This topic and model is a bit old, but I’d like to share a couple of hacks on acoustic tuning with my fellow DT770 Pro owners.
I needed a new pair of pads for my 6 y/o DT770 Pro 32 Ohm, so I decided to experiment a bit with pads. I also found an interesting thread on Head-fi about using various types of insert materials to tune the Beyers acoustically. So, I decided to try a couple of experiments.
Hack 1: Bass and stage boost with thicker and denser velour pads
The DT770 is quite bassy, but as it’s currently supposed the most bass-heavy headphone in my collection, I wanted to give it some extra warmth and boost the sub-bass, which rolls off quite quickly with the default velour pads. I also tried it with Beyer’s pleather pads, but this time I wanted to try something different.
So I bought these cheap pads by Xberstar on Amazon:
On the photos they looked suspiciously similar to the DT1990 Pro “Balance” pads. And as I owned a pair of DT1990 before, I know that those pads boosted the bass and the treble. So I wondered if these would do something similar to DT770.
Which they did. The bass with these pads is not only stronger but surprisingly cleaner than with the original ones. It isn’t bloated at all and feels better separated from other instruments. This helps the mids to be better separated and more distinct as well. As a downside, the Beyer’s already peaky treble got elevated even more, to an uncomfortable level. But before returning these pads, I decided to try a second hack to fix the treble peak, see below.
Thicker and denser pads also increased the soundstage, at the cost of decreasing overall volume level, which is not a problem for such sensitive dynamic headphones.
The quality of those cheap Chinese pads is not very good though, so I wouldn’t recommend everyone to try get it at any cost. What you can do instead is to roll DT1990/1770 pads onto DT770 for a similar effect.
Hack 2: reducing the treble peak with paper inserts
This one is a more interesting hack for any Beyer owners who are not fond of the Beyer treble peaks. You can find a more sophisticated mod on Head-fi which combines multiple types of materials added to different parts of the headphone. What I went for is a much more simple yet effective solution, and you can try it without having to disassemble your unit.
The “theory” behind this method is simple: paper appears to be a good filter material for high frequencies in the range from 6 to 9KHz. Depending on paper density and thickness, you get different width and amplitude of the filter on the spectrum.
I made 2 types of paper inserts which I cut from paper towels (more coarse, less density) and napkins (more fine and higher density paper):
The advantage of using paper towels and napkins for these crazy cheap acoustic tuning inserts is that they already consist of multiple thinner layers of paper. So you can add or remove layers to get the sound that you like.
I ended up with 2-layer towel and 2-layer napkin inserts for each side. If I put more layers, the overall dynamics and highs detail is gone. If I put fewer layers, treble is higher than I want.
If you are lazy and just want to experiment (like me) putting these inserts inside the pad on top of the standard foam is enough:
For more stable build, you can put it under the plastic ring that holds the foam.
With these 2 hacks applied I got a better and cleaner bass, wider stage, and no fatiguing treble from my good old DT770 which I still use a lot as an “utilitarian” headphone in the office, or at home when I don’t want to bother my family with the sound blasting from the open-backs. I even got a new problem now: I don’t know to which close-back headphones I would upgrade from these, without going 7x the price. Which is a nice problem to have 
