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I'm trying to understand if the phase inverting and signal summing capabilities of some DSPs (Helix?) might help me deal with a challenge I'm facing ….
Background
Try to 'cancel' the L and R (music) component of the (L+R+V) FR Center OEM amp output so that the FR Center can be used as a DSP input>output to retain vehicle generated voices and tones without screwing-up music imaging / staging.
My (maybe wrong) Understanding of Theory

Real World Implementation (?)
Anyone see a different possible / better way to accomplish the 'no compromise' objective given the constraints descibed?
Thanks In Advance
Background
- > 2019 Honda Ridgeline RTL-E (with ANC disabled via module disconnect)
- > OEM amp/DSP has 8 output channels, one for each speaker (FR L&R Tweeters, FR L&R Woofers, FR Center, Rear L&R, Sub)
- > Most vehicle generated voices and tones are on FR Center along with a mono music signal apparently consisting of simple L+R. So, using "V" for vehicle voices and tones distinct from music, let's call the OEM FR Center signal (L+R+V) for this discussion.
- > There is no method within my capabilities to 'extract' "V" as a discrete analog signal from the OEM system ("V" is generated and combined with the L+R music within the OEM amp/DSP module based on several digital CAN inputs + analog music input from the "HU" and I'm not an electronics hacker)
Try to 'cancel' the L and R (music) component of the (L+R+V) FR Center OEM amp output so that the FR Center can be used as a DSP input>output to retain vehicle generated voices and tones without screwing-up music imaging / staging.
My (maybe wrong) Understanding of Theory
- In theory, this phase inverting and signal summing scheme would achieve my objective: [(L+R+V)+([email protected]*)+([email protected]*) = V] , is that correct?
- For that to work, each instance of L and R must be the exact same amplitude (as well as frequency of course) at every instant in time, is that correct?
Real World Implementation (?)
- I believe that in my case the Rear L and Rear R signals 'match' the frequency of the respective FR Center L & R components (but maybe not close enough to cancel if phase-inverted due to minute differences in the amp/DSP circuitry?).
- I have no reason to expect the Rear L&R signals to match the amplitude of their FR Center counterparts, and I'm skeptical that I can force an 'exact amplitude match' sufficient to achieve cancellation using level-setting controls in either the OEM system or the external DSP.
Anyone see a different possible / better way to accomplish the 'no compromise' objective given the constraints descibed?
Thanks In Advance