Fostex TH-X00

The Fostex TH-X00 (here, Mahogany wood variant, others woods are Purpleheart and Ebony) is a closed-back model made in partnership with Massdrop and sold only through that platform (like the Sennheiser HD6XX, Hifiman HE4XX or AKG K7XX).

It uses a Foster basis with bio-cellulose diaphragm and a similar housing to old Denon D2000, D5000, D7000 and recent Fostex TH600/610/900.  The E-mu Teak is also based on this platform. I find the stock earpads quite uncomfortable, and more on-ear than over-ear.

○ Release : 2015
○ Current status : In Production
○ Type : Over-ear / Closed-back
○ Measured weight : 351g
○ Impedance : 25 Ohms
○ Sensitivity : ~99.7 db/mW
○ Average used price : $250-300

Sound Impression
The TH-X00 is an extremely dynamic and fun headphone. Super bassy (absolutely great for bass-head people) and warm, thick sounding balance.

Bass is super elevated ; well above my ideal level but I take it that way. I would say it sounds a bit too bloomy but extension is nice, easily down to around 20-25hz.

Midrange is smooth, with lower-mids forwardness and a dip in the upper-mids. Treble is fine as well ; some impressions mention the TH-X00 as being V-shaped. I don’t totally agree with the statement, as I find them mostly very warm with a downward slope frequency response. The D2000 or the DT770 are cans I consider V-shaped. The Fostex’s treble lacks a bit of sparkle in my opinion.

Soundstage is decent but the TH-X00 lacks clarity to my ears ; not very open sounding, a bit closed-in. It’s mainly due to the stock pads, as they have a very small opening (not even 4cm wide). I tried D2000 pads and it widened the staging quite a lot.

I compared a lot the TH-X00 to the D2000 and D5000, and it’s not even close. The old Denon sound way wider and more open, but also with much treble sharpness. The newer models (TH-X00, TR-X00, E-mu Teak, TH610) have better tonal balance than the old Denon ; less treble peak and more midrange body.

Measurements & Resources

Bass extends all the way down to 20-25hz, with a slight upward slope from 100hz to 25hz. Mild 1khz bump and recessed upper-mids/low-treble. Mid-treble is indeed a bit peaky but the big amound of body this headphone has compensites for it and helps with the brightness.