Sand Fleas and EIB Audio Compression

RUSH: Don in Winston-Salem, North Carolina, hello.
CALLER: Rush, I have a Friday-type question. When I’ve listened to this show on the Dittocam, it doesn’t sound nearly as good as when I listen over the air and I was curious if you can tell us what sort of digital processing or what you do to the signal to make it sound so good?
RUSH: You’re telling me that the streaming audio that you hear on the Internet while watching this program on the Dittocam doesn’t sound as good as it does as when you listen to AM radio?
CALLER: That’s correct.
RUSH: I told you, Brian! Engineers don’t listen to me, and I’ve been hearing this complaint. When we installed the low-end Cork modularity bus here, we had an infestation of sand fleas. (laughing) I don’t know where they came from. I think the guy that came in to install this stuff (interruption). They’re laughing at me on the other side, but I think what that has led to is that we’re not able to compress the signal because it would fry the sand fleas. When you listen to AM radio, the signal is compressed. I wish I had a way to demonstrate this, because it does make a huge difference. FM is not as compressed, and when I say “compressed,” it’s even hard to describe. How old are you, Don?
CALLER: I’m 57.
RUSH: All right, then, you remember back in the sixties driving around in your car when all there was AM radio, and you’re listening to Top 40 music and the Motown stuff and how little bass just thumped at you, and the songs didn’t fade out because the compression kept them as loud as ever right to the very end and it sounded like the music was literally being sucked up to get to the loud volume? That’s what compression does. I only listen to music compressed, I loved it so much — and you can tell the difference, and the reason AM radio stations did it was there were a lot of convertibles back then and it makes the music louder and every radio station wanted to be the loudest on the dial. As people were punching buttons and turning the dial, the loudest stations are the ones you tend to stick with, and certain kind of music doesn’t lend itself to being compressed because as a purist engineer will tell you, it’s pure distortion, but that’s rotgut. I went out and bought a compressor like are in radio stations. It’s called the Aphex, right? The Aphex 2020, and the high setting is called “flamethrower.” So I put everything through the flamethrower setting and listen to music that way. When you buy a CD at the store or download it or whatever, it’s just flat. There’s no compression added to it at all. I wish I could do a side-by-side comparison to show you. Anyway, we’re probably not compressing it. It does the same thing to voices, too.
CALLER: Yeah, your voice sounds great on the radio, but very plain over the Internet.
RUSH: Well, it’s not that bad.
CALLER: (Laughing.)
RUSH: I’m hearing myself, and one thing I do not sound is plain. There’s nothing about me that is plain. I can understand how it would sound different.
CALLER: Yeah, let’s just say different. (Laughing.)
RUSH: Yeah. I’m telling you it’s because AM radio their signal. They still do. It’s part and part of amplitude modulation, which is what AM stands for. FM is frequency modulation; you compress it in a different way. At any rate, I’m happy for the question. It’s a great Open Line Friday question. It had nothing to do with anything, but I got to tell people about the sand flea infestation here in the Cork modulator bus.

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