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@maru shared this effect so you can build on it and use it in your DAW.

AvailableEffect

Stereo Widener

Adjust stereo width without changing the dry signal.

About

Make a stereo sound wider or narrower. Stereo Widener splits the signal into what the two channels share (the middle) and what differs between them (the sides), then turns the sides up or down. The middle passes through untouched.

Controls

  • Width sets how much of the side signal survives. At 0 the sides are removed and the image folds to a single centre point; at 0.5 the sound passes through as recorded; at 1 the sides are doubled and the image pushes out past the speakers.
  • Mix blends the processed sound with the original. At 0 nothing changes whatever the Width; in between, some of the original stereo image always remains, so Width 0 with a partial Mix narrows the sound rather than making it mono.

The display shows how much side signal reaches the output with the current settings.

Getting started

Stereo Widener needs a stereo source: a stereo recording, a synth pad or a mix. A mono source has no side signal to widen, so no setting will make it stereo. Start with a factory preset:

  • Default: neutral width, fully wet.
  • Mono Fold: sides removed, the image collapses to the centre. A quick way to check how a mix holds up in mono.
  • Tighten: pulls a loose stereo source back toward the middle.
  • Open Up: a modest lift in width that stays safe in mono.
  • Wide Blend: strong widening at half mix, the original image underneath.
  • Maximum Spread: as wide as it goes. Impressive in stereo, thin if folded to mono.

How it works.

The signal is split into mid and side, the sum of the two channels and their difference, the side is scaled by Width, and the two are recombined. Everything a stereo widener does follows from that: the mid is what both speakers agree on, the side is what they disagree on, and widening is simply turning the disagreement up.

This is also why the effect has a hard limit that no setting escapes. A mono source has no side signal at all, so there is nothing to scale and no width setting produces any change, feed it something genuinely stereo, either a stereo clip through the input panel or the chain's two oscillators panned apart, or this module will sit there doing nothing and be right to.

The browser preview does not build an explicit encode-scale-decode chain, because width control is already linear in L and R and collapses into a single 2x2 gain matrix. Substituting mid and side back into the output equations gives each channel a `same` coefficient on itself and a `cross` coefficient on the other, which is four GainNodes between a splitter and a merger and no summing stages beyond the merge itself.

Those coefficients are where the param range comes from. Width maps onto the side scaler as twice its value, which puts 0.5 at unity, the signal passes through exactly as recorded, 0 at full mono, and 1 at double side, where the image pushes out past the speakers and anything panned centre starts to feel hollow.

What would you make with Stereo Widener?

Describe what you want to make. Build it with the Studio agent.

Goes well with.

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