[Galaxy S III I9305 (4G LTE + 2GB RAM) Android Deve] Glenn2:
I think you are unclear on what Boeffla Sound is. It switches on some hardware functions that are built into the sound chip's DAC (digital-to-analog converter) that Samsung don't enable by default - you cannot emulate this with software DSP, but neither to they need to be used instead of software DSP. I'll try to explain the important ones:

DAC Direct - switching this on changes the signal path in the Wolfson DAC, bypassing the analog mixer which in our case is an unnecessary stage in the audio processing as there are no analog signals (such as those from an FM chip) to mix in with the digital ones from the DAC's digital conversion stage.

128x digital oversampling - by default the DAC oversamples at 64x. Oversampling pushes quantisation noise from digital to analog conversion out of the audible spectrum. The more you oversample, the less audible this distortion becomes (and easier to filter out) thus reducing distortion, hence the higher performance 128x setting.

FLL tuning - conversion 'jitter' is time-domain distortion caused by timing errors in the clock signal. FLL tuning attempts to smooth these and re-clock the DAC with a smoothed clock. (I actually prefer this off.)

5-band EQ - this is the only place where we overlap with the functions of software DSP such as Viper4Android and Dolby etc. This is a simple 5-band parametric EQ, to boost or cut specific frequency bands to 'tune' them to you headphones and personal taste. If simple EQ is all you need, and no other DSP effects, you are still better off using this as it is not putting the EQ burden on the rest of the system. As soon as you want more from the EQ like the excellent dynamic bass in V4A, you are better off switching the EQ off and using the software-based DSP solution instead.

Headphones volume - the headphone analog amp level is normally fixed. When you change the volume with the volume controls and even when you boost it with a gain setting such as in V4A, you are only changing the digital level. You can't make the maximum achievable level any greater doing this, you will just get digital clipping. Changing the headphone level in Boeffla changes the actual analogue headphone amp level in the chip, making the overall achievable volume level higher (or lower, if you want). Think of it like a TV receiver plugged into a hifi system. If you have the hifi amp set to 5/10, as you adjust the TV level the maximum will be limited by that amp setting of 5/10. If you turn that knob up to 10/10, you will have more overall volume headroom to play with. If you set it too high you may get slight background hiss from the amp in very quiet environments with very sensitive headphones in very quiet musical passages. Samsung default is 50/63, AGNi default is 57/63. I use 60/63.

It should be obvious from the above that even if you are using software DSP like Dolby or Viper for EQ, it is still worthwhile using Boeffla - apart from the EQ - to improve sound quality further, or even just to get more volume which is much better than using a gain setting in software.

I use Viper4Android for EQ and I also use Boeffla to switch on DAC Direct, 128x oversampling, and boost analogue headphone amp level. I refuse to use a kernel that doesn't have it.

I got a bit carried away there... :)