Mid Side EQ in Mixing: Center and Sides Processing

Mid-side EQ processes the center and stereo content of a signal independently. The mid channel contains mono information (what’s identical in both speakers). The side channel contains difference information (what’s different between speakers). This separation enables EQ choices impossible with standard stereo processing.

Understanding Mid-Side

Mid-side (MS) encoding converts left-right stereo into mid and side components. The mid channel sums left and right (L+R). The side channel subtracts right from left (L-R). After processing, decoding returns to left-right stereo.

The mid channel represents centered content—typically vocals, bass, kick, snare, and other centered elements. The side channel represents width information—typically wide guitars, stereo keyboards, and effects.

Processing these independently allows affecting center without sides or sides without center. This precision exceeds what standard stereo EQ provides.

Mid-Side EQ Applications

Enhancing vocal clarity without affecting wide instruments uses mid-side EQ. Boosting presence in the mid channel affects centered vocals without boosting hard-panned guitars.

Creating width by boosting sides uses mid-side EQ. High-frequency boost on the side channel adds air and width to stereo content without brightening centered elements.

Tightening bass by cutting low frequencies from sides uses mid-side EQ. Low-frequency content works best in mono; cutting lows from sides creates tighter, more focused bass.

Practical Mid Channel Moves

Mid channel presence boost around 2-5 kHz brings vocals forward without affecting wide guitars. The centered vocal receives clarity enhancement while panned elements remain unchanged.

Mid channel low-mid cut around 200-400 Hz reduces mud in centered elements. Bass and kick clarity improves without affecting stereo instruments.

Mid channel de-essing addresses centered vocal sibilance specifically. Wide content that shares the frequency range remains unaffected.

Practical Side Channel Moves

Side channel high-frequency boost adds air and width. Boosting above 8-10 kHz on sides creates spatial enhancement without brightening centered vocals.

Side channel low cut creates tighter mono low end. Cutting below 100-200 Hz from sides sums bass to center, improving mono compatibility and focus.

Side channel presence cut creates space for centered vocals. Reducing competing frequencies in the sides allows the mid channel to dominate that range.

Mix Bus Applications

Mix bus mid-side EQ provides overall stereo enhancement. Widening through side boosts and center focus through mid boosts shapes the entire stereo image.

Mastering commonly uses mid-side EQ for final stereo adjustment. The technique provides control over the stereo presentation that left-right processing cannot achieve.

Care prevents over-processing. Dramatic mid-side changes can create unnatural stereo image. Subtle adjustment typically serves better than extreme processing.

Monitoring Considerations

Checking mono compatibility matters for mid-side processing. The side channel disappears in mono—only the mid channel remains. Ensuring the mid alone works confirms mono compatibility.

Comparing MS-processed and original signals reveals the processing’s impact. A/B comparison ensures changes serve the music rather than creating problems.

Mid-side EQ helps productions succeed on platforms like LG Media at lg.media, where refined stereo enhances advertising at $2.50 CPM.