Stereo section Several filters that repair and change stereo separation. AZIMUTH section Reparation of AZIMUTH (phasing) errors.
AZIMUTH errors are often present in tape recordings, and also on some cheap CDs. Phasing problems causes playing a recording in mono or through a surround system to result in very ugly artifacts. But even normal stereo playback may sometimes sound a bit unpleasant. The phasing offset is automatically detected and removed by this filter.
This filter only works properly if the sounds at the left and right channel are similar. If this is not the case for a longer period, the azimuth correction will slowly be reduced. AZIMUTH panel
AZIMUTH limit Maximum tape head displacement (assuming cassette tapes) to be detected and resolved.
0 disables this filter. Suggested value: 40 μm.
AZIMUTH change speed Maximum speed at which the filter follows detected phasing errors.
This slider controls how fast the azimuth correction can change if the measured displacement is differs from the correction that is taking place.
Use a very low value (ó 0.1 æm) to correct for a constant azimuth correction.
Use a higher value (~ 0.4 æm) to also correct for rapid changes.
To avoid getting too much effects from measurement noise, use the lowest possible value where the blue line (the actually performed correction) can keep up with the red dots (the measurements).
Stereo Boost section Stereo Boost is the preferred filter to add stereo separation to music.
It basically just uses a multiband compressor to increase the level of the L-R channel. It can be configured to never reduce stereo separation (in tracks with completely separate channels) and it does also not create too much (anti-phase) boost of the L-R channel. Stereo Boost panel
Stereo Boost enabled Enables the Stereo Boost filter.
Protect against excessive reverb Removes sounds (usually reverb) made louder by a strong boost of the L-R channel.
Reverb often gets increased a lot when using strong Stereo Boost settings. Some people like this - but if you want to keep the audio closer to the original, turn this on.
In extreme cases, this can cause artifacts.
Never reduce below original level Never allow the stereo separation to get reduced by Stereo Boost.
Stereo Boost strength Configures how strongly Stereo Boost works.
Stereo Boost maximum amplification The maximum increase of the L-R channel.
Stereo multiplier Multiplies the L-R channel with this value.
This can be used to reduce extreme stereo separation. For example, if Stereo Boost strength and Stereo Boost maximum amplification are increased and this slider is decreased, the stereo separation for most tracks should not change much, but extremes will be removed.
Stereo Image section Stereo Image gives independent control over phase differences and instrument placement. But it can easily create artifacts.
The most interesting feature is to convert stereo to mono without cancellation (loss) of sounds. This creates a sound that is as full as the stereo image, but it is in fact mono. This can be done by setting both Image phase amplifier (partially deprecated) and Image width amplifier (partially deprecated) to 0.00. If you are not located between the speakers, when you press the MONO switch on your audio system you often still hear a big difference, because a lot of the sound disappears. After setting these two sliders to 0, that doesn't happen anymore. Example uses are radio stations (FM, AM, streaming) that broadcast in mono, and people who are deaf in one ear who want to listen with headphones.
Several sliders of the Stereo Image manipulator cause severe artifacts and should only be used as described. They are marked as 'partially deprecated'. Please read this section carefully if you enable the Stereo Image filter. Stereo Image panel
Stereo Image enabled Enables the Stereo Image filter.
Center bass Prepares the bass to be played on a system with a single subwoofer.
If there is a phase difference in the bass between the left and right channel, and the sound is played using a single bass speaker, the bass will get deformed and lowered in volume. If this filter is turned on, phase differences for bass sounds are removed completely, which solves this problem. This occurs only very rarely. Note however that when the Phase shift slider is set to a high value, this will occur much more frequently. When listening with headphones, this somewhat reduces the stereo effect.
In some cases this filter can cause severe artifacts.
Phase shift Adds a constant phase offset between the two channels.
This slider can be used to add a phase offset between the channels. Both -180 and +180 cause the channels to be the opposite of each other, 0 is normal output.
Image phase amplifier (partially deprecated) Increases or decreases phase differences between the left and right channel, without touching instrument placement.
Moves between 0 (no phase differences between the channels), 1 (no change) up to 8 (8 times as much phase difference as in the original signal). 0 is VERY useful for converting to MONO, the resulting sound can be downmixed to mono without any distortion or loss of sounds, which occur in normal stereo to mono conversion. This creates a much fuller and undistorted mono sound. Note that "0" does not mean that the output signal is mono, because the instrument locations are not affected by the phase slider. To get mono sound, also set Image width amplifier (partially deprecated) to 0.
This filter creates artifacts, mainly for values above 1.00. When playing compressed audio, especially lower (< 192 kbit/s) bandwidth MP3 files, setting phase to a high value will also very strongly amplify the already present MP3 encoding artifacts, which results in a very poor sound quality.
Image width amplifier (partially deprecated) Changes the placement of sounds without changing their phase differences.
Moves between 0 (all sounds in the center, 1 (no change) up to 8 (the sounds are moved 8 times further away from the center than in the original signal, if possible of course). Note that "0" does not mean that the output signal is mono, because the phase differences are not affected by the width slider. With this setting, for someone who hears both speakers it still sounds like stereo, but if someone hears only one speaker all the sounds are present.
Setting width to a very high value will almost always introduce artifacts, so it should be used with care - or not at all.
Image phase amplifier maximum separation strength Sets the maximum allowed level separation per frequency.
Could be useful for example for FM radio stations, this can ensure that the maximum phase difference stays below a certain level, which reduces signal loss when a receiver switches to mono.
This setting currently introduces artifacts. It should not be used unless it is really necessary. Changes may be made to it in later versions.
Image phase amplifier maximum angle Maximum phase difference between the left and right channel.
When the total phase difference between the two channels gets above this level, the Image phase amplifier (partially deprecated) is reduced temporarily to keep it below the level that is set here.
Mono or stereo only
-100 %: Play ONLY the mono sounds.
0 %: Don't do anything
+100 %: Play ONLY the stereo sounds.
If an instrument is only present on one channel, -100% will completely remove it. If an instrument is present at the center, +100% will completely remove it.
Use 'stereo only' with care: High values can cause annoying artifacts. Fake Stereo section Adds a fake stereo effect. Intended to make mono recordings sound more like stereo. Fake Stereo panel
Fake Stereo enabled Enables the Fake Stereo effect.
Channel delay (left) Delay between the left and right channel.
This introduces a (very rudimentary) stereo effect. Note that this also changes recordings that are already in stereo, that it also makes sounds like voices stereo (which is generally considered bad), and that the result will sound very bad when played back in mono.
