[PurpleAngel]

  Hi,
I just got my new 558 from Germany, I opened them up, and to my surprise, there was no foam, it's not there anymore.
Could they have stop putting it there? can anyone confirm?

 
Assuming you mean the BRT (black rubber tape) that normally covers 40% of the air holes.
Maybe someone at the factory made a mistake or someone else bought those headphones before and removed the BRT and returned them without putting the BRT back in.
 
Personally I prefer the HD558s without the tape anyways.

 

[Sundown]

I had HD558's for 2 years, they broke and I bought a new pair a few weeks later. When I first tried on the new ones I was immediately hit in the face with the mids. They didn't sound as good as I remember and they felt very hollow/boomy sounding with vocals. It was bothersome that my cringe level was 4/10 every time someone talked. After about two days I remembered the mod. I had done this mod about a year in from my first pair and forgot all about it since. I did the mod with the new paid and the vocals came more to life. They were still present as before, not recessed after the mod nor more forward. They just became ALOT less boomy/hollow. Cringe level 1/10 after the mod. I highly recommend it. 

 

[balvan]

   
Assuming you mean the BRT (black rubber tape) that normally covers 40% of the air holes.
Maybe someone at the factory made a mistake or someone else bought those headphones before and removed the BRT and returned them without putting the BRT back in.
 
Personally I prefer the HD558s without the tape anyways.

I find that hard to believe, as they were in a sealed package and bought from an actual store, not online.
And the foam was missing from both sides, so I don't know about someone forgetting to put them in at the factory.
 
But who knows....

 

[djmuzi]

Today I ordered the HD558 from Amazon.de and will have a look inside as soon it arrives

Will make a comparison with the Teufel Aureol Real and decide which one I will keep...

 

[djmuzi]

The German version has such a rubber too


Untitled by m1.m1., on Flickr

 

[djmuzi]

Btw. I did the mod and after few hours put them back soundet too aggressive to my ears... With rubber inside it sounds more relaxing which I like more

 

[Sennheiser84]

Today decided to remove that piece of foam there as it was buging me already
if HD 518 doesn't have such a thing why should 558 have? lol to my surprise i can hear everything better than before.

 

[djmuzi]

I put 2nd time the foam inside. Like the sound more without this mod

 

[Sennheiser84]

In my experience there was nothing worse (the reverse actually) as that piece of foam was basically just obstructing the back (whatever they were trying to do...)
wide stage improved well, can tell as i was playing same game for a while on Vita triggering same kind of music (Danganronpa 2)

The bass is basically same (a bit more clear though) and everything else can be heard better also stands out more,
that piece of foam was always buging me cause HD 518 never had that and wasn't feeling the wide stage people talked about
until i removed that useless piece of foam lol now i can clearly say that that this are a dam great headset

 

[djmuzi]

I think I'm not able to hear the thing called stage
Sound gains more space in terms of it extends further left and right. But sound gets never in front of me. It stays in the middle of my head or slightly behind
So I enjoy the smoother sound signature of the foams. I didn't experience better soundstage without the foams (mod) .
My ears are broken LOL

 

[streetdragon]

Had my pair of HD558's for 3 years now, changed its earpads twice already, done many mods onto it, so I decided to go for it and try this one out, in an effort to match or beat the HD598.

Modded with the grill completely removed, the silver ring removed, the inner mesh removed, and the protruding wire plug sanded down holder to stay flush with the headphone's now flat earcup shape.
Sound wise i compared it to a demo HD598 at the shop.

Overall tonal balance: HD598 was really neutral with a little general mid and mid treble focus, a bit bright and has a little sparkle in the treble, while the modded HD558 is on the warm side of neutral with more lush lower mids and bass, with more relaxed treble with a little less micro detail.

Treble: HD598 treble was sharper, and slighly clearer while the HD558 modded was quite a bit smoother and relaxed.

Mids: The HD598 was more polite sounding in the mids oddly while being a little clearer, while the modded HD558 has more body to it due having more lower mids.
 
Bass: The modded HD558 has a lower extension a bit more more mid bass and also a bit more texture than the HD598.

Soundstage: This is a bit tricky, the HD598's soundstage is wide, and direction is quite clear with quite a lot of distance from the centre. The HD558's soundstage though is generally closer to the centre, a bit cloudy in comparison but the air of the instruments seem to spread out much wider than the cylinder feel of the HD598. The HD598's presentation overall feels more spacious, while the HD558 modded presentation feels a bit more 'cozy'.

Pictures of the modded pair:

Conclusion: which one is better? It's a tough decision as the HD598 is still more detailed and textured, however I really like the extra warmness and more 'soulful mids' of the modded pair. 
So, HD598 and modded HD558 are roughly equal with trade-offs. Analytical or Musical

update: managed to retry comparing them to the stock HD558 and stock HD598. For the HD558, it doesn't even compare. For the HD598, upon further testing, modded pair the soundstage sounds bigger without feeling empty. The sound characteristic is much more organic and live sounding.

Also ps: i first tried comparing with the silver ring on, it reduced clarity and texture throughout the entire spectrum, and also significantly reduced the air around the instruments.

 

[relikk356]

Awesome, thanks man! I was thinking about doing the same thing. I thought, "they are the same driver so why not try to mod a bit more." Make them as close to the 598 as possible. Your end result is how I would absolutely describe the 558; I mean that is precisely what they sound like right now to me (rubber removed only)! So I wont be pushing any further and will learn from your discovery.
 
ps: comparing them to a DT880 (600 ohm) and not a 598.

 

[Athanas1us]

This is so strange, why is the sound even slightly different between your modded 558 and the 598 at the store? They have the same driver so I can't figure out how the 598 could be more analytical, I want to listen to a 598 so I can compare them to my 558. 

 

[streetdragon]

  This is so strange, why is the sound even slightly different between your modded 558 and the 598 at the store? They have the same driver so I can't figure out how the 598 could be more analytical, I want to listen to a 598 so I can compare them to my 558. 

The enclosure plays a super big role in how this particular pair of headphones perform, seeing how the HD598 has a thin cloth and a metal grill ontop of a little bit of plastic grill, i believe this enclosure removes the warmness of the modded completely open HD558, making it sound more analytical.

Even placing netting style of cloth over the earcup with the silver ring reduced the airyness and texture fidelity of the sound a lot when i was experimenting with the HD558

 

[mindbomb]

I think the main purpose of the foam was to cushion the driver in cases of the headphone being dropped. The byproducts of the foam are a slightly better frequency response and slightly worse imaging.