Z-axis offset for 6.5 woofer and an AMT tweeter

Ed_Perkins

Has anyone measured the Z-axis offset for a 6.5 in. woofer and an AMT type tweeter?  I'm doing a simulation and don't have the drivers so I'm looking for an estimated value to use.  IIRC a typical value for a 6.5 woofer and a "standard" tweeter is in the 1  to 1 1/4 inch range.  I'm guessing that using an AMT tweeter would increase that value since since most AMTs are shallower and would have their acoustic center closer to the baffle and farther away from the woofer's acoustic center.  Thanks in advance.

PWRRYD

I think you meant to type "decrease" that value if the AMT isn't sitting proud of the baffle like a lot of 25 mm domes do.

dcibel

Acoustic centre is a combination of the physical speaker dimensions as well as the phase difference that is a result of its frequency response. Because there is a change in acoustic offset as a result of frequency response, we determine the acoustic offset for every speaker individually.

Until you have the drivers in hand you might as well just use 25mm offset, and expect to adjust your crossover once you can take real world measurements.

jhollander

Between my AMT3-4 and RS180P I had about 27.7 mm Z

Ed_Perkins

Thanks all for your inputs.  I'll go with John's measured value for the sim.   Looks like it's the same as the standard estimate.