Overview

The Duet was designed from the ground up to work with voice over IP (VoIP) services such as Skype, Gizmo, and SoftPhones as well as Instant Message clients such as MSN Messenger, Yahoo! Messenger, and Google Talk. With proprietary Acoustic Echo Cancellation, Noise Suppression, and equalizer algorithms built in, the Duet PCS offers remarkably clean sound.

The first question you might ask is “who needs a business class speakerphone that plugs into a USB port?”. I actually had to think about that for a minute until I stopped to think about my own usage habits. To start off with, a USB sound device is much more efficient than using a soundcard for VoIP applications. With a soundcard you are using the processing power of the computer for the analog to digital conversion when the strength of a soundcard is not in its input, but rather than in its output abilitty. With a USB audio device, the device converts the audio into digital signals before sending it to the computer. This results in much better sound quality and compression which can have a dramatic efect on VoIP conversations. As a USB audio device, the Duet PCS not only functions as a speakerphone but also has a stadnard headset jack available essientially turning a standard headset into a high quality sound platform. Since it registers as an audio device, it is not specific to VoIP or IM applications, the noise reduction and echo cancelation make this device an excellent choice for podcasters as the recording quality is so good.

As a field technician and Asterisk PBX user, we built an Asterisk PBX to handle our company's phone needs and provide remote softphone access. On my phone alone, this cut cell phone minutes by more than 500 minutes per month. However, quality has suffered as I typically use a standard headset plugged into the mic and speaker jacks on my laptop. While we have played with several bluetooth headsets, let's be nice about it and say there has been a certain amount of frustration with bluetooth devices. While the promise of wireless freedom with bluetooth typically means about 10 feet before quality falls apart, if you are going to be that tethered you might as well go back to a USB device. How much better does it get to have high quality speakerphone with all of the echo cancelation and noise suppresion and be able to take advantage of those features when using a regular headset?

Specifications:

Size: 

• 3.75 in x 1.25 in x 4.5 in (W x H x D)

Weight:

• Carrying with USB cable 0.55 lbs.

Power:

• USB power for PC and Laptop (LED will illuminate)

Audio:

• 100% Full Duplex Performance – No attenuation (either way) during full duplex
• Acoustic Echo Cancellation >40 dB
• High-end Performance: Conforms to ITU-T G.167 Standard
• Noise Cancellation >10dB
• Residual Echo is Suppressed to the Environment Noise Level to Prevent Artificial Ducking of Signal
• Voice Level Equalization
• Convergence speed 40 dB/sec
• Tail length (200ms)
• Convergence during full duplex (no recovery time after full duplex)
• Low delay (10 msec)
• Bandwidth 20 – 7500 kHz for Speech Processing Maintains the Soundcard bandwidth
• Integrated Loudspeaker
• Mute Button and loudspeaker volume control buttons (LED will blink in mute mode)

Performance:

• Speech processing and echo suppression at 16KHz sampling rate
• Maintains Audio Performance of the PC for HiFi audio applications when external speakers are connected. will automatically turn off the internal loudspeaker.

Connectivity:

• USB (PC, Laptop connectivity)

• 3.5mm (External loudspeakers or headphones)

First Impressions

Opening the box and pulling out the unit I was actually a little surprised as it was a bit heavier than I expected. At about half a pound, the Duet feels exceptionally solid and the fit and finish is what you would expect from a true business-class device. The Duet PCS is designed for simplicity with only a mute button flanked by volume up and down buttons. The USB port and headphone jack are the only connections. Since it is powered off the USB port, there are no batteries or power connections.

I was a little surprised to only find the Duet device itself, a top quality USB cable, and a simple tri-fold manual. The setup instructions are basically two sentances, plug the unit into a USB port and it will be detected and start working. To my surprise, that is exactly how it worked. No CD, no drivers, just plug & play at its finest. The first test was to fire up SJPhone connected to our Asterisk PBX and try some phone calls. Being in the early evening, the office was bustling with people coming and going right next to me and the Duet picked up all of it and yet the called party said it sounded quite good even though there was a lot of background noise with a large server, a fan, and the AC running on high. In a boardroom setting, it will easily pick up the voices in a good size room while blocking out most of the ambient background noise. The real test will be getting putting it to use under real business conditions over the next few days.

Testing

Oddly enough, on my laptop, a Compaq nx7010, the volume on SJPhone was very faint regardless of settings, however, switch to X-Lite solved the problem. Gizmo also worked flawlessly. In different conditions at numerous locations, the Duet PCS performed great. Using a speaker phone actually turned out to be an excellent means of demonstrating VoIP technology to some clients.

One of the best features of the Duet PCS has got to be the simplicity in getting it up and running, you simply plug it in. Once it is detected, fire up your VoIP client, go to the audio settings, and select the device for your output and microphone input and you are ready to talk. This worked absolutely perfect on every machine we plugged it into.

I won't go as far as to say it is a “must have” in my travel case, but if I had to do without it, it would certainly be missed. At close to $200, it is a bit on the pricey side but when you add in the high quality echo cancellation and noise reduction, it does perform as good or better than some more expensive speaker phones I have used. If you are heavy VoIP user, either using a softphone PBX client, Gizmo, Skype, or IM clients, and you are looking for a business quality speaker phone, then you really can't go wrong with the Duet PCS.

Phoenix Audio Technologies
Duet PCS (Personal Conferencing Speakerphone)
Retail Price: $199.95
http://www.phnxaudio.com/