28Eliminator

I need help from all you boat stereo guys for my 28” Eliminator. Sorry for the long post.

I pulled the interior out of my cockpit and repaired some wiring issues and installed some LED lights. I decided to do some upgrades to the stereo system as my sub sound has never been very good. I have a Rockford 600.5 amp. The 4 channels (50rms) run 2 Ultra Linear 6.5 coaxial in the front, up above the cup holders, and 2 Audiobahn triaxial 6.5 under the rear seat facing forward. Under the bolsters in the front there were 2 – 10” Audiobahn subs (open air) mounted in the side cover panels, which operate on the 5th channel (100rms). They face towards each other under the seats. I am definitely underpowered for the rating of all of the speakers, but my mids and highs sound pretty good considering the power.

I don’t really want to have 3-4 batteries to support major power, but figured I would upgrade the subs and amp to get better low end sound. I bought 2 12” 4ohm DVC Kicker Comps, and built custom boxes to go behind the side panels in front of the fuel tanks. The sound was marginally better than the 10” subs, so a buddy loaned me a sub box with 2 RF 10” subs and RF350 amp. It sounded a little better, so then I hooked up my 12’s to that amp and it sounded about the same. So now I figure I just need more power and I bought a Soundstream TN1.1200 class D amp. It sounds a little better, but still not what I would expect as it just don’t have a low high power hit to it. They just sound weak and I only have my front coax’s hooked up and they overpower the subs. All the interior is out so that changes the dynamics of the interior, but now I’m thinking my boxes are not cutting it, I need to port them, or having them face each other is not going to work. Specs on boxes are ¾” MDF and 1.6 cu in.

The boxes are angle cut, to contour the outside of the boat and are about 6” deep on the bottom and 11” deep at the top, but they are wide and tall, so maybe that is why they don’t seem to be working so well. Not much clearence behind the sub and the back of the box. If I run on 1 speaker it sounds about the same as when both are connected. I need some ideas of what I can try the next time I go work on this thing. Should I try some foam/insulation in the box. On the front side of the boxes the panel is removable for access which is where the amp wires connect to the terminals. Should I try to cut some new panels there and add a port to them. The port would be behind the big open space in front of the boxes where the amps are at on the dash bulk head. There is a side cover panel there with the head unit mounted & storage vinyl pockets below that can allow sound from behind the panel itself, which is removable for access to the amps and box. Maybe I should put subs under the back seat, but the other subs and holes were located here already.
Thanks for any help or ideas. Rock

Wally

iTrader: (1)

its hard to get good bass in a boat since its all open. When i had my scarab i had 4 10's in the back seat powered by a 1000w amp...the bass was crazy inside the cockpit but step outside the boat and move 10' away and you cant even tell there is any.
The Rockford 600.5 from what i remember the sub channel was 200w @ 2ohms....ar e your subs 4ohm then wired in parralel? and hopefully you didnt swap the pos/ned leads on one of the subs.....then they would be canceling each other out when the bass hits. Only other thought i have is the box's for the subs are not built to the subs volume needs. Its amazing at how different a sub can sound if the volume of the box is too small or too big. You can measure the volume with packing peanuts to get a good idea of what your workign with...

28Eliminator

You might be right on the RF amp 200w, but now I step up to an amp that is around 900w at 12v and there is another marginal incease in sound! The 4ohm dvc subs are wired in parallel to make 1ohm. I will check all the wiring this weekend as I still need to figure out where I am mounting the amp and run the power to it. The min volume for the boxes is 1.25 for the speakers, so I think I am good there. But if I change to ported, the specs call for a min of 1.75, but I have to subtract the size of the port then so I would be undersized. I also wonder if I need a cross brace or brace on the back wall since it is about 20x23" panel and maybe it needs bracing to make it more rigid.

Wally

iTrader: (1)

The hard thing about trying to diagnose something over the net is not being able to see it first hand and hear it for yourself.....what may be not enough for you may bee just right or too much for the next guy......
If the box is a 3/4" MDF there shouldnt be enough flexing going on to knock the box out of whack...but if you are unsure about it you can install a threaded rod with nuts and washers through the center of the box between the two panels and stiffen it up.
Now when you say you are getting marginal increases....what do you expect out of the system....are you looking for bone shakin bass that makes your vission wobbly...or do you just want a good hard hit you can feel??

BIGBREW

I have my subs mounted up in the cuddy, gives them some air space to bounce off of, I have a 1200w rockford fosgate running 2x12" speakers and then I have another 500w rockford fosgate amp running my highs, wish you were in N.Y. There is a kid in my area that builds some sick boat stereos, you can hear them a mile away, think im going to have him go through mine in the spring and see what we can get it to do.

Nightlife1970

Ok here is what I need.

Model numbers of the amps and subs you are using. Basically if you give me all the model numbers of the equipment you are using will help.

Actual inside volume of the box.

I have three 12 Rockford P1 subs in my boat. They are in 1.25 Cu.Ft. boxes powerd by an Autoteck 99 amp. Total power is probably around 450 watts and they HIT. So you have something not right someplace.

28Eliminator

I agree I don't have something right. I am not looking for blow me away sound, but would like it to sound good inside the boat at least. By marginal, I mean it is not much louder and it don't sound good unless I am sitting on the floor. I would think if I am sitting on my motor without any interior, that even 1 of the subs with 900w would drownd out 2 6.5 coax speakers in the front of the cockpit, but it don't. I might even borrow a 12" sub box from someone to test with, as several boating buddies are using them. I think another test I will run is to hookup the new amp to the 10" Rockford sub box a friend loaned me to test with. I am going to work on this some this weekend, and am looking for other ideas to try. Checking battery power is another thing that I didn't check the last time I worked on it.

The sub amp is a Soundstream TN1.1200d, with 6ga power, running the kicker 12" comp dvc 10C12D4.
The 4 mid/high speakers are running off a RF 600.5 punch amp with 4ga power. I don't have the model # of the mids with me. The volume inside the boxes are right at 1.65 cf, and can check/verify that this weekend. I will check my camera to see if I have any pictures worth posting that might help give a visual.

Powerquest230

I think two of your comments are the answer of what is wrong.
" but now I’m thinking my boxes are not cutting it, I need to port them, or having them face each other is not going to work.
The boxes are angle cut, to contour the outside of the boat and are about 6” deep on the bottom and 11” deep at the top, but they are wide and tall, so maybe that is why they don’t seem to be working so well. Not much clearence behind the sub and the back of the box. If I run on 1 speaker it sounds about the same as when both are connected."

What is the distance between the two subs, could they be cancelling each other out somehow? Two subs should produce more than one.. Can you move one enclosure to see if the sound changes? Sounds a little bit out there but it would be quick and free to rule it out.

browjenofer

The hard thing about trying to diagnose something over the net is not being able to see it first hand and hear it for yourself

28Eliminator

Thanks for the input. Here are a couple pictures of the project to help give you a visual. I will be able to spend a few hours this weekend, and I think I will try to move 1 of the boxes in the cabin as a test and also check all my wiring to the speakers. Another boating buddy said we could pull his sub box out of his boat and test with it tomorrow. He has some good base out of his box and I think it has an amp on it. I will try and get some better pictures now that I have lined up other parts to test with, and post the results.

http://i1173.photobucket.com/albums/...ps8b270836.jpg
http://i1173.photobucket.com/albums/...psa4d71e40.jpg