At the end of the day, most Bluetooth speakerphones do pretty much the same thing. They sit on a car's sun visor and let people answer and initiate calls. It can be a struggle for hardware manufacturers to differentiate their speakers from the next one. In SuperTooth's case, its SuperTooth HD stands out for its voice-commanded social network integration, a feature called Handsfree Assistant that, at the touch of a button, enables you to check and update your Twitter and Facebook status, fire off quick text messages, and send and receive e-mail using little more than the sound of your voice.
The SuperTooth HD has both physical and voice controls. On the face of the unit, there's a large volume knob that can be pressed as a button. Just below that are two LED indicators for Bluetooth connection status and power status. Moving down, there is a power button and a SuperTooth Handsfree Assistant button, which we'll discuss later. The back of the unit is home to two powerful magnets that attach the unit to its removable metal visor clip. We liked that the LED lighting automatically dimmed at night, since other units require a manual disabling of the indicator lights.
Along the right edge of the chassis is a Micro-USB port for charging the device using the included 12-volt USB adapter and Micro-USB cable. Charging from a dead battery takes about 3 hours, after which you'll have between 20 hours of talk time and 40 days of standby.
On the first boot of the SuperTooth HD, the unit offers a choice between U.K. English, American English, and French female voices for spoken prompts. We chose American English, despite the fact that the voice sounded rather depressed compared with the U.K. English voice. Next, the unit automatically enters pairing mode, in which the chosen voice prompter guides you through finding the SuperTooth HD and pairing via your handset's Bluetooth menu. An automatic detection feature allows some handsets to skip the formality of four-digit PIN entry. Once paired, the unit will attempt to download address book entries from the connected handset.
Incoming calls are announced with spoken caller ID for synced address book entries and can be answered or rejected by simply saying "Answer" or "Reject," without touching the device.
Other voice commands are accessed by pressing the center of the volume dial and include basic commands for checking battery level, checking connection status, and calling home, office, emergency services, or one of up to five preset contacts. There's also a command to hand off voice controls to your phone's voice dialer application if one is present.
We had a hard time telling which end of the SuperTooth HD was the business end at first, the rounded one or the flat one. The rounded end is home to a single pinhole microphone. The flat end holds the unit's two speakers (hidden behind a metallic grille) and yet another pinhole microphone. Now, one of those mikes is for noise cancellation and the other for voice pickup, but the manual doesn't really explain which is which. After an entire day of using the unit in the wrong orientation, we noticed on the manufacturer's Web site that the speaker is actually supposed to point away from the user--which explained why callers initially complained of not being able to hear us clearly.
With the SuperTooth HD in the right orientation, microphone quality seemed to dramatically improve when we tested it in our parked and stationary test vehicle. Callers also said the microphone's capture quality did not decline when we got the vehicle moving, so the noise-cancellation technology seems to be doing a good job of filtering out road and wind noise.
Behind the SuperTooth HD's grille are two small speakers that fire sound away from the user in a "V" shape. Because of the orientation, most of the sound that you hear actually seems to be bouncing back at the driver from the dashboard and windshield. This means that the voice of the caller seems to be coming from ahead of you, rather than from above you. Our audio podcast test takes the cellular network out of the equation by streaming audio straight from the handset's media player and yielded reasonable clarity, but there's no escaping the slightly harsh hollowness of such small speakers when the volume is cranked to higher levels.