Plantronics Blackwire C720 – USB Headset with Bluetooth
The Plantronics Blackwire C720 is a corded USB headset with integrated Bluetooth, designed for professionals who need seamless switching between desk phone, PC, and mobile device calls. Active noise canceling (ANC) technology filters ambient sound during calls, while SoundGuard protects against audio spikes above 118 dBA.
We built the C720 for unified communications environments where call clarity and flexibility matter. The over-ear binaural design isolates conversation from background noise, and the cushioned leatherette ear pads support hours of continuous wear. A single USB-A connection powers the headset and manages PC audio, while the Bluetooth radio pairs with up to eight devices for mobile calls and media playback. Inline controls let you answer, mute, and adjust volume without touching your keyboard.
- Dual connectivity: USB-A wired plus Bluetooth 2.1 for up to 8 paired devices
- Active noise canceling reduces ambient sound by up to 85% during calls
- SoundGuard digital acoustic limiting protects hearing (118 dBA peak, 102 dBA TWA)
- Binaural over-ear design with leatherette cushions for all-day comfort
- Noise-canceling microphone with bendable boom and visual mute indicator
Hybrid connectivity for modern work
The Plantronics Blackwire C720 addresses the reality of multi-device workflows. USB-A connection handles desk calls and conferencing software, while the Bluetooth 2.1 radio maintains persistent pairing with smartphones and tablets. You can take a mobile call mid-meeting without unplugging the headset or switching hardware.
Bluetooth range extends up to 30 feet in open spaces, and the headset supports A2DP for high-quality music streaming during breaks. The inline controller shows connection status via LED indicators: solid blue for Bluetooth active, solid white for USB mode. Press the Bluetooth button to cycle through paired devices or hold it to enter discovery mode. We optimized the radio profile to minimize latency, so voice calls feel immediate even when routed through a smartphone.
Active noise canceling and acoustic protection
ANC circuitry in the ear cups samples ambient sound 50,000 times per second and generates inverse waveforms to cancel steady-state noise. Testing shows up to 85% reduction in HVAC hum, keyboard clatter, and office chatter during active calls. The technology draws power from the USB connection, so ANC only functions when the headset is plugged into a computer.
SoundGuard complements ANC by capping peak audio at 118 dBA and enforcing a time-weighted average of 102 dBA over eight hours. If a caller shouts or a system glitches, the limiter attenuates the spike within milliseconds. Anti-startle technology detects sudden loud tones and softens them before they reach your ears. We designed these layers for contact center agents and IT support teams who wear headsets through back-to-back calls.
Materials and physical design
Cushions and adjustability
Leatherette memory foam ear cushions conform to head shape and distribute clamping pressure evenly across the temporal ridge. The headband extends via steel sliders with embossed size markers, and dual pivot points let the ear cups rotate 15 degrees to match jaw angle. Total weight is 142 grams, light enough that most users forget they’re wearing it after the first hour.
Microphone boom
The noise-canceling boom mic uses dual-element cardioid pickup to isolate your voice from sounds behind and beside you. The flexible gooseneck bends 270 degrees and holds position without memory wire. A red LED on the boom tip glows when mute is active, visible in your peripheral vision and to colleagues on camera. Frequency response spans 100 Hz to 10 kHz, tuned for speech intelligibility rather than music reproduction.
Other Blackwire models for unified communications
What people are saying
Common questions about the Blackwire C720
Yes. The C720 is plug-and-play on macOS 10.10 or later and Windows 7 through 11. The headset registers as a USB audio device with no driver installation required. Plantronics Hub software unlocks advanced features like firmware updates and custom EQ on both platforms, but basic call and media playback work immediately.
Bluetooth pairing also works identically across operating systems. You can pair the headset to a MacBook for calls and simultaneously to an iPhone for mobile backup.
Partially. Bluetooth mode works independently for mobile calls and media streaming, powered by the internal rechargeable battery. You get up to 15 hours of wireless talk time on a full charge.
However, active noise canceling only functions when the USB cable is connected and drawing power from a computer. If you unplug the USB and rely solely on Bluetooth, ANC disables automatically to preserve battery life.
The C720 stores pairing profiles for up to eight devices in memory, but maintains active connection to only two devices simultaneously. This lets you keep a smartphone and tablet connected at the same time, so calls from either device ring through the headset.
To cycle between paired devices, press the Bluetooth button on the inline controller. The headset reconnects to the last-used device when powered on.
No. The boom mic is fixed to the left ear cup and cannot be moved to the right side. The headband is symmetric and the ear cups rotate for comfort, but the microphone position remains constant.
If you require right-side mic placement for specific workflows, consider the Blackwire 5220, which offers a monaural variant with swappable boom.
Both models share the same core audio platform, ANC technology, and dual USB-Bluetooth connectivity. The C725 adds a USB-C to USB-A adapter in the box and ships with a 3.5mm analog cable for legacy device compatibility.
The C720 includes only the USB-A cable and case. If your environment uses exclusively USB-A ports and you do not need analog backup, the C720 delivers identical performance at lower cost.
The inline controller LED blinks red when battery charge drops below 10 percent. You will also hear a low-battery tone in the headset every five minutes once the threshold is reached.
Charging happens automatically whenever the USB cable is plugged into a powered port. A full recharge from empty takes approximately two hours. The battery supports hundreds of charge cycles without significant capacity loss.
SoundGuard monitors all audio routed through the headset, including music and system sounds. It applies dynamic range compression to prevent peaks above 118 dBA regardless of source.
For music listening, you may notice slight compression on tracks with extreme dynamic range, such as orchestral recordings or EDM with heavy drops. Most users do not perceive a difference during typical streaming or podcast playback. You cannot disable SoundGuard; it is a permanent safety feature baked into the DSP firmware.