Adding a subwoofer

[Traxx822]

Hello guys,

I am looking to add an extra subwoofer to my set up. I already have one in the walk through, the next one will likely be in a box at the drivers seat.

Both subs are JL10IB5 @ 4 ohms

Currently I run my existing single subwoofer with a M700/5. The same amp powers my cockpit M770's. The amp is 100W x 4 +300W.

My dealer recommends I buy a M600/1 and just drop using the 5th channel on the 700. But I would like to not have 3 amps in there. I also have the M400/4 for the tower speakers.

I think that IF i can sell both of my current amps. and then buy a M800/8 and the M600/1 and have a perfectly balanced set up. 100Wx8 @ 2ohms on one amp and Split the 600 single between the two subs. For about $300-$400. 2 amps out and 2 amps in. Instead of 3 goofy amps I don't know where to fit.

Your $0.02?

Is my idea the better alternative than the dealers?

[MC25]

Wait are you putting an IB sub in a box?

[supreme112279]

I did 3 amps. One is 4 channel with a 5th for sub only. 2nd it tower speakers. Third is for subs in my engine compartment. I mounted them. One back wall in storage at copilot seat. 2nd right wall where you mounted your sub. Third under copilot seat. No issues after 3 years

[supreme112279]

The only thing with your idea I don't like is running amps at 2 ohms. Georgia heat tends to make them cut out

[Tristarboarder]

I would like to see pics of the sub placements in the engine compartment....intriguing...if possible...

[supreme112279]

Can not get pics for at least another week. One far back left and far back right facing forward. There's a lot of room back there in a maristar

[Tristarboarder]

No prob, if I read that correctly you have 4 subs in the boat? I bet that thing is loud

[supreme112279]

3 ....12s. Third is at my drivers feet. 144 decibels

[Traxx822]

Here is a pic of my mounting.

With JL amps you have to run 2 ohm to get the right amount of amps out of the cockpit speakers. If I run in 4 ohms I get about half. I have had no trouble with my current system.

I', also pretty sure I mentioned that both subs were 4ohm subs and would be run as such. Where my current set up only runs one 4 ohm sub at 2 ohms.

Yes I will be putting the IB in an enclosure. I know it sounds funny but it has to go somewhere. I havent decided on dimensions or ported etc but I can figure this out.

I as well would like to see your subs installed in the engine compartment. It might make me change my placement setup.

As well, does anyone else think its a bad idea to do away with the 700 & 400 and change to the 800 & 600?

[David Analog]

A few sound system basics to follow would be....
*Do not place an IB (infinite baffle) woofer in a small sealed enclosure, although a 10-inch IB does view a sealed enclosure of 2.25 cu.ft. or larger as infinite, but that is a very large box. JL Audio also makes the identical marine 10-inch subwoofer in a W-series, which is an air/acoustic suspension woofer intended for a small box (best results are a 1.0 cu.ft. box).
*Never under any circumstances use a high 'Q' IB woofer in a bass-reflex/ported application. Bass-reflex specifically requires a lower 'Q' woofer.
*Do not place a fullrange coaxial and IB sub side-by-side, in close proximity, in the same cavity without some form of isolation chamber. The smaller fullrange speaker becomes a sympathetic radiator for the dominant sub = nasty modulation distortion.
*If you want any degree of bass tonal contruction (pitch accuracy, sound quality, etc.) then use all identical subs, all tightly collected in the same location, loaded in the same form of enclosure (whether I.B., A.S., or Bass-reflex), oriented the same, and loaded into the boat the same. Otherwise you have created phase soup. Will you still get more bass output as you indiscrimanently add more woofers and power? Sure. But never with the SQ and efficiency as the initial and best positioned sub.

[Traxx822]

A few sound system basics to follow would be....
*Do not place an IB (infinite baffle) woofer in a small sealed enclosure, although a 10-inch IB does view a sealed enclosure of 2.25 cu.ft. or larger as infinite, but that is a very large box. JL Audio also makes the identical marine 10-inch subwoofer in a W-series, which is an air/acoustic suspension woofer intended for a small box (best results are a 1.0 cu.ft. box). 2.25cuft under my helm is no problem.
*Never under any circumstances use a high 'Q' IB woofer in a bass-reflex/ported application. Bass-reflex specifically requires a lower 'Q' woofer.
Noted
*Do not place a fullrange coaxial and IB sub side-by-side, in close proximity, in the same cavity without some form of isolation chamber. The smaller fullrange speaker becomes a sympathetic radiator for the dominant sub = nasty modulation distortion.
This was already brought up on the forum, old photo. We built an enclosure around the around the 7.7
*If you want any degree of bass tonal contruction (pitch accuracy, sound quality, etc.) then use all identical subs, all tightly collected in the same location, loaded in the same form of enclosure (whether I.B., A.S., or Bass-reflex), oriented the same, and loaded into the boat the same. Otherwise you have created phase soup. Will you still get more bass output as you indiscrimanently add more woofers and power? Sure. But never with the SQ and efficiency as the initial and best positioned sub.

Thanks for the tips, Retail space is short so where do you suggest? FYI they will not fit under my seats, or in lockers. And i'm surely not going to point them at each other one in each side of the walk through. So one where existing and one where my feet go. Thats about all the space I have left on my 1995 20' Maristar.

[bsloop]

This situation is a prime example of why every boat should have dedicated zone amps.

As speakers change, usually amp needs will change as well. With multi use amps, that means a compromise in amplification or wasted $$ for features not necessary. Also, if one part fails, the entire setup (usually overly expensive) does not need to be replaced, the rest soldiers on.

First, the sub question - A single 12" at the drivers feet, preferably ported, but sealed is simpler, would be my recommendation. Don't continue to get hung up on the need for "marine". Your application will be non-salt and protected. Any good sub with synthetic cone and rubber surround is a viable solution. A 12" will be significantly louder than a pair of 10" IB and eliminate potential standing wave and passive radiator problems pointed out above.
Install a dedicated mono amp.

Personally, I do not get hung up on single brand brain washing. Sometimes a brand is designed and "tuned" to sound the way that mfg wants something to sound but sometimes parts of their line undergo redevelopment or are simply the closest fit. Either way, what sounds good musically to one's ear, does not sound as good to another or in a different environment.

IF you are married to JL amps, I would consider Rockford P3 or T1 or Kicker L7. The tight JL will keep things very controlled while the extra efficiency of the other sub brands will give an additional sound boost.

[Traxx822]

This situation is a prime example of why every boat should have dedicated zone amps.

As speakers change, usually amp needs will change as well. With multi use amps, that means a compromise in amplification or wasted $$ for features not necessary. Also, if one part fails, the entire setup (usually overly expensive) does not need to be replaced, the rest soldiers on.

First, the sub question - A single 12" at the drivers feet, preferably ported, but sealed is simpler, would be my recommendation. Don't continue to get hung up on the need for "marine". Your application will be non-salt and protected. Any good sub with synthetic cone and rubber surround is a viable solution. A 12" will be significantly louder than a pair of 10" IB and eliminate potential standing wave and passive radiator problems pointed out above.
Install a dedicated mono amp.

Personally, I do not get hung up on single brand brain washing. Sometimes a brand is designed and "tuned" to sound the way that mfg wants something to sound but sometimes parts of their line undergo redevelopment or are simply the closest fit. Either way, what sounds good musically to one's ear, does not sound as good to another or in a different environment.

IF you are married to JL amps, I would consider Rockford P3 or T1 or Kicker L7. The tight JL will keep things very controlled while the extra efficiency of the other sub brands will give an additional sound boost.

Thanks loop, I will stick with the mono amp for the two subs. And since my boat stays moored in the water (not on lift) and I do travel to coastal waters I would like to stick with the JL subs because of their ability to withstand the elements better than any other brand.

As well, the JL amps for the limited space. Most every other area in my boat gets wet. Under the seats, in lockers etc. So in the observers locker is the only place I can put amps. Not to mention I don't want 5 batteries in my boat. I have 2 now and have never run out of power.

I'm kinda stuck with the subs I have. One is installed in the walk through. I can never get that piece back unless I reupholstered it and put the fiberglass back. So it's gone. The other sub I got for $100 on the forum. It was too good a deal to pass up. I don't want booming bass. I don't need it. I just want a bit more than I have now.

So I think you are basically answering my question that the subs should be run Mono like I thought, and instead of having an amp that has parts unused and just upgrade to the 800/8 so I can conserve on wall space.

And I'm not brand brainwashed ... I have a WS420sq installed

[bsloop]

As for enclosures. Like the advice in every other thread.
Sealed is easy with tighter sound that some rock music lovers prefer since the bass drum kicks truer.
Ported requires a little more space but is within the 2.25 cu ft you mention and I can assure you there are MANY boats with a ported 12" under the console. Definitely within the capabilities of an amateur but better results will usually come from a pro build or pre made box. Bass will carry farther and the thumping boom of pop tracks that are produced with electronic bass machines will usually perform best.

[Traxx822]

Thanks again, Yeah ... i don't work on my own boat, for deniable responsibility, I have a professional installer that will build a proper sealed box custom to fit under there.

This sub box will also help out with my under dash panel, because I can get rid of that annoying cover under the helm that does nothing but fall down anyways. Two birds in one stone.

I don';t know why everyone is suggesting 12's and bigger. I have one 10IB5 with 300 watts and it shakes the entire boat. I think 2 will be plenty for my tastes.

I do have a friend with a go fast boat ... has maybe $45 clarion speakers ... but 2 alpine type R's in a ported box with a RF 1600 and he thinks his system is so baaaaad. Because his bass is louder than mine and I spent a lot more. Not to mention all you hear is nasty bass and no music with his ... I still can't be turning up one sub and feel all that cool. One more would be plenty for me.