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We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-24 · 6 min read · Independent comparison
• Fostex TH-610 biggest strength: A 50mm dynamic driver with a 1 tesla (1,000 gauss) magnetic circuit and a "Bio-dyna" diaphragm, tuned for rich lows, natural mids and smooth highs — a wired, wood-cupped audiophile build.
• Fostex TH-610 biggest trade-off: No Bluetooth, no noise cancellation, no battery. It's a wired headphone with a 3.5mm jack, so it's tethered to whatever you plug it into.
• Bowers & Wilkins FP39691 biggest strength: Adaptive noise cancellation plus a wireless Bluetooth 4.1/aptX-HD design with smart sensors that pause music when you lift an ear cup and sleep when you set the headphones down.
• Bowers & Wilkins FP39691 biggest trade-off: Its 20Hz–20kHz frequency range and 40mm drivers are narrower on paper than the Fostex's 5Hz–45kHz span, and it leans on firmware and an app to get the most out of it.
• Pick the Fostex if you listen at a desk or with a wired amp and want a classic, wood-grained, over-ear headphone.
• Pick the Bowers & Wilkins if you fly, commute, or work in noisy spaces and want one headphone that does everything untethered.
The Fostex TH-610 is a wired, over-ear headphone built around a 50mm dynamic driver and a 1 tesla magnetic circuit. That's a serious amount of magnetic force for a headphone driver, and Fostex pairs it with its "Bio-dyna" diaphragm, which the spec sheet describes as delivering rich lows, a natural midrange and smooth highs. On paper, the frequency range stretches from 5Hz all the way to 45kHz — well beyond what most listeners can hear, but a sign of how much headroom the driver is designed to handle.
The design language is the other half of the story. The housings are made of black walnut with a matte finish, so this is a headphone you notice on a desk. The ear pads use a low-repulsion cushion material wrapped in artificial leather, which matters because these are the kind of headphones people wear for long stretches. The cable is detachable via a 2-pin connector and is compatible with the TH900mk2, so if you already own that cable ecosystem, this slots right in.
Who should buy it? Someone who listens critically — at a desk, through a DAC or amp, or straight from a good source — and wants a warm, wood-cupped over-ear with a replaceable cable and a classic look. Sensitivity is listed at 98dB/mW, so it's reasonably easy to drive, though a wired setup is the whole point here. Who should skip it? Anyone who wants Bluetooth, noise cancellation, or to walk around untethered. There's no battery, no app, no active features — just a 3.5mm jack and the music. If that sounds like a limitation rather than a feature, this isn't your headphone.
The Bowers & Wilkins FP39691 — sold as the PX — is a wireless, over-ear active noise cancelling headphone in a soft gold finish. It runs Bluetooth 4.1 with aptX-HD, and it also accepts a 3.5mm cable, so you can go wired when you want to. The headline feature is adaptive noise cancellation, which the spec sheet frames as customizable to your preference, aimed at planes, streets and offices.
The smart features are what separate it. Built-in sensors pause playback when you lift an ear cup and put the headphone to sleep when you set it down; pick it up and it resumes. That's a genuinely useful behavior when you're constantly taking headphones on and off — at a desk, in a coffee shop, on a flight. The drivers are 40mm full-range units derived from Bowers & Wilkins' P9 Signature headphones, and they're subtly angled to create a more natural stereo perspective. Impedance is 22 ohms in passive mode.
Battery life is where the spec sheet gets detailed: up to 22 hours with Bluetooth and ANC on, up to 29 hours with Bluetooth and no ANC, up to 33 hours with ANC and a wired connection, and up to 50 hours wired with no ANC. The battery is an 850mAh lithium polymer cell. Bowers & Wilkins also notes that you should install the latest firmware via its dedicated Headphones app to get the best from the PX — worth knowing, because this headphone is partly a software product. In the box you get a headphone cable, a protective case and a USB-C cable for charging and firmware updates.
Who should buy it? Frequent travelers, commuters and open-office workers who want one headphone that cancels noise, goes wireless, and handles calls and casual listening. Who should skip it? Listeners who want a purely analog, no-app, no-battery experience, or who prioritize the widest possible frequency range on paper. The PX is a lifestyle headphone with serious acoustic ambitions — not a studio tool.
Side-by-Side: Which Should You Choose?
• Best for wireless freedom → Bowers & Wilkins FP39691. Bluetooth 4.1 with aptX-HD means no cable required.
• Best for long listening sessions away from a charger → Bowers & Wilkins FP39691. Up to 50 hours wired with no ANC, or 22 hours wireless with ANC on.
• Best for wired, purist listening → Fostex TH-610. A detachable 2-pin cable and a 3.5mm jack, nothing else in the signal path.
• Best for wide frequency range on paper → Fostex TH-610. 5Hz–45kHz versus 20Hz–20kHz.
• Best for smart, hands-free convenience → Bowers & Wilkins FP39691. Sensors pause and resume playback automatically.
• Best for a distinctive, furniture-grade look → Fostex TH-610. Black walnut housings with a matte finish.
• Best for travel and commuting → Bowers & Wilkins FP39691. It ships with a protective case and folds into a portable, app-managed package.
In my opinion, these aren't really competitors — they're two answers to two different questions. If I were buying for a desk, a dedicated amp, and long evenings of critical listening, I'd take the Fostex TH-610: the 50mm driver, the 1 tesla magnetic circuit and the black walnut cups are exactly what a wired audiophile headphone should be. But if I could only own one headphone for real life — flights, trains, an office, a walk — I'd buy the Bowers & Wilkins FP39691. Adaptive noise cancellation, 22 hours of wireless playback with ANC on, and sensors that pause music when you lift a cup make it the more useful object day to day. Buy the Fostex for the sound-first ritual. Buy the PX for everything else.
No. The Fostex TH-610 is a wired headphone with a 3.5mm jack and a detachable 2-pin cable. There's no Bluetooth and no battery, so you'll always need a source to plug into.
Yes. The FP39691 (PX) features adaptive active noise cancellation that you can customize to your preference, which makes it a strong choice for planes, streets and open offices. The Fostex TH-610 has no noise control.
Only the Bowers & Wilkins has a battery — an 850mAh lithium polymer cell rated for up to 22 hours with Bluetooth and ANC, up to 29 hours with Bluetooth and no ANC, up to 33 hours wired with ANC, and up to 50 hours wired without ANC. The Fostex TH-610 is passive and needs no charging.
For home listening through a wired setup, I'd lean toward the Fostex TH-610 for its 50mm driver, 1 tesla magnetic circuit and 5Hz–45kHz range. If you want to move around the house untethered, the Bowers & Wilkins FP39691 is the more flexible pick. Either way, check the current price on Amazon before you decide.
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