Today, the best solution for Ham Radio in terms of lightness, comfort and audio quality
Why Bose® QC25?
Essential, Functional, and Comfortable! The only things that matter when it comes to Ham Radio Accessories.
The Bose® QC25 Ham-Set is essential because, in addition to the Noise Cancelling System, it does not have circuits that could cause annoying audio feedback, such as Bluetooth. Moreover, the Bose® brand guarantees unparalleled clarity and precision of sound, especially in CW mode.
The Bose® QC25 Ham-Set is functional thanks to its lightweight boom microphone, which is high-quality and highly compatible with all major radios, enabling operations in all bands and modes. Additionally, it comes with a new RF-proof connection cable that prevents interference even at higher transmission powers.
The Bose® QC25 Ham-Set is comfortable because you can wear it for the entire 48 hours of a contest without experiencing the slightest ear discomfort!
Bose® Noise Cancelling System
Bose’s renowned noise cancelling system is an advanced electronic technology designed to dramatically reduce external sounds. By using internal microphones and processors, it analyzes ambient noise in real time and cancels it by generating an opposite sound wave.
How Active Noise Cancelling (ANC) Works in Bose QuietComfort Headphones
Bose QuietComfort headphones (such as QC25, QC35, and QC45) use an advanced electronic system called Active Noise Cancelling, designed to actively eliminate ambient noise before it reaches your ears. This is very different from passive isolation, which relies only on ear cushions to block out sound.
Internal and External Microphones: Each earcup contains two microphones: An external mic that listens to the surrounding environment (like airplane engines, traffic, or air conditioning). An internal mic that monitors what actually reaches your ear inside the cup. This dual sensing system gives the headphones a more accurate picture of the noise, improving how it’s cancelled.
The Brain of the System: The Processor Inside the headphones, a small digital processor constantly receives input from the microphones. It analyzes incoming noise and instantly generates an opposite sound wave, phase-shifted by 180 degrees. This sound isn’t audible, but it’s used to cancel out the noise.
The Actual Noise Cancellation The inverted signal is played through the headphone drivers, alongside your music or audio. When the real noise wave meets the opposite wave, they cancel each other out. This effect is called destructive interference, and it drastically reduces the amount of noise that reaches your ears. The result? Low, steady noises (like engine hum or fan noise) are almost completely removed, while sharp or sudden sounds (like voices or keyboard clicks) are only reduced, not eliminated.
Constant Adaptation The system isn’t static — the processor checks and adjusts everything hundreds of times per second, adapting to how the ambient noise changes. This makes the noise cancelling extremely effective even in dynamic environments like moving trains or busy offices.
Aware Mode (QC45 Only) The QC45 model includes a mode called Aware, which turns off noise cancellation and allows external sounds to pass through the microphones. It’s useful when you need to stay aware of your surroundings or have a quick conversation without removing your headphones.
Good to Know The system only works when the headphones are powered on. QC25 uses a AAA battery, while QC35 and QC45 have a built-in rechargeable battery (USB charging). The headphones are designed to work even without playing music — you can use them just to cancel noise. If you attach a boom mic to use them as a headset (e.g. for radio communication), noise cancelling has no effect on the microphone. It only acts on what you hear, so no technical adjustments are needed.
Customize your QC-25 HamSet®
Unlike the old “Grade A, B, C” system, today you can customize your QC25 Ham-Set exactly as you prefer. All headsets are refurbished, fully tested, cleaned, disinfected, and fitted with new ear pads. Any worn or broken parts are replaced before installing the new boom microphone and the connection cable.
You can customize your headset with the following options:
Earcup Shells: choose between original Bose finish or professionally repainted shells.
Original Cardboard Box: when supplied, the headset is in as new condition, never used. ⚠️ Please note: this option is only available with original Bose earcup shells and excludes the repainted shells variant.
Microphone Elements: Dynamic Standard – 600 Ohm, –55 dBV, universal compatibility. Dynamic DX – 600 Ohm, tuned for pile-ups, enhanced presence. Electret IC – 600 Ohm, high-definition, requires bias power (ideal for Icom).
This system lets you build your perfect contest headset, combining the comfort of Bose® with Ham-Set® engineering, fully tailored to your operating style.
A true commitment to Refurbishing
Every Bose® QC25 offered by Ham-Set® is a refurbished unit. Each headset is fully tested, cleaned, disinfected, and fitted with brand new ear pads. Any worn or broken components are replaced or restored before the new boom microphone and RF-proof cable are installed. This guarantees that every unit is ready for intensive use in contests and daily operation, with the same comfort and performance that made Bose® famous.
We want only original parts!
At Ham-Set, we source genuine parts exclusively from other headsets, carefully selecting them for refurbishment. Damaged aluminum components are re-anodized and recolored to restore their original appearance. Ear pads are always replaced with a new pair, and both the cable and microphone are brand new. This rigorous process guarantees a product that feels and performs just like new.
The Microphone That’s Right For You
The Ham-Set® boom mic is permanently mounted for maximum durability and RF safety. Each element is carefully selected to match the needs of serious operators.
Dynamic Standard – 600 Ohm, –55 dBV, Cardioid
The Dynamic Standard element is the most universal solution for amateur radio. With an impedance of 600 Ohm — exactly what most radio microphone inputs are designed for — it is plug-and-play with virtually any transceiver: Yaesu, Icom, Kenwood, Elecraft, FlexRadio, SunSDR, MicroKeyer and more. This element does not require power to operate. Inside every Ham-Set® dynamic headset we add a small decoupling capacitor, ensuring safe connection even to Icom radios or MicroKeyer devices that provide voltage on the mic line. For this reason, no special adapter cables with inline capacitors are required — just a simple 3.5 mm jack adapter to the radio mic input. Its cardioid polar pattern helps reject ambient noise, making it ideal for multi-operator contest environments where several radios are running simultaneously in the same room. The frequency response (150 – 10,000 Hz) emphasizes clarity and midrange presence, giving intelligibility without fatigue. Sensitivity is –55 dBV/Pa, with a maximum SPL handling of 136 dB. For large contest stations, this is the preferred element because it allows any operator to plug in within seconds, without changing any radio setup.
The Dynamic DX element shares the same technical base as the Standard — 600 Ohm impedance, –55 dBV sensitivity, cardioid pattern — but it is acoustically tuned for maximum presence in pile-ups and DX conditions. Its response has an intentional boost in the 2–3 kHz region, where consonant intelligibility is most critical, cutting through QRM and crowded band noise. This gives the operator’s voice more “bite” on the air, while still avoiding harshness or fatigue during long 48-hour contests. Compared to the Standard, the DX version sacrifices a little warmth in the lows for extra clarity in the highs — making it especially effective for SSB contesting where intelligibility is everything. This is the element of choice for operators who want their modulation to be heard fast and sharp in the middle of a pile-up.
Electret IC – 600 Ohm, –47 dBV, Omni Noise-Cancelling
The Electret IC element is a high-definition choice specifically designed for radios that provide bias power on the mic input (Icom, MicroKeyer, some Elecraft models). Compared to dynamic elements, the electret offers: Richer low-end response, giving more depth and warmth to the voice. Wider dynamic range (100 – 20,000 Hz), for a fuller and more natural sound. Higher output power, making the signal more robust without additional processing. Its omni noise-cancelling design helps reduce background noise while keeping the timbre natural. However, the electret element requires powering. For Icom radios, this is straightforward, but for Yaesu, Kenwood, FlexRadio and others, a special powering cable is necessary — which we can provide upon request. ⚠️ Important note: Electret elements are inherently more sensitive to RF feedback. If your station experiences RF issues at high power, we strongly recommend choosing one of the dynamic options instead.
The Cable
Every headset is fitted with a permanently attached RF-proof cable, with fully shielded separate paths for audio and mic signals to avoid RF feedback at high power. Choose your style: – Straight heavy-duty semi-rigid cable (length 1,80 m) – Lightweight braided soft cable (length 1,60 m) – 5-meter coiled audio cable (length 1.40 m relaxed and up to about 5 m when stretched)
Connect it to your Radio
Adapter cables are available for connection to your radios: Yaesu, Icom, Kenwood, Elecraft, FlexRadio, SunSDR… and more.
The Contest Station Choice
The Bose QC25 Hamset is becoming a must-have for major global contest stations. Their reliability and durability ensure intensive use, such as in a high-traffic contest station, without any issues. The quality of Bose’s noise-cancelling system ensures perfect listening even in noisy and crowded environments, such as a room full of radio amateurs in the midst of a pile-up. About the mic choice, contest stations prefer the use of the dynamic capsule just because it can be connected directly to all radios (including Icom) without the need for specific cables. It is preferred for its plug-and-play speed. The tests for functionality, RF returns, and ergonomics were conducted at CN3A and II2S radio stations. Their teams use these headphones with the dynamic microphone capsule in all their contests.
Bose QC25: Everything You Need to Know -Hidden Strengths and Common Flaws-
The Bose QC25 are among the most iconic noise-cancelling headphones ever made. Lightweight, durable, and incredibly comfortable, they’ve been a top choice for travelers, professionals, and — with the right microphone element — also for demanding radio operators. But like any great product, they’re not without weaknesses. Here’s a clear breakdown of what makes them exceptional — and what you should watch out for.
What Makes the QC25 So Special
Unmatched Comfort and Lightness The QC25 are among the lightest over-ear noise-cancelling headphones in the world. You can wear them for hours — during long flights, work sessions, or contest operations — without fatigue. This makes them a top-tier choice for long listening or operating sessions.
Durable Fabric Headband Unlike most modern headphones that use synthetic leather (which flakes over time), the QC25 headband is covered in woven fabric. This material doesn’t peel, crumble, or degrade — even after years of use — making it far more durable and comfortable in the long run.
Known Issues and Design Weaknesses
Degrading Blue decorative rubber strip (see picture below) One of the most frustrating issues with the QC25 is the soft blue rubber strip around the speaker enclosures. Over time, this material becomes sticky, deteriorates, and collects dirt, making the headphones look and feel unpleasant. At HamSet, we fully clean and restore this area, replacing the original coating with a UV-resistant polymer that doesn’t degrade over time and maintains a clean, professional finish.
Speaker Rotation Weak Point The ear cups rotate to a mechanical stop, which is useful for storage and portability. However, if forced beyond their intended limit, the mechanical stops can break. Once broken, the speaker may continue to rotate freely — putting stress on the internal cable that carries audio to the driver, and eventually causing damage. Advice: Always handle rotation gently. Normal use won’t cause damage, but excessive force can break the stops and compromise audio performance.
Loose Drivers: The “Ticking” Issue In some QC25 units, the internal speaker (driver) is glued into the enclosure, but the adhesive can dry out — possibly due to minimal application during assembly. When this happens, the speaker may come loose and rattle inside the housing, producing a faint “clicking” sound when shaken or during audio playback. This can cause unwanted vibrations and reduce sound quality.
If you own a pair of QC25 and want to restore them, modify them for ham radio use, or simply bring them back to life — HamSet is here to help.
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Specifications:
Headphones Speaker: 40mm Impedance: 32 Ohm Frequency response: 20 – 20,000 Hz Battery life with Noise canceller on: 35 hours The headphone also works without battery with Noise canceller turned off. Dynamic range: -54dBFS Connection: 3.5mm stereo male jack+ 6.3mm adapter
Microphone Capsule: Dynamic Impedance: 600 Ohm Polar Pattern: Cardioid Sensitivity: -60 dBV/Pa (1mW) Frequency Response: 150 – 10,000Hz Max SPL: 136dB SPL Connection: 3.5mm male jack
