Most DOA estimator shipped in Phased Array System Toolbox is indeed narrow band so they are probably not the best tool for wideband audio signals.
However, you could consider using a wideband beamformer to scan the space and look for the direction where you get the maximum peak. There are several wideband beamformers available in Phased Array System Toolbox. The phased.SubbbandPhaseShiftBeamformer uses the subband approach you described in your post. You can also use phased.TimeDelayBeamformer to perform time domain beamforming which does not assume whether the signal is narrowband or wideband.
Does this address your concern? Please let me know if you need any further clarification.
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