Koss Pro DJ 100 (Midrange Monster Mod™)
Apr 3, 2011 at 12:55 AM Thread Starter Post #1 of 26

tdockweiler

Headphoneus Supremus
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I've been trying to mod the DJ100 for months and was so impressed with my latest results that I just had to post it in it's own thread. The mids are now more forward and it feels as if the clarity has been improved slightly. The mids are not as fatiguing as these were in previous mods. Even the bass feels a bit better, but not in quantity. For me these have the best mids on any headphone under $200 that's closed. Female vocals are just amazing on these. Fans of asian pop music will love them.  You've just got to try Utada Hikaru's Japanese music on these. It's my favorite headphone I've ever owned and it's only $80! There's some things I prefer an open headphone for. I want an open headphone with this driver!

For those that don't know, this headphone has a fun signature, but one that still feels fairly balanced. It reminds me of my Sextett LP, but with more detail, more bass, more forward mids and a bit better clarity. I can't think of many headphones that sound similar to the DJ100. On paper the HD-598 might be, but not when you listen to them. The HD-598 is a favorite though and I use it mostly for gaming. DJ100 has a more aggressive sound signature I think.

Since the DJ100 is so under-appreciated, I doubt this thread will be of interest to many, but that's OK! BTW these sound great (when amped) but even better with the mods. These headphones I've found very unforgiving of poor quality files and badly recorded music. Previously I'd try and put the blame on the headphone but it's the actual recording. I still can't get over how bad some classical music albums sound. I have some piano music that sounds like it's recorded in a cave.

Here are the first mods I've tried, but were not good enough for me:

(feel free to skip this section if you want!)

1) Covering the entire round center and outside ledges with blu-tack.
 
RESULT: More forward mids and better quality bass, but not in quantity. I didn't want that. I used this mod for a month and it was fine. Eventually I felt the mids were too forward, but I absolutely loved the resulting bass. At first I thought the soundstage was improved, but it really wasn't. Something had me fooled! I only noticed this after removing the blue-tack from ONLY the ledges. I think too much blu-tack on the ledges caused the mids too be too forward and negatively affect the soundstage, however that's possible.
 
2) Added Akasa Foam to the center and sides.
 
RESULT: Minor improvements in sound. Not worth it.
 
3) Added Akasa Foam to the round center and Blu-Tack to the outer ledges.
 
RESULT: Mids far too forward and fatiguing after an hour or so.  Even more so than mod 1. The most forward mids out of any headphone I own. I don't really want them THIS forward. The bass wasn't as good as mod 1.

FINAL AND BEST MOD

Just a few warnings first:

Take extreme care with  opening and closing the shell. The internal wires are super thin. Be 100% sure not to accidentally close it and cut the wires.

Do all mods with the cups completely flat or you will pull out the wires!
 
Be sure that the screws don't fall into the exposed driver. I did this and thought I killed my driver, but it was a wire that got cut. Luckily I could fix it easily.
 
All of these mods sounded best to my ears with the Sony MDR-V6 pads which have thin foam on them. Your results with other pads may vary.
 
Now the mod..
 
First apply Blu-tack to the outer ledges. Make it paper thin. This is extremely important! Too much and it will screw up the mids and make them too forward. When it's there, press down with your thumb as hard as you can. You can bend the Blu-tack around the inner edges if needed. Don't put any blu-tack on the outer edges or the cup is hard to close.

Take a small Phillips screwsdriver and with it's edge make lots of indentations on the Blu-Tack so that it's not flat. I don't know what this does, but it can't hurt.
Next take a square piece of foam and place it in the center. Make sure it covers the whole area. I used the type found in the Auto section of any Wal-Mart that's used to apply wax to a car. It's the perfect size and thin. It only costs $1.50. If you use a different material make sure it doesn't touch the back of the driver.
 
Here's some pictures:
 
Here you can see the "ledges". Ignore that Akasa foam. That's from a previous mod that didn't turn out.
 

 
I made a complete mess out of my poor DJ100's guts. Oh well. This is the final result. Don't be dumb like me and try cheap modeling clay. Oops.
The Blu-tack is actually thinner than it looks.
 

 
Here is what I used. $1.50 in the Auto section of any Wal-Mart. It's the perfect size.
 

 
An old picture I took months ago of the DJ100 folded and before I beat it up with mods. I love the simple design.
BTW did you know that it's headband fits the Grado SR-80? My old DJ100 headband is used on my SR-80
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You just need to make the SR-80 holes larger.
 

 
EDIT: Today I tried swapping out the foam with a super thin piece of Blu-tack for the inner circle. It INCREASED the bass and there was even a very slight mid-bass boost. The biggest different is that somehow it increased the level of detail, but muddied up the sound. How the heck does that happen?! The mids were at least not too fatiguing. The results were not really good and this ruined the sound clarity. I added back the foam and the mids were just so much better and more clear. So the final mod in my original post works best.
 
May 15, 2011 at 1:40 AM Post #2 of 26
I spent another two hours tonight modding my DJ100. I started over and listened to the resulting sound after each change. The difference between modded and non-modded is huge.
It seems my main problem was trying to change the DJ100's signature too much. This time around I tried to retain it's default sound while still improving it.
 
Here's what I did:
(removed all mods first)
 
Added a square of Akasa Foam on the inside cup. It's OK to leave the corners exposed.
Added strips of Akasa foam to the "ledges" (see photos).
 
The bass is now a lot better, but better controlled somehow. Sound clarity and detail is better than stock. There's some details in some songs I can't even hear on my HD-650 and K702! I wish I was lying.
They're also there on the Sextett though somehow.
 
It seems that if you add a ton of blu-tak to everything inside it makes them a bit too bass heavy and the mids just aren't as good and overall sound clarity goes down.
 
Love this headphone still, even after owning headphones that cost 3 times as much. I recabled it with Mogami, but it wasn't at it's best at the time, so I did the mods from scratch.
 
For an $80 headphone, these are quite impression for gaming with Dolby Headphone. I think I even prefer them to the HD-650 for gaming!
 
 
Aug 28, 2011 at 12:07 AM Post #3 of 26
I'm bumping this, because I have no clue why this didn't get more notice. I've got a pair of DJ's and am fighting the urge to open em up now! Kickin mod
 
Aug 28, 2011 at 12:43 AM Post #4 of 26
Yeah I think the problem is that very few here still own the DJ100. Or they got a crappy pair (like me a few times) and returned them.
I think a thin layer of blu-tack might be good enough for most. My DJ100 is out on loan, but I got another pair on the way.
 
Wow, is that obsessive much? I've now owned the DJ100 four times (none of them died). The burn-in variations between pairs make me sick though.
My open-modded pair I use a lot, but I kind of wish I didn't do it considering how much work I had to do it get it to sound right.
 
With a few experiments I've found you can make the DJ100 bass heavy somewhat but you sacrifice the mids.
 
The only negative thing about this mod is that it seemed to reduce the soundstage. I don't know if it's still worth it.
If someone does try take EXTREME CARE when doing it. Those internal wires are super thin!
 
BTW how do you like your DJ100? some pairs seem to need 3-5 days of burn-in to sound great.
My last two pairs needs this amount, but the first didn't need any. Very strange.
 
I bought some M50 pads for them and will make a report when I can try them.
 
Aug 28, 2011 at 1:04 AM Post #5 of 26
I like it, I don't want to do too much as far as bass mods, because I'm not real big on bass. I actually got them as portable substitutes to the Grado's I use in my home setup. I feel like they could use a bit more bass though, and could stand to open up a bit more (the slight treble roll-off is getting me coming from the Grados), but they probably only have 2 total days burn-in/playtime on them yet. I've been playing them from my uDac, and they sound pretty good out of that, definitely need more "oomf" than my Fuze can give them though, so an E11 will probably be in my future. They're my only headphone I have with me in college, and I feel like I can be pretty happy with them.
 
As for the wires, they'll probably be eventually replaced with a decent dual-entry Canare or Mogami cable anyway. I don't like single-sided cables, they make me feel unbalanced, and coils are annoying. I'll look at V6 pads though, right now I've got the stock pads with peices of foam tucked in them so my ears fit them.
 
Aug 28, 2011 at 1:18 AM Post #6 of 26
The MDR-V6 pads also fit. I've heard of two people on here say they lacked treble and were as dark as the HD-650. I don't understand this because I like my treble and I'm perfectly happy with their treble. One strange thing I've found is that the treble actually improves with better pads that are more open inside of them. I think the stock pads might be not deep enough and bass and treble may suffer if there is not a good seal. Seriously, you'd be surprised how many people probably use headphones with their ears still sticking out and not even realizing it. The V6 pads also improve the bass.
 
All my pairs have had very good bass, but not quite bass heavy. Just under that I think. Just enough so that it doesn't bleed into the mids. My opinion though is that when bass suffers the most it is when people use them without an amp. They'll still sound good, but it seems they prefer to have an amp. UDAC should be way more than enough.
 
I'm really hoping the M50 pads are good with them. I think another person on here uses them and said they were good. They should improve the comfort a lot too. RX300 pads also fit, but they're angled and you have to buy the $20 headphone to get them. M50 pads are $9 each.
 
The DJ100 is a pain to recable. You have to take out the volume button (it's trick) and then cut a piece of the plastic inside the cup. It's such a pain and the benefits are not so huge, so I don't suggest it more for this headphone. I used Mogami on mine.
 
Just for fun, I'd suggest sticking them in a drawer playing music fairly loud while you sleep. Totally not required, but it can only help. My 3rd pair needed 5 days to sound like my original pair. This makes no sense!
 
Quote:
I like it, I don't want to do too much as far as bass mods, because I'm not real big on bass. I actually got them as portable substitutes to the Grado's I use in my home setup. I feel like they could use a bit more bass though, and could stand to open up a bit more (the slight treble roll-off is getting me coming from the Grados), but they probably only have 2 total days burn-in/playtime on them yet. I've been playing them from my uDac, and they sound pretty good out of that, definitely need more "oomf" than my Fuze can give them though, so an E11 will probably be in my future. They're my only headphone I have with me in college, and I feel like I can be pretty happy with them.
 
As for the wires, they'll probably be eventually replaced with a decent dual-entry Canare or Mogami cable anyway. I don't like single-sided cables, they make me feel unbalanced, and coils are annoying. I'll look at V6 pads though, right now I've got the stock pads with peices of foam tucked in them so my ears fit them.



 
 
Aug 28, 2011 at 9:32 AM Post #7 of 26
I see what you mean, even with the foam mod I'm still not getting a perfect seal (I have really "out" ears). The foam seems to suck up some of the highs too. I'll definitely try the v6 pads since my dad's V6 fit me wonderfully.
 
Aug 29, 2011 at 2:42 PM Post #8 of 26
I'm thinking these things are finally burned in, the last few days they've been playing almost non-stop, and the sound seems to have opened up quite a bit. The sound seems less muddy in the bass, like it has more snap, and the highs seem to be more open. Oddly enough, they almost seem to be less picky, the sound difference between my uDac and my Fuze seems to have decreased, although I still like the sound out of the uDac better. Maybe it's psychoacoustic, but who knows.
 
Aug 29, 2011 at 6:08 PM Post #9 of 26


Quote:
I'm thinking these things are finally burned in, the last few days they've been playing almost non-stop, and the sound seems to have opened up quite a bit. The sound seems less muddy in the bass, like it has more snap, and the highs seem to be more open. Oddly enough, they almost seem to be less picky, the sound difference between my uDac and my Fuze seems to have decreased, although I still like the sound out of the uDac better. Maybe it's psychoacoustic, but who knows.


I'm going to be doing some more testing related to the burn-in with these. I have a new pair on the way from J&R. I scored a pair for $60, but they're back up to $70 now.
Just for my own amusement (and because I'm weird) I'm going to take notes through the burn-in process and make sure to listen to them as little as possible. I know exactly how a DJ100 should sound like, so this will be interesting.
I actually just hope this pair sounds great out of the box like my first pair. This sure is a good headphone for those that don't believe in burn-in.
 
On my 3rd pair the mids were not forward sounding in any way and kind of muffled. Treble felt as if it was chopped off. Bass was OK from what I recall. The strangest thing is that music with a large soundstage (like classical) sound just "off". I've mentioned this before, but on TWO occasions I actually felt as if I had a defect!! One pair needed 3 days of burn-in and another 5. One reason I think the last pair needed 5 days was because I didn't turn them up loud enough during burn-in. They say a good headphone shouldn't "Wow" you with it sound, but the K501 and DJ100 do this for me.
 
A well burned in DJ100 should have those forward upper mids, not be too dark and have very good bass. I always felt the sound was crystal clear, but this may vary between songs and pads. Best upgrade for these is new pads. I'll know how the M50 pads are on them in a few days. They cost about $9 each from Sweetwater.
 
It'll be nice to have a burned in and a new pair to compare. I really just do have a feeling that lots of Koss headphones need burn-in to be at their best. This seems to be the case with the Pro4AAT and others.
 
Someone recently told me he didn't think there was many differences between amped and not amped. I do prefer them amped, but maybe I'll do some testing on this more. I myself believe they suffer in some areas when not amped well.
 
I want to do another review of them too, but a more in depth review. I think they deserve it. Maybe I'll be totally unfair and compare them with my KRK KNS-6400 just for fun. It'll be a close one I imagine.I'd rather compare it to the SRH-940
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Sometimes I wonder how much more popular the DJ100 would be if it wasn't labeled as a DJ headphone and had better pads? Maybe someday Koss will make us an open headphone similar to the HD598 and K501 and be just as comfortable. Not likely it happen, but it'd sure be nice! Koss really needs to work on it's comfort with headphones a bit. I sure wish they had more headphones with memory foam pads like the KNS-8400.
 
Aug 29, 2011 at 9:13 PM Post #10 of 26
   I love mine even unmodded .  Use them thru a Onkyo Stereo receiver.   I think they sound great with almost any type of music.   They are a bargain for the price .  
 
Aug 29, 2011 at 9:22 PM Post #11 of 26


Quote:
   I love mine even unmodded .  Use them thru a Onkyo Stereo receiver.   I think they sound great with almost any type of music.   They are a bargain for the price .  


Yeah, they sound perfectly fine without mods. I still need to do more experimenting with mods though. I have a hard time suggesting anyone to do the mods because it's a bit risky with this headphone. There's lots of extra wires inside because it also has a mono/stereo switch.
Somehow I STILL haven't tried it with my Onkyo receiver. I need to do that.
 
The price seems to have come down $10 from $80, but $80 is totally worth it. Last year Best Buy had some $50 sales on them but not this year. They were $60 at J&R this Sunday, but the sale is gone. I bet one could haggle with them on the phone
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I'll be comparing them to the Kicker HP541 this week.
 
 
Aug 30, 2011 at 3:10 PM Post #13 of 26


Quote:
T, do you have a picture of the Koss headband on your SR-80?


Sorry, I did, but I can't find it. It was posted in the old SR-60 mod thread by me about 6 months ago.
If I find it I'll post it.
 
Unfortunately it does require you to drill larger holes into the SR-80/60. So it's probably not worth it.
 
 
Aug 30, 2011 at 3:30 PM Post #15 of 26


Quote:
Plastic shells?  I ain't trippin.
 
Seen your pictures here, btw: http://www.head-fi.org/t/508459/sr60-mod/1530#post_7291096
 
I would do it, personally, assuming I had both phones and wanted a more structural sort of wear.


The one thing someone needs to be careful of is to not make the holes too big. If you do this, the driver enclosure will just spin around in circles!
It's also a bad match for those with a huge head I think. The headband only expands so much. It seems to be the most comfortable with the flat pads.
 
Destroying a DJ100 for the SR-80 makes me sad though
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My first DJ100 died due to modding (oops) so I figured it can't hurt.
 
With this mod, there is also the chance the old SR-80 headband will no longer fit.
 
 

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