for the amperior or HD25 aluminium."

Evidently the alu cups are different enough that a custom version is required.

 

Almost worth getting multiple kits as shipping is probably more than the kits themselves.

 

Absolutely love the sound of HD 25 but can't get over the comfort even with the Yaxi comfort pads. Wish you could adjust the clamping force.

 

When I bought the Senn HD6xx mod kit 2 years ago, shipping from the UK to western Canada was 9.60 GBP. So for the 8.50 GBP HD 25 mod kit (similar size & weight so likely the same shipping rate), definitely.

 

Never tried stretching the headband over a stack of books for a few days?

 

Amperior arrived, the seller was right: the capsules are in pristine condition, the headband padding and earpds look like never used.
First the build:
I got Amperior with just a cable and single set of pads. No in line remote etc.. but for 60% less I really do not care.
The HPs look really premium, the pads and the headband padding are made of the same material as the earpads of HD800S. They are much softer and more comfortable then HD25 standard velour pads. That is important because the clamping force is ferocious. I think it feels stronger than my HD25 because they were not used much.

The cable solution is a bit weird: a short cable ending with male 3.5 plus very shitty looking, very thin extension cable. But it has Sennheiser logo on it. The first problem if you want to use a standard HD650 cable, or go balanced, is that the cable clamp is integrated into the stock cable. If you remove the cable, the right side looks ugly. But the standard HD 25 cable clamp fits into this place, and can be bought at Custom Cans for $6 plus shipping.



And after turning the capsules upside down, with balanced cable




It is important to position the cups on your ears carefully. When I just put them on, it started hurting after 20 minutes. But I found the right position and now I can wear them for hours without much discomfort and with very good seal.
More on the build you can find in Tyll's review, one of the pictures explains why Custom Cans would have to make different dumping kit for Amperior: the caps are different inside and they are made of machined aluminum. That's probably what accounts for most of the price, and weight, difference. Drivers are also different; Amperior has lower impedance but I could not find exact spec.
https://www.stereophile.com/content/most-excellent-sennheiser-amperior-and-hd-25-1-ii

Amperior disappeared from the market but the HD-25 Special Edition ($249) is available, with the capsules from machined aluminum (black). They also weight close to Amperior, the cable assembly is the same. My take: it is Amperior but, because the standard HD25 headband, it does not look that good.

Now to the sound.
So far I used only one disk but it has enough variety to understand the difference between Amperior and HD 25.
https://i.imgur.com/o6Nr9Ka.png
My HD 25 has the Custom Cans dumping kit installed. On stock HD 25 those differences may be more pronounced.
You will find more competent take on it in Tyll's review but to make it short:

1. Let's start with a good thing, Amperior is addictive. I got it yesterday morning and have spent possibly 8-10 hours listening to it already, I am writing this post and still listening with pleasure.
2. Both need exactly roughly the same EQ to tame the low end and add a bit of air.
3. I would say in terms of tuning, sound stage, instrument separation those are exactly the same ehadphones, the difference is delivery. Amperior is cleaner, touch more pronouced, I would not call HD 25 muddy but comparing to superb clarity of Amperior they are a bit congested.
4. Without EQ there is too much bass on Amperior, just like HD25, it is just a bit cleaner and better articulated. But Amperior better responds to EQ, I was able to reduce bass 60Hz-300Hz a bit less and get still get it better controlled.
5. If you look at Tyll's FR graphs they are almost the same, where you see the difference is the impuls reponse. Those heavier metal caps are just vibrating less.
6. I compared HD 25 and Amperior using Liquid Gold X, HD 25 was the only Sennheiser that worked really well with this amp, and Monolith THX AAA 887.
   But where the difference was the most pronounced and Amperior was really more satisfying, was with DAPS: Kann Cube and DX220. It could be the result of lower impedance of Amperior, I do not know. I was very happy with HD25 and Kann Cube setup but Amperior sounded not only cleaner with better articulation, but also a bit more resolving. For example, comapring to higher end open back, like LCD-X 2021, the vocals on Amperior and HD 25 lack texture, I mean human voice sounds... a bit like another instrument. Amperior paired with DX220 or Kann Cube makes the vocals sound natural, human.
   Add to it very good passive noise cancelling and Amperior makes almost perfect portable headphones.

Amperior, with good EQ can be compared to Vega, a bass heavy, but very clean. Not as resolving as Vega and does not have so well compartmentalized frequencies. Bass is bleeding a bit into midrange in spite of my best effors with EQ.
I did not look or remembered my impressions on HD 25 here before I wrote the last sentence, but I had exactly the same association.

My desire for the "audiophile" sounding closed back at a reasonable price is fully satisfied Amperior....and Audeze Maxwell.

 

If I recall, the Amperior drivers are low 20 ohms.

 

Ah from the article itself, page 2 has the InnerFidelity graphs:


So it has a hump of 26 ohms at 100 Hz, otherwise floats around 23-24 ohms.