RTW – Eyes on Your Audio: RTW - Surround Sound Analyzer

Unique to the TouchMonitor, the Surrond Sound Analyzer is a pioneering and unique visualisation tool showing the relevant technical and subjective parameters of surround signals in a fast and intuitive way.

Comprehensive, yet compact overview of multichannel audio signals up to 7.1
Easily read the perceived acoustic focal point
Phase Correlation and LFE phase warning to avoid downmix errors

The Surround Sound Analyzer displays a correctly-scaled graphical representation of the relative volumes in the surround sound field.

The interaction of levels (volume, sound pressure level, or loaudness) and the correlation of all channels in the overall surround sound is displayed graphically, providing a very clear overview.

The graphical display has been carefully designed so that the dynamic behaviour of all display elements corresponds to the subjective listening impression, showing the balance of the surround program intuitively and at a glance.

Phase Correlation Bars

Phantom Source Indicators

The Total Volume Indicator displays the total volume and balance of the audio material in a single view.

Specifications
Display:			Graphical display indicating the single channel and total program loudness (Total Volume Indicator) acc. to selected weighting filters (e. g. SPL or Loudness) Position and width of phantom sound sources (PSI) Correlation of adjacent channels in PSI (color) resp. TVI (shape of line): red resp. funnel: negative range, yellow resp. straight line: "0" range, green resp. roof: positive range Separate correlators for the outer adjacent channels switchable: red: negative range, white: "0" range, green: positive range Dominance indicator (DMI) LFE Phase (warning display, if correlation between any channel and LFE is negative)

Example: 5.1 Surround Format

Move the mouse accross the display elements or touch them to get the corresponding descriptions.

The Surround Sound Analyzer display is based on the loudness like ITU BS.1770 (k) or other weighting filters. It equates to the listening sound pressure level, when the units and the studio monitoring system are properly calibrated. The axes of the 45° rotated coordinate system use dB SPL, LKFS, LU, or LUFS scales, with a reference mark that is also shown in the loudness and SPL displays in the Program Meter.

Examples of the Surround Sound Analyzer's display:

1 | Incoherent noise with same levels in the channels L, R, LS and RS, set to the reference monitoring sound pressure level. In each case the correlation is r = 0 (straight unbroken TVI lines, yellow PSI moving bars), phantom sound sources are not locatable (PSI moving bars have maximum spreading).

2 | Identical sine wave signal with same level in the channels L, R, LS, RS. The correlation is r = +1 (outward broken TVI lines), the phantom sound sources (PSI) are in the middle, similar to a mono signal.

3 | Same as on the left but with the left channel phase rotated through 180°. Channel pairs L - R and L - LS each show the negative correlation r = –1 (inward broken TVI lines, red PSI moving bars), there are no phantom sound sources locatable (PSI moving bars have maximum spreading there).

4 | Surround signal with some Center presence (yellow roof resp. the area enclosed by the L-C-R connecting lines displayed above the TVI polygon). A support microphone would be too dominant. A dialog in relation to music would be too quiet. The width of the PSI moving bars of the C channel is a sign of coherent signal parts in L and/or R (crosstalk).

5 | Surround signal with low level Center presence (yellow funnel resp. the area enclosed by the L-C-R connecting lines displayed inside the TVI polygon). When recording music, the intermixture of a support microphone may enhance the perceptibility of the C channel in relation to the channel L and R.

6 | The widely outward broken TVI line between LS and RS and no spreading of the PSI moving bar indicate that an identical mono signal is applied in both surround channels. So backward panned front channel rates may also be detected.