Tweaker's Asylum

Posted by tc on March 23, 2000 at 06:32:26:

A thread below was discussing errors in the design of the ME2 (the smaller version of Lynn Olson's Ariel). Here are the details of the calculations made using equations and tables from the Speaker Design Cookbook.
For two VIFA P13WH-00-08 (Qts=0.33, Vas=10 liter, fs=60hz):
BE4 alignment: Box volume=640 cu. in., fbox=58.4 hz, Vent D=1.5" L=6"
SBB4 alignment: Box volume=585 cu. in., fbox=60 hz, Vent D=1.5" L=6.26"
QB3 alignment: Box volume=565 cu. in., fbox=72.2 hz, Vent D=1.5" L=4.04"
SC4 alignment: Box volume=555 cu. in., fbox=66.4 hz, Vent D=1.5" L=5.18"
For all of these, two vent tubes are used.
The author gave a box volume of 521 cu. in. for the BE4 alignment, a box tuning frequency of 48 Hz, and 2 1"dia x 4.125" vents. Put the speaker parameters and this box volume into any speaker design software, and it will predict a response with essentially no bass. A box built to Olson's drawings, but with the diagonal braces removed to give 640 cu in volume and the vents changed to 1.5" x 6" gives very good bass.

• Ariel and ME2 web site