[shake]

Hi, this is a very simple, free mod that will very noticeably  increase the amount of bass, increase bass extension, and give an overall warmer presentation on the Ultrasone HFI-780s.  I'm using a set with over 200 hours on them easy.
 
I shouldn't have to say this, but doing this mod voids your warranty.
 
1. Remove the earpad (pull it off) to get to the mu-metal shield and remove the three screws holding it down with a small electronics philips screwdriver.

2.  Once you remove the 3 screws and take the mu-metal plate out, look behind the drive and you will find a white pacman-shaped sticker with a single hole where the "mouth" is.  This sticker is covering 3 more holes.  Uncover an extra or all the other holes to to allow the driver to breath more and produce more bass. EDIT 7/17/10:  It 's best to leave 1 hole covered, as uncovering all of them causes a slamming/distortion in the drivers.  This keeps the bass tight.

It will look like this when you're done if you chose to remove the entire sticker.

That's it!.  Just put everything back the way it was (the earpads just snap back on) and enjoy!
 
Deep, emphasized rumbling bass, and a very warm, welcoming sound to it. Before I was contemplating doing a recable of these myself to try and improve the sound, but now I'm only doing it because the cord length is stupid (1m or 4m with adapter, What?)  I'm going to use 7-8ft of Gotham GAC-3.
 
EDIT 7/17/10:  It 's best to leave 1 hole covered, as uncovering all of them causes a slamming/distortion in the drivers.  This keeps the bass tight.

 

[JxK]

It looks like a simple and effective mod, but I'm just wondering what it accomplishes that a simple equalizer couldn't? And that is totally ignoring the fact that it looks to be non-reversible, another point in favor of equalizing...

 

[shake]

Quote:

It looks like a simple and effective mod, but I'm just wondering what it accomplishes that a simple equalizer couldn't? And that is totally ignoring the fact that it looks to be non-reversible, another point in favor of equalizing...

The sticker is a physical restraint on how much air the driver could move.  Trust me, I've spent 2 weeks trying to EQ and DSP these the way I want them too, but it always started distorting when it got close to how I wanted it to sound (I love me some bass long time).  When I did this, the results were so good that I just had to post them here .  And I seriously doubt this is irreversible, all you have to do just block the three holes with anything; tape, sticky tack, etc.  This mod + EQing =

 

[Ultrazino]

Did anybody else try this? I'm willing to but I don't want to lose my (5 year) warranty over a little sticker.

 

[jms91]

Cool mod but these already have enough bass for me

 

[Phenomenalz]

I decided to do this mod to my HFI-780's the morning after I got them because I was so disappointed with the bass on these cans. I'd like to first note that I'm a newbie to head-fi and these are my first set of cans. I bought these based on all the reviews on head-fi that claim these have amazing bass. I do realize that Ultrasonses have a long burn-in period but I just didn't have the patience. I needed more bass NOW. Enough about that, I wanted to add some higher definition photos to the thread so that others who decided to do the mod have a cleaner image of how relatively easy this is.
 
I removed that pads prior the first image.

 
I started with the right can. There are (3) tiny philips screws. One in each hole.
 

 
Right can opened. BE CAREFUL!!! On the right side the wires that attach the driver the the encasement is very thin and short. Don't yank it out while pulling the plate and driver out.
 

 
Close up. You can see the one breather hole and if you look closer you can see the the bumps through the stickers. There are four total.
 

 
On the right can I was able to fold the sticker back to leave one hole covered as recommended by shake.
 

 
Reassemble the right can and repeat for the Left can.
 
I didn't get this sticker off as cleanly as I did on the right can but it works.
 

 
And reassemble the can.
 
I apologize for the lack of proper terminology in advance but I thought I could at least contribute some better images.
 
Shake, I don't know how you came up with this mod but it worked. The bass is definitely more present and the cans seem a bit less harsh. Now it's time to be patient and burn them in....

 

[shamrock134]

It seems very few people have tried this mod. I've mentioned it a few times in the Pro900 thread but nobody else (even those who think the Pro900 lacks bass) have tried it.
 
I've had my Pro900 running with all 4 holes uncovered (stock is 2 uncovered on Pro900) for some time now with no negatives that I'm aware of. The only thing to be careful of is rounding out the tiny screws that fix the buffer board to the cups.

 

[dyl1dyl]

^^Interesting, I may go and try it.

 

[xaval]

Maybe it's safer to open 1 hole at a time. I very much like these cans - amazing bang for the buck.
 
I found the bass after burn in (400 hours) lacking articulatness. It's very powerfu, deepl and thumps a lot which makes them perfect for electronic music and metal. I just damped the drivers and the inner shell with great results. Got what I wanted. Maybe I'll poke a bit

 

[Bloodflowerz]

Does this mod affect the sound leakage in any way? I would not want to sacrifice isolation for a bit of bass. Defeats purpose of the closed headphone idea. Can anyone comment on this please?
 
Cheers.

 

[Coq de Combat]

Quote:

It seems very few people have tried this mod. I've mentioned it a few times in the Pro900 thread but nobody else (even those who think the Pro900 lacks bass) have tried it.
 
I've had my Pro900 running with all 4 holes uncovered (stock is 2 uncovered on Pro900) for some time now with no negatives that I'm aware of. The only thing to be careful of is rounding out the tiny screws that fix the buffer board to the cups.

How does the mod affect the rest of the sound spectrum? Clarity? And so on.. 

 

[risenfallen]

So the one hole to be covered is whichever we choose to leave, right? Or does it need to be a specific one? I know it sounds dumb, just want to confirm so I don't get my 780s all messed up

 

[shake]

Sorry, I know this is really late.
 
Quote:

So the one hole to be covered is whichever we choose to leave, right? Or does it need to be a specific one? I know it sounds dumb, just want to confirm so I don't get my 780s all messed up

I don't think it would matter, but I never really tested.
Quote:

Does this mod affect the sound leakage in any way? I would not want to sacrifice isolation for a bit of bass. Defeats purpose of the closed headphone idea. Can anyone comment on this please?
 
Cheers.

It shouldn't.
 
Quote:

I decided to do this mod to my HFI-780's the morning after I got them because I was so disappointed with the bass on these cans. I'd like to first note that I'm a newbie to head-fi and these are my first set of cans. I bought these based on all the reviews on head-fi that claim these have amazing bass. I do realize that Ultrasonses have a long burn-in period but I just didn't have the patience. I needed more bass NOW. Enough about that, I wanted to add some higher definition photos to the thread so that others who decided to do the mod have a cleaner image of how relatively easy this is.
 
I removed that pads prior the first image.
 
 
I started with the right can. There are (3) tiny philips screws. One in each hole.
 
 
 
Right can opened. BE CAREFUL!!! On the right side the wires that attach the driver the the encasement is very thin and short. Don't yank it out while pulling the plate and driver out.
 
 
 
Close up. You can see the one breather hole and if you look closer you can see the the bumps through the stickers. There are four total.
 
 
 
On the right can I was able to fold the sticker back to leave one hole covered as recommended by shake.
 
 
 
Reassemble the right can and repeat for the Left can.
 
I didn't get this sticker off as cleanly as I did on the right can but it works.
 
 
 
And reassemble the can.
 
I apologize for the lack of proper terminology in advance but I thought I could at least contribute some better images.
 
Shake, I don't know how you came up with this mod but it worked. The bass is definitely more present and the cans seem a bit less harsh. Now it's time to be patient and burn them in....

Thanks for posting those pictures.  I didn't have a decent camera back when I did this.  I hope the mod is still working out for you.
 
Has anyone else tried my mod?

 

[drtturnip]

 I have also found this an effective way to tune a drivers bass response. On some htf600 I covered a couple holes to lower the amount of bass.

 

[Rpeezy]

It's amazing how many people don't consider this mod. I come from a Grado background, so modding is no new territory. Besides, this is just the Grado hole punch mod Ultrasone style. I think they do this mod to the ATH-ADX00 series too.

I just did this on my 300+ hour 780s after I stuck some DT250 velour pads on them -- the bass suffered! Naturally I had to try this mod, and it brought my bass back! But even without the velour pads, I felt like the bass of my 780s had settled down quite a lot after burn-in.

I hope this mod gets more exposure, given the popularity of the Grado hole punch mod.