school me on 6.5" subs
 

After re-arranging battery banks and testing out the boat stereo for the first time this year, i quickly found that one of my subwoofers took a crap over the winter which is causing me to re-evaluate my entire sub game.

I have/had two Boston 10" G3 subs with a 1200.1 class D amp.

I have a small amount of space for subs in a Calabria with under floor hard tanks and a short freeboard.

Two questions:
1. has anyone had any experience with 6.5" subwoofers JL/Wet Sounds? Pros/cons?
2. with my limited space I'm thinking of going with one of the following:
a) four 6.5" subs
b) three 8" subs
c) two 10" subs

Open to suggestions.

Thanks!

The 8's I've ran in the past only required .5 cu ft per woofer porter so 1.5 for 3 vs around 2 cu ft for 2 10's ported. So that would help in tight spaces.

The only thing I really remember with subs as i'm not a huge audiophile would be that the bigger the diameter of the sub the deeper the base it can produce. I would think 2-10's would be a heck of a lot louder than 4-6's.

With engines, theres no replacement for displacement. Same with woofers, surface area rules. Going smaller reduces surface are. To gain that back, you have to add more subs. Also, smaller subs dont dig as deep as larger subs. So no number of 6.5" will ever deliver the bass extension of a larger woofer. Next issue is multiple subs. Where are or where would they be located? Why not a single 12" on your 1200/1 amp?

anything under 10" really isnt worth it. Id shoot for a 12" in a big ported box in the compartment under the pass side console. I have heard some single 12" systems sounds pretty damn impressive.

If you are willing to cut... the possibilities really start to open up...

I have a bass-reflex JL Audio 6.5" W3 at the base of each captain's chair in my RV. I'm also using time alignment between the subs and satellites. It's fairly impressive since each occupant is sitting on an individual subwoofer. I did this because a) I couldn't fit anything larger, and b) there was no way to boundary load in this vehicle.
If I had the option of running two 10-inch subs in an optimum position, I certainly would have gone that route instead.
2 X 10" is slightly more surface area then 6 X 6.5" and still more surface area than 3 X 8".

David,
Just shooting theory here, but won't you also have more motors therefore having higher power handling, and more piston force?
Figuring we are talking apples to apples power handling and coil size.
I know larger woofers can play lower but how low do we really need in boats?

I would bet 3 8's would be louder than 2 10's. 10's have slight cone area advantage but the 8's have the motor force and more power going to them. The 8's I had would get plenty low. Most thought I had 2 12's lol. But like you said in a boat you really don't need the lows 30 and below,

Certainly three of four tightly collected and beefy 6.5" with that motor to mass ratio would be incredibly responsive with some amazing attack. I would think this would be even more impressive in a small vehicle cab combined with the cabin effect.
In an open air boat? I still would favor the easy efficiency of a couple of 10" subs. You cannot make up that efficiency difference with a 3 (6.5") to 1 (10") ratio, let alone a 2 to 1 ratio.
35 Hz is nearly impossible to reproduce in an open boat with any degree of significant output at any distance away from the sub. But getting down to 50 Hz is important and a 10" sub can do that without a discernible loss, where a 6.5" cannot....at least not at high output levels.

Small 6.5" and 8" usually need to have slightly larger motors to be relevant in sensitivity. But large motors and larger motor force generally means a higher Q and a higher resonance. The narrow baskets of 6.5" and 8" also means smaller spiders (even a smaller spider radius with a big diameter VC) and less linear excursion. Just hard to make up for that easy displacement of the larger subs...IN A BOAT.

How about a over sized 8 with a 7.5" spider and 2.5" coil?

Yes. After the one 10" went out this is what i did >

Currently running one 10" Boston g310 in a 1.3ft^3 ported box which barely fits under the passenger storage. All 1200.1 is going to it.

Overall- the subwoofer is poor quality and is time to upgrade thus my original question.

Sounds like the 6.5" are out. Next is to decide:
three 8's
two 10's (one under helm & one in passenger storage)
one 12 (must be sealed box for size. Either under helm or in passenger storage)

- JL w3
- Sundown SA series
- Kicker L7

so many options... :)

I'm running Sundown ZV3 12 in a 1.5 ft ported enclosure and it pounds pretty good. The SA and ZV3 require very little enclosures. I would not run one of them in a sealed enclosure though.

The wetsounds XXX also works good in a small enclosure. 1.5 or so.

Why not a single 10W7 in the ported box you already have? Plug and play and should pound with 1200 watts to it. Ideally you'd have 1.5cuft, but 1.3 should still do the trick quite well. You can always add a little poly to make the sub think it's in more airspace if you needed to.

The two 10-inch option should be out because you do not want to split sub locations unless they are perfectly symmetrical in all aspects....same loading, same depth, same orientation, etc. Terrible to have one starboard sub direct-radiating and one port sub vented out of a compartment. It's generally hard to do properly without some custom alterations to the boat structure.

Any single sub with a 2.5" voice coil is going to have trouble with an honest 1200 watts. You need a 3.0" voice coil in a single sub, or two subs with 2.5" coils, or three subs with 2.0" coils (it may be a little harder to optimize the impedance for the amplifier with three subs and net less than the 1200 available watts). Which amplifier and how accurate is that 1200 watts?