5.1 → Stereo Downmix Level Calculator
Predict the stereo Lo/Ro level of a 5.1 mix using ITU downmix coefficients — see whether your downmix will clip or duck dialogue.
Stereo TVs and soundbars fold your 5.1 down with fixed coefficients: center at −3 dB into both sides, surrounds at −3 dB. Coherent material (dialogue + center-panned music) can sum 3–6 dB hotter than any single channel — the classic cause of downmix clipping that QC catches and this calculator predicts. Worst-case (fully coherent) summation shown.
Rule / Formula
Note: Real downmix level depends on inter-channel correlation; this shows the coherent worst case QC tools flag.
Predict the stereo Lo/Ro level of a 5.1 mix using ITU downmix coefficients — see whether your downmix will clip or duck dialogue.
About 5.1 → Stereo Downmix Level Calculator
Predict the stereo Lo/Ro level of a 5.1 mix using ITU downmix coefficients — see whether your downmix will clip or duck dialogue. Stereo TVs and soundbars fold your 5.1 down with fixed coefficients: center at −3 dB into both sides, surrounds at −3 dB. Coherent material (dialogue + center-panned music) can sum 3–6 dB hotter than any single channel — the classic cause of downmix clipping that QC catches and this calculator predicts. Worst-case (fully coherent) summation shown.
How to use 5.1 → Stereo Downmix Level Calculator
- 1Enter your values into the fields in 5.1 → Stereo Downmix Level Calculator.
- 2The result and any pass/fail verdict update instantly as you type — no button to press.
- 3Check the substituted formula and worked example to see exactly how the result was derived.
- 4Copy or note the result for your spec, delivery or planning.
Why use 5.1 → Stereo Downmix Level Calculator?
- ✓Runs entirely in your browser with instant, private results — no data leaves your device.
- ✓Built on a published reference: ITU-R BS.775-4 (downmix equations).
- ✓Shows the governing formula and a worked example, so you can trust and check every result.
- ✓100% free with no sign-up, no watermark and no usage limits.
- ✓Works on any device — desktop, tablet or phone — and keeps working offline once loaded.
Frequently asked questions
What does 5.1 → Stereo Downmix Level Calculator do?+
Predict the stereo Lo/Ro level of a 5.1 mix using ITU downmix coefficients — see whether your downmix will clip or duck dialogue. Stereo TVs and soundbars fold your 5.1 down with fixed coefficients: center at −3 dB into both sides, surrounds at −3 dB.
Is my data private?+
Yes. 5.1 → Stereo Downmix Level Calculator runs entirely in your browser — your inputs are never uploaded, stored or logged.
What standard or source is 5.1 → Stereo Downmix Level Calculator based on?+
It follows ITU-R BS.775-4 (downmix equations); ATSC A/52 Annex (downmix levels). Always confirm against the current official document, as specifications and rates can change.
What formula does it use?+
5.1 → Stereo Downmix Level Calculator uses: Lo = L + 10^((C+cmix)/20)·C + 10^((S−3)/20)·S (worst-case coherent sum, ITU-R BS.775 coefficients). The tool shows this formula with your own numbers substituted so you can verify the result.
Is 5.1 → Stereo Downmix Level Calculator free to use?+
Yes — it is completely free with no account, no sign-up and no usage limits. There is no watermark and no paywall.
Embed 5.1 → Stereo Downmix Level Calculator on your website
Want 5.1 → Stereo Downmix Level Calculatoron your own site? Paste this snippet into any HTML page — it's free, with no API key or sign-up. The tool loads in an iframe and keeps working exactly as it does here.
<iframe src="https://tooljolt.com/tools/surround-downmix-level-calculator" width="100%" height="640" style="border:1px solid #e5e7eb;border-radius:12px;max-width:680px" title="5.1 → Stereo Downmix Level Calculator — ToolJolt" loading="lazy"></iframe>Related Broadcast tools
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