scoop

Fairly sure keV from Dub Smugglers saying he created them. 

Edited by BigSoundNorthWest - 06 February 2022 at 11:59am

turbo7 wrote: i did once build one polar bear for comparison, it has a long horn but for drivers xmax greater than 10mm the throat is too small and it will suffer from turbulent airflow.

That’s not quite how a horn throat works, at least in theory. It’s not a vent, and the acoustic impedances of the rear chamber and first horn section either side of the throat opening will be much closer than a port meeting free air.

The increased compression may push the air into nonlinear behaviour when driven at full chat, but thats more because the pressure at that point might exceed 150 dB as it can in many high power horns, even those for HF.

Doing a proper analysis of the Polar Bear has been on my personal project to-do list for a while, but at first glance, a large portion of its clean, flat and powerful sound appears to be due to the fact it's been designed as a good transmission line as well as an efficient horn.

Rear loaded horns aka scoops have an even smaller mouth than a FLH of the same dimensions, so the acoustic behaviour typically transitions from horn to quarter wave resonant pipe at the low corner.

pfly is the designer and original builder, but I believe both Kev Smuggler and Matt at studio45 in Sheffield are licensed to build them. The plan isn't for general sharing otherwise, as far as I know.

My mistake guys,