Why 10", 12", 15" and 18" inch subs? (1 Viewer)

[Stephen Bort]

Just curious...why doesn't anyone ever boast a 13.5" inch sub, or a 16.5"? Or 19"

Is there something about the physics of a speaker which makes these sizes impossible? Or are companies just rounding up and down?

 

[Tyson Wetzel]

It's more to do with the manufacturers of the stamped steel frames and other parts that go in the subs, there are "odd" sized subs, but they are inherently more expensive because they are built from the ground up, including the tooling to build them. One example from the mobile audio world is JL Audio's 13W7 which is a 13.5" driver costing roughtly $1,000 for the driver alone.

 

[Kenneth Harden]

No, there are all possible sizes. 14" is popular with JBL (hi-end and pro), some companies have 11, 16" woofers.

The sizes like 10, 12, 15, and 18" are just popular, but nothing is limiting them to that.

Look at these:

http://www.partsexpress.com/webpage....WebPage_ID=153

 

[Robert Cowan]

i think a lot of it has to do with surface areas.

a 10" is roughly 78 in2, a 12" is 113 (roughly 50% gain), a 15" is 176 (another 50% more). and of course, the big daddy, and 18", is 254 inches squared, another 50% increase.

they are all about a 50% increase from eachother really... that is of course starting from a 10" driver.

 

[StephenHa]

marketing has a ton to do with it it's easier to put 12 12's in a box than 2 13's (figure a 2 foot space)

 

[MikeKaz]

I got yer 13.5" right here

http://www.jlaudio.com/subwoofers/13w7.html

 

[Stephen Bort]

Thanks, guys, live and learn. I guess it once again comes down mostly to economics.

Now, why are there only 5 guages of shotgun shells...10, 12, 16, 20, and 410?

 

[Tim Stumpf]

How many licks does it take to get to the tootsie roll center of a tootsie pop? The world may never know.

 

[Tyson Wetzel]

ha ha

 

[frank manrique]

Don't forget that Hartley used to make a 24" bass driver...while Electro Voice (EV) manufactured a 30" monster infrabass transducer (don't know what ever happened to that company; does any one else knows?).
That 30" bass driver was the grand-daddy of them all...

-THTS

"...hi, my name is Frank...and am an SVS bassaholic..."

 

[ChrisBee]

The sizes used are probably just historical inertia. They started out from the early radio industry using imperial (inch) units. There is probably little pressure to change.

Though roll surrounds later replaced corrugated paper. The actual piston diameters don't seem to have changed much (at a glance). Though the centre dome (originally a simple dust cap) seems to have grown and is now often inverted.

It should not be forgotten that there are many oval, elliptical and oddly shaped units around. The KEF B139 was a rectangular oddity as an earlier bass-specialist driver.

ChrisBee

 

[John F. Palacio]

Hi, Frank.

I believe they are still making PA speakers. At least they were about two years ago. I recently saw a DJ with Electro Voice speakers.

BTW where do you put (8) 16-46 CS's?

 

[frank manrique]

quote:

"It should not be forgotten that there are many oval, elliptical and oddly shaped units around. The KEF B139 was a rectangular oddity as an earlier bass-specialist driver."

Ah, yes...the famous KEF B139 bass drivers...I used two of those to build my first pair of sub(not!)woofers to augment the lower end of a pair of Rogers LS3-5A mini-monitors (15 ohms version; I still have them puppies). Back then I had a John Curl-designed electronic crossover; I used it to bi-amp those two transducing systems (what a beautiful piece of electronic engineering! I wish I would have kept it :frowning: ).

That "DIY" adventure was even featured in the back pages of an issue of the once famous Audio Amateur journal (I had a few of those DIY adventures through the years...like the building of Prof. Marshall Leach's "Low TIM" power amp and preamp projects--designs taken from late 70s articles that appeared in issues of Audio magazine, which were built from the ground up with a minimal knowledge of electronics!--as well as the construction of the original Joe D'Appolito "MTM" monitors, a design taken from the long defunct Speaker Builder journal).
I still have the 2 cu. Ft. boxes (they presently contain some old Speaker Labs [!] 10" bass drivers--don't use them woofers anymore--drivers that replaced the KEF B139s since they were sold long ago)...as well as the D'Appolito monitors; the latter are being used as the center channel speakers in the "big" HT system...for the time being...

-THTS

"...hi, my name is Frank...and am an SVS bassaholic..."

 

[frank manrique]

quote:


Hi, Frank.

"I believe they are still making PA speakers. At least they were about two years ago. I recently saw a DJ with Electro Voice speakers.

BTW where do you put (8) 16-46 CS's?"

John,

Thanks for the heads up!

As to the 16-46 CS subs...well, they're sort of bunched up in one corner of the HT room, behind the 12 foot wide "scope" ratioed screen.
Look for pics of that particular set up (subject to change!) which I hope to post in Robb's Webpage soon...

-THTS

"...hi, my name is Frank...and am an SVS bassaholic..."