BillFitzmaurice.info

Hey guys,
I've owned a Harman Kardon Onyx Studio bluetooth speaker for a while now, and decided to look up the specs on frequency response and overall setup design. I came across the passive radiator system and how they use that in most of their speakers. It seems like a cool idea and I know it works very well (trust me, my little bluetooth speaker blows any Bose speaker out of the water) anyway I was wondering why this setup isn't used in the folded horn enclosures. It definitely ups the bass power from what I've found researching.
Most speakers that use this system have two drivers that both get a full signal, but on the Harman Kardon it has baffles on the front and back with little 2 inch drivers.
How does this system work? I know it has to do with if there are two drivers they become out of phase. but other than that I'm kind of clueless
Is it all a hoax?
is it just not practical?

Just wanted some input.

Thanks!

PRs work in almost exactly the same fashion as bass reflex, they just use a PR cone's vibrating mass in place of the vibrating mass of air in a port. Sensitivity is no better than a ported cab, so they don't come close to a horn.

The first studio that I built back in 1980 had EV studio monitors with passive radiators. 8 inch driver with a 12 inch passive radiator. Nice boxes.

Passive radiators look nice to the marketing department because it looks like you have another woofer. They also have some benefits over ports in that there is no port noise or port resonance. They also block out any midrange bounce back that can travel out the port and they seal the cabinet so you can use fiberglass insulation without bits of itchy stuff flying out the ports to irritate your sinuses.