Fostex/Denon/Emu Cup Swaps

The Foster variants of headphones include several headphones that share the same driver family and mostly the same frame, headband, etc. These include:

Fostex TH-600, TH-610, TH-900, TH-909 MK2, TH-909, TR-X00, TH-X00
Denon AH-D2000, AH-D5000, AH-D5200, AH-D7000, AH-D7200, AH-D9200
Emu Teak

The main differences between the lower end and upper end models are the voice coil improvements and the type of wood used. One of the interesting and nice things about the common framework is the ability to mix and match woods between models, or use custom woods made my companies like Lawton Audio, who make custom wood cup chambers that fit on every model.

In my case, I own the Drop version of the Fostex TR-X00 with Ebony wood cups. I really enjoyed the Ebony model and reviewed it previously with a solid rating. The Ebony had a very well-balanced sound signature that was warm but did not have a large mid-bass bloat or extremely sharp treble that can be found on such models like the TH-900 series or the Purpleheart version. Instead, the treble was generally smooth. I mostly enjoyed it for the great mid-range which was rich but natural and very pleasing.


A few months ago, I started contemplating modding up the Fostex headphone with a new cup. I looked at various options including the Lawton mods, but discovered that these added a lot of weight and thickness to the headphone, which I did not want, despite how beautiful some of Mark Lawton’s works are.

After a few weeks of searching and contemplating, I decided to buy the Emu Rosewood cups. Emu offers various wood cup types if you email their customer service and they’ll collect payment through Paypal and ship out via FedEx. I considered purchasing other woods too, but decided to try just the Rosewood for now.

Why did I choose Rosewood? Well, besides that it’s a very nice wood look and wood stain color, Rosewood is widely used in many different instruments and I thought that may give a nice organic sound to things. Ebony is a denser wood, and because of that makes the overall weight higher. It also hits a bit faster with less decay and sustain. Rosewood is a little bit lighter and is known for its warm resonance. But let’s save that discussion for a little bit later.


The Emu cups came after about a week. The cups look great, with nice glossy finish, and are logo-less, which is a nice change from the white Fostex branding on the Ebony cups I had. I don’t really mind the logo but it sure is nice to have a brand-less look too.

The rosewood look had a defined horizontal grains and a rose colored stain that is a light red color and makes it pop out.

The cups are also very, very light. The total headphone weight reduced the Ebony by 60 grams with the Rosewood cups installed in it’s place, putting the total weight of these headphones to below 400 grams.

The cup itself is thinner than the Fostex variant, and makes this an overall slimmer look. There’s a little bit less defined lines than on the Fostex Ebony cup, but this one looks a little sleeker with a smaller overall shape.


Putting on new cups is pretty easy. It requires popping off the stock pads, which can be performed by a twisting motion. It’s held by clips. Then you’ll have access to the screws. You can get away with just unscrewing the 4 screws that are below the cut outs and those hold the wood cups in. Once you remove the cup, you can replace it with the new cup in the same position and fasten it together, and re-install the pads.

Sound Impressions

These sound impressions will be mostly be a comparison between the Fostex Ebony and the Emu Rosewood cups. The majority of my listening was played on the following systems:

  • Schiit Bifrost 2 -> Schiit Saga+ -> Schiit Jotunheim
  • iFi Zen DAC
  • Sony NW-ZX507

I also did try them on a few other amps like the Topping A90, Soundaware P1, and the Loxjie P20.

Right off the bat, I found the rosewood had a more engaging sound to than the ebony, which I had already really liked. The rosewood had a touch more warmth to it, and it seemed like the bass and lower mid-range may be just a little more elevated, while the rest of the response seemed very similar. There was a slight rise in treble and upper range.

The biggest change to me was the added resonance. This can be one where people love it or hate it, but to me this added effect, stemming from sound reverbing off the wood, adds a very natural and “live” effect to music. It makes some of my music really come alive, and adds a little more depth to music, and improves layering.

In effect, it gives me a more open feel that I am at a live concert in some ways. This really becomes apparent when I listen to jazz and orchestral music, where strings have a little extra twang to them and bass notes hit with more oomph.

I wasn’t fully expecting the sound to have a major characteristic change. I do want to clarify that these changes as drastic as it may seem in my written text, but subtle, and something that I noticed in songs I listened to a lot and know many of the ins and outs of certain passages.

The changes are less apparent when I listen to busier rock songs and EDM type music. The rosewood cups benefit the most from the use of acoustical instruments. Now that said, there’s nothing wrong with these other genres at all when played with this headphone combination.

The rosewood cups still retain the great sounding mid-range of the Foster headphone line, which I truly admire and I have been constantly reaching for when I decide which headphone to choose. I never thought this would ever be the case to be honest, because I’ve read so much about how V-shaped the TH900 series was, and that’s quite true.

But this TH600-style combination is much more balanced and I really love how it sounds, with most of the cup choices I’ve tried in the past. The shallower pads really make the biggest difference. And even through my pad rolling, I’ve quickly reassured that finding.


Great write up!

Maybe I missed it, but what earpads are you using? Stock pads?


Thanks. I am using lambskin leather pads that’s the same shape and size as the original pads. They tame the bass slightly and increase the lower treble a little bit which makes these sounds more balanced


Nice Review Antdroid! I definitely recommend the Lambskin pads/Sheepskin pads that E-MU makes instead of the protein ones. I just recently did a review of the E-MU Teak, and have always wondered about the other E-MU cup variants.

I’d like to try them all! Right now, I have the Bamboo Cups on mine instead of the Teaks for review… Unfortunately, the Teaks “have the magic,” and the Bamoboo Cups are a little too V-shaped for me.
They sound like the Teak and the Ebony had a baby; which isn’t bad, but not as magical as the Teaks, I’m afraid.

I’ve always wanted to hear the Rosewood though. I’ll release a review of the Bamboo cups on the next drop. I’ll place a link to my Teak Review below if you haven’t checked it out yet! Maybe I get a chance to hear the Rosewood one day! Until then, I’ll rely on your findings! Great job!


@antdroid if you ever have interest in swapping your ebony cups for purplehearts, drop me a line!

Do the E-mu cups fit Denon D2000? Damn, that would be a cool mod.


I don’t own Denon or Emu (I have a Lawton modded Fostex), but they should. My understanding is that the Foster BioDyna’s all have the same build/similar assemblies.

For reference:

They do but you’ll have to cut down the screw mounts on the D2000 or the cups will sit a bit too high and basically make them more have a much bigger vent hole :slight_smile:

added picture of what it looks like if you don’t.


Ah, that looks like a bit of a hassle. Thanks for the info and photo anyhoo!

Just caught this, very useful comparison since I had the X00 Ebony for a long while and loved it! What are the pads you used specifically, if I may ask? The guy I gave my X00s to is bearing with flaked pads and that’s not doing bass response many favours haha.

One poke: there’s a TH910???

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Ooops. I meant TH900 Mk2. Numbering convention isnt consistent. haha.


Thanks! Shooting the link his way. And agreed on the numbering being a bit ridiculous— TH909 indeed haha. Still rather curious to get ears on that one but I’m not entirely sure I’ll want another Foster variant after the Klipsch, pretty as the lacquer and lattice are.

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