I've always folded using an equiangular spiral but mostly because it allowed smaller turn angles. If crossed over low, it seems to me that the angles wouldn't matter much. As long as the horn was used at frequencies below 1/4 wavelength of each section, and as long as the horn is braced well, can you see any reason why a spiral fold basshorn would outperform a "W" fold? If the path length is the same and the area expansion is the same, it sems to me that performance would be the same at low frequencies. I would think the main deal is packaging and layout if all other things are equal. Could the preference be a new misconception?

Thoughts anyone?