View Full Version : DAB (mp2) or FM?

2005-01-25, 09:45 AM

I know that compressed formats are frowned upon so I thought I'd ask here before I make a recording.
Duran Duran are due to give a 1 hour exclusive set on BBC Radio 2 here in the UK on Saturday.
I have two choices about recording it - I can either grab it directly from the digital radio stream (DAB is used in the UK which uses MP2 compression) or I can plug an FM tuner to the line in of my soundcard and record it in wav.
I'm assuming that to seed the file here it would have to be recorded from FM using the line-in - is this correct?

2005-01-25, 11:25 AM
So then would the version from your FM tuner also be sourced from .mp2? If it isn't, then you should record it that way and it would be okay to seed here. If the source is .mp2 either way then the best way to record it is to capture the original digital stream. .mp2 and .mp2-sourced broadcasts aren't allowed at TTD, we discussed this at great length at the inception of this site, and the only time that lossly is allowed here (even if it's the best available source) is if the recording was made on a MD recorder. So, my recommendation is to capture the audio as close to the original source as possible, and if that turns out to be .mp2 it unfortunately can't be traded here.

2005-01-25, 05:02 PM
Assuming you have good FM reception, then record the FM broadcast - it will be infinitely better than your DAB radio, which only uses 128kbps for Radio 2 (and most other music stations). The best digital version of Radio 2 will be the 192kbps satellite stream (or the 192kbps "Freeview" stream), but even those are probably not as good as a decent FM recording.

However, the BBC use NICAM digital links to feed their network of FM transmitters (NICAM is 14-bit, 32KHz PCM audio, transmitted using a lossy compression scheme reducing the 14-bits per sample down to 10 bits per sample - a system that's also used for transmitting digital sound with analogue TV in most of Europe). So an FM signal is far from lossless, even before it leaves the transmitter.

New Homebrew
2005-01-25, 08:43 PM
An interesting and timely topic. I just traded for a recording from BBC 2 broadcast that was made in September 2004. You can read on the BBC website about the DAB options and there is also FM.

This is what the BBC 2 FM broadcast looks like in spectral and frequency views. Recorded using a Nomad JB3 at 44.1kHz.

New Homebrew
2005-01-25, 08:45 PM
Shamone, motherfu*cker.