114. Mixing up the demo scene

Scan status ? Whether the station’s analyser could read this mp3. “OK” means every number in this box was measured from the actual audio, not copied from a tag that somebody typed.

OK

measured from the file itself

Scanned ? When the file was last analysed. If the mp3 is replaced afterwards, these numbers describe the old version until it is scanned again.

19 Sep 2026, 10:19 UTC

File size ? How much room the mp3 takes on a disk, and how much data you use when you play or download it. It is roughly the bit rate multiplied by the length.

84.0 MB

88 105 792 bytes

File last changed ? When the mp3 on our server was last written - usually the day it was uploaded, or encoded again.

27 Nov 2022, 08:15 UTC

Length ? How long the recording plays. It is measured from the audio itself, so it is right even when a tag in the file says something else.

1:00:05

hours : minutes : seconds

Bit rate ? How much data is spent on each second of sound. More data keeps more detail when the audio is squeezed into an mp3: 128 kbit/s is acceptable, 192 is good, and 320 is the most an mp3 can hold.

196 kbit/s

good quality

Sample rate ? Digital audio is a long row of measurements of the sound wave. This is how many are taken every second. 44.1 kHz is the CD standard and 48 kHz the video and broadcast standard - both capture everything a human ear can hear.

44.1 kHz

44 100 measurements a second

Channels ? How many separate signals the file holds. Mono is one. Stereo is two - left and right - which is what lets a sound be placed somewhere between your speakers.

Stereo

2 channels

Codec ? The method used to shrink the audio. MP3 leaves out the detail an ear is least likely to miss, which makes the file about a tenth of the size of the original recording.

MP3

Loudness ? The average loudness of the whole recording, the way a listener hears it (“integrated loudness”, in LUFS). The closer to 0, the louder. Music services aim for about -14 and podcasts for about -16, so that you do not have to reach for the volume between tracks.

−14.3 LUFS

typical for streaming and podcasts

Loudness range ? The distance between the quiet passages and the loud ones, in LU (1 LU is 1 dB). A small number means an even, compressed sound - good in a car or on a phone. A large number means big swings between soft and loud.

2.2 LU

very even

True peak ? The highest level the signal ever reaches, including the peaks that appear between the measurements when the file is turned back into sound. 0 is the ceiling: above about -1 dBTP, a recording can crackle (“clip”) on some players.

−2.6 dBTP

safely below the ceiling

Dynamic range ? How far the loudest peaks stand above the loud parts of the recording, in dB - the “DR” number that music collectors compare albums by. A low number (under 8) means the sound has been squeezed until everything is equally loud: punchy, but tiring to listen to. 14 and up means the music has room to breathe, with real hits and real quiet. It says nothing about how loud the file is: turning the volume down does not change it. Chip music made of steady square waves naturally lands low.

DR 10

10.1 dB · moderately dynamic

Left channel level ? The average strength of the left channel over the whole recording (“RMS”), counted in dB below the loudest level a digital file can hold (dBFS). More negative means quieter. Compare it with the right channel.

−16.7 dBFS

average (RMS) over the whole file

Right channel level ? The average strength of the right channel over the whole recording (“RMS”), counted in dB below the loudest level a digital file can hold (dBFS). More negative means quieter. Compare it with the left channel.

−16.8 dBFS

average (RMS) over the whole file

Channel balance ? The left level minus the right level. Close to 0 dB means both sides are equally loud. More than about 1 dB and the whole mix leans towards one ear.

0.01 dB

balanced

Stereo width ? How strong the part that DIFFERS between left and right is, compared with the part they share. A very low number (-40 dB or less) means both sides carry the same sound - mono in practice. A higher number means a wider stereo picture; a very high one can sound thin on a single speaker.

−13.2 dB

ordinary stereo

Cover art in the file ? Whether a picture is stored inside the mp3 itself. A player shows it as the album art when the file is played somewhere else - in a car, on a phone, offline.

Yes

ID3 tags ? Text stored inside the mp3 file itself - title, artist, album and so on. It is what a music player, a phone or a car stereo shows while it plays the file, and it travels with the file wherever it is copied.

album ? The album or collection the file says it belongs to. Stations and encoders sometimes use this field for notes of their own.

Flashback - Tracks from the past

artist ? Who made or performs the recording, as it is written inside the file.

The ERICADE Radio Network

comment ? A free note somebody left inside the file.

https://radio.ericade.net/podcast

composer ? Who wrote the music, when that is somebody other than the performer.

Erik Zalitis

genre ? The style of music, or the kind of programme, the file says it is.

Podcast

title ? The name of the recording, as it is written inside the file.

114. Mixing up the demo scene

track ? The number of this recording within its album - for a podcast, usually the episode number.

114

date ? The year, or date, the file says the recording is from.

2022

Measured from the mp3 file on our server by the station’s own analyser. Point at a label, or select its question mark, for what the number means.