Isobaric Types: Planar Load

This alignment is similar in concept to a "clamshell" or face-to-face isobarik and will behave in a similar manner.  However, it also has some of the problems of the tunnel-loaded isobaric that are associated with having a coupling chamber between the two drivers. It is somewhat space-inefficient since it requires you to give up usable space behind the outside driver, but it produces a very interesting visual effect if you put a sheet of plexiglass in front of the speakers.

Isobaric - Planar

The loading chamber (indicated by the yellow shaded region) should be as short as possible while still allowing for free movement of the speaker's surrounds. You should also do everything possible to minimize the surface area of the loading chamber since any trapped air in it essentially becomes part of the moving mass of the speaker system.

If you intend to utilize a ported design, port lengths can be rather large. This is common with single iso-group enclosures because of the small box volumes. For this reason, you may want to fire the port as shown in the diagram below. This should allow you to extend part of the port tube outside the enclosure without it being visible.


Isobaric - Planar / Ported


Learn about other Isobaric Enclosure Types:

"Piggy-back" tunnel load

Isobaric - Piggy-Back

Back-to-back tunnel load

Isobaric - Back-Back

Isobaric Enclosure