Mackie SRM450 v1 interesting tweeter polarity confusion.

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You canīt hear absolute phase but as mentioned above, *two* speakers working at the same frequency will add/substract, big time, producing a bump or a notch.
Pick your poison but results are definitely audible or visible on a graph.

As of the apparent "polarity inversion", typically woofer will be in series with an inductor, tweeter with a capacitor, which advance or delay phase.
At the exact crossover frequency *both* will be so much out of whack that often inverting one takes them closer, go figure.

For what it's worth I agree .. but I had already closed the cabinets by the time I noticed the schematic error and these cabinets are a faff to open and close so they are going back to owner tomorrow wired as they were from the factory I think. The amp is fixed & the diaphragm replaced so I've no more time to wonder about the possible phase issue.

If the service centre ever get back to me with a definite polarity I'll post an update ...