FreqSense — RF Frequency Coordination for Wireless Mic & IEM (DE/UK/US/EU)

Find clean RF in a venue in under a minute.

FreqSense is a visual RF frequency-coordination tool for wireless-mic and IEM engineers. See occupied TV channels, intermod danger zones, and safe coordination windows across four regions — overlay a live scan, then print an A4 field document.

Works offline Try it here, no account Prints to A4

A spectrum analyzer's brain, in your browser.

Everything an RF tech needs to coordinate a show — the spectrum, the regulations, the intermod math, and the print-out.

Visual UHF spectrum

See occupied TV channels, intermod danger zones, cellular blocks, and safe whitespace on one scrollable, zoomable 470–960 MHz spectrum — colour-coded and click-to-pin.

Multi-region plans

Switch between DE, UK, US and EU regulatory regions (plus FR, JP, AU, CA) and the channel map, guard bands, and licensing rules update instantly.

Manufacturer band overlays

Overlay the tuning range of your actual hardware — Shure, Sennheiser, Sony and more — and pin multiple systems to check them against each other at a glance.

Intermod-aware coordination

Coordination windows are sorted widest first, with 3rd- and 5th-order intermod products and TX-on-RX hits computed and flagged — not just empty gaps.

Drop a scan, overlay live RF

Drag a scan CSV from RF Explorer, Shure WWB6/7, R&S FSH or a generic two-column file and the real noise floor overlays the plan. WebUSB SDR too.

Print an A4 cheatsheet

Turn the result into a clean A4 field document — spectrum image, window table, and assignments — to tape to the FOH desk. Save plans as JSON for next time.

Drop a scan. See the real noise floor.

Drop a scan CSV to overlay live RF
— or click to browse

RF Explorer.csv / .rfe

Shure WWB6 / WWB7Freq (Hz), dBµV

Rohde & Schwarz FSHCenter, Level

Generic two-columnMHz, dBm

Your plan, measured against reality.

The regulatory map tells you where TV is supposed to be. A scan tells you what's actually on air in that room. Drop a sweep and the live trace overlays the plan, with a noise-floor threshold you can drag to shrink the windows around real interference.

Auto-detects MHz / kHz / Hz and dBm / dBµV units per format.
Overlay up to four traces at once, each in its own colour.
On Chromium, stream a WebUSB SDR for a live sweep — no file needed.

Four steps to a clean show.

Pick your region

DE, UK, US or EU — the spectrum redraws to that regulatory plan.

Overlay your gear

Select a manufacturer band, or drop a scan CSV to see the live noise floor.

Read the windows

Safe coordination windows are listed widest-first, intermod already flagged.

Print or save

Export an A4 cheatsheet for the desk, or save the plan as JSON.

Four regions, real regulatory plans.

Each region carries its own channel map, guard bands, and licensing status — verify against the current database before deployment.

Germany

BNetzA

470–694 MHz · DVB-T2

United Kingdom

Ofcom

470–694 MHz · Ch38 PMSE

United States

FCC

470–608 MHz · post-repack

CEPT / EU

Harmonised

470–694 MHz · CEPT

Built for anyone fighting for clean spectrum.

Wireless mic coordination

Find clean windows for handhelds and bodypacks between occupied DTT channels, fast.

IEM / monitor engineers

Coordinate transmitters with intermod and TX-on-RX awareness, not just empty spectrum.

Touring & festivals

Land in a new city, pick the region, drop a scan, and print a venue-specific cheatsheet.

Broadcast & AV

Check large multi-channel deployments against guard bands and protected services.

Rental houses

Pre-coordinate a package for a client's region and hand over a printed plan with it.

Houses of worship

Keep a saved plan for the building and re-verify against a fresh scan each season.

Frequently asked questions.

What does FreqSense do?

FreqSense is a single-page RF frequency-coordination tool for wireless-microphone and IEM engineers. It visualises occupied TV channels, intermod danger zones, and safe coordination windows across DE / UK / US / EU, so you can find clean RF in a venue in under a minute.

Which regions and regulations are covered?

The core regions are DE (BNetzA), UK (Ofcom), US (FCC post-repack) and EU (CEPT), with guard bands and licensing status shown per region. The data is informational — always verify against the current regulatory database before deployment.

Can I overlay a real spectrum scan?

Yes. Drag a scan CSV onto the spectrum and the live noise floor overlays the plan. Supported formats include RF Explorer, Shure WWB6/WWB7, Rohde & Schwarz FSH, and a generic two-column Frequency, Amplitude file. On Chromium you can also stream a WebUSB SDR live.

How are coordination windows calculated?

The tool finds the whitespace between occupied channels, subtracts guard bands and any scan-flagged ranges, and sorts the results widest first. It also computes 3rd- and 5th-order intermod products and TX-on-RX hits so flagged frequencies are excluded, not just empty gaps.

Does it work offline?

Yes — it's an offline-capable PWA. Load it once and it runs from a venue laptop with no connection, and prints a clean A4 field document of your coordination windows and assignments.

Is it free?

Yes. It's a free tool on Squaresmile Tools — try the live spectrum on this page with no account; the full tool opens with a free account, no install.

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