DSP Virtual Room?

[EffinHelpMe]

I was wondering if its possible to replicate this http://www.bel.fi/~alankila/android-dsp/ I have it on my android device, its awesome! Virtual Surround Sound, room,large room,etc, or my favorite.. Stage!

[nls]

Rockbox already has a compressor and equalizer and the "virtual room" feature sounds to me like it does what our "crossfeed" feature does, have you tried playing with these features?

[EffinHelpMe]

Rockbox already has a compressor and equalizer and the "virtual room" feature sounds to me like it does what our "crossfeed" feature does, have you tried playing with these features?

yes I've tried but can't replicate it exactly, what kind of settings do I need to make it sound like im hearing the music on a surround sound stage?

[bertrik]

I'm not a big fan of these kinds of effects (basically just reverb as far as I understand), because of its lack of subtlety.

I have wondered a couple of times if we could extend crossfeed with a simple delay from one ear to the other, though. This would make it another step closer to a true head-related-transfer-function (crossfeed already implements frequency-dependent amplitude of the cross-fed audio). The delay would be equal to the time difference between sound coming in at one ear and and the same sound arriving at the other ear. This should be easy to implement, basically a delay line for each channel of about 20cm/0.6ms/26 samples (assuming speed-of-sound is 340 m/s, at 44100 kHz sample rate) to delay the sound before doing the processing and mixing it to the other channel.

[bertrik]

replying to myself: it seems that cross-feed already incorporates a subtle delay as far as I can tell from the code.

Some of the parameters seem to be a bit off compared to what you can find on http://en.wikipedia.org/wiki/Sound_localization for example. For example, the interaural distance for the current cross-feed seems to be equivalent to only 10 cm (13 samples). Also the currently-used default high-frequency cut-off for the cross-fed audio seems a bit low (700 Hz, wikipedia suggests a value between 800 and 1600 Hz)