> I know this post has been on this board for awhile so
> hopefully you're still looking for advice.
>
> 1. You've got a couple different things going on here so
> first things first; let’s talk about the bit rate.
>
> Bit rate is important, but not the #1 thing you need to
> consider… If you don’t wish to cater to a dial up audience
> then you can give up on anything below 32kbps. A great
> (middle of the road) bit rate for broadband is 64kbps.
> 128kbps, as suggested by others in this post, is an
> excellent bit rate but could end up being pretty expensive
> in bandwidth fees so I suggest probably starting with
> 64kbps. Depending on how you encode the stream, you may be
> able to take advantage of an MBR (Multi-Bitrate) sreams in
> which you encode 2 streams into 1 (example: a 20kbps for
> dialup and a 64kbps for BB). Then when the stream is
> clicked on, the buffering time indicates what version of the
> stream the person on the other end gets. That way you can
> provide your webcast to dial up and broadband.
>
> 2. Second thing to consider so let’s talk about the source
> audio.
>
> If I understand you correctly, you’re talking your off air
> FM audio and encoding it. If that’s the case, that’s
> another one of your problems. Whether you hear it or not,
> FM audio has noise in it. Noise that you’re streaming
> encoder (the machine you’re encoding with) will try to
> encode. The codecs that run on these encoders look for
> information they can disregard without affecting the
> original audio. That’s what allows you to get good audio at
> 32kbps. Providing your encoder with FM audio adds noise and
> makes the encoder work that much harder to determine what to
> keep and what to disregard. You would be MUCH better off to
> run the audio off a DA at your facility into some type of
> audio processor and then into the encoder. I’m not sure
> what your budget is, but Orban makes a PC based audio input
> card (sound card) that includes a DSP/audio processor built
> into it. I’ve heard it on the air and it sounds wonderful
> (model # PC1100).
>
> 3. Your question about using the same machine as your
> automation computer…
>
> BAD IDEA. As someone has already mentioned, encoding takes
> a tremendous amount of system resources and would most
> likely kill both routines. You’re much safer running a
> separate machine to do the encoding.
This is all very good advice. The only thing I'd add is to try processing your signal before it is sent to the encoding computer. This will take dedicated processing equipment, not the processor you use for your on air signal. The requirements will be different for each purpose. While there are some dedicated processors out there that are intended for the purpose (DSP-X, Orban, etc.) a simple graphic equalizer and a decent compressor limiter will help a lot and not break the bank. You might even have them lying around. We did. You may find that an Aural Exciter like an Aphex, Barcus-Berry or Behringer helps a lot too.
We're using a 32 kBs stream in an effort to be user friendly with a fast dial up connection. The distribution amp from the console feeds a Behringer EX-3200 Aural Exciter, an ADC graphic equalizer and a DBX 166 compressor limiter. The order you choose for this signal chain can vary with the program material you are using, and the desired effect you are looking for. Don’t be afraid to experiment. We’ve found that boosting highs helped a lot.
I’d never call our stream “Hi-Fi,” but it sounds pretty reasonable for its low bit rate. Judge for yourself at
www.kzqx.com As more and more people get high speed connections, we will probably change to 64 kBs in the future.
