LADSPA plugins

[arjunm009]

Hey there.


Is there any known LADSPA plugins for stereo widening and psychoacoustic bass boost.


I have been wanting to experiment with them with my system, Rpi with DSP.


Alternatively, is there an alternative to those effects one can use in a Linux setup?


Thanks.

 

[CharlieLaub]

Hey there.


Is there any known LADSPA plugins for stereo widening and psychoacoustic bass boost.


I have been wanting to experiment with them with my system, Rpi with DSP.


Alternatively, is there an alternative to those effects one can use in a Linux setup?


Thanks.

Not sure what you mean by "psychoacoustic bass boost". Can you be more specific?

I looked over your DSP program. That is pretty nice! There are some users on here who are calling LADSPA plugins directly within ALSA using asoundrc configuration files to implement a loudspeaker crossover. The problem seems to be that the complexity of the filtering is limited because channel routing and implementing multiple LADSPA filters (for eg higher order filters) under ALSA is very difficult and error prone. Your approach could really make this much easier for people.

I see that you have figured out how to call your DSP program from within ALSA. That may be something of great interest for those people. One goal for them is "bit perfect playback" that is when the audio format (sample rate and bit depth) of the audio stream changes, the LADSPA plugins implemented within ALSA are updated to the new format and data can be passed through to the DAC(s) without any need to resample, etc. Would that be the case for your DSP program?

Also, you might ask for this thread to be moved into the PC Based forum since that is more applicable to this topic.

 

[arjunm009]

Not sure what you mean by "psychoacoustic bass boost". Can you be more specific?

Sure. I found this nice thread which lists definitions from many manufacturers which use in their setup.


In a gist, signals below a cutoff, preferably the F3, is filtered, fundamentals removed, and their harmonics amplified and remixed into the original signal.


This way any small driver setup never produces low ends but only their upper harmonics, above their F3, which still gives a perception of bass from a small system. It is actually pretty neat effect.

I found this MATLAB description which details on its technical aspect.

I constantly find myself working with smaller setups. I have been trying to find a solution for bass. Only thing which I fallback is Linkwitz transform, which this library supports, but my drivers are not always capable.

I see that you have figured out how to call your DSP program from within ALSA. That may be something of great interest for those people.

I had written a gist on its installation.


For configuring ALSA this guide is handy and straightforward.

One goal for them is "bit perfect playback" that is when the audio format (sample rate and bit depth) of the audio stream changes, the LADSPA plugins implemented within ALSA are updated to the new format and data can be passed through to the DAC(s) without any need to resample, etc. Would that be the case for your DSP program?

On this I am not certain. Though this issue was mentioned for PulseAudio. Not sure on ALSA. I can ask the author for confirmation.