[NoXter]

+++ UPDATE 07-24-2011 +++

What you need:

- a DT880 edition/pro with 250ohm or 600ohm
- a pair of EDT770Velour (black or grey) or Beyerdynamic EDT990Softskin or EDT300Leather or EDT300Gel
 
The mod doesn't work with the older DT880.
 
Alternatives:
 
- a DT770 edition/pro and just change the drivers 
- a Superlux HD660 + DT880 drivers and maybe edition cups.

How to:
 
[size=medium]Step 1:[/size]

 In this picture you can see all the holes in the housing which have to be closed. The original felt which is glued into the housing must be removed.

[size=medium]Step 2:[/size]

 This is the taped version. Doesn't look good, but you cannot see it in the end. It is important to tape the holes particular. The material which you use don't play a role. It should be just durable. In this variant I used textile-tape. 

[size=medium]Step 2.5:[/size]

 On the marked position there is a 4mm hole. Hard to see, but it is there...
 Well, there are few ways to make such a hole. Use a drill or stick it with a spike.
 
Alternative Step 2.5
 


To increase the modding potential of the bass it is possible to drill a hole in the housing as shown on the picture.
Why does that work?
Between the housing and the grill is a black cloth (see the 'how to improve isolation' part) which dampens the bass when you do it like shown in original step 2.5.
I prefer the alternative step.Of course you can also remove the cloth, but that destroys the look of the cups.
 
[size=medium]Step 3:[/size]

  This is a thin felt. About 1,5mm I think. You can also user thicker ones to experiement with.

[size=medium]Step 4:[/size]

Put the driver back into the housing. What you see directly above the driver is the original felt.

[size=medium]Step 5:[/size]

 I don't know for sure what this material is called. I would say wool-felt. Take a look in a Shop where you can buy material for handicrafts. In the picture I used 1 slice of it, but you can also use more. It tames treble an upper mids, so you will earn a darker sound.

[size=medium]Step 6:[/size]

 


Instead of using the original foam (no influence on sound) I recommand to use one slice of 2 component foam which AKG uses with their K271 for example. http://images6.thomann.de/pics/prod/197073.jpg
The foam is much thicker and additionally covered with some kind of nylon.
This foam gives a warmer soundsignature and dampens sharp sibilants.
 
[size=medium]Finished:[/size]

And finally the earpads.
 As you can see, you can see almost nothing.

Well, thats it.

[size=medium]What changes?[/size]

First: The closed-back DT880 isolates very well!

 For me, who couldn't find a isolating headphone that fits for my taste, it makes an excellent job.

The Bass is stronger than stock, but you get real sub-bass an the bass is in general more precise. The mids get warmer an get more consistence. Vocals sound fuller. Treble is significant lowered. HD650 niveau I would say, but whithout the veil in sound.
The airiness and soundstage of the DT880 lacks a bit with the mod, but compared to HD650 for example nothing you should worry about.

There are some points you can experiment with:
- damping materials
- the bass-reflex-hole. If you make this hole (shown in step 2.5) bigger, you will earn more bass and ground-tone. So a bassheavy variant is possible.
- pads. You can use leather-pads and dt660 pads.

250ohm vs 600ohm

 The 600ohm driver have much more precise bass and the overall sound is clearer. Mids get a warmer touch and Treble is a bit smoother. These are really a big step and should be preferred. Of course the result is good with the 250ohm systems but you give away potential.

Grey or Black 770pads
 
 
They sound almost identical. The upper-bass is with the black ones  a bit cleaner. The black ones look better than the grey ones, but the grey ones are much more comfortable due a slightly different velour. Well, your choice.
 
Leather and Gel pads

With my damping scheme the soundsignatur is pretty close to EDT770V pads. The leather/Gel pads are lacking a bit in warm mids, but the isolation is much better.
 
 
How to improve isolation:
 
What you need:
 
- alubutyl (1,8mm - max 2mm)
- compasses
- alcohol
- scissor
- tape
 
First, detach the outer grill of the housings. Just curve the hook inside the housings to the side and push out the grill.
 

 
To avoid seeing the alubutyl later (as seen on final step) you must keep this cloth which is directly behind the grill. Mine were destroyed after hours of modding. 

 

 
Now cut the alubutyl to size.
 

 
The dimensions for the templates:
 
1. inner dimater - 26mm; outer diameter - 60mm
2. dimater - 70mm
3. inner diameter - 58mm; outer diameter - 78mm
4. width - 9mm; length about 360mm
 
Before  attaching the alubutyl in the housings, you must clean the surfaces with aclohol particular. 
 

 
Now you can reattach the grill. In the housing you have now the choice to cover the alubutyl with tape. I used duct-tape.
 

 
 
From here you can go on with Step 2.5. 
Well that's it.
 

 
Results?
 
 
First I have to say the weight of the headphone increases to 350g without cable. 55g more than a stock DT880. Fortunately this has no negative effect on the wearing comfort.
From now on this headphone isolates really good and the leakage of sound is reduced. It could get even better when you use leather-pads.
Another point is clamping-force. I have a frame of a PRO model, so the clamping-force is even higher and improves isolation as well.
At the moment the isolation is only a bit inferior than my Shure SE425 and these are InEars.
 

 

[YGingras]

I was under the impression that DT-880 2005 had more or less the same driver as DT-770 but that the improved response curved of the 880 was entirely due to the open design. How would you compare your closed back DT-880 to DT-770?

 

[Nick 214]

Quote:

Originally Posted by YGingras /img/forum/go_quote.gif I was under the impression that DT-880 2005 had more or less the same driver as DT-770 but that the improved response curved of the 880 was entirely due to the open design. How would you compare your closed back DT-880 to DT-770?

Yeah, I think the OP just made a restricted-flow DT-770..

NK

 

[NoXter]

Quote:

Originally Posted by YGingras /img/forum/go_quote.gif I was under the impression that DT-880 2005 had more or less the same driver as DT-770 but that the improved response curved of the 880 was entirely due to the open design. How would you compare your closed back DT-880 to DT-770?

The drivers of DT880 and DT770 seem to be similar, but at least they're not the same. Imo Dt770 is a closed version of DT990, respectively DT990 a open version of DT770.

The closed-back DT880 is a complete different headphone compared to DT770. Deeper and more precise bass, no recessed mids (they're better than stock DT880), no sharp highs and it has a much more warmer tone.

This was one of Nickchens and my concerns when we closed the DT880, that it is just some kind of DT770. But it isn't. It is now more something like a Sennbeyer.

 

[lutwey]

Quote:

Originally Posted by NoXter /img/forum/go_quote.gif The drivers of DT880 and DT770 seem to be similar, but at least they're not the same. Imo Dt770 is a closed version of DT990, respectively DT990 a open version of DT770. The closed-back DT880 is a complete different headphone compared to DT770. Deeper and more precise bass, no recessed mids (they're better than stock DT880), no sharp highs and it has a much more warmer tone. This was one of Nickchens and my concerns when we closed the DT880, that it is just some kind of DT770. But it isn't. It is now more something like a Sennbeyer.

i believe that dt770 880 and the 990 share the same dirver. its hust that the

770 is closed
880 is semi open
and the 990 being open.

 

[QQQ]

Drivers basically the same in 770\880\990. At least, there's nothing you can't diy to make them completele same: http://www.head-fi.org/forums/f4/how...0-info-351227/

 

[nickchen]

The DT770/880/990 drivers themselfes don't differ, but I think that it's their backwards dampening material and the housing that provide different sound signatures.

I must say the the DT880cb is a real awesome headphone. What I like most about it that some of my major Beyer dislikes (mediocre bass, cold mids, sharp highs) get cured, but without entering into the undesired DT770 or Ultrasone territory. NoXter's desciption of a Sennbeyer nails it perfectly down. I personally preferred it to NoXter's new HD650, the Senn is a bit boring in comparison.

It also sounded a lot like my beloved DT271, but with much more authority and musicality. I'm pretty sure I'll convert my DT880'2003 in such a creature as soon as I'm fluid again. I'll need 2005 housings for that, so it's not that simple and cheap for me.

 

[apatN]

Ah, your mod. Very interesting I must say as I stated before, a closed DT880 sounds like a recipe for disaster. For example, if I lay my hands on the DT880's (03 though) back the sounds loses a lot of its airy tone the Beyers are famous for.
Thanks for sharing!

 

[nickchen]

You can't simulate the mod that way, as padrolling and a different housing than your 2003 model are dominant part of that mod.

 

[QQQ]

What's so special in 660's pads? And what if use them on dt 770?

 

[NoXter]

There is nothing special with the dt660 pads. But these pads work with the mod and dt770 pads do not. That's all.

I never tried dt660 pads on DT770 but the result will be another than in this case.

 

[QQQ]

Hi Nox!
But, what is the differencies between 660 and 770 pads? They look pretty alike aside from color..

 

[NoXter]

I think the main difference is the foam inside of the pads. At the least the velour itself changes the sound also a bit and the one of dt660 is not so fluffy and coarser.

I wish it would work with 770er, because they're more comfortable. I will try also the silver dt770 pads. In our tests we used black DT770 pads which use another velour. But I don't have much hope that it works. On k271 these pads sounded siginifcantly different, but ... We'll see.

 

[CDBacklash]

Quote:

Originally Posted by nickchen /img/forum/go_quote.gif The DT770/880/990 drivers themselfes don't differ, but I think that it's their backwards dampening material and the housing that provide different sound signatures. I must say the the DT880cb is a real awesome headphone. What I like most about it that some of my major Beyer dislikes (mediocre bass, cold mids, sharp highs) get cured, but without entering into the undesired DT770 or Ultrasone territory. NoXter's desciption of a Sennbeyer nails it perfectly down. I personally preferred it to NoXter's new HD650, the Senn is a bit boring in comparison. It also sounded a lot like my beloved DT271, but with much more authority and musicality. I'm pretty sure I'll convert my DT880'2003 in such a creature as soon as I'm fluid again. I'll need 2005 housings for that, so it's not that simple and cheap for me.

are the 770 pro drivers the same as the 770 consumer edition?
If they are, whats different in the packaging, and is there a mod around that changes them back and forth (removing padding on the back?)

 

[nickchen]

Okay, I got 2005 housings and DT660 pads and of course did the mod. Very content until now, got something like a "better DT770" (no mids recession, tamed highs, more warmth).

As this mod allows to adjust bass amount exactly according to personal liking, I ended up somewhere in the middle between DT770 and DT880.