Head-Fi.org › DIY and Mods › Sennheiser Hd4 8 Modding For Newbies

Sennheiser Hd4 8 Modding For Newbies

So why did I create this thread? I recently mustered the guts to open up my HD438s to do some modifying, so yes I'm fairly new to modifying. I suppose this guide could help other newbies too. The methods in this thread have been covered in several other threads, but there was no thread dedicated to the modding of Sennheiser HD4*8 models so I thought I'd share.


The internals of the HD418, HD428, HD438 and HD448 are very similar, so I believe these mods will apply to all four headphones. Be extra careful with the wires and the drivers. You do not want to damage anything since opening your headphones up will void the warranty.


Legend: Blue title = sound mod

            Brown title = cosmetic mod


First off we have the,


Tape Mod 



This is what it looks like. [Disregard the 4 holes, that's for later] 


Step 1: Detach the ear pads from your headphones. This requires quite a bit of force.

Step 2: Get some double-sided tape and tape the sides of the circle ring as shown in the picture.

Step 3: Attach the ear pads back on, all you have to do is clip them to the tiny hooks on the edge of the oval. 

Step 4: Press the gauze of the ear pads inwards towards the drivers to ensure the gauze sticks on to the tape.


What this modification does is it reduces the vibrations caused by the gauze of your ear pads when playing music at a high volume. Personally I don't think this mod is that important (I did it anyway) but if the gauze vibrations bother you, try it. 


♞ There should be no noticeable differences in sound quality.                                                                                 


The next mod requires you to open up your headphones even further. What it does is increase/decrease/tighten the bass on your headphones, depending on your preference. By default, there is a black mesh that covers three holes (iirc). This image below shows the backside of your HD4x8 headphones' driver enclosure.


Bass Mod 










Step 1: Use your fingers to locate the 4 screws hidden under the grey foam. 

Step 2: Get a Phillips screw driver and twist the screw out from above the foam.

Step 3: Once all the 4 screws are out, pull the driver enclosure out by pivoting from one end of the ear pad hooks. 

Step 4: Remove the black mesh. 


There are a couple of configurations.


Leaving all the holes (which were initially covered by the black mesh) uncovered will give you a full-blown bass. There will be lots of bass but the quality of the bass will not be as refined as it was. I suggest you experiment with the covering the holes with tape (this involves repeating steps 2-4 a couple of times) to get the best results. 


You can also try adding some deadening material in the chamber that surrounds the driver enclosure to tighten the bass, dynamat or cheaper alternatives would be good for this.


♞ There is a huge difference in sound before and after this mod. 

♞ Left and right cups have different internal wirings. 


Dubstep mod (koolkat) 



  1. Remove all the tape covering the 3 holes. Leave them uncovered.
  2. Spread out blue tack on the insides of the cup or on the back of the driver housing (refer to pics)




That's it. 


By right, leaving the three holes open muddies up the sound due to the massive increase in bass but the blue tack helps to dampens the resonance in the chamber. The result is real heavy bass impact-wise (good for dubstep and similar genres) but it still has that edge in bass guitar. Without the blue tack, guitar sounds really blunt.


It's a reversible mod, so give it a go.  



Resistor mod (Credit's to Solderdude at RockGrotto) 



You can also do the resistor filter mod for the 438 that makes the frequency on the low's more prominent and revealing by soldering a resistor to filter the different frequencies on the low end. The process can be done by following Solderdude's first post with the pdf file. 




HD438 cups without the chrome spokes










Modifying tips:


☛ Place all the screws in a cup.

☛ Preferably do it on a table with a large surface area with ample lighting.

☛ Careful with wires, you might accidentally rip them loose.





sbwf mod


bass mod


Resistor mod

Comments (33)

Thanks for the tutorial! I was searching all over headfi for mods I can do to my HD 428's. So far I'm planning to apply 3M Di-NOC carbon fiber to each of the ear cups, recable the headphones with 24awg silver plated copper with a neutrik plug, and maybe do the blue tack mod. I'll probably do the double sided tape mod as well.
Hello Smirnoff,
The sole reason I wrote the wiki was for HD4*8 owners to share their mods. It seems these headphones aren't very popular around here, and I figured those who own them might be interested in modding them to improve their sound. So if you have any material to add, feel free to contribute to the wiki article.
I haven't added any damping material in my headphones yet, I tried stuffing a thin piece of egg-carton-like material and I couldn't fit it in. Another member suggested that I use blue tack but it seems like there's no space to even put any damping material in the chamber surrounding. The bass mod and tape mod should do just fine.
I'm new to this whole modding thing, so if you're able to add some damping material in the surrounding chamber, do edit the wiki and add some pics :)
Good luck with the recabling :)
For those that have the HD438 or 448, with the bass mod, cover the 3rd hole towards the direction (when wearing the headphones) inwards, covering the middle hole with anything leads to rubbish bass. Best results as mentioned above covering the 3rd hole, tape it over with single layer of electrician tape.
You can also do the filter mod for the 438 (on Rockgrotto forum) that makes the low's more prominent by soldering a resistor to filter the different frequencies on the low end.
Another mod is with the HD438, instead of doing the tape mod to prevent the inner layer of the pads vibrating from the bass, cut that layer out (like the HD650 pad mod), no need for the tape mod once this is done, your soundstage will open up a bit, as the drivers directly send sound waves to your ear without the veil layer in the inside of the pad, so the sound is more direct to your ears, but if you have dandruff or long hair, the inside of the drivers may get dusty and dirty easier from time to time of usage.
Hope this gets added.
I think you can edit this article yourself but I'll do it for you. As for the hole covering, I guess it's best to experiment. A couple of days ago I let all 3 holes be exposed and was kinda happy with the boomy bass, I just taped up the hole closest to the "front" of the headphone and things sound a little clearer. I don't know if it's just me, but the HD438s improve a lot on some eqing. They sound a little muffled without the eq.
Anyway, thanks for sharing DefQon :)
Yeah no worries, I've just edited it a little bit, will be uploading pictures just for easier examples and the process of doing the mod.
Yeah the HD438's do improve a lot on eq-ing or through amping. So its one or the other basically, these sound incredibly good using any tube amp to a Rockboxed source. And I can say this as I heard the M50's, that these modded with a amp look better, sound better, and are much lighter then the M50's.
And cheaper too. :)
Just found a way to reduce the rattling, muddy bass on loud volumes with a new mod.
Hey thanks for the updates.
I have just started modding my Senns again (did Grado modding for quite some time). I haven't tried the capacitor and resistor mod since I don't really have the means to solder things together but I did find a really good solution for dubstep and a good configuration for movies (imo).
Short guide for dubstep (pics later in the main article)
1. Do not cover any of the holes.
2. Cover the cup surface with some blu tack, or you could cover the back surface of the driver housing (pics later).
Simple, basic mod. http://www.youtube.com/watch?v=u8C-ZTQJIkU&feature=related
Massive bass slam, without getting too muddy.
I also downloaded the pdf file for HD438 modding (credits to solderdude on rockgrotto) and gathered some balls to remove the chrome spokes. I think they look pretty good now.
Will update article later.
I've updated my mod sections where I posted back on the 11th with the mod I was talking about that gives it perfect bass, no rattling, no driver distortion at loud levels and no muddy bass at all.
@Koolkat's I thought you were banned?
I've also done the exact mod you've have done, but found the bass still muddy. The new mod I have done now is the perfect mod for bass reproduction without any drawback to the bass losing clarity, becoming muddy interuppting the rest of the sound becoming overpowering.
Having all holes open can damage the driver, just letting you know. I had about 3 of these headphones and 1 of them are starting to distort and rattle loudly from the driver itself, because the clear membrane over the driver is starting to loosen up from the adhesive over the magnets.
who ever put in spoilers, don't I can't edit the whole section without having errors popping up.
bah just wasted 40 minutes uploading pictures and writing up this article, whole thing wasn't saved because it stuffed up due to the spoilers.....not going to upload any more mods...good luck to those further experimenting mods.
I was unbanned last week. I added the spoilers to clean up the format. The spoiler error is actually quite easy to fix. All you have to do is remove the <<<< and >>>> signs in the text. I already removed the spoilers. Anyway the mod I did was for dubstep. The bass impact is crazy, but the loss in clarity wasn't as bad as without the dampening. How does having all the holes open damage the drivers? As long as you don't play the headphones at really high volume, then you should be fine. You could've gotten something into the holes which is the common cause for rattling (happens to my Grados as well).
Why were you banned? Yeah removing the arrows didnt help it resulted in my sections I was editing being deleted. As with the rattling, think about this, hot boiling water steaming inside a closed box.
I got the max amount of infractions.
I removed the arrows and everything was fine. Weird.
Anyways, I think the rattling is a result of overdriving the headphones to very high volume. Either that or something got loose. I'm really liking this dubstep config. Are you using any external amp/DAC along with your Senns? I suppose the sound signature of your amp/dac also has a part to play in the overall sig.
There are infractions given out on headfi?
Yeah with my current configuration and my mods I am using E11, but I find there is no need for amplification with the current mods because the sound and bass is already perfect for me which I suggest you trying as well. Since I don't have the time now which I did earlier but this crap messed up, I will upload a detailed process with pictures next time.
Also as these already have an extreme warm signature, using certain amp's would make the sound too coloured and sound very unenjoyable. A neutral source/amp + these would sound better.
I'm using the Fiio E7. The amp doesn't really impact the sound signature but the DAC section is definitely a step up from my onboard audio. I already have my Grados for rock so this will be my electronic/dub/bassy stuff headphone. Anyhow, it seems like some of your sections have been deleted, so you might want to repost them. What I do is write everything out in word and then copypaste it here.
Btw yes, there are infractions given out. If you troll/cuss and someone reports you, you get an infraction. 3 or 4 infractions and you're suspended for a week, lol.
I took off the ear pads and put them on reverse so the thin piece of cloth is against my ears now. Doesn't get warm as easily, and just as comfortable.
Instead of the tape mod remove the cloth that covers the drivers which also brings up the higher end of the spectrum and sound more balanced overall.
I have 2 of the holes removed and the cloth removed and also have uplifted the earcups with wool and have found best results with these :D
Well I've had the HD448's for some time now and I just did the bass mod, removed the stock tape and put electrical tape over the hole closest to the face (I tried leaving the stock tape on that hole with the other 2 uncovered and preferred electrical tape much more.
Do you mean the foamy stuff around the driver? I don't have a problem with the highs, although more sparkle would be nice.
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