Should I move my sub?

[Chatty21VLX]

Right now I have a 12" sub in a sealed box in the observer's compartment. I was thinking of moving to a free air sub in the kick panel under the helm. What would be the pros and cons of this? Do free air subs require more power? My sub is powered by the sub channel on a JL M700.5 and I wouldn't want to be changing amps at this time.

[David]

Moving the subwoofer location from the enclosed observers compartment to under the open helm would be a great choice, even if you had to downsize from a 12" to a 10"(as an example). The sound quality will be much improved for a variety of reasons.

However, a free-air subwoofer would be completely wrong for this particular boat. "Free-air" denotes infinite-air, as in an infinite baffle, but still requires a complete enclosure to provide full front to rear acoustic isolation. So you still need an enclosure, although it would be a huge enclosure. An IB subwoofer is best applied when a boat compartment provides the enclosure. The kick panel is a very small baffle that offers little to no enclosure. 

You will still need a box on the starboard side.       

[Chatty21VLX]

32 minutes ago, David said:

Moving the subwoofer location from the enclosed observers compartment to under the open helm would be a great choice, even if you had to downsize from a 12" to a 10"(as an example). The sound quality will be much improved for a variety of reasons.

However, a free-air subwoofer would be completely wrong for this particular boat. "Free-air" denotes infinite-air, as in an infinite baffle, but still requires a complete enclosure to provide full front to rear acoustic isolation. So you still need an enclosure, although it would be a huge enclosure. An IB subwoofer is best applied when a boat compartment provides the enclosure. The kick panel is a very small baffle that offers little to no enclosure. 

You will still need a box on the starboard side.       

So if I wanted to move it there I would have to have a box custom made with the kick panel?

[MLA]

Moving the woofer from the closed port locker is a great move. Well worth the effort. What woofer do you have now? For the best performance, you want a woofer thats designed for an infinite-baffle setup. Like the Wet Sounds Revo-12FA or the JL 12IB. Next, is the under helm wall a solid, continuous wall bottom to top, left to right? I have a feeling that is a false wall thats open at the top. if so, you will not want to try and do an IB woofer setup.  I think the best route is to retain the existing woofer and build a new enclosure for it that fits under the helm. 

[Chatty21VLX]

13 minutes ago, MLA said:

Moving the woofer from the closed port locker is a great move. Well worth the effort. What woofer do you have now? For the best performance, you want a woofer thats designed for an infinite-baffle setup. Like the Wet Sounds Revo-12FA or the JL 12IB. Next, is the under helm wall a solid, continuous wall bottom to top, left to right? I have a feeling that is a false wall thats open at the top. if so, you will not want to try and do an IB woofer setup.  I think the best route is to retain the existing woofer and build a new enclosure for it that fits under the helm. 

I have a Diamond 12" now. Can't remember the model #. 

The wall under the helm is not solid. There is a gap at the top. Behind the wall is my heater core/blower box so i would need to measure how much depth i have to work with. The sides go all the way across to the hull, but they're not sealed or anything. The carpet just butts up against the hull and side kick panel.

[David]

3 hours ago, Chatty21VLX said:

I have a Diamond 12" now. Can't remember the model #. 

The wall under the helm is not solid. There is a gap at the top. Behind the wall is my heater core/blower box so i would need to measure how much depth i have to work with. The sides go all the way across to the hull, but they're not sealed or anything. The carpet just butts up against the hull and side kick panel.

Start by matching the boat to a maximum enclosure. Box shape isn't especially critical until you design something extremely shallow, extremely elongated, or chopped up into too many appendages. Most 12" small-sealed-box woofers require an external displacement of around 1.85 cu.ft. Or, 1.05 external cu.ft. for a 10". Making a modest compromise, you can get away with about 10% less. With any more reduction than that, it is often better to downsize the woofer.  

[Chatty21VLX]

@David sorry for my ignorance, but I don't understand the 1st sentence of your last post.

[ahopkins22LSV]

For sure move it. I did last spring and it is so much nicer now, sounds wise and the tremendous amount of freed up storage space. Wish I would have just put it under the helm in the first place.