[Angaria]

In a quest to work out a "slim" OB design, I was wondering putting one of the 10" Hawthorne coaxial drivers firing forward in a baffle that twists like a DNA helix so that the bass is @ 90 degrees to the top where the 10" is.  This is where the 15" driver (potentially their Auggie if that works with the 10") would be installed.  Obviously, this design only makes sense for this purpose if you have two different sized drivers.

I was envisioning (possibly in correctly) that just as a subwoofer's orientation doesn't matter, so too the bass driver could point wherever.

Is this a bad idea?

[JimJ]

Unlike true subbass, once you get above 100Hz or so you'll be able to localize where the sound is coming from...so while 300Hz and down might not be as easily localizable as say, off-axis midrange, you still might have some phase and imaging issues to work with.

I'd probably run the Silver Iris and the Augie on the same plane just to be safe.

[Russell Dawkins]

Orienting the bass drivers sideways would be a great idea if you didn't like bass, because if you were edge-on to the bass driver you would be in the null area where the front and back cancel. If you aimed it very carefully, you would hear almost nothing from the bass driver!

Sorry, slim appearance is basically not possible for OB bass due to the inherent radiation pattern.

[JohninCR]

Is this a bad idea?

Yes absolutely.  Unlike boxed speakers (monopoles) the bass from OB's is highly directional because at the sides of the baffle is where you have the greatest cancellation.  Think in terms of travel distance for the front and rear waves, and where they travel the same distance, they effectively cancel completely.  It has nothing to do with the perceptive directionality of low frequencies. 

There are alignments that allow the narrow front you desire by forcing the rear wave to the back of the unit and the front wave forward before they clear the baffle to expand on their own.  The most compact form was coined with the term "ripole".  This is a baffle shaped like a squared off "N" with the driver mounted on the center line.  The rear wave is forced out of the back, and the front wave out of the front.  The point of equal travel distance is at the sides, just like a flat baffle, so they enjoy normal dipole radiation.  For more info check out a thread called "honey I shrunk the dipoles" over at the DIYAudio forum.

[9anda1f]

Angaria,

Is this the shape you were talking about?



9anda1f