311 sub placement
 

Hey guys,
I have a question about sub placement in a 1988 311. Has anyone tried putting subs in the spot under the lounge seats in their cuddy? There is the removable panel in the middle that i was thinking about using. But what about underneath the port and starboard cushions???? I can't seem to figure out how to access underneath them. I think this would be a good location utilizing all three areas because i have 3 jl audio 8w3's i'm planning on using. I was planning on modifying the three seperate areas to make them the exact volume jl recommends. Maybe even tune them really low with their recommended port tuning. Question is though, what is under those cushions, how do i get the cushions up, am i nuts????
thanks
tyler

There is suprising little space under the seats in the fastech boats....and the vertical surface under the seat (front of seat to the floor) is the boats stringers....hope you weren't thinking of putting the speaker faces there facing each other near the floor.

subs
 

Aha, was wondering bout that............hmmmm, wonder if that holds true for the older boats. I would still like to know how to access that area. A friend has a 32 fever with a sub mounted in the middle portion of the lounge seat and it sounded really nice, kinda using the whole cuddy as a bandpass enclosure. i'm beginning to think about putting one sub in the middle section of the lounge area, and the other two under the front seats with gunnel mounted enclosures. Of course i would have to flush them so i could still slide my gunnel storage doors open.

btw, jl recommends .35 cubic feet of air space for each sub in sealed enclosure, and .75 cubic feet of air space for vented enclosure. they want about a 8 square inch vent to tune down to 35 hz. i experimented with three jl's in a previous appication where they shared a common enclosure with one tuned vent.....sounded like 12's. keep the ideas coming, i appreciate it

Hi Tyler,

I have a 88' 311 as well. I looked the same spots that you are currently thinking about too. What I ended up doing was replacing the front speakers with 6.5s (in the v berth) and in the cockpit on the port side beside the bolster I put a 10" sub with reforcement behind of 3/4" plywood glued to to the storage compartment wall. I also replaced the front speakers same holes w/6.5s and added 2 more 6.5s under the bench seat for rears all components are jl audio ( sounds freak'in awesome) .....
Just another idea if it helps .....

Jeff

thanks for the info twins. I am now seriously thinking about building some enclosures for the same area you installed your subs. according to jl if i build a sealed box .35 cf (pretty small actually) my subs will tune out to 53 hz which is great for the cockpit area. what were the model of your subs, how do they sound down low? when you cut your holes how did you trim them out, sounds like a flush mount install. do the plexiglass doors still slide over them? thanks

I "think" the area under the lounge seats in the cabin is filled with foam. I haven't torn out those seat cushions myself, but you've got to really pull the edges up and look around for screws. The front edge material might be screwed in under the carpet.
Also, even if you went gung-ho to get in there, there's a lot less room under there then you think. You could probably get your .35cf, but that's not the area I'd mess with. That front/center compartment could work though. I know next to zilch about audio stuff...would a sub in that location provide good bass throughout the boat, like up in the cockpit?
Keep us posted (with pics if possible) as you progress.

All of the speakers are flush mounted. The sub is located at about your left knee on the port side bolster seat maybe a hair lower. There is no problem opening and closing the storage compartments (sliding the plexiglass).It is a pain in the ass but what I did is ... on the inside of the wall I installed a piece of 3/4" plywood by glueing it right to the fiberglass to strengthen the wall once it dried I cut the hole for the sub. It has been solid as a rock .... no vibration no loose screws.... In behind wear that "storage area' is I put all my life jackets (8) two reasons 1) they are soft and not going to damage anything when I am pounding in big water. 2) Acts as a enclosed box for better sound. There is no loss of sound what so ever. Now as you know you need a serious amp to power these speakers to get "clear music" as opposed to loud music. My goal was to be able to listen to anything I wanted at 50 - 60 mph with out distortion or "noise". You can listen to thump'in dance music ie channel bpm on XM or big tracks (rock) on XM it doesn't matter it rocks with the five speakers in the cockpit .... 4 - 6.5s 1- 10 sub. Something else when you hook up your v berth speakers only run them off the deck not your sub .... save your power. 1) You can't hear them anyway when you are in the cockpit. 2) If you are the cabin you turn off the cockpit speakers by turning the amp off.

I don't think you need to make specific "boxes" for you subs if you mount them the way i did.

Good luck

Jeff

P.S. another reason I mounted the sub where I did is you can't see it as much ... people look and can't figure why you thump as much as you can it is hillarious to see peoples responces.

thanks for the info z28, i think i have given up on the effort to put subs under the side cushions. i think i will stuff one 8" jl w3 under the middle cushion for now and throw an amp on it. cool thing about the subs i'm wanting to use is that i can parallel the voice coils on one since they are dual 6 ohm coils and have a small amp push them at 3 ohm load....for now...then later add the other two...series the voice coils (12 ohm load) then parallel them all (4 ohm load). i really don't want to put subs under my rear seat, that's where i stow my anchor and ropes. where in ftl are you z28, i spend at least one month a year in davie

parallel...voice coils...ohm loads...might as well be chinese :) I know ohms, but don't know how all that works.
I'm actually up north...near Deerfield Beach. Keep boat in Pompano. Check out www.raft-up.com and let us know when you're in town.

got twins
I am close to completing what you have or recommend

I have purchased and mounted 2 JL 6x9's ( top of the line part number, can't remember) at teh front passenger knee areas
and I am buying two kicker component sets (6" plus tweter) from my buddy mitch ( so basically 4 cockput full ranges)
and I plan to buy 1 10" sub

I also planned to power the cabin speakers with radio head output ( to save power)

so, my question - what power amp or specific amp do you recommend.
I assume parallel the full ranges for one pair of channels, and bridge the other two for the sub

454captiva
sorry for the highjack,
but to contrubute, :ernaehrung004:
what about mounting the sub in the area rear of the gunwhale door openings, that is where i plan to mount the pre made sub/box in my 336

Ramb

Hey Ramb,

I will get back to you tonight or tomorrow with regards to the models .... I can't remember them. With regards to the question about the gunwhale .... if I remember correctly you have a "step / compartment" on the port side that the 311s don't . Therefore you are on your own there. Just remember to strengthen the hell out of it so it won't come loose.
The other thing I didn't mention is where I mounted the amp. In the storage / fridge area (311) there is a area with all your switchs I mounted my amp vertically to the wall behind the mirror and mounted my XM boxes to the port side wall of this storage area. The only complaint if I was going to have one is, it gets really warm in there. So if I know I'm going to use the stereo "all" day ... I undo the pin that conects the fridge door to storage door ... close the fridge and open the storage door a crack for air when I am not moving.

Jeff

hey ramb
i don't think my 311 has that area you are describing behind the gunwhale doors. i have thought about putting my subs mounted under the seat but using the gunwhale space for my enclosure. the subs would then fire under the back seat....make sense? my goal was to not make my boat any more stern heavy, i actually have plans to remove my silent thunder platform in lieu of an extreme marine black one.

got twins
i think i will use the same area to mount my amps also, high and dry. i use the area where the fridge used to be for a closet, i put all my life jackets in there. i'm just glad to hear there is so much interest in these old boats still.

Tyler,

I love my 311, I tell my friends it's having and old chevelle she's an oldie but goodie.
With regards to the area Ramb wants to use we don't have these compartments he is reffering to.
On the starboard side straight down from the throttles you will see a little door that opens into a compartment ie VHF just to the rear of that so your are about centre of the bolsters legs you could mount another sub the same way i did with other side with no interference of anything what so ever. This way you could put both of your subs in the cockpit. I don't think you are to have enough room under the rear bench anyway or better yet you are going to sacrifice good storage area with easy access . My 6.5s are pushing it in there. I put my lines and cockpit cover and cleaning supplies in there.
Good Luck ....

Cool,
i am gonna be home tomorrow night so i will take some measurements. i'll see how much room i have with the gunwhale doors all the way open. i'm picking up my components tomorrow afternoon on the way home so hopefully i can update next week with some pics. thanks all

how do you post pics, i'm confused. i took some good shots of where i think i want to start my sub installation

nevermind, i think i figured it out....i'm a dumb$hit

any thoughts on installing the sub facing up in the airspace pictured above. Has anybody done this already? I am curious as to how it would sound. Of course if would be mounted so the face of the sub wouldv't interfere with the cushion when playing music hard.

Hey, just a thought .... could you place that sub under the "backrest" rail. Can you get to it fron the vberth storage area. My thinking is when the cushions are placed down you would have may be 2" covered but they would be set back 3-4" under the rail.....

Jeff

I looked at that area but decided there just wasn't enough room to put anything there. I think the fresh water tank is on the other side of it. I was also wondering if that back rest rail was structural. I am gonna look closer at that area though. By the way, i found the factory wiring for the factory amp behind the fridge. It was 10 ga, hopefully i can use that wiring to power my small 4 channel amp for mids and highs.

RE: backrest rail, and forward storage...
"on my boat at least"...there's 3 storage areas...behind the backrest is open, the second one has the tank, and the forward most one is where the pump is...FYI
I should start my own thread, but since I've been known to hijack before...I've got all original Kenwood stuff still in there and only my cockpit speakers work. I fiddled with the fader and when I go full forward, I've got no sound in the cabin. So I "should" have two speakers way up front over the v-birth? And is there a way I can look at/swap the amp wiring to see if that's the issue?

v berth speakers
 

Michael, you should have two speakers in your v berth if it is similar to mine. i'll post a pic, i just replaced mine.

This is what mine looks like. I can see the outlines, just need to get that awful '80s material out of the way.
Assuming I actually find speakers there, I still need to come up with a way to diagnose my lack of sound...

mine looked like that too until i cut the holes in the fabric. the speakers are actually mounted on a piece of plywood behind what you are looking at. i cut the fabric to let the highs come through better. eventually i will probably make a custom fiberglass enclosure for my 6.5's up there so i can ditch the trim panel

Hey Michael,

I mounted mine behind that trim piece.... when you remove that you will see where the other ones were. Be perfectly honest with you i ran the speakers with and without the cover .... miner miner difference. Comes down to what you are looking for .... I wanted a clean "factory look" as opposed to showing the speakers. If it would have made a greater difference i might have put them on the outside.
Good Luck ....
Jeff