Free-air sub for our boat.

I am getting close to having everything for our install that hopefully will be done this week.

Right now, the system consists of the following.

6 Pold DB651 speakers in the boat powered by a JL Audio 600/6

4 Polk DB-651 on the tower and 2 Kicker KMT6 on the tower powered by a JL Audio HD 600/4

The HU is a Pioneer DEH-P5000

I already have an Alpine PDX M600 to power the sub(s).

Originally I was going to go with a couple of Kicker SKM10 as I can get them off of ebay for about $165 each. But, they would be mounted in enclosed storage compartments and that concerns me. I'm afraid it will baffle too much of the sound since there is not an opening and for the sound to get out.

I didn't want to cut more holes in the boat, but I am starting to lean that direction.

From an amp standpoint, if I needed to I would not be too opposed to buying another M6 or an M12.

At my disposal, I also have a Kicker KX 850.4 or a Kicker KX 650.4.

I am not 100% opposed to building a box to fit, but I would really rather not.

We listen mostly to country and rock, some rap, some R&B, etc.

I would appreciate any help or guidance. I know there are a lot of varying opinions and I am not really knowledgeable on subs. Budget is a consideration, but I have spent about $1500 already so what's another couple hundred.

Sealed box FTW. Free air subs blow IMO

With 600 watts rms, I would recommend a good 12" and sealed enclosure. IF, going the "free-air" route is better for your particular install, then I would recommend the Wet Sounds XS-10FA or the Kicker Comp Vr-10. There are others i'm sure, but these are two that I have had great results from.

I agree, last fall I spent WAY too much time trying to get a free air Alpine sub to work. Finally gave up and bought a XS12 Wetsounds and built a box for it.

I would bet one XS12 will it harder than 2 SKM10 and I know it would cost less. The XS12 only takes .9 cu ft in a sealed enclosure. And, 1.4 in a ported box.

I used 3/4" MDF board and sealed it with EPOXY resin (not polyester).

I tried both a sealed and ported box. I ended up using the ported box but the sealed box worked very well and they are more simple to build.

Thanks guys. I guess I have some thinking to do. The free air is a way simpler given the layout of our boat and the storage space. I guess I could build a box an try it fully enclosed which is what I would prefer to do. If I don't like it, as long as I build the box so it would work mounted to the other placer I would put it I should be fine.

Took some measurements and did some looking around for places to put a sub. I'm trying to accomplish many things. Not take up too much storage space, not cut holes in the boat (if possible) and still get decent bass that sounds good. I'll cut a hole if I need to, but I would prefer to not go through the pain.

On the drivers side, there is an access panel that gives access to the rear of the dash. The cut out is 20" wide by 7" tall and the plate is removable. If I remove that panel, it will provide an opening from the storage compartment to under the dash. On both sides, in the storage comparment there is a cavity that goes in between the hull and the liner. there are openings in the side that would allow sound out, I just don't know if it is enough to make it work.

In the end, I guess I need to broaden out my question. What kind of set up should I be looking at?

Originally Posted by Silverbullet555

Took some measurements and did some looking around for places to put a sub. I'm trying to accomplish many things. Not take up too much storage space, not cut holes in the boat (if possible) and still get decent bass that sounds good. I'll cut a hole if I need to, but I would prefer to not go through the pain.

On the drivers side, there is an access panel that gives access to the rear of the dash. The cut out is 20" wide by 7" tall and the plate is removable. If I remove that panel, it will provide an opening from the storage compartment to under the dash. On both sides, in the storage comparment there is a cavity that goes in between the hull and the liner. there are openings in the side that would allow sound out, I just don't know if it is enough to make it work.

In the end, I guess I need to broaden out my question. What kind of set up should I be looking at?

Sounds like you have a real conundrum. You will have to cut a hole in order to install a free-air sub, and if cutting a hole is out of the question, then a box will be needed and it will take up some space, some where.

A this point, I am looking at cutting the hole and building a box. I did the math and I can make a shallow box that is taller and wider to ensure the right volume. It will actually work well with the install and I am ok with the loss in space as it will be minimal. The final question comes as either 1 12 or 2 10's. I can fit 1 12 in the passenger console or 1 10 in each of the drivers side and passenger side console.

Talked to Tim and got some good ideas. Going with 2 XS-10 installed in the same plane. One on the passenger side and one on the drivers side. That will be mounted a little on the inboard side so they have a clearer shot to the bakc of the boat. The drivers side has to be mounted this way since there is a fire extinguisher on the drivers side and I want them to be in the same spot in the console.

The box will be between 1 and 1.2 cuft based on input from Tim and I will power them with the PDX-M6. I am going with the 4 ohm version so they can be wired at 2 ohms dow the road in the event I switch amps later.

I will wire each one as an 8 ohm sub then run them in parallel to drop it back to 4 ohms.