Implementation of Simultaneous Deconvolution on a Real-time Smartphone App

In-room speaker system equalization was traditionally implemented by exciting one speaker at a time. With a higher number of speakers, restrictions of measurement microphone setup, the annoyance factor due to traditional stimuli, and background noises, the process of measuring the impulse response of a multi-channel system in real-time can be cumbersome. With FFT computation restrictions on a smartphone DSP, the accuracy and resolution of the impulse responses are compromised. This paper addresses all of these concerns with a novel approach to implementing the Simultaneous Deconvolution of a multichannel speaker system. It uses a set of circularly shifted Sine-Sweep stimuli to excite the speakers and calculate the impulse responses in real-time on a smartphone app over a cloud-based architecture. An independent recording and playback system, along with manual delays or system delays due to Bluetooth, Wi-Fi, or cloud-based communication, pose further challenges to the accuracy of our measurements. To surmount these complications, we discuss a time-alignment method that uses bin-wise matched filtering of spectrograms, followed by a statistical analysis of its results.