Port Side Compartment Sub installation????

[cbaarestad]

I've been pondering this upgrade all summer, but has anyone out there put their sub in the port side under-dash compartment? I think this would be the best place to keep it out of the elements and easiest to wire up! I'm wanting to stick a 12in kicker in there but usual boxe sizes will be difficult due to the fiberglass molding from the dash tray itself. Any suggestions???? I really don't want to place the sub under the steering colum because I don't really want to take the brunt of it. Any help would be very much appreciated since I've never done an audio upgrade before!!!! Thnks in advance!

[kaneboats]

I put one in there in a sealed box on my outback. It was a bit muffled but when just floating we would open the seat back on the observers seat. I probably wouldn't do it again.

[bergermaister]

Muffled is the consensus I've heard as well (on many different boats) unless you have it opened or well vented somehow. I debated on adding a second 12 up in there to match the 12 under my helm on the other side but decided against giving up that much storage space. Especially if the additional output isn't all that great.

[ian ashton]

I have one in there, and another under the drivers side. I had the single observer compartment sub for a season and a half before I added the second under the dash, and I found that if I pop up one of the bow cushions or the observer seat it gets quite a bit louder, but I wouldn't describe the sounds as muffled, just quieter, still of good quality. I know someone was trying to get the chrome heater vents from Heatercraft to put on that side as a sort of sub vent, that would match the opposite side heater vents, not sure what came of it though.

[cbaarestad]

My personal prefference to a definate bass sound isn't necessarily loud but a definate sound unlike the muffled/scratchy wanna-be sound speakers throw out! If that explains what i enjoy! Is it difficult to mount the amp on the walls of that compartment? is there any wood under there to fix it to or is it all fiberglass which would make it alot tougher of an install....

[mmandley]

My personal prefference to a definate bass sound isn't necessarily loud but a definate sound unlike the muffled/scratchy wanna-be sound speakers throw out! If that explains what i enjoy! Is it difficult to mount the amp on the walls of that compartment? is there any wood under there to fix it to or is it all fiberglass which would make it alot tougher of an install....

Theres always the option of the older style Bandpass box. These have there own air and only need the vent tube it will require less air space but does take up a lot more physical space. Other wise look into a completly sealed bass box that requires very little air space to operate in.

[EarmarkMarine]

The enclosed port locker is going to have the same subwoofer characteristics whether its a Moomba or a Malibu.
You can get reasonable output although it is attenuated with the observer's seat closed. I don't like it because:
a) in measurable output terms you can easily lose 6 dB. That doesn't sound like alot but it will take four times the amplifier power and alot of current consumption from your charging system to make up for that loss.
b) the subwoofer and amplifier have to work much harder for the same output which can translate to increased thermal issues and eventual problems with product reliability. Its harder to hear clipping from within an enclosed locker.
c) but here is the part I really don't like. You can get plenty of bass rumble from this location but its very indiscriminant sounding bass. No tonal construction, poor midbass airticulation and little to no transient response. The quick attack is just gone. In two words..." not musical".
You can remedy alot of this by installing a large vent in the pass-through surface that is equal to the radiating surface area of the woofer.
Also, mmandley suggested a bandpass box which is a very good idea. You can run some of the port of a single-reflex bandpass external to the enclosure and exit the port in the pass-through wall. The port can completely seal up against the exterior of the locker which will nullifiy all compartment losses. The right design can retard water from entering the port and getting to the inside of the enclosure.
A bandpass enclosure, when designed correctly and well-damped, can sound very good. Plus a conservatively designed bandpass can produce 6 dB more output over a sealed enclosure. That's four times power! Now, contrast this with a 6 dB loss from within the locker. A 12 dB differential. A 1 to 16 power ratio. The sub that sounds the best is almost always the one that is run the most under capacity to produce equal output. The bandpass in this application definitely qualifies.

David
Earmark Marine

[cbaarestad]

Wow, that was a lot of information that I personally didn't know about or consider..... This is exactly why I figured I consult the geniuses! Anyways, I'm guessing my best bet would be to go with a bandpass style enclosure if I continue with installing it in the port compartment? Would it be best to attempt to make one to fit or hope to the big guy upstairs I can locate one online? Thanks again for all the help!

[mmandley]

if your skilled in building the boxes and with measurments then you can build one. The issue with a Bandpass is the port is a very specific size and depth in the box to tune it correctly. I do not know how porting exactly works. I do know i ran a Bandpass box for a long time in my cars and it would blow people away when they realized how little amp i was really running.

[EarmarkMarine]

cb,
You don't want to buy an off-the-shelf bandpass enclosure because it will be a standard automotive box that won't last in a boat, it will likely be a universal box which isn't a good match with a specific woofer and because most bandpass boxes are like off-the-shelf bass-reflex boxes in that they are tuned for maximum and peak output only. They will hammer but only as an undamped, narrow, single note instrument. Very similar to bass-reflex, the quality can be all over the map depending on the design priorities. A musically accurate bandpass, which can be absolutely outstanding, will have to be designed for the Thiele Small parameters of a specific woofer and the design is seriously complex requiring computer program assistance. Plus, it will be an exercise from a design and execution standpoint to perfectly mate the enclosure and port against the external compartment vent. If you don't have the tolerance for this then its easiest to go with a custom sealed enclosure or perhaps a custom bass-reflex enclosure. In any case you will need to add a vent into the pass-through area.

David
Earmark Marine