Many mono Bluetooth headsets these days have A2DP functionality, meaning they can stream audio wirelessly. However, mono headsets don't offer nearly the same listening experience as stereo headsets, especially for music. You can get a stereo Bluetooth headset, of course, but mono headsets are more convenient for making calls in certain situations, in the car, for example.
Enter the mono-to-stereo convertible headset, such as the Plantronics Voyager 855, the Samsung WEP870, and the latest one from Samsung, the HM3700. The HM3700 looks like an ordinary Bluetooth headset at first glance, but it comes with a pair of stereo earbuds that connects via the Micro-USB port on the top. You can then wear the HM3700 like a pendant, or attach the optional clip so you can clip it to your shirt. What sets the HM3700 apart from the other headsets is that it offers voice controls and it's compatible with FreeSync, an Android application that adds additional features like text-to-speech, caller ID, and alarms. The Samsung HM3700 is $59.99 retail.
The HM3700 is shaped like a regular Bluetooth headset. It's rectangular with curved corners and tapered sides, measuring around 1.9 inches long by 0.7 inch wide by 0.4 inch thick. On the front is a noise-cancelling microphone. On the right spine are the power slider switch, the talk button, and a tiny LED indicator. We like having a dedicated power switch as it's much easier to turn the headset on and off this way. The volume rocker is on the left, while the primary microphone is on the bottom. On the top is the Micro-USB port, protected by a removable cover.
Turn the headset over and you'll find a simple small earbud that fits easily in the ear. The HM3700 comes with three different earbud covers. Two have small loops attached so the headset can be worn without the optional ear hook. The third and default option is a regular round earbud cover that does require an ear hook for headset stability. We found all choices quite comfortable, though we personally preferred the hook option for added security.
The stereo earbuds that come with the HM3700 have curved and slightly offset earpieces that are designed to fit snugly in the ear. We found the fit quite agreeable, but we certainly recommend using a clip with the HM3700 when wearing it with the stereo earbuds--otherwise, the headset has a tendency to pull down on the ears. The earbuds have a built-in microphone on the left wire, so you can still answer calls when the earbuds are plugged into the headset.
If you would rather not use the provided earbuds, the HM3700 comes with a Micro-USB-to-3.5mm jack connector, so you can use your own standard headphones with it. We recommend using a pair of headphones with a microphone built in so that it's easier to answer calls.
The HM3700 can of course be used to answer, end, and reject calls. It also has last-number redial, call mute, and multipoint support, meaning it can connect up to two Bluetooth devices at once. Its A2DP functionality means you can stream music wirelessly to it with or without the stereo earbuds. The HM3700 has voice prompts, too, informing you of various conditions of the headset such as whether pairing mode is on or off, if the headset is connected, or if multipoint mode is on.
With the HM3700's voice controls you can answer and reject calls just by saying "Answer" and "Ignore." Other voice commands include "Pair mode" to enter pairing mode, "Redial" to redial the last number on the primary phone, "Redial two" to redial the last number on the secondary phone, "Phone voice command" to access the voice dialing feature of the primary phone, "Phone voice command two" to access the voice dialing feature of the secondary phone, "What time is it?" to check the current time (only available when using the FreeSync app), and "Cancel" to cancel the previous voice command.