Jens Guell released JAX Convolutor PRO (AU), the paid version of the recently released Impulse Response app JAX Convolutor PE. This one lets you import your own IR files! The App Store description includes a note that while it is intended to be used as an AUv3 effect, you need to run the base app once to install the IR file library.
JAX Convolutor PRO (AU) App Store Description:Remarks: This is an Audio Unit, but you have to open the distribution app ones at least to install the included IR file library.
Convolution is a highly complex signal processing approach, that needs some certain computation power. The recorded impulse response of a real world environment is used to render a reverberation effect onto any audio material, so that it sounds like the source was played in that original room or at that location. Some further adjustments and manipulations can be applied to refine these results.
Now this all may sound somewhat naive at first listen but the entire calculation is extremely complex math, so that the very first processors and computers were able to perform this in realtime rather around the end of the last millennium.
Basically, the impulse responses and the audio stream are completely analyzed with FFT algorithms and then the entire analysis data will be cross-modulated into the realtime audio stream by performing a repeated highly performance intensive re-synthesis and accumulation processing for each analysis block of the impulse response.
Therefore it is a crucial performance factor that you use JAX Convolutor with larger processing buffer sizes (1024) samples. Shorter buffers may raise the CPU hit exorbitantly for several reasons.
The manual is embedded into the main app.
Developer Jens Guell posted this demo showing the low CPU usage from 6 instances of the free app!