Really basic TL question

[weinstro]

Hi all,

Suppose I have a sealed enclosure, with an appropriate driver mounted. I used one of the many box size calculators to arrive at the enclosure size, aiming for a Qtc of 0.7.

Now suppose that one dimension of the box happens to equal the quarter wave length of the driver's Fs. Volume is unchanged from above, but the box is a tall column.

What happens? How would the performance of the driver differ from that predicted by say, Unibox? Does it matter where the driver is mounted?

[Scottmoose]

Yes, it will make a difference where the driver is mounted. In effect, assuming it's stuffed properly, what you have there is a 'real' transmission line, rather than the more usual aperiodic lines, or mass-loaded lines. Will the differences be significant? Depends on the driver & cabinet. What exactly are they?

[GM]

Greets!

Assuming the box is still sealed, then there will be 'room' modes beginning at 1/2 WL with a deep notch at every harmonic, so its response will be tuned lower and anything but smooth. Driver placement makes a big difference with the midpoint yielding the smoothest, though still relatively ragged response which stuffing will smooth out to a great extent at the expense of a much higher F3.

Bottom line, not a good plan IMO.

GM

[Shae]

woops wrong thread