Hello, I'm sorry I didn't post sooner.<P>One of the main reasons for our signal quality is the digital audio path. The system is centered around a 32 channel digital audio router that interfaces with our digital studio consoles and the computer storage system. CD's are either played from our Denon decks through the console or are ripped into the computer system and stored at a 4:1 data compression ratio via Mpeg 2 encoding. For rock and other forms of music you can get away with squashing the data up to about 16:1 using MP3 encoding without noticing too many artifacts but with classical music content, the artifacts really stick out at higher compression ratios.<P>Because our Chief Technical Officer is primarily a terrestrial radio engineer, he insisted on using similar professional audio processing equipment as our FM stations to improve the sound quality. Our microphones feed into Symetrix processors that adjust the tone of our announcers voices and outputs a digital signal to the consoles. All audio is then mixed and fed into an Orban 6200 digital processor that slightly compresses the audio (not the data) so that the dynamic range of the music messes with that of a quality computer speaker system. This box was designed specifically for Net broadcasters and helps to prepare the audio for “lossy” encoding. Many Internet radio stations lack this kind of hardware processing and simply play CDs or MP3s into their encoders which can result in distortion during loud, exciting passages, and loss of audio for quiet measures.<P>Regarding the bit rate, there has been talk of bringing the MP3 stream up to 128Kbps and we may do so if Shoutcast allows us. However in my experience the 64Kbps stream has been very stable (compared to higher bit rates) with fewer drop-outs when I’m straining my cable connection at home. Increasing the bit rate would improve the sound quality some but would also increase drop-outs for users with less-than-stellar high-speed Internet connections and then we would be at the point of diminishing returns. Of course if there were enough subscribers, we would be happy to offer a stream at 328Kbps but this would be very expensive to implement due to the exponential increase of bandwidth usage and most listeners wouldn’t notice any difference compared with the 128Kbps stream. Having the Orban processor allows us to stream at a lower bit rate by optimizing the sound before it’s encoded.<P>The studio page is at: <A HREF="http://www.beethoven.com/digitalstudio.htm" TARGET=_blank>http://www.beethoven.com/digitalstudio.htm </A>although I need to update it.<P>Please let me know if you have any other questions and thank you for your support of Beethoven Radio! <BR>
by superich » Fri May 10, 2002 12:59 pm 