Stereo Field and Width

Width is not depth, and a field widened by generated reverb has to survive the mono sum first.

Related

Stereo TechniquePanningPhase Check

The problem

AI material sounds wide, and on headphones it seems to have space. Sum it to mono and the vocal thins, the drums collapse to the centre, and half the pad disappears. Width is the easiest thing for a generator or a reverb to fake, and the first thing to vanish on a phone, a kitchen speaker or a club system. Make mono work before asking for width.

How it works

Real depth comes from arrival time, early reflections and high-frequency absorption, so sounds have a front-to-back position and a defined place. Panning only places a sound left or right, while depth comes from level and reflection; the two are not the same. Fake width comes from decorrelating the left and right channels; it reads as wide on headphones and cancels when summed. Generated space is often spread across the whole mix, with stereo reverb even in the low end, so the mono sum leaks. Long wavelengths cancel most easily, which is why everything below 120 Hz usually belongs in the centre.

Practice

Switch the project to mono and listen through, then solo tracks to find the ones that collapse. A correlation meter that leans left or right calls for a polarity check, and any width plugin has to pass in mono before it stays. Keep bass and lead vocal centred, and get width from arrangement and panning, placing real instruments left and right rather than relying on a plugin. Check that left and right levels are symmetric; if the lead sits to one side, give the other side something to answer, or the field leans. Use mid-side EQ in small amounts, perhaps lifting the side highs, but never scooping the mid lows. Finish by listening on one speaker across the room; what stays clear after the width is gone is real.

What to listen for

In Cambini's Wind Quintet No. 1, hear how five winds separate through panning and timbre, which is width from arrangement. In the 87 BPM hip-hop groove, hear that kick and snare stay centred and do not collapse in mono. In Satie's Gymnopedie No. 2, hear how much space a sparse texture retains after summing. Listen to all three again in mono.

Sources

• 宽度的来源与单声道兼容，依立体声与混音通识核对，未抄文本
• Width sources and mono compatibility, based on general stereo and mixing practice, no text copied

Used for fact-checking only; all prose is original.