Large spikes at bottom and top of bandwidth.

[Etocynned]

Designing a tapped taper for a higher qts car audio sub.

Goal is peak output at bottom of the range. Fundamental will be at 15hz.

In my hornresp sim i see a 12db spike at the top and bottom of the bandwidth.

Is this a defect or a feature?

When i sim a 4th the peak isnt nearly so huge.

 

[Brian Steele]

If designing for a flattish response curve, that's usually a sign that the box size is too big.