|Choosing an alignment
Be careful when choosing a 6th order bandpass alignment for your driver. An ultra-large
box with an ultra-low cutoff frequency may not produce the best results, because of the
reduced power handling and lower efficiency. Examine carefully the cutoff frequency and
box size and tradeoff in efficiency to determine whether or not this alignment lives up to
Where should I put the ports?
Ports should be placed at least one diameter away from any adjacent walls. If this is not
possible to do this, the tuning frequency for a given port length will be lower than that
predicted by the equations, and this may adversely affect the results.
Lining the box
One layer of lining on every wall for each section will generally give better results, as
the lining will help to reduce the out of band noise. Ensure that no lining obstructs the
ports. Fiberglass will work here, but make sure that none's located near the port
entrance, as air turbulence can rip chunks of it off the walls and eject it through the
port. Any change in the tuning frequency introduced by lining the enclosure can be
adjusting by shortening the port(s) slightly.
Use the largest ports possible for your design. This will reduce power compression effects
and port noise caused by turbulence. Flaring the ends of the port will also produce better