2. Proposed Circuit

3. Notes Vo+ and Vo- should never be at a higher voltage than VDD
This means that both devices must be powered on while the other device is driving the speaker.
When the TPA2005D1-Q1 drives the speaker, the output signal will be visible on the IN+/IN- pins of the TPA6211A1-Q1
This is because there is a 40kOhm resistor connecting the outputs to the inputs, even when in shutdown mode.
The customer must consider the impact of this signal on the “IN” line. Could it adversely affect anything else on that node?
The 1uF capacitance on the TPA6211A1-Q1 output could cause stability issues.
If this occurs, then the capacitance of the TPA2005D1-Q1 LC filter could be reduced, or possibly changed to a ferrite bead filter (which requires a much smaller capacitor)

4. Feedback through TPA6211A1 when TPA2005D1 is driving speaker

5. Test Data
This is the output of the TPA6211A1-Q1 with a 1uF capacitor on the outputs. By zooming in, the ripple caused by the instability can be seen.
Zoomed out
Zoomed in