Subwoofer size and location

[4wheeldeal]

Guy doesn't even know the basics, like how to correctly calculate Sd. So much misinformation. So sad.

Do you have some information you can post up on how to correctly calculate them?

 

[David Analog]

Do you have some information you can post up on how to correctly calculate them?

Sure, for the 'Sd' (radiating surface area) you start with the speaker diameter which is the center peak of the surround to the center peak of the surround....and not the cone edge to cone edge.
Then the surface area is (radius X radius) X Pi (3.14).

But then that covers just one issue when the entire T-Line tutorial is garbage information.
Of course the port output can only be in-phase and spiked at one frequency and is entirely out-of-phase at some other frequencies.
A total distortion machine. Sacrificing speaker surface area for massive tube/port displacement. Seriously confused.
Equally as sophisticated as a Bose table radio T-Line....which I really like....but then again it's not a subwoofer. It's a table radio! When Bose does transition to an actual subwoofer they use a bandpass or a bass-reflex enclosure in order to maximize the efficiency of available cabinet displacement. Same with every other commercially available subwoofer from a respected brand.
T-Lines do work beautifully but not the Frankenstein concoctions you've referenced.

 

[Speedling]

Ok, through this thread there has been mention of 15" subs.
Where do you gind a 15" marine sub or are you guys not going marine?

If i get this clarion marine amp, it can be 4,3, or 2 channels. If using 2 channels it can go 2 ohm ot it can bridge 2 channels for a sub.
Bridged it is 320 watt rms. Thats good punch for a good sub.
I would use the other 2 channels and power my 4 tower speakers to get a 2 ohm load each channel.
Problem is finding a sub to take 320 rms watts.
Unless of course i am thinking it all wrong.
Link to amp:
http://www.clarion.com/us/en/products/2012/marine/amplifiers/XN3410/us-en-product-sc_1259559425193.html

 

[David Analog]

Ok, through this thread there has been mention of 15" subs.
Where do you gind a 15" marine sub or are you guys not going marine?

If i get this clarion marine amp, it can be 4,3, or 2 channels. If using 2 channels it can go 2 ohm ot it can bridge 2 channels for a sub.
Bridged it is 320 watt rms. Thats good punch for a good sub.
I would use the other 2 channels and power my 4 tower speakers to get a 2 ohm load each channel.
Problem is finding a sub to take 320 rms watts.
Unless of course i am thinking it all wrong.
Link to amp:
http://www.clarion.com/us/en/products/2012/marine/amplifiers/XN3410/us-en-product-sc_1259559425193.html

Wetsounds will soon be coming with a true, fully marinized 15-inch subwoofer. It has to be marine in coastal applications, but unlike an IB sub, a marine product isn't mandatory for a fresh water boat when the sub driver is shielded from UV and receives some protection from the enclosure. In any case, I would avoid pulp/paper/hybrid cone subwoofers in a boat. JL Audio has an economical WO 15" that will work well with 300 to 500 watts.
There are two primary reasons for a subwoofer to handle more power. First, would be to handle abuse, and in this case performance compromises become a trade-off for additional power handling. Second, while greater surface area is the most efficient way to produce more output, the other method is with more excursion, and more excursion requires an inordinate increase in amplifier power. So there is nothing wrong with a subwoofer of less power handling that has higher sensitivity. It's simply a matter of correctly pairing your gear to your application.