Owen PalmerBy Owen Palmer

Updated November 2026

Bose QC 45 headphones usually misbehave for a handful of predictable reasons: a stale Bluetooth pairing, a firmware version that needs updating, a low battery that affects noise cancelling, or a dirty microphone or ear cushion that throws off the sound. Most of these can be fixed at home in under ten minutes. Work through the causes below in order, starting with the simplest.

Why Bose QC 45 Headphones Act Up

The QC 45 is a Bluetooth headphone with active noise cancelling, so it depends on three things working together: the radio link to your phone or laptop, the internal battery, and the microphones that sample outside noise. When one of those slips, the symptoms look different. A dropout in audio points to the connection. Weak cancelling points to battery or fit. Strange voice quality on calls usually points to the microphones or to a device that has picked the wrong input.

Shopping for one? See our guide: 7 Best Bose QC SE Headphones of 2026: Buyer's Guide.

Owners often report that problems start after a phone update, after pairing with a new device, or after the headphones sit unused for several weeks. None of that means the hardware is failing. It means the software state has drifted, and a reset or re-pairing usually clears it.

The Factors Involved

Bluetooth pairing and multipoint

The QC 45 can remember several devices. When it switches between them, or when your phone holds an old profile, audio can stutter or cut out. Clearing the pairing on both sides fixes most of these cases.

Firmware

Bose releases firmware updates through its companion app. An outdated version can cause connection drops, and some updates specifically address noise cancelling behavior. Check the app before assuming a hardware fault.

Battery level and charging

Manufacturers specify that noise cancelling draws more power than passive listening. When the battery runs low, the headphones may reduce performance or behave unpredictably. A charge cable that carries power but not data, or a weak USB port, can also make charging seem to fail.

Fit, ear cushions and cleanliness

Noise cancelling depends on a good seal around your ear. Cushions that have flattened, cracked or collected oil and dust leak sound, which makes the cancelling feel weak even when the electronics are fine. Lint or debris in the microphone openings can also muffle voice calls.

Device settings

Phones and laptops sometimes route audio to the wrong output, or set the headset microphone as the default input. A mismatch here can mimic a headphone fault.

What to Do About It

  1. Charge fully. Use a known-good USB cable and a wall adapter rather than a weak laptop port. Let the headphones reach full charge before testing.
  2. Update firmware. Open the Bose companion app, check for an update, and install it while the headphones are charged and nearby.
  3. Forget the device on your phone. Remove the QC 45 from your phone’s Bluetooth list, then turn the headphones off.
  4. Reset the headphones. Consult the Bose manual or support site for the reset sequence for your exact model and firmware, since button combinations vary by version.
  5. Pair again. Turn the headphones on in pairing mode and reconnect. Test with a song, then with a call.
  6. Check the cushions. Inspect for cracks, flattening or residue. Replacement cushions are sold separately and are a simple swap.
  7. Clean the openings. Use a dry soft brush or a clean, dry cotton swab to gently clear the microphone holes. Avoid liquids and do not push anything deep into the openings.
  8. Test on another device. If the problem disappears on a second phone or laptop, the issue is in your original device’s settings or Bluetooth stack.

If the headphones still fail after these steps, or if you notice swelling in the battery, a burning smell or physical damage, stop using them and contact Bose support. For battery or electrical concerns, a qualified repair technician is the safest route.

What We’d Use

A replacement set of ear cushions is the most common fix for weak noise cancelling, and it is a low-risk upgrade: View on Amazon.

A short, data-capable USB-C cable keeps charging reliable while you troubleshoot: View on Amazon.

A soft-bristle cleaning brush suited to small microphone openings helps keep debris out of the mesh: View on Amazon.

How do I know if my QC 45 needs a firmware update?

Open the Bose companion app while the headphones are connected. If an update is available, the app will prompt you to install it. Keep the headphones charged during the process.

Why does my QC 45 sound worse only on calls?

Calls rely on the microphones and on your phone choosing the headset as the input. Check your device’s sound input setting, clean the mic openings and confirm the headphones are the selected microphone.

Can I use any USB cable to charge the QC 45?

Use a cable that supports data and power and is in good condition. Cables that only charge or that are frayed can cause unreliable charging. For model-specific guidance, see Cord for Bose Headphones: 5 Best Replacement Options Compared.

Will replacing the ear cushions improve noise cancelling?

Often, yes, if the old cushions are flattened, cracked or leaking. A better seal improves passive isolation, which helps the active system work. For step-by-step guidance, read Replacement Earpads for Bose Headphones: A Step-by-Step Guide (2026).

Should I worry about the warranty before troubleshooting?

Try the simple steps first, but do not open the housing yourself, since that can affect coverage. For coverage details, see Warranty for Bose Headphones: How to Check, Claim and Protect Yours.

Ready to choose one?

Owen Palmer

About Owen Palmer

Owen Palmer is part of our editorial team and reviews and edits our brand headphones & noise cancelling guides, checking product details against manufacturer specifications and owner feedback.