[roguerto]

This made a big difference for me....... I was disappointed with the bass when I bought them awhile ago and just stumbled across this mod.
 
Now I can actually hear the bass where I could not before.... much appreciated for the video!

 

[HD555spain]

hi all:
 
Ive bought my new pair if HD 555, i just modded as you teach in the youtube video, and i have to say i notice no diferences at all.
 
I removed the two foams and just used a little strip of it, to stick the speaker audio cables. I think they sound just like b4.
 
It is true i have them only 24h and maybe they will gain that bass you all are talking about.
 
will see what happens, i dont have any amp and use win 7 with winamp and sounchip is onboard. ( hi def).
 
anyway thank you for your effort , and i think your video is very good to do the mod i had no probles at all by following your instructions.
 
See ya!
 
PD_ is there any bassy song to make a difference with this pair of headphones?

 

[xnor]

HD555spain, as I wrote earlier I couldn't find (nor measure) an improvement in bass. Most of the frequency response changes due to foam removal are around 2kHz, iirc.
 
If you really want to add bass then I suggest to look at parametric EQs or play around with adapters that increase the output impedance (basically just a resistor per channel in series with the headphones).

 

[HD555spain]

thank you for your comment, well im happy with my 555HD, i  just i didnt understand why everyone said that bass was improved noticeably by doing this mod.
I'll use EQ to increase the bass a little bit and think ill be happy with the result.

 

[Koopa989]

 
HD555spain, i just tried the mod myself and ive absolutely noticed a difference with the bass. the rubber foam piece blocks the port on the driver so the amount of air it moves is limited, taking the foam off lets the drivers push freely.
 
i noticed two things about your posts. one is that you said that you left a piece of the rubber foam in. is it blocking the port at all? the other thing about what you said is that you use winamp and dont use an amp. i used to use winamp on my PC and ive noticed that the lower frequencies on winamp are light compared just about any other media player, especially WMP. even its EQ didnt make much of a difference.
 
anyway, im just trying to help you on that issue because im loving the improvement on my 555's. i use a Sansa Fuze Rockboxed with an Fiio E5 amp. it pushes these(especially now) and my RE0's very well. 
 

 

[xnor]

Quote:

HD555spain, i just tried the mod myself and ive absolutely noticed a difference with the bass. the rubber foam piece blocks the port on the driver so the amount of air it moves is limited, taking the foam off lets the drivers push freely.

There's no limiting of air movement because it's a totally open design. There is no "port" as we know it from speakers.
All the foam does is reflect some frequencies which changes the frequency response a bit.
 
Without it, the main difference is a bit less treble (but I've also noticed a bit steeper bass roll-off), which in turn could feel to some like "moar bass!!!".

 

[markbrauer]

Seeing that this forum helped me a lot in my recent move into Head-Fi I've decided it's time to contribute.  
 
After burning-in my new 555s and amp for well over 100 hrs, and liking what I was hearing, I decided to do the foam-removal mod. I've now been listening to the modded 555s for over 2 weeks now and here are my observations.  I listen mostly to jazz, vocal jazz, acoustic blues, and chamber music with some electric blues and older rock thrown in for good measure.
 
The mod indeed does what is claimed.  Soundstage is bigger and transients are quicker.  The bass is improved in that it there is more detail.  Bowed acoustic bass has more bite and growl.  Electric bass has more pitch definition.  Good things.
 
But...  with my setup the mod also introduced a harshness affecting a narrow band of frequencies in female voice and instruments such as piano and trumpet. (I'm not knowledgable enough to identify the frequencies.)  The effect made listening much less enjoyable.  Even turning down the volume didn't help.
 
So today I put the foam back in and things are right again.  The harshness is gone, the bass is good but smoother, the whole persentation is more "polite".  But ever so much more listenable - even at too-high levels.  A good example of YMMV!
 
After this experience I suspect that Sennheiser found the 555 to be a bit harsh compared to it's same-driver sibling the 595, and stuck in the foam as a "bandaid" (literal and figurative).
 
I also notice now, that with the foam in place everything needs somewhat less gain on the volume knob to produce the same listening level.  This increase in apparent efficiency could also have driven Sennheiser's addition of the foam - possibly making the 555s work better with the portable devices.
 
All in all, a great mod.  Easy to do.  Easy to undo.  Easy to hear the difference.  A very worthwhile experience.  Tempts me to experiment with varying the size/shape of the foam, or the consistency of the foam.  Maybe it is possible to have your cake AND eat it too?
 
Thanks all

 

[bowlerama]

has anyone tried the hd 555 foam mod and the soundstage mod as well? if so how do both of these mods compare to the HD595.

 

[turimbar1]

the hd595 does actually use different drivers as you can see by the impedance vs freq graph http://graphs.headphone.com/graphCompare.php?graphType=7&graphID[]=563&graphID[]=2851
 
edit: it is the 598 in the graph (instead of the 595) this is because headroom does not have the 595 graph on their site (which is rather curious considering they have it in stock), so the drivers might have changed since then (perhaps because of the modding?).  according to my sources the 598s do not sound remarkably different than the 595s. same with the 558s compared to the 555s (even though their freq response graphs are different in the treble, 558s being better)

 

[pp312]

If that's so how is it that the drivers bear the same markings, as we've seen several times? Does Sennheiser use psychics to determine which is which?

 

[Kevin Brown]

Quote:

the hd595 does actually use different drivers as you can see by the impedance vs freq graph http://graphs.headphone.com/graphCompare.php?graphType=7&graphID[]=563&graphID[]=2851

There is a picture somewhere here where the driver in the bag from Sennheiser says 555 and 595 on it.  Maybe someone can dig that up.

 

[xnor]

Quote:

the hd595 does actually use different drivers as you can see by the impedance vs freq graph http://graphs.headphone.com/graphCompare.php?graphType=7&graphID[]=563&graphID[]=2851
 
edit: it is the 598 in the graph (instead of the 595) this is because headroom does not have the 595 graph on their site (which is rather curious considering they have it in stock), so the drivers might have changed since then (perhaps because of the modding?).  according to my sources the 598s do not sound remarkably different than the 595s. same with the 558s compared to the 555s (even though their freq response graphs are different in the treble, 558s being better)

I still have the 595 graph and it lines up with the 555 driver, because it's the same. Though keep in mind that even within the same model line there can be quite some differences. Even between the left and right driver's impedance! I have measured e.g. a 5 ohm difference at DC.
 
The newer 598 model seems to have, as you said, slightly modified drivers. Therefore the impedance curve is different, but that doesn't change that 555 = 595 driver.
 
This is not something bad or uncommon.
For example, you can also find the PX100 drivers in various other Sennheiser headphones. Or take a look at the Grados..

 

[Kevin Brown]

Quote:

Quote:

the hd595 does actually use different drivers as you can see by the impedance vs freq graph http://graphs.headphone.com/graphCompare.php?graphType=7&graphID[]=563&graphID[]=2851

There is a picture somewhere here where the driver in the bag from Sennheiser says 555 and 595 on it.  Maybe someone can dig that up.

http://www.head-fi.org/forum/thread/403963/sennheiser-hd555-and-hd595-internal-comparison-shots/90#post_7010137
 

 
Same driver.
 
 

 

 

[turimbar1]

ahh thx for the pics , I assumed the 595 and the 598 shared the same driver, but I am glad that they have gotten off their collectively lazy asses and at least put a different (perhaps better?) driver in a more expensive headphone, now whether anyone cares is beyond me, people tend to favor the cheaper end (555, 558) or the more expensive end (650) and the 600 and 595 seem to be generally regarded as not enough of an upgrade to justify the $$$.
 
that is just my perception of the head-fi sentiments toward senn's audiophile line.
 
oh and which grados use the same driver? they all have the same impedance, but I cant imagine the rs1 having the same driver as the sr60. I have a friend with a defunct sr80 (the cord is messed up) modding is fun

 

[pcgo]

I just did this mod (my first!) and there really is a nice and very noticeable difference to the sound: The bass seems punchier and even a little deeper; the cans just seem to have more air to work with and the stage does seem larger! (To be fair, the trebles really don't seem to have changed, but the bass does and that has an overall effect of a larger soundstage.) If anything, this is also the one con that I've noticed so far: since the trebles are nice (no sibliance to notice) and the bass is (now) greatly improved, the mids do seem (relatively, post-mod) a little weaker at times. Small price to pay, and one that doesn't come up in most songs I'm finding.
 
All in all, this is a great, easy, safe and cheap mod that adds clear improvements! *This* is how I've always wanted my 555's to sound!
 
...Now on to the next mod!