quest for low bass

[jonjon wompwomp]

besides the box, what is the determining factor/s for how low a subwoofer can play and still be
loud and clear? is it something mechanical, i.e. the coil size/lenght, motor force, cone area... or is it simply a combination of some or all of the above?

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[hispls 5,000+ posts]

besides the box, what is the determining factor/s for how low a subwoofer can play and still be
loud and clear? is it something mechanical, i.e. the coil size/lenght, motor force, cone area... or is it simply a combination of some or all of the above?

Mostly box but to some degree mechanical limits can be a limiting factor. Keep in mind that everything that allows for higher excursion will sacrifice efficiency and after a certain point will gain you very little in potential for more output.

 

[audioholic 5,000+ posts]

In a sealed enclosure or IB, linear excursion will be a limiting factor. In vented enclosures, excursion is minimized at or near tuning where the enclosure is it's most efficient, so thermal limits become more of a factor. But generally speaking, the enclosure itself, and the characteristics of the vehicle (like its transfer function) will be the biggest factors in perceived performance.

 

[jonjon wompwomp]

Kinda what I come up with as well. I figured the mechanical limits effect power handling more so than bandwidth... My inquiry stems from my experience with my new sundown 18" U series subwoofer. I am having trouble hitting that sweet spot of 28 to 32 Hz. Ive owned the D series, SA series, and the Z series... All of which seem to love those frequencies. I was thinking it was just the design of the driver with that steep surround and all. I have it in a 3.94 ft3 aero port box with a 6"single port at 28 in2 of port area. As it stands with displacement the enclosure is tuned to 30 Hz
I dont get it...

 

[shredder2]

sundown 18" U series I have it in a 3.94 ft3 aero port box with a 6"single port at 28 in2 of port area.
I dont get it...

single 6" aero?.. for an 18?

Id redesign and try an 8" aero next time... thats a hi-excursion sub and if you power it right it'll def hit port compression WAY too soon with a 6" imo.
My 30mm xmax 18 in 5.25ft3 or so uses a 10" and gets down tuned 34. (around 26"long)

In 4 cubes a 8" is about right for your application if you ask me.

 

[jonjon wompwomp]

Thanks for the good info... I think im gonna give it a try..