[IDEA] Haas Surround

[STUDI]

Suggested functionality:

Moode audio running on an old Raspberry Pi 2B (with an old processor) works perfectly as a portable player. Despite the addition of a USB WiFi dongle and a DAC card with a lot of its equipment, using a cheap powerbank you can easily use such a system for over 8 hours of continuous play. The two DACi - ES9038Q2M and HifiBerry DAC +, can drive the Koss Porta Pro headphones with an impedance of 60 ohms without any problems. I miss one feature that I have in Rockbox. It's about the Haas Surround DSP effect. Its working is sensational because it brings the headphone listening closer to the one in the room with the use of loudspeakers (without reflecting the sound from the walls and furniture). In advance, this is the opposite of one of the trends of narrowing down the stereo base because the space is dynamically expanded depending on the time dependence of the sounds played. Contact with the authors of Rockbox will provide more details and I think that their DSP filter can be implemented in the environment used in Moode.

[TheOldPresbyope]

A quick check of the Rockbox repo shows that the surround effect is implemented via the Simple DirectMedia Layer, a library developed primarily to support game developers. A glance at the C-code suggests the SDL supports 8-bit and 16-bit audio. IMHO this is a nonstarter for moOde.

You're best bet is to find someone to take on the challenge of implementing similar functionalities in, say, the CAPS audio plugin suite, which is the source of moOde's parametric EQ and graphical EQ code. That's a challenge for a different forum.

Regards,
Kent

[STUDI]

Maybe it is based on SDL, but the result is great for long listening with headphones (long journeys are sometimes the only opportunity to listen to music, there are periods when I have no chance to stay at home longer than to sleep).

Moreover, a long time ago hardware portable players can do more than 16 bits and 44.1 / 48kHz. We already have an oversampling or FIR settings (realted to DAC chip in player). Therefore, I was careful with this evaluation that it is 8 bit. (As for even 16-bit, however, most of the music is published in this resolution. I will not give up on a good album just because it was not released in SACD. It may never be released in this format or in any other high-resolution format).

The algorithm used can be scaled to a different arithmetic.

Hass Surrond is the position to create a filter using even a 32-bit 64-bit samples. Yes, I know that it is rather external software in relation to both MPD and Moode.