The drivers were first broken in for 24 hours using 25Hz at just about Xmax excursion (about 0.4 inches total). They were then tested using the Woofer Tester. Vas was measured by added mass method (6 nickels taped to cone with Scotch Tape symmetrically about the cone/dustcap junction). We have chosen to measure drivers laying horizontally on about 2 feet of acoustic foam on the carpet.
Some have said that drivers should be mounted vertically during testing rather than horizontally when vertical orientation will be the final box mounting. A while ago we found that the orientation didn't affect the results with 8 inch and smaller woofers. Horizontal orientation gives us a very high percentage of valid readings, while vertical orientation often resulted in difficulty keeping good mechanical contact between the cone and the added mass (producing buzzing sounds at resonance, unreproducible measurements, and even impossible calculations by the Woofer Tester software). |
