Welcome to Audio Techniques. This guide walks through what each tool does and how to fix the most common issues.

What’s in the app

Audio Techniques has four tools, each on its own tab:

• Polarity — Plays calibrated test signals (Pink Noise, Sweep, Clicks, 1 kHz Sine) on both channels with a toggle to flip the right channel’s polarity. Used to check speaker wiring and phase alignment.
• Noise — A continuous noise generator with three flavors (White, Pink, Brown) and a volume slider.
• Tone — A sine or square wave tone generator from 20 Hz to 20 kHz, with one-tap frequency presets.
• RTA — A 31-band Real-Time Analyzer that listens through the microphone and shows the spectrum and the dominant frequency.

Getting started

1. Plug in (or pair) the speakers you want to test.
2. Set your device’s volume to a comfortable level before pressing Play — test signals can be loud.
3. Pick the tab for the job: Polarity for wiring checks, Noise/Tone for source signals, RTA for measurement.

Tip: The app’s audio session is set to mix with other audio, so you can play test signals over a track from another app if you want a reference.

Polarity (Test Signals)

What the buttons do

• Polarity: Normal / Flipped — Toggles the right channel between in-phase (“L:+/- R:+/-“) and inverted (“L:+/- R:-/+”). The status line under the button always shows the current state.
• Pink Noise / Sweep / Clicks / 1 kHz Sine — Plays the selected signal in a loop. Only one signal can play at a time; tapping a new one stops the previous.
• A button turns red while its signal is playing and green when stopped.

How to use it

1. Press Pink Noise (or Clicks — clicks are often the easiest to hear polarity on).
2. Stand centered between the two speakers.
3. With Polarity: Normal, the sound should appear to come from directly between the speakers — focused and “in your head.”
4. Toggle Polarity: Flipped. If the image becomes diffuse, vague, or seems to come from behind/outside the speakers, your speakers are wired correctly. If the image tightens up when flipped, one of your speakers is wired out of phase.

Common issues

I only hear sound from one side.
That’s normal in flipped mode for a moment if your wiring is reversed — but if it stays one-sided in both normal and flipped, check that your device’s Mono Audio setting is off (Settings → Accessibility → Audio/Visual → Mono Audio) and that audio balance is centered (same screen, Balance slider).

Nothing plays when I tap a signal button.

• Make sure the silent/ring switch on your iPhone isn’t muting media (it shouldn’t, but worth checking).
• Raise the volume with the hardware buttons while the signal is playing.
• If you have Bluetooth headphones connected, audio is going there, not the speakers.

Noise Generator

Controls

• Type — White (flat spectrum), Pink (−3 dB/octave, the standard for audio testing), Brown (−6 dB/octave, deeper rumble).
• Volume — 0–100%. Starts at 50%.
• Play / Stop — Big button at the bottom.

Tips

• Pink noise is the right choice for most room measurement and speaker comparison work.
• If you need to test sub-bass response, Brown noise concentrates energy in the lows.
• White noise sounds hissy because human hearing is more sensitive to highs — that’s expected, not a bug.

Common issues

Noise sounds distorted or crunchy.
Lower the in-app Volume slider. If your device’s master volume is already high, the combined signal can clip on small speakers.

Volume slider doesn’t seem to do anything.
Make sure the device’s hardware volume isn’t at the floor (or ceiling). The in-app slider scales the signal before the system output.

Tone Generator

Controls

• Frequency display — Large readout in Hz or kHz.
• Frequency slider — Logarithmic, 20 Hz to 20 kHz.
• Presets — One-tap shortcuts: 50, 100, 200, 440, 500, 1k, 2k, 4k, 8k, 10k Hz.
• Waveform — Sine (pure tone) or Square (rich in odd harmonics).
• Volume — 0–100%.
• Play / Stop.

Tips

• 440 Hz is concert A — useful for instrument tuning.
• 1 kHz is the standard reference tone for level calibration.
• Square waves at low frequencies will sound much louder than sine waves at the same volume setting; turn the volume down before switching waveforms.

Common issues

I can’t hear high frequencies above ~12 kHz.
This is almost always normal. Adult hearing typically rolls off above 14–16 kHz. Small phone/laptop speakers also struggle to reproduce the top octave. Test on good headphones if you want to confirm.

The tone has clicks when I change frequency.
The slider re-targets the oscillator continuously and small discontinuities can produce a tick. Use the preset buttons for clean jumps, or move the slider slowly.

RTA (Real-Time Analyzer)

What it shows

• Peak Frequency — The loudest band the analyzer is hearing right now (or --- when too quiet).
• Spectrum — 31 third-octave bands from 20 Hz to 20 kHz. Bars are green at low levels, yellow as they get louder, red when hot, and white on the band containing the peak.
• Start / Stop Analyzer button.

First-time setup

The first time you press Start Analyzer, iOS will ask for microphone permission. Tap Allow. Without it, the RTA can’t receive any audio.

How to use it

1. Press Start Analyzer.
2. Speak, clap, or play a tone — bars should respond.
3. Use the Tone or Noise tab from another instance, or play a reference track on another device, and watch the spectrum.

Common issues

All bars stay flat / Peak shows ---.

1. Microphone permission — Go to Settings → Audio Techniques → Microphone and make sure it’s enabled.
2. Another app is using the mic — Phone calls, FaceTime, or some recording apps can hold the microphone exclusively. Close them and try again.
3. Bluetooth headset with a mic — When AirPods or other headsets are connected, iOS will route the mic to that device. If the headset mic is muted, occluded, or the headset is in your pocket, the RTA hears nothing. Disconnect the headset to use the device’s built-in microphone.
4. Case or finger covering the mic — On iPhone the bottom mic is small. Make sure nothing is over it.

The RTA picks up its own output and loops.
The RTA shares the audio session with the generators. If you start the Noise or Tone generator on the same device while the RTA is running, the mic will hear what the speaker plays. This is by design — it’s how you’d measure room response. To avoid it, play the reference signal from a different device.

Peak frequency seems off by a little.
The displayed peak is the FFT bin center, which has finite resolution (≈ 21 Hz per bin at 44.1 kHz sample rate). Expect small differences from a known input tone, especially at very low frequencies.

RTA stops responding after a phone call or after switching audio routes.
iOS interrupts the audio session for calls and sometimes when headphones are plugged in/out. Press Stop Analyzer and then Start Analyzer again to re-arm the input.

General troubleshooting

No sound at all

• Check the device’s volume with the hardware buttons.
• Disconnect Bluetooth or wired headphones if you expect to hear the device’s speaker.
• On iPhone, check the silent switch (though media playback should still pass through it for this app).
• Quit the app fully (swipe up in the app switcher) and relaunch.

Audio is too quiet, even at max volume

• The in-app Volume slider on the Noise and Tone tabs is independent of the system volume. Make sure both are turned up.
• Some Bluetooth speakers have their own volume control that is separate from the phone’s volume.

The app crashes or freezes

1. Force-quit (swipe up in the app switcher and flick the app away).
2. Relaunch.
3. If it persists, restart the device.
4. If it still persists, please email davemickey@mac.com with: your device model, iOS version, and what you were doing when it crashed.

“This app needs microphone access” popup keeps appearing

You denied microphone access once and the RTA needs it. Go to Settings → Audio Techniques → Microphone and toggle it on. Then return to the app and press Start Analyzer again.

Background audio

The app is not designed to play in the background. Test signals, tones, and noise will stop when you switch to another app or lock the screen. This is intentional — running calibrated audio while you can’t see the controls is rarely what you want.

Privacy

• The microphone is only used by the RTA tab, and only while the analyzer is running. Audio is processed on-device and is never recorded, stored, or transmitted.
• The app does not collect analytics or personal data.

Contact

Found a bug, have a feature request, or have a question this guide didn’t answer?

Email: info@mickeydesigns.com

Please include your device model and iOS version — it helps a lot when diagnosing audio issues.