Do drivers shake their mounting boards?

[buggsson]

This is a simplified plan view

An externally hosted image should be here but it was not working when we last tested it.

Drivers wired in phase to acoustically act as a larger driver, but mechanically opposite phase to cancel most of the reactional energy. The channel they sit in is acoustically small at frequencies it is operated at, so it acts just like a flat baffle acoustically.

dave

I would presume this method require drivers with unvented pole pieces?

 

[Brian Steele]

This is a simplified plan view

An externally hosted image should be here but it was not working when we last tested it.

Drivers wired in phase to acoustically act as a larger driver, but mechanically opposite phase to cancel most of the reactional energy. The channel they sit in is acoustically small at frequencies it is operated at, so it acts just like a flat baffle acoustically.

dave

Wouldn't one of those drivers have to be reversed?

 

[planet10]

I would presume this method require drivers with unvented pole pieces?

Yes. If they had vented pole pieces, and you didn't want to just block them off (often a good idea sonically -- especially in an OB), then you'd need to add somesort of vented coupler (pushing the drivers a bit further apart). A good stiff piece of round pipe with holes drilled in it and loaded with stuffing would do the job.

dave

 

[planet10]

Wouldn't one of those drivers have to be reversed?

No.

If you mechanically reversed one (and its electrical connection), you would get push-pull benefits at the expense of poorer mechanical coupling. If you electrically reverse one driver then they acoustically cancel and you get no output.

dave