Fostex TH1100RP Review

October 9, 2024 3:08 pm

Fostex is one of the most reputable brands in audio for a reason. Their entry level headphones are as revered as their high end ones. With popular entry level models like the TH50RP and cult classic high end ones like the TH909, the brand often faces lofty expectations. Now they’ve released a new flagship headphone, the TH1100RP. Coming in at $2,699.99, Fostex intends for this to be its open-back top of the line model. So does it achieve flagship greatness? We’ll talk about that and more in this review.

What’s in the Box:

TH-1100RP
Leather pouch
Owner’s Manual
7N grade high-purity OFC unbalanced cable

Build:

The Fostex TH1100RP headphones stand out for their masterful craftsmanship, which merges modern audio technology with traditional Japanese aesthetics. The build starts with the solid hard maple wood housing, a material commonly used for musical instruments due to its tonal qualities. This wood is dyed using “Aizome,” a traditional Japanese indigo dyeing method that originates from Tokushima. The result is not just a visually striking deep indigo finish but also a unique tactile experience, as each piece of wood reveals its individual grain patterns, making each headphone slightly different from the next. The solid wood housing isn’t just for looks; its density and specific gravity provide acoustic advantages by minimizing resonance and allowing for clearer sound reproduction, especially in the bass and treble ranges.

In addition to the carefully crafted wood housing, Fostex has prioritized comfort and durability with its use of lightweight magnesium alloy for key mechanical parts. These components, including the hanger and housing base plate, help to reduce the overall weight by 20% compared to traditional aluminum-based designs, making long listening sessions more comfortable. The attention to detail extends to the ear pads, which are asymmetrically shaped for an optimized fit, and crafted from silk protein synthetic leather that is three times more durable than conventional materials. The headband and head pad are made of natural sheepskin, offering a soft and supple fit to further enhance comfort over prolonged periods.

Design:

At the core of the Fostex TH1100RP is its refined RP (Regular Phase) planar magnetic driver technology, which has been a staple of Fostex’s audio engineering since its debut in 1974. The TH1100RP features a larger planar diaphragm than the earlier T50RP models, coupled with an increased number of magnets to sandwich the diaphragm. This re-engineered magnetic circuit optimizes the magnetic flux distribution, which in turn suppresses unwanted resonances in the diaphragm. The result is a significant improvement in sound reproduction, with high sensitivity and a smooth, extended frequency response.

Fostex has also incorporated high-purity 7N (99.999999%) oxygen-free copper (OFC) for the internal wiring, paired with rhodium-plated terminals for the detachable connectors. This ensures an ultra-pure signal path, minimizing signal loss and preserving audio integrity.

Fostex’s approach in both build and design show that the company is dedicated to creating something that is refreshing in new, while not fixing what ain’t broke at the same time. But how does all of this translate to the sound of the headphones?

Listening Impressions:

Low End:

Fostex is known to make some of the most rumbling headphones out there. The TH900MkII, for example, is lauded for its bass prowess. And so this is something from their DNA that Fostex looked to reimagine with its new tuning. Timbrally speaking, you get a warm and rich low end. Sub-bass is deeply extended. But more than just extended, it’s fast, punchy, and tight. That said, the bass response feels pretty neutral, if a bit V-Shaped. Where you get the low-end bombast to some degree, there’s a sense of space left open by an apparent lack of bloom. To my ears, this isn’t a bad thing as it allows for more room for details to resolve.

On rock and jazz tracks, the speed of drums and bassand the clarity with which they’re presented was delightful. While not necessarily the most elevated bass response, I actually didn’t mind losing the midbass bloom that would bring that extra presence. Instead I enjoyed hearing great instrument layering and a tasteful balance in sounds.

Mids:

As I said, the TH1100RP has a slight V-shape to it. In this instance, that means that the midrange is a bit more relaxed and recessed. I found the mids to sound present and nimble at the same time, with vocal details becoming more apparent and separation taking a front seat in presentation. With classical music, it allows for a clearer sense of layering. Rather than an immediate presence, you get a more gentle and careful approach. It’s a great take on the V-shape and makes Fostex’s headphone highly versatile.

Listening to rock or pop, you don’t lose sense of the vocal or any dynamics in the midrange, it’s just they’re more subdued. Perhaps micro-dynamics take a back seat to nuanced detail retrieval, but I think enough energy comes from the low and high end to keep things feeling exciting and musical.

Top End:

The top end on the TH1100RP brings everything together. The treble response is cohesive and airy, allowing great breathing room for higher frequencies. That makes this a pretty pleasant headphone to listen to, even despite this strong treble performance. Oftentimes on bright headphones, it feels like the higher frequencies are being played to the max, with no room to resolve. That’s not the case with this headphone, which manages to have a brighter top end to pair with its warmer low end.

Soundstage:

I am quite impressed with the soundstage on the TH1100RP. With the technical adjustments that Fostex made to their design, the soundstage feels expansive and natural. I most enjoy the sense of space it creates. There’s always room for sound to resolve to, minimizing fatigue while presenting lush detail. There’s a sense of front to back and top to bottom that you can really only get in flagship equipment. In that case, that makes this a pretty impressive value from the Japanese manufacturer.

Final Thoughts:

The TH1100RP from Fostex is another great performer from a company with a reputation for excellence. It’s beautifully crafted with technological design to match. Its indigo color makes it a sight for sore eyes. Add to it is versatile in pleasing sound signature and I think Fostex has a winner on their hands.