My journey modding DT770/250s (WARNING: long read)
Jul 30, 2007 at 9:06 PM Thread Starter Post #1 of 10

darkswordsman17

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Basically, this last summer, I custom made my own deep cup DT770s, and thought I might share the information I gained, in the hopes of possibly helping others to follow my footsteps as an introduction to DIY/modding. If people aren't interested, then no big deal (hey it'd save me the time of doing a writeup and taking better pictures), but if there is an adequate level then I'd consider it. My hope, is that it would be a catalyst towards people trying even further modifications with headphones (how do you think Darth Beyers have become what they are, by Larry not trying out some new ideas?).

This is not in any way intended to harp on Headphile's mods, as they are truly magnificent results, but rather, just an alternative that would in the process help people learn more about headphones in general. Similar to the way the DIY mod iPod is not meant to detract from RedWine's iMod.

My reasoning for thinking the Beyer DT770s is great for this:
1.) Very easy to work with/on
2.) Popular.
3.) Pretty high quality parts, but not too expensive as to make it worthwhile only to a few.
4.) The mod itself is actually quite cheap as far as material cost goes (for basic concept), while allowing people to apply their own ideas (so if you've got some nicer materials, your result will probably end up nicer as well).
5.) I so thoroughly dislike the stock sound of these, that I want to show they can have even more bass that is higher quality (of course only testing and comparison by others will verify my claims).

Now, I will be the first to admit that I tend to be overly ambitious in my ideas, however, oftentimes with the support/nagging of a community of interested people, it helps motivate. Will this turn into what I hope it would? I have no delusions that it actually will, but at the same time no harm in seeing what would come of it.

Currently, I'm considering reworking them, well mainly the cable as my original job, while very functional (and in some ways nice actually, as it is cloth which is so much nicer than the rubbery feel of so many cables) does suffer from some key faults (mainly the y split is about a foot or more too long). I'm debating trying to find someone who might be willing to do the job for me (and fix my poor soldering job) for a fair wage (while perhaps giving them a comparison listen to some of their own headphones). I've also considered trying to implement a removable cable system like that found on several headphones (some Sennheisers, some Ultrasones, and probably other ones as well). Anyone interested might drop me a PM (even if nothing but to add insight, or just a recommendation or anything).

Well below is my story, read it you feel like, it was meant to be entertaining more than informative, although I did try to include little details that I discovered so that maybe you might "learn" a little bit, but hey, I will be the first to say you'll be sorely disappointed if that is what you're hoping to get from my personal account.

WARNING: Below here is an overly wordy, probably not as amusing as I thought it was when I was writing it, story.

************************************************** *********************************

The mugshot and cliffs at the end, feel free to skip ahead.

Earlier this summer I bought a used pair of DT770/250 Pros on here. I had been wanting to try them out for some time, and so I bit. Got them, and yeah, the bass was definitely there, and I do agree it overpowered the midrange. Overall, I wasn't too impressed with the sound though. The bass was kinda muddy and everything else sounded muffled. I wasn't a big fan of the stock cord either, it was too short and wasn't even as good as the similar one of the HD-280s I had a while ago.

Now, having had a pair of A900s and being familiar with the blu-tak mod on them, I decided to see what could be done with these. Pulled the pads off, and with little trouble was looking at the interior of the cups within a few moments. Right away I notice the ring of black plastic and cotton that surrounded part of the backside of the driver. I wonder how things sound with removing that. Done. And within moments I had it back together for a listen. Eww, not the result I was looking for. My one ear was met with the sloppiest bass I had yet heard, easily putting to shame the stock sound in that aspect.

Ok, let's go back and take another look. I notice the little cutout in the cup from the raised section (where Beyerdynamic is emblazoned). Let's get some plasti-tack and make that a nice round shape. Done. Put the plastic and cotton rings back on and see what the result is. Hmm, it’s ok, but just isn't a sound I would want. Back into the cups. Let's get rid of the cotton ring and stuff cotton balls around the entire space between the plastic ring and the cups. Back together to test. Now this is what I'm talking about. Mids have come out to say hi, the highs are actually a bit shrill, and the bass, well it’s definitely tight but it lost the oomph. Since I had an idea of what to do, I decided to go ahead and start on the other side. Didn't use as much tak, pulled the cotton apart and used less. Now this is what I was wanting. Tighter bass that still has plenty of oomph, but doesn't overpower the midrange. The foam screen in place took the shrillness out of the highs.

Now let’s just finish up the other side, simple right? Wrong. I guess all the taking apart and putting back together put some strain on the wires, and they got disconnected from the driver. I didn't notice at first, but after I put it back together and didn't get sound I knew something was up. Once I see what’s wrong, I have a decision to make. Try a simple fix and then never mess with them again? Now where's the fun in that. Might as well use this time for a recable. Thinking some more, why not go whole horse and mess with the enclosure itself? Now we're talking.

I looked around at various places, hoping to find a nice small wooden bowl so I could make my own Darth Beyers. Not much luck, either it was crap fake wood or too big. Kept looking, but still nothing. Finally I go to a local craft store and find some plastic spheres designed for making your own Christmas ornaments that would fit great. Ok, I'll use that instead, paint it and then put tak on the inside. I pick up some circular foam and a nice looking fake leather material (a dark crimson/brown scale-like pattern) thinking I might make my own pads (and warp the headpad in it too).

Next, I take a dremel and cut the circular end part of the cups out. No turning back now. It turned out to be quite a bit of a pain. I had a couple different sizes of the plastic bowls. At first I had decided to cut one down but they turned out to be too fragile how I did it, so I ended up using the other. This would give a deep bowl, which I originally didn't want. Oh well. More work and it doesn't seem like I'm making any progress. Finally I get a small break and things start to go better. I decide I'll put a layer of tak on the outside of the plastic bowl to make it seamless with the lower part of the cup. As you would expect, it wasn't looking the prettiest. Hmm, I do have some black spray-paint. So I sand things down a bit (the tak too) and put on a few coats. The result was actually fairly impressive, nice shiny black. The only problem is that the tak wasn't completely smooth so there were some dimples and notches, but still not too bad looking.

Now it was time to rewire. Oh crap, I had not even researched that. Hmm, spend a nice amount of money on some good cable for the first time I ever did it? Not such a good idea. I look around locally, but nothing works, its either guitar cable or slice up some A/V cables. I try the latter but find it way too difficult to work with. Hmm, getting impatient. I wonder how well speaker wire would work. I try some of the I think 16 gauge that I have but it proves to not fit into the sleeving that I had contrived (bought some bungee cords and cut off the end hooks and then removed the internal rubber part. I spent too much time trying to force it through and gave up. I ended up getting some 22 gauge instead which worked significantly better. I wrapped the lower portion (before it splits for each cup) in some plastic sleeving material (more to keep the wires together than for shielding) and slide it through. Wire up the ¼” plug (it wasn’t until now that I discovered the beautiful simplicity of the headphone plugs (before I wondered how they split things for the left, right, and ground channels with one plug). Solder the other ends to their respective drivers and I’m ready to get back to the inside of the cups (secretly hoping that what I just did isn’t completely stupid).

Liberal use of the tak inside, then push the plastic ring into it (so I can spread out the cotton around it). Put things back together, and I’m ready to see, er, hear the fruits of my effort. I’m not completely sure what I’ll be greeted with, just merely hoping it’s not silence. Everything plugged in and turned on, okay, I’m ready to push play. I sit there with some apprehension, my ears finally met with……..silence. No, not this again. I begin to unplug them, then remember that I had unplugged the optical cable running from the computer to the receiver. D’oh! I quickly remedy this, check again (make sure the volume isn’t high so as to avoid some catastrophic calamity and lose my functioning eardrums. Push play and………glorious, horrible sound fills my ears. Bleh. Uh-oh, looks like I did the inevitable, turned my perfectly listenable Beyers into ugly Brayers (as in you know, bray like an ass, hey this is what passes for wit around here).

With sheer stubbornness I resign myself back to tweaking. I will make these sound good. I’ve come too far for them to not sound good. The next couple of days are filled with constant disassemble, tinker, reassemble and test. Hmm, just can’t seem to get things how I like. Ok, I’ll start over, pull all of the tak out (after adding layers bit by bit). Put things back in (I had fairly early on figured out the minimum amount needed to put it back together so as to be able to test thereby speeding up the process), plug everything in. Holy god of bass, I couldn’t believe the sound. It was like sticking my head in the center of a subwoofer. A low quality one, as the sloppy bass I had found earlier had now returned, only it seemed to have quadrupled in size, like some kind of mythical beast. Ok, well that’s interesting. Open them back up, put in the plastic and cotton rings, seal it up for the umpteenth time. Now that’s more like it. The bass became controlled, the monster was caged, but I was back to something that resembled the original sound signature, that’s not what I was looking for, or was it? I take them off and sit there contemplating my discoveries when I notice the two holes where the original wires had run out the top of the cups. From reading Head-Fi, I had learned about people’s experience with these. I fire up some music and then plug all four with my fingers (the cups weren’t mounted to the headband). Open, the bass overpowered the midrange again, but then all four closed and the highs were overpowering with the mids more noticeable than the lows (like an upside down pyramid). Ok, let’s go with just two holes covered. Whaddya know? The bass, mids, and highs all kinda even out (although still far from balanced). Progress, but I still had some work to do.

I remembered that spreading out cotton was better than using the cotton ring, so I yank that out and put cotton around on the backside of the driver (well the paper part that surrounds the driver). Test once again, only this time, I’ve finally found what I’m looking for. I fire up some test songs, the ones that I’ve been using specifically for bass. I fire up Superman by Eminem, as it has some nice authoritative bass slam. A grin spreads slowly from ear to ear. The monster bass has returned, only, this time, it’s tight and refined, not unlike the transformation of the monster in Young Frankenstein (you know when he decides to put on the show, complete in tuxedos and top hats). Wow, this is like strapping a high quality sub to your head. The sound becomes intoxicating, so I keep listening to song after song, loving the overwhelming bass. That’s right, while it was a very fun sound, I knew it was not what it could and should be. It’s odd, I say overwhelming but in a way it wasn’t, it was just very pronounced, but it didn’t seem like it was actually taking away from the mids, it just had more presence and quantity. I know that there’s more, I can turn these into something better, more balanced, if less fun (I knew that while it was a fun sound it would become fatiguing having slam after slam inundate my poor little head trapped between these two freaks of the head-fi world.

Tinker here, tinker there, and there it is. I’ve finally found the sound that I began this journey searching for. And here is the result. The bass, oh the sweet lovely bass. Tight, controlled, but unrestrained enough to have a fun weighty slam to it. The mids are out of the shadows, but still slightly recessed (inherent in the drivers from what I can tell). The highs are pronounced, but not shrill. Instruments have their sparkle, but they don’t bore into your brain like I’ve heard before. The overall sound is much more energetic than before, making the stock sound seems almost lethargic in comparison. I very much doubt it’s Grado-like (unfortunately I don’t have experience with any Grados), but it certainly seems as energetic as the KSC-75s I have. This makes it much better for rock music and live recordings, although to me it doesn’t make it worse for other types either (in fact, its become better all around to my ears).

So there you have it. One guys erotic journey from Milan to Minsk, er I mean, search for that elusive sound that I knew was possible. Do I recommend attempting the same? A journey to achieve my same results I would say absolutely not (as you can achieve similar for much less effort or get Darth Beyers which would blow them away easily), but the journey of your own, then I would give a resounding yes. I write this as I look at the freakish child that is the result of my work, and I think back fondly. I very much enjoyed the trip, although I’ll be completely honest in saying that the end result does not exhibit all of the work and effort. You’ll certainly never mistake them for Darth Beyers, although if you were double blind tested your ears might possibly confuse you, I wouldn’t know at this point in my Head-Fi life (another headphone I will certainly try some day, but not yet). I can definitely understand why these were chosen as the main can for him to modify, the DT770 chassis is great for that (easy to work on, solid, and of course sounds good after modding).

And lastly, is a picture. I didn’t get the cable in the pic, but rest assured it looks equally ghetto. As you can see, the black paint has wrinkled over some of the tak, not unlike the “skin” on the top of homemade pudding. It looks worse in the picture than in real life, but again, it won’t win any beauty contests. The orange blob on the right is a reflection from a lamp, not anything on the can itself. Of course all of that fades away when listening to good music.



Well, hope you liked it, I’m doubtful it was worth the read, but hey, no problems if you don’t bother or don’t like it (and actually read the whole thing only to end up angry that you wasted so much time doing so).

Ok, here's the cliffs:
1. Bought DT770s, wasn't happy with them stock
2. Started out as a simple blu-tak mod but a broken cable complicated matters
3. Never really modded or recabled before, so things got...interesting
4. After plenty of trial and error, finally got it figured out
5. End result doesn't look pretty, but the sound makes up for it.
6. Wrote a longwinded account of my struggles, sorely lacking in pictures of the process.
7. You either read the story or the cliffs and rolled your eyes, looked at the pic and then rolled your eyes again.
 
Jul 30, 2007 at 9:33 PM Post #3 of 10
Good read; thanks for the story.

P.S.--
Your entire story appears twice, as does the paragraph after the picture.
 
Jul 31, 2007 at 2:16 AM Post #5 of 10
Quote:

Originally Posted by ueyteuor /img/forum/go_quote.gif
too long didnt read... but anyways, did they ended up sounding better or worse? They dont look better but looks dont really matter, sound does


Much better. Livens them up a lot to my ears and makes them better in pretty much every way.

I'll try and go back and get things fixed. I'll also try and add some cliffs for the ones interested in the bread and butter.
 
Jul 31, 2007 at 2:33 PM Post #7 of 10
They are very easy to take apart. You just pull the pads off, use a flathead screwdriver to pop a plastic ring off (holds the drivers in place). Then the driver should slide out (be careful, you don't want to stress the internal wire although there is a fair amount of slack).

On the back of the driver is a plastic ring surrounded by a ring of cotton. Its up to you if you want to remove the plastic, I didn't find it made much of a difference in the sound and its nice for keeping the cotton away from the back. Now take some cotton balls and pull them apart (more like stretch them out so they aren't really dense). Take some of the stretched cotton and put it on the back of the driver (well the paper outer part).

Now, you want to take the tak (blu, plasti, whatever you want to call it, I used some yellow version I got at Hobby Lobby) and spread it on the bowl. I filled in the little canyon and spread it around and tried to get a nice round shape. I don't know how much the amount you put affects things, I would try to get something not real thin but I wouldn't go overboard either. In a way I wonder if you even really need to tak or not, as I didn't see what it sounded like and while I don't have any on the inside of the new bowls I have it is on the outside (and I think the tak is there to stifle vibration than for any real sound damping). You might see how it sounds with and without.

Now, just put it all back together and get to listening. The really nice thing about this is that its completely reversible and also allows you to fine tune the sound some. For instance the more cotton you use the more affect on the bass (so using quite a bit and making it dense will tighten the bass a lot but also kill the impact of it).

Oh, I forgot one other thing. Since I got mine used, the pads were pretty worn and so were very squishy. I found that by taking some cotton balls and rolling them in your palm (it ends up sorta looking like a joint if that helps) and then stuffing them under the earpads (in between the pads and the black edge not on the driver itself). It lessens the highs and ups the bass a bit, but might not be necessary (I would guess its the same effect the leather pads give).
 

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