Sub Location

[Merlino13 0]

Hi all. First time question poster, long time reader... Question is, I'm struggling with finding the correct Sub application / combination in my boat. Everything sounds great except the sub. It's loud and goes deep, but just sounds muddy and boomy not all the time, but most of the time. Current set up is an Alpine MRP M1000 amp pushing a Rockford Fosgate 12" P3 Sub in a ported 13"X16"X18" pre-built box. My boat is a 2000 Elite V with the famous footrest under the helm, and fiberglass box that the driver seat sits on. Awesome combination when trying to stuff a box under the helm... See attached picture of current set up.

 

My question is, should I go non-ported, fire the sub at the hull, build a custom box, or ??? What have others done that sounds great in a similar boat?

 

I would appreciate any and all suggestions

[Wylie_Tunes 146]

Pre-built box as in a car audio uncoated carpet covered raw MDF? If so, it could be water soaked and swollen. This will certainly make one sound muddy and unresponsive. Next would be the amp settings, especially the subsonic and cross-over points. This is assuming that the enclosure is tuned correctly for that woofers T/S parameters.

[Merlino13 0]

Yes, it is a car audio uncoated box. Not the best choice I guess... I did put it on rails to keep it off the deck, but who knows, still might have gotten wet. Assuming I'm going to replace the box, (right T/S parameters) would you go ported? I have heard ported does make it louder, but lacks the tight punch. Good point on the amp settings. I'll climb in and double check them also.

 

Thanks for the reply Wylie!!

[Wylie_Tunes 146]

Ok, looking at the sub's T/S, its better suited for a sealed enclosure. So if the current enclosure is suspect, toss it and go with a new custom enclosure.

 

Under the helm is ideal, and radiating directly into the main cabin is perfect.

 

The other thing that jumps out at me, I dont see that the amp has a subsonic filter. This make setting up and tuning a ported setup, tough.

[truekaotik 458]

P3 is a sealed subwoofer application.. Change sub and box..

[Merlino13 0]

Thanks for the comment truekaotik. Is it a general rule to use ported/open boxes in boats, or is it a matter of taste?

[truekaotik 458]

Taste in my opinion. A sealed enclosure provides and easier application and tuning. Plus can be driven harder and sounds well rounded in sound, inside the cockpit... A ported enclosure is a bit more complex to make and tune, you have many variables that can change the sound easy, best example is port location. It requires a larger enclosure than sealed, easier to drive and gives a 3db increase in audible volume though when done right. It will give a louder sound inside the boat or sound boomy..

[Wylie_Tunes 146]

Why change woofer and enclosure? D4 sub wired in parallel is a 2 ohm, amp delivers 1000W rms @ 2 ohm and the P3 looks to have a 600W rms/1200W peak. That part looks like a match made in heaven. I think the weak link is poor box design as its a universal ported 12" enclosure with a sub that leans to the sealed side. Re-tune the amp, and roll with it. Just curious.

[truekaotik 458]

If he would like ported and a better sound, he may as well replace the woofer when he replaces the enclosure (per your first suggestion). Right now it will take some proffessional tuning or a Nice college try to make it just OK... His choice by all means..... A ported enclosure on a P3 doesn't give enough back pressure and fatigues easy. That's all, it can be done though for sure..

Edited May 28, 2014 by truekaotik

[Wylie_Tunes 146]

10-4, that makes sense if he wanted to retain a ported setup.

[Merlino13 0]

So as I see it, I keep the P3, toss the existing box and pick up a sealed box which will be a tighter but softer sound, or... Scrap both and get a 12" sub suited for use in a ported box and get louder and possibly better sound. Pretty sure the ported choice will require a custom built box to fit under the helm though. Overall the Alpine MRP M1000 is well suited either way.

 

Am I reading this right?

 

Last question, If I decide to go ported, any suggestions on a moderately priced sub?

 

Sincerely appreciate the two of you weighing in.

[Wylie_Tunes 146]

Sealed enclosure = Big Mac

 

Ported enclosure = Whopper

 

Take your pic which one tastes, or sounds better as they most definitely sound different. What I can say is, a properly executed ported enclosure will yield more output, about 3 db, compared to the same size woofer with same excursion, in a sealed enclosure with the same wattage.

 

Sealed is easier to build and requires less gross dimensions. A ported requires more detail and larger gross dimensions. Although there are some woofers that will fall in the middle for either type of enclosure, the woofer does need to be taken into account for the best overall sound quality. Personally, I'm partial to a sealed setup thats on the large side of the recommended volume. Not as peaky as a sealed on the smaller side.

 

IMHO, you have a perfectly good wood woofer and amp combo. I would not hesitate to just build a good sealed enclosure for that woofer, re tune the amp and enjoy the summer.

[truekaotik 458]

That would be my choice if I didn't really know what to do^^^ . Tackle the ported version over next winter if sealed doesn't suit your wants... I also go larger on a lot of my builds but I have done hundreds of different set ups and heard the difference in box sizing...

[Merlino13 0]

Thanks guys!! Again, another sound solution to what was thought by me to be a difficult decision... I'm going with the sealed version as suggested for this Summer. Rockford suggests a 14"X18"X10" sealed enclosure for the P3. When you say "I also go larger on a lot of my builds but I have done hundreds of different set ups and heard the difference in box sizing... " How much bigger is advisable / tolerable?

 

Thanks again!!

[Wylie_Tunes 146]

14 x 18 x 10 is just a hair over 1 ft3. I would gather that is using .75" material and factors out the woofers volume. For a sealed enclosure, the actual wall dimensions are irrelevant, its the net internal volume that counts. So as long as there is about 1.5" air space between the back of the woofer and back wall, and the enclosure does not have a bunch of crazy appendages, make the enclosure to fit the boat, with a target volume of 1.2 ft3.

[Merlino13 0]

Thanks for all your help! Off to find an enclosure.