About The Audio Toolkit

Free, professional-grade audio calculators for live sound engineers. Built by someone who uses them at real shows.

Who's Behind This

I'm a freelance FOH/monitor engineer working venues across the UK — clubs, theatres, festivals, corporate events. Every week I'm calculating delay times for speaker alignment, converting between dBu/dBV/dBFS on unfamiliar consoles, and figuring out if the SD card in my recorder has enough space for the gig.

I built these tools because the existing ones were either paywalled, bloated with ads, didn't work offline, or got the formulas wrong. Now they're here — free, fast, and accurate.

Why This Exists

  • Works offline — Service worker caches everything. No signal backstage? Tools still work.
  • Mobile-first — Big touch targets, readable in sunlight, no horizontal scroll.
  • No tracking — Zero analytics, zero cookies, zero third-party scripts. Your calculations stay on your device.
  • Pro references — Formulas from Bob Katz (Mastering Audio), Rumsey & McCormick (Sound and Recording), Talbot-Smith (Audio Engineer's Reference Book). Not Stack Overflow.
  • Shows the math — Every tool displays the formula and explains the "why", not just the answer.

Current Tools

  • Audio Delay Calculator — Distance ↔ ms ↔ samples with temperature/humidity compensation. Subwoofer alignment + delay tower Haas alignment.
  • dB / Level Converter — dBu, dBV, dBFS, volts, watts. Add multiple sources. Selectable digital reference (-18/-20/-14/-16 dBFS).
  • Recording Storage Calculator — Any sample rate, bit depth, channel count, duration. SD card presets. WAV/FLAC/MP3 estimates.

More tools coming based on search demand and real-world needs.

Guides (Coming Soon)

Long-form articles written from experience:

  • Complete Guide to MIDI for Live Sound
  • Audio Levels Explained: dBu, dBV, dBSPL
  • Live Sound Setup Checklist
  • How to Choose the Right Microphone
  • XLR vs TRS vs RCA — Which Cable Do You Need?
  • Understanding Gain Structure
  • Monitor Mixing for Beginners

Monetization & Sustainability

This site is free and will stay free. Revenue comes from:

  • Affiliate links (Amazon Associates, Thomann, Sweetwater) on tool pages — only gear I'd actually recommend.
  • Future: Google AdSense — applied after 15–20 pages + 6–8 weeks of organic traffic, per AdSense approval guidelines.

No paywalls. No "pro" tiers. No email required to use tools.

Tech Stack

  • Plain HTML, CSS, JavaScript — no frameworks, no build step
  • Hosted on Cloudflare Pages (free tier)
  • Domain: theaudiotoolkit.com (Cloudflare registrar)
  • Service worker for offline caching
  • Server-side rendered content for SEO (no JS-only content)