+++ 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.
- a DT770 edition/pro and just change the drivers
- a Superlux HD660 + DT880 drivers and maybe edition cups.
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.
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.
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.
To increase the modding potential of the bass it is possible to drill a hole in the housing as shown on the picture.
This is a thin felt. About 1,5mm I think. You can also user thicker ones to experiement with.
Put the driver back into the housing. What you see directly above the driver is the original felt.
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.
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
And finally the earpads.
As you can see, you can see almost nothing.
Well, thats it.
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)
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.
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.
Edited by NoXter - 7/24/11 at 7:15am