Hello, how can I find out what that would be?
Was recommended as a starting point for setting my sub.

thx!

I would guess that could be derived from this graph:

This is from Axiom's product page for the M3s.

From looking at this graph, I would say that 150hz would be the best choice.

I would never cross a sub that high.

And I don't see 150Hz as being a -3dB point in that graph anyway...

Looking at the specs the +/- 3dB point is 60hz, however, I would follow normal practices and start around 80hz or possibly a bit higher.

OK, thanks - I had it set around 70 anyway...so I guess I was in the ballpark.

150 still looks like where +3db starts. I would try here to see what it would sound like to eliminate that bass hump. Then adjust downward if it didn't help. This would make the subwoofer reproduce directional bass though.

80hz or 100hz is ideal. The M3 connoisseur (2X6spds) on these forums likes his crossed at 100hz used with a subwoofer.

I was assuming he wanted the MINUS 3Db point, as you would normally crossover to the sub where the main speaker is rolling off (if you didn't want to use the 80Hz standard, at least).