Hi Charles, The Phoenix Audio SOHO echo canceller is the cheapest room-level solution. We have built three nodes with it, and it works quite well. This is a PCI card, so it is not suitable for a laptop.
The problem with it is that it is designed for PC level microphones, not for professional level ones, so you need some kind of pre-amp if you want to use decent boundary mikes. Suppression of hum is not always easy with setups like that. It works well with the cheap little plastic boundary mike that comes with the card. Phoenix Audio have three other devices that avoid this problem. They are essentially USB boundary microphones with built-in echo cancellers. The SOLO is just a microphone, and it should work well with small conference rooms where you need only one microphone to pick up all participants.. It needs separate speakers. We have not tried this, we could not get one here in Australia. The DUET adds a built-in speaker, and it works well for desktop conferences with a single person. We are using one for that application. The QUATTRO is a sophisticated four-microphone pod with built-in speakers. It is USB connected and performs echo cancelling, noise cancelling and phased array steering of the microphones to the identified audio source. In a room conference situation, it is able to handle about a dozen participants around a table. If you need to cover more people, you can daisy-chain multiple units. In conference situations, the build-in speakers are not able to produce sufficient volume (if you increase the volume, you get echo artifacts). You need to connect external loudspeakers to it, but that is easy and cheap with a set of ~50 W 2.1 PC speakers. In that kind of setup, it works brilliantly. All these units are plug-and-play both under Windows and Linux (our room conference systems run Fedora Core9). I have no experience with MACs, but they should be fine. To the OS, they are just ordinary USB audio devices. So take your pick according to the number of participants on your side: a DUET for one or two, a QUATTRO without external speakers for up to four, one or more QUATTROs with external loudspeakers for more. Regards, Claus. Jeremy Mann wrote: > On Fri, Mar 6, 2009 at 3:06 PM, Charles Nichols > <charles.nich...@mso.umt.edu> wrote: >> AG-tech- >> Is there an inexpensive way to echo cancel? I'm using a MOTU UltraLite for >> audio, with my PowerBook, and am getting feedback. > > Charles, I have built two AG nodes that use the SOHO Echo Canceling > PCI card. It works surprisingly well. > > > -- -------------------------------------------------------- Claus Endres | Phone: +61-3-5998 2310 Endres Consulting Pty. Ltd. | Mobile: +61-418-595 136 10 Facey Road | Fax: +61-3-5998 2540 Devon Meadows, VIC 3977 | cl...@endresconsulting.com
