Тъй като не съм на нивото на проектиране
само гледам проекти 
Интересно ми е да чуя мнението ви за следната конструкция: Helix-AG150
This is the second example of the angular spiral.
Similarly to AG100, six acoustic fins are fixed on each side-plate.
But, they are put in different angles for forming an expanding sound passage.
A damping material was not used initially, but it was revealed later that a small quantity of Thermo-wool (fluffy 5 cm cube) in the throat was effective for obtaining a high quality bass.
Full range drivers used are Fostex's 12 cm FE126E with low Qts (0.25) designed for back loaded horn.
The sound is clear and crisp with sufficient and well controlled lower level.
The frequency response of AG150 is surprisingly similar to BL100, the round spiral back loaded horn. Both have a strong and broad peak at about 150 Hz.
Full-range FE126E (Fostex)
Height 800 mm (except base)
Width 150 mm (except base)
Depth 180 mm (except base)
Air chamber volume; V 2.9 liters
Rotation number of spiral; n 5
Rotation number of sonic fins 6
Max length of sound passage; L 280 cm
Cross sectional area of throat; S 37 sq. cm
и неадекватни площи. И това чудо няма и най-малък намек за хорна... Моля за извинение, ако съм в грешка...