Field Report: Audio Compass 1.0

June 1, 2008

ISDN is a cumbersome technology for broadcasters. While it works fine for permanent remote broadcast sites, it can be difficult and slow to use as a casual remote platform. Adding to ISDN's problems is the harsh reality that phone companies are eager to do away with the technology. The Internet represents the obvious alternative to copper wire, but it has always presented issues regarding delay. No longer.

A new software application called Audio Compass makes remote radio broadcasts easy. Now we can produce shows wherever there's high-speed connectivity and a PC. Audio Compass is a simple software application that turns your PC into an audio codec. A fully functional trial version lasts for 30 days.

Goodbye ISDN

I moved to a new home recently and discovered that Verizon wouldn't install ISDN for me. Too far from the central office, they advised. Verizon is getting out of the ISDN business during the first half of 2008 — no new installs, and no support for existing ones. I needed a solution.

Performance at a glance
Low-delay audio connection
8kHz to 44kHz sampling rates
Bidirectional connectins
Auto reconnect
Optional buffer for challenging connections
Multiple encoding algorithms

I spoke to my friend Howard Monroe, owner of WVLY in Wheeling, WV, who I recalled had mentioned that he used Skype, a VoIP service, for remotes. It worked fine, but I had my doubts about it for my purposes. I have a syndicated talk show with several FM talk stations carrying my weekend program, and I couldn't imagine how Skype could provide adequate quality for a three-hour program.

Howard, feeling challenged, located Audio Compass, a just-launched application that allows the transfer of low-delay, crystal-clear audio over the Internet from one location to another, or even several destinations at a time. It encodes audio on the fly using UDP to transfer datagrams via the public Internet, then decodes it at the receiving end for instant playback. It's broadcast quality and peer-to-peer (no server in the middle). You make contact by typing in the destination IP address and the two sides are instantly connected.

An instant success

Audio Compass allows me to do my talk show from home once again. But this is the first edition, and it isn't without its quirks.

Because it operates in the Windows environment, there are Windows issues to deal with. Most important has been the need to leave all the computer's processing power available for the broadcast.

If poor connectivity is a problem, it is possible to adjust how much bandwidth the software uses. I've been quite comfortable using it at 32kHz rather than the maximum 44kHz, and the sound quality is great. But software developer Sam Bushman says the quality remains fine going down to 22kHz or lower.

Delay can be adjusted to protect against dropped bits of data. This is a great option if the software is used to send audio in one direction, but is a compromise if used for two-way talk. For example, Howard now uses Audio Compass to send his air signal to the transmitter, so there's no reason not to add some extra delay to give the packets more time to get to the transmitter side.

The program creates a very stable connection, disconnecting only once during a broadcast in the two months I've been using it. But thanks to an automatic reconnect command, the impact was not of great consequence.


Configuration options are written into the properties of the program shortcut, effectively hiding the software's flexibility from the innocent user. The concept is that an engineer can set it up, and a host can't mess it up. This has some advantages, but also some disadvantages. What happens when you're on remote, there's no engineer around, and you need to reconfigure to adjust to a slow Internet connection, for example?

Audio Compass

Also, the program configuration must be identical at both ends or things might not work. This makes it harder to make quick changes, requiring that someone savvy is on both ends of the broadcast. It would be better, I think, to make one end the boss, so if changes need to be made on the fly, they automatically affect both sides.

Audio Compass is the first of a new generation of broadcast codecs that will be entirely PC-based and operate over the Internet rather than telephone lines, digital or analog. A new version of the software will be out soon, and some options will be added to deal with some of the challenges.

Audio Compass provides a solid option to ISDN, with flexibility that ISDN could never offer. It's a no-brainer when you want to be able to remotely broadcast, and is a fine alternative for doing live radio shows from permanent remote locations.

While you may be satisfied with the remote technologies you're using, the cost of entry is so small that I'd recommend getting Audio Compass now so you can explore its powers. With ISDN on the road to extinction, Audio Compass has arrived just in time.

Feinburg hosts a nationally syndicated weekend talk show and consults on Internet-based radio technologies.

Editor's note: Field Reports are an exclusive Radio magazine feature for radio broadcasters. Each report is prepared by well-qualified staff at a radio station, production facility or consulting company.

These reports are performed by the industry, for the industry. Manufacturer support is limited to providing loan equipment and to aiding the author if requested.

It is the responsibility of Radio magazine to publish the results of any device tested, positive or negative. No report should be considered an endorsement or disapproval by Radio magazine.

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