FM radio

[leroyishere 0]

Hi guys i have always heard you all talk about encoding in 128 kpbs... 192.... lossless and so on. the thing is i enjoy listening to FM a lot, and am not too bothered by its sound quality, as i am always listening when i'm travelling.

 

but just out of curiosity what is the SQ of FM? is it 128? or way below that? all my mp3s are 128 so i don't think i can discern between the different encodings yet.

 

please advise =)

[mashimaro 0]

I am not a Electrical Engineer but so I give you a QUICK but "roughly and layman" answer.

 

FM Radio is an analogue system. Basically, each band is a 20kHz range (human's range) and the exact source that I want to broadcast is frequency-modulated (that's where the FM comes from). Eg:

 

For Perfect 10, 98.7MHz (98 700kHz), you "add" your music to 98 700kHz to 97 720kHz. So once transmit over the air, a receiver will "minus" the 98.7Mhz to get back the original music.

 

In radio, there is no compression, you receive the music RAW (of course, you have to "minus" the carrier frequency) but that also means it is very prone to noise. Say some joker run some generator or high electrical current thingie next to your receiver. Your signals will all be distorted.

 

MP3 and all those codec thingie we are talking about DIGITIZING the data, so that the data can be EXACTLY preserved and COMPRESSING the data. LOSSY means COMPRESSED the ALMOST EXACT copy of the data. LOSSLESS means COMPRESED the EXACT copy of the data.

 

how? layman enough?

 

Some EEE engineer, please correct me if i am wrong. haha....

[ahdui 0]

im an EEE engineer but im nt gd at such lol

something i learnt today

[leroyishere 0]

Hi mashimaro. when u say we receive the music RAW, does it mean we are actually receiving lossless music? that good?

 

[aaron-xp 0]

I still think it all boils down to reception. You could either get a really clear signal or a bad fuzzy one.

 

Anyway, I doubt is really that good though, trust your ears. Radio simply doesn't sound as good as tracks from a CD.

[mashimaro 0]

Hi mashimaro. when u say we receive the music RAW, does it mean we are actually receiving lossless music? that good?

 

In a sense, yes but the problem with all analogue system is prone to noise. By the time, you receive the signal, a lot of noise has been added from the modulation, transmission, demodulation stage. That's why everything in our world now is digital. We are no longer satisfied with almost "EXACT". Imagine I transmit an almost EXACT Word document to you using radio waves. Don't know if you dare to receive it or not.