its time for stereo work in my boat and i have been looking around on here and it seems like the best option is to build a box under the rear bench seat and have the subs firing downwards.... any opionions on this? should i be doing this sealed? i am kinda thinking that but you go to the stereo shops and they have ported boes just sitting out on the floor that are noticeably louder then a sealed box... i have been doing car audio for almost 15 years, did some comps but nothing major, the marine world is a new ball game since you dont have a trunk to reflect the sound off of which is why i am asking. the plan as of right now is looking like doing 4 kenwood kfc-w2511 10s which are nothing too crazy, i have one here which is why i am looking at them, i an get them for 45 each shipped so 135 bucks and i have 4 of them, sealed box firing down..... another question, how far off the floor should i be going? i am thinking 4" or so, maybe 6? 6 almost seems like too much? i think i am use a older crossfire 1000d which should be more then these subs should ever need, gonna have to turn the gain down some. anyone have any input? i am trying not to spend a bunch but if there is a better option? i dont want too insane but i also want something that is gonna turn heads a little. i was gonna to some kicker L7s or jl w6s but i dont want something that desirable in there for the effers with sticky fingers if that makes any sense.

on another note where are most people mounting their amps? i am thinking cuddy cabin under the seat and i can have the seat pulled up when using the system for good ventalation.

I have 3 JL 10's under my back seat, firing forward, free air, and they are very loud. Im not an expert, but have heard that a ported box in a boat isnt worth the effort because the space isnt enclosed like a car. A sealed box will always sound better in my opinion but I didnt do it because it would take a bit of work to turn the seat box into a good solid, sealed enclosure, and it would have to be completely sealed(difficult with wires, battery switches already there etc). Plus didnt want to lose my already limited storage space. I am happy with the sound I have, and get lots of compliments. They arent quite as tight sounding as a sealed box but plenty good enough for a boat.

i agree with hotjava.. I have 4 jl 10inch free-airs running off of one 750/1. run at 4 ohms they are wild.. perhaps not as "tight" as a sealed box (although I hear ported on a boat is the way to go) they sound great never the less. no box means more space.. my 2cents.

I have done several boat systems. It comes down to a series of comprimises. The best you can hope for is good sound quality working within the space confinements. For most people I think free-air hidden subs make sense. I run a sealed box setup in my Corvette and it kicks good. Now with the boat I run two Boston G5 12s in a ported box with 1000+ watts in the cuddy and it beats your chest. The comprimise is that it takes up cuddy space.
So its a trade off between space, having it hidden, type of music and quality of sound. If all-out bass is your thing, ported box in a cuddy for sure. If not free-air subs are good.
Also try not to have speakers face each other, and aim the staging at the listener. This is very important in a boat.

I have 2 Alpine 10" Free airs and they are plenty adequate. If I wanted better sound, I would have had go to sealed boxes and I did not want to use that much space.