Thoughts on ProDJ100


tgia note: I’ve had them (and listened to them) for a long enough period of time, so here’s a quick review!


The Koss ProDJ100 is a pair of portable, closed, over-ear headphones currently priced at ~$50 on Amazon. They are known (or not) for their good build quality and bang-for-buck. While opinions on them differ on Head-Fi, I decided to give them a try, as well as compare the stock pads to modded HM5 pads.

Setup used:

Portable: Hidizs AP100

Desktop: Macbook Air –> O2 Combo

Appearance, Build Quality and Comfort

Being a budget-orientated headphone, the packaging is more of the no-frills approach. You get the headphones, a 3.5-6.35mm adapter and that’s it. If they were more expensive headphones I would complain, but for the price I got them there’s nothing to complain about.

I was surprised by the build quality of the these cans and how sleek they look. For under $100, these seem very sturdy. The outer shells are presumably made of aluminum and have a very nice finish to them – I’ve abused them since I bought them, leaving it in my bag without a case, and they’ve held up very well. I think the hinges are also made of metal, so I wouldn’t worry about them breaking on me. The headband, especially, is what I like the most about these headphones. It’s very well padded and sits on my head very comfortably. The one issue I have is the coiled cable – sure, it’s very well made and sturdy, but for portable use I’d like to have something just a bit more portable. Nonetheless, build-quality wise there’s not much to complain – it seems very well-built and probably would be able to withstand some torture.

The pads deserve some mention, and not really for a good reason. Those with large ears will especially feel the pain – the stock pads are extremely shallow and uncomfortable. I had issues wearing them for more than ~2 hours with the stock pads because of the medium clamping force and the fact that my ears were constantly being compressed by the base of the pads. Many people mentioned the M50x pads as an alternative, but personally I have issues with pleather/leather pads of any kind so I bought some HM5 pads and modded them. That solved the comfort issue. After changing pads, these are fairly comfortable, especially with the velour HM5 pads and low clamping force – I can see myself using them on 16-hour plane rides. Although the velour pads somewhat reduces the isolation, the sound leak is still small enough for these to be used in public areas.

Sound Quality

For a sub-$100 headphones, these aren’t bad. Changing the pads did alter the sound signature somewhat – however, I would still characterize both configurations as relatively balanced with a slight boost in the mid regions.

First Impressions:

Slightly harsh and tinny on the upper-mid and treble regions with some sibilance and somewhat boosted bass. Not exactly the best first impression, but people did mention something about burning in. The midrange is pretty clear for something of this price, though. Oh well, I guess I’ll let it warm up (literally) for a bit…

Note: I did find the harshness in the treble to soften after burning in. However, I do think that it may be a psychological effect – take this with a grain of salt! 


The difference between HM5 pads and stock pads is small enough for me to discuss them together. Although the sibilance I heard out of the box has subsided somewhat, there is still some sharpness and harshness to the treble – by no means unacceptable though. The highs are slightly grainy but pretty detailed.


I don’t really know how exactly to describe the mids… Imagine some honey, really thick and luscious. Then dilute it with some of water and sprinkle some table salt on it. Essentially that’s the mids – it’s not exactly thick and luscious, but not really thin either. In my opinion they do shine the most, but that’s also because I listen to a lot of vocal music. The upper mids are especially prominent, making them a good choice for female vocals. For example, listening to this track showcases to which the upper mids stand out – Solji’s voice sounds very vivid and forward.


This is where I felt pad-switching really made a difference. The stock pads made the bass somewhat heavier and there was a noticeable bump in the mid-bass region that I didn’t really like. However, even with the bump, the bass wasn’t overly prominent and was fast enough for the music I listen to. With the modded HM5 pads, it brought the sub-bass further up but pushed the mid-bass down, resulting in a more linear bass response that I liked better and made the mids shine more (which is what I live for anyway – liquid-gold mids!)

Across the spectrum:

This is another place where I found that the pads influenced the sound. With the stock pads, the headphones sound more closed-in – it was a good, well-rounded soundstage for a pair of closed headphones, but I would immediately feel closed-in after listening to open or even semi-open headphones like the HD668B. Switching to the HM5 pads, I didn’t get as good of a seal, so the soundstage got wider and the headphones opened up a bit more. I personally like the space and air of the HM5 pads, but YMMV (of course). Overall, I would characterize these as pretty balanced and neutral headphones that are perhaps slightly mid-centric.


These are hella picky. I made the mistake of listening them unamped out of my phone and cringed at 1. the bad quality of the 128kbps mp3 that Spotify kindly provides to poor students like me, 2. the sibilant highs and 3. how closed in everything sounds. These headphones need POWER. Running them out of AP100 was a lot better, they sounded more balanced and less harsh – it was a nice pairing overall. Pairing them with the XDuoo X3 made the sound somewhat warmer and the treble less harsh, but much of the detail was smoothed out so I preferred the detail of AP100 to the smoothness of the X3. Of course, the desktop setting brought the best out of the DJ100 (IMO), providing enough power to drive these. They sound the most balanced from my desktop setup with no frequency overpowering others (which is kind of sad, considering I bought them for portable use…).


I’ve already discussed the way HM5 pads affected the sound, so this is just on how exactly I “modded” the HM5 pads. Per the DJ100 thread’s instructions, I turned the pads inside out so the pleather backing (on the back of the velour, just between the thin fabric driver protection layer and the cushions) was facing out. I then carefully cut out four small holes (top, bottom, left, right) so that the memory foam inside the pads were exposed. It may be placebo, but I felt like this brought the bass back up a bit and added a bit of warmth to the sound that wouldn’t be present with stock HM5 pads (they did kill the bass and made them so harsh that I would scream).


These are good headphones for the price. Sure, it’s not perfect and I never expected it to be, but it did do the job well. I’m not sure I would recommend them at their MSRP, considering you still need to get pads to bring the best out of them. They aren’t exactly the best at portability and treble quality (IMO), but for the current street price I’d say these are pretty good everyday headphones if you need something to bring around and torture, as they provide a decent all-rounded package.


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