Spectrum Analysers

Is your Hi-res download true Hi-res or just a up-sampled CD?
Spectrum analyzers will tell you if there is live above 20 kHz.

MusicScope

 

Supports WAV, FLAC, AIFF, ALAC, DSF, DFF from 1Bit to 24Bit with sampling rates between 44.1 and 384 kHz and DSD64 / DSD128 (resampled to PCM).

 

Features

TPM: True Peak Meter

RMS: (Root Mean Square) 400 ms averaged RMS

CREST: Indicates the amount of dynamic compression

 

Loudness (according to the standards EBU R128 and ITU-R BS-1770)

M = Momentary = 400 ms
S = Short Term = 3 s
I = Integrated = Averaged over the whole music track
LRA = Loudness Range produced by the music track

 

Linear Frequency Spectrum: the frequencies in the recording.

Spectrogram: the spectrum over time.

 

The website and the online manual explains all this measurements and present use cases like checking if a high-resolution recording is truly high-resolution or a upsampled CD.

 

€ 29.00 incl. VAT

 

A nice example, a 24 bit 192 kHz file but obvious no life above 22 kHz or below -96 dBFS.
This is a typical case of an up-sampled CD.

 

A true 24/176 recording.

Frequencies close to ½ fs (176/2=88) and down to approximately -110 dB.

 

A DSD64 file.

Typical DSD is the enormous amount of quantization noise starting at 22 kHz.

 

A DSD64 converted to PCM by JRiver.

Understandably there is a filter used in the conversion process to get rid of the quantazation noise.

At 77 kHz the level is -144 dBFS.

Mathematical spoken,   the entire conversion by JRiver will be preserved if you convert to PCM using a 176 kHz sample rate.

A 24 bit / 192 kHz file with a lot of high frequency noise.

Notice the blue bands in the spectrogram.

Makes me wonder what the source is.

 

A 24/88 piano recording with a noise floor around -100 dBFS

Spek – Acoustic Spectrum Analyser

Spek

Sonic Visualiser

Sonic Visualiser is an application for viewing and analysing the contents of music audio files.

We hope Sonic Visualiser will be of particular interest to musicologists, archivists, signal-processing researchers and anyone else looking for a friendly way to take a look at what lies inside the audio file.

Sonic Visualiser is Free Software, distributed under the GNU General Public License (v2 or later) and available for Linux, OS/X, and Windows. It was developed at the Centre for Digital Music at Queen Mary, University of London.

Source: Centre for Digital Music, Queen Mary, University of London.