other subwoofer locations

[hunter61]

I have two MTX T6124 12" subs that i am trying to put in my 05 LSV.

Has anyone been able to get two 12" subs to fit under the driver's dash?

If I put one of the 12's under the port-side storage area, can you hear it, or does it just rattle everything in my glove box? Does mounting in this location require cutting a vent/port to the outside, or leaving the sealed box inside the storage area?

And now the biggest question, Has anyone tried to make a box out of the rear removable seat that covers the V-drive?

Thanks for all of your help with this. Any other suggestions are appreciated.

[KG's Supra24]

I have seen 2 12s under the driver.

Earmark puts subs in the rear facing seats of supras. The same principle could be applied to any seat, with the exception of where the cooler is. Just have to give up storage.

Does your moomba have the place where you can put a removable cooler? Someone on here made a real clean box for that area.

[EarmarkMarine]

I wish there were alot of other or better sub location options but its really hard to beat under the dash.
Subs that are far to the rear lose output to the driver when underway. An analogy might be that you can hear the exhaust of a boat directly in front of you while in motion better than you can hear your own exhaust.
The starboard rear observer's seat in a Supra has a good bit of height for a downfiring sub. Moombas' generally don't have as much seating console height to deal with. Plus, a downfiring sub in combination with a vented compartment tends to choke the output far more than one or the other. Add the adjoining gunnel cavities and there isn't alot of impetus for the bass radiation to exit the compartment even when its vented.
The storage compartments next to the engine compartment is a total waste since the rear bulkhead and engine hatch are designed to specifically block sound.
Using the port side storage locker behind the observer's seat is an option we use in other boat models when there isn't another alternative available. The locker is huge which is counterproductive. A large compartment equates to a more compliant air mass. So again, this doesn't create alot of impetus in getting the bass energy to exit the compartment. You will need a vent in the pass-through that is equal to at minimum the woofer surface area and hopefully the sum of the woofer and port in a bass-reflex enclosure. The larger the vent and smaller the compartment the greater the energy that gets radiated from the locker. Its tough with a huge locker and a small vent. This scenerio usually results in a boat shaker rather than a bass maker. It may rumble but you'll get little midbass transients or what I would call good tonal construction.
Multiple and dissimilar locations don't sum very effectively.
That brings us back to the dash most of the time in a towboat. The typical I/O is a horse of a different color as they're usually constructed with a different layout and seating console elevations.

David
Earmark Marine

[hunter61]

Thanks for the feedback. So, it sounds like I need to focus on the drivers dash location.

Any ideas, or better yet pictures, on how to properly fit 2 12's under there?

Thanks again.

[EarmarkMarine]

hunter67,
With two 12s side by side you'll need at least 26.5" of width across the bottom face of the enclosure. Add the fact that the box gets a little wider as you insert it into place at an angle. You really need to orient the subs in a symmetrical manner if you can. Either both side by side and direct radiating, both sidefiring with one into the exterior hull and one into the interior pass-thru surface or both downfiring side by side. In any sidefiring or downfiring scenerio you will want to have the woofers well removed from any plane (soul or side surface) that they are aiming at (by at least several inches). Never place one woofer behind the other in the context of an underdash installation. While I would resist this, you may have to cut out the face of the hump if you are committed to two twelves. You can shrink a sealed enclosure a little below its optimum displacement. This will raise the point of the bass roll-off and coincidentally introduces a bit of a peak in the upper bass. Too much of this narrow emphasis does not make for a good sounding sub. Packing the enclosure with polyester fiberfill will offset a bit of this reduction by making the enclosure appear to be larger but only to a point. If you shrink the enclosure more than 15 percent then a single 12 might do better in an optimum sized enclosure. Also keep in mind that a single bass-reflex 12 will approach the output of two sealed 12s. You will have to reconcile the load with your amplifier if you go from two subs to a single so that you don't lose power but this can often be worked out. Those are a few of the basic considerations. Good luck with this.

David
Earmark Marine

[moombadaze]

go for it, 2 15" subs and you should have the water dancing around Martha

[hunter61]

Thanks. I got the amps, second battery, and tower speakers mounted today, but still haven't fingured out the subs. I may have to use only one, but already have both, and would like to use them if I can make it work.

I would still like to see some pics of two 12" subs mounted under the dash if someone has done it. Thanks again.

Chuck