WMP100: SPK1 output


I have found (another) discrepancy between the WMP100 datasheet and the reality. In the document “Product Technical Specification and Customer Design Guidelines Rev-12”, chapter “SPKx Single-Ended Connection Example”, it says: “If SPKxP channel is used, SPKxN can be left opened. If SPKxN channel is used, SPKxP can be left opened.” I measured both SPK1P and SPK1N and I expected to see the same output on both signal lines, but the output is only on SPK1P. I measured directly on the lines, with no connection (only 100nF to GND on each line). Is my measurement wrong or the reference document is wrong?