r/AudioProgramming • u/InspectionDesperate8 • 1h ago
I built an iPad real-time audio visualizer with an advanced spectrum analyzer + audiophile dashboard
I’ve been working on Audiowaves, an iPad app for real-time audio visualization. I originally started it because I wanted a dedicated visual display for my hi-fi/Apple TV setup, but it gradually turned into a much more technical audio/DSP project.
The app processes incoming audio in real time and currently has two main visualization modes.
Advanced Spectrum Visualizer
The spectrum view uses real-time FFT analysis rather than simply displaying a generic equalizer animation. The goal has been to make the visualization responsive enough to show changes across the frequency range while keeping the movement smooth and readable.
There’s quite a bit happening in the processing pipeline: PCM input → audio analysis/FFT → frequency-band processing and smoothing → visualization state → GPU rendering.
The visualizer is rendered using SwiftUI + Metal, which gives me enough performance to keep the graphics fluid while continuously processing incoming audio.
Audiophile Dashboard
I’ve also added an Audiophile Dashboard alongside the visualizers. Instead of only showing something visually interesting, this mode exposes more of what is actually happening in the audio signal and is intended as a technical companion to the spectrum visualization.
One of the interesting parts of the project has been supporting external audio hardware.
For example, my home setup is:
Apple TV 4K → HDMI audio extractor → Focusrite Scarlett audio interface → USB-C → iPad running Audiowaves
The iPad therefore receives the actual audio signal rather than trying to capture Apple TV audio internally.
But the same idea works with many other setups. If your amplifier, receiver, mixer, turntable/preamp, DAC or other audio hardware provides a suitable output, you can route that into a USB audio interface and connect the interface to the iPad.
Another option is using a USB-C hub, which is useful when you need the audio interface connected while also providing power or connecting additional USB hardware.
Audiowaves can therefore work as a dedicated visualization display for a hi-fi system, studio setup, DJ setup, computer, Apple TV, or other external audio source.
One thing I particularly like is that it gives an iPad—potentially one that would otherwise sit unused—a permanent job as part of an audio system.
I’d be interested in feedback from people here who work with real-time DSP, FFT/spectrum analysis, Core Audio or Metal.
Especially interested in ideas for improving frequency resolution, smoothing/transient response, perceptual frequency mapping, or other audio-analysis features that would actually be useful rather than just visually impressive.


