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dbmaxpayne / Sonos-DSP

Make Sonos Play:5 Gen. 1 recycle-mode speakers sing again
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[Q] Why a DSP is needed? #1

Open unaiur opened 8 months ago

unaiur commented 8 months ago

First, I would like to thank you for all this work.

I just have one question... Why is the DSP required? What happens if you connect the I2S to the raspberry pi directly and perform the processing by software?

I understand that it converts an stereo I2S signal from raspberry pi in two stereo channels for high and low frequencies and a mono crossover subwoofer channel, isn't it? I think this processing can be done by the raspberry pi... I was doing this kind of processing 20 years ago in a Pentium at 166Mhz... What is the problem? Maybe the i2s hardware in the raspberry does not support 5 channels?

dbmaxpayne commented 8 months ago

Hi unaiur,

Yes, indeed the Raspberry Pi does not support more than two channels. It would be perfect if it did. There are apprarently other SoCs that do support multichannel TDM, but I had no access to any.

The DSP in my configuration is set up to do a three-way crossover in Stereo for all six individual amp channels of the Sonos Play 5.