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Thread: Waterproof sub box
06-08-2010, 09:07 PM #1
Waterproof sub box
I am planning on putting a 12x12x12" sub box above my kickplate for a 10" kicker L5 sub I plan on buying... Even though I am a huge diy'er, for some reason I have no desire to build a sub box... That being said, I found these guys on eBay... Anyone seen them before?
http://WWW.edgeenclosures.com/2007 Mobius LSV
06-09-2010, 03:49 AM #2
I'm pretty familar with these guys as they are local to me. We looked into having them do contract work for us when we launched into the marine enclosure product line a few months back. I don't want to bad mouth anyone but our experience wasn't a good one. We struggled to get sample product cut.
That doesn't mean that their designs on eBay are not worthy. I've no idea. One thing that concerned me about their material is that it is flexable. Without significant bracing, you'll loose performance characteristics of whatever woofer you put in there.
On that note I'd also suggest you look at putting a 12 " woofer into your lsv. If possible use a port tuned setup. A 10" setup just doesn't offer the output that a decent 12" woofer can. Sometimes people often think that they don't want or need a larger diameter 12" woofer. Case in point would be "Cab" on here. He was very reluctant to step up and I think ultimatley he was pretty happy now that he did. I know razz and a few other guys on here also made the jump. I'd solicte some of their oppinions.
There are threads on here about the Exile LSV bass setup if you want to read what's available for your boat. But beyond the exile setup... Whatever brand you choose... Go with a 12. Assuming you have an amp that can run it.
06-09-2010, 11:12 AM #3
A 10" L7 has basically the same surface area as a round 12, within 10% or so depending on whose calculations you use, it has the potential to generate the same output for a given power input, assuming similar enclosures, and power, etc. Sorry, Brian, I had to point that out.
As for the enclosures you found, I am inclined to believe this is either Medite/Medex materail, basically water-resistant MDF, or some sort of synthetic material, like TREX decking. Brian's comment regarding it being flexible tells me it is more like the latter TREX decking material.
A subwoofer enclosure does not have to be complicated. A simple sealed enclosure like I think you are suggesting can be built from good 13-ply marine or birch plywood and deliver good performance while not having the problems associated with MDF. Use a water-proof glue for construction like Franklins Tite-Bond II or the ir new Tite-Bond III which is very similar to the waterproof Gorilla glue. Use a little polysulfide sealant on the interior seams and you will have a very marine-worthy enclosure that will stand up to getting wet occasionally. Use stand-offs or feet to keep it of fof the floor, in order to keep both the enclosure and the carpet dry.
A vented enclosure can provide greater output, but it requires a larger box and it requires tuning, so it might not be a direction to pursue in your case. IF you decide you have the room though, holler or post back and I can help you with figuring out what volume you might be able to get, what area of port you should use, and how long it should be.
Which L5 woofer do you have, the dual 2-ohm or the dual 4-ohm ? Let me know that and we can help out with amp and power recommendation. If you have not purchased the woofer yet, consider the dual 4-ohm woofer, as we can parallel the coils and run it on a class D sub amp for max power.
Let us know!
06-09-2010, 12:44 PM #4
I can echo brian's reply on the sub choice. I went from a 10" in a free-air setup(kenwood factory sub) to a jl 12w6 in a sealed and the difference is night and day. I'm real glad I didn't stick with a 10. buddy has a 10 in his and he's thinking of trading up.
phil makes a good point on the kicker being larger, but their 10" square vs a 12 will still be no comparison(phil, demo'ed both jl 10 and 12 and kicker 10 and 12 at our local shop and there was a difference. all drivers were in boxes they stated were within specs for each sub). I was so close to buying a kicker 12" L7, but the jl came along at a little better price. kicker makes a fantastic speaker you will not be upset with, but do it once and don't be sorry. remember that your boat has a lot of open space around to fill with sound'06 Supra Launch 20SSV-gone but never forgotten
06-09-2010, 01:31 PM #5
I gotta respond. You say you went from a free-air factory 10 to a 12 in a box.... of course it is night and day!
Were this a scientific experiment, a critical observer will point out that you have introduced too many variables.... You changed woofer sizes, offering that as proof of improved performance, but you ALSO added an enclosure. Adding a proper enclosure to any woofer, designed for that woofer, will always improve its performance. Even so-called free-air woofers have a proper enclosure that they can be put in, based on their Theile-Small parameters. Free-air woofers often have much stiffer suspensions, higher resonances, and higher Q's to alllow them to work in a free-air environment without bottoming out, but they still can be put into an enclosure for improved performance.
Don't take this as an argument, or a fight.... I just want to make sure we are not misleading adsman with subjective information.
While we are on it, and in general:
* Given similar or same motors with sufficient strength, a larger cone will deliver more sound pressure. This is a function of area
* A free-air installation of any woofer is the least effective in converting amp power into bass sound you can hear, and it is usually the lowest power-handling installation choice of the three we are discussing in these bullet points. A free-air installation needs to be done so that the pressure waves off the back of the woofer cone do not mix with the pressure waves coming off the front. This results in lowered sound output.
* A sealed enclosure will almost always deliver better performance when compared to free-air installation, and will do so with improved power handling due to the compliant spring-force provided by the air volume trapped internally. It is also the easiest enclosure type to build. A sealed enclosure can be relatively small, depending on the woofer. It also can be rally big for a select few woofers!
* A vented enclosure will out-perform both sealed and free-air instllations, provided you are using a woofer that will work well with a vented enclosure of "X" volume. Unfortunately, "X" volume is a function of the size of the enclosure, and vented enclosures are usually the larger option when compared with sealed enclosures. Vented enclosures are also the most complex to build. For a given tuning, smaller boxes need longer ports, and their port velocities can be high. We lower port velocity by increasing port area but this further necessitates lengthening the port to maintain the target Fb. Put another way, small vented boxes need big long ports. Big ported boxes can be tuned to the same Fb with smaller shorter ports, but who wants a great big box?
Lastly, a vented enclosure has good power handling as long as you use it at frequencies above Fb. Below Fb, a vented enclosure's power handling crashes, as the port basically quits working, the spring-force of the air in the enclosure is non-existent, allowing the woofer to move in-and-out at or beyond its x-max with basically no acoustic output. Many vented enclosures really should be used with sub-sonic filters set to near Fb to prevent mechanical failure to the woofer. What can be taken away from all this mumbo-jumbo? If you go and build a vented enclosure and get the port too short, resulting in the tuning being too high, you will have an enclosure that performs actually worse than a free-air installation, with lower power handling.
While I am writing a book on vented enclosures, let me point out another fact, just informationally. You need to build a vented enclosure more tightly than even a sealed enclosure because at certain frequencies the internal pressures in a vented box are greater than those in a sealed box. Vented enclosures are louder because you are of course getting sound from the woofer cone's face, but you are also getting sound from the port. For the sound from the cone and the sound from the port to add, they must necessarily be in-phase; when the woofer is moving outward towards your ears, the air in the port is also moving outward towards your ears.... similarly, when the woofer is moving in, so is the air in the port.... the woofer is moving in, and there is air flowing in so there is a greater compression in the enclosure; simply because we have set up a condition where we are pumping more air in....
Okay, I have rambled enough, so let me stop for now.... To adsman's original post, I think I agree with Brian in part about your find not being the best solution. We can help you out with a better solution for the woofer you choose, whatever it is. Your choice of an L5 is good, and there are other good choices out there. Just be sure to make an educated decision of you decide to go with another woofer based on objective quantifiable measurements, and by all means, use your own ear to listen to as many woofers as you can prior to deciding. We all have our preferences, and sometimes our loyalties get in the way. I like Skippy peanut butter, you might like Jiff though.... and I am okay with that. Just make sure you tasted both and made your own decision...
thanks for listening!
Last edited by philwsailz; 06-09-2010 at 01:36 PM.
06-09-2010, 02:11 PM #6
phil, great points above, and I agree with everything you have written, having had everything from free air subs in cars to a 3-chamber bandpass box in the bed of a truck using 2 12's and a 6" tuned port for the sound. I do understand that the 12 in a box will outperform any 10 in a free air(and I added much more variables than just a replaced sub), I was simply echoing brians comment on stepping up to a 12, not a 10. I am suspecting that adsman is looking for subjective information from those that have upgraded as anyone can look at woofer specs till they are blue in the face, but listening at a shop and opinions of those that have already installed them to me mean much more.
after all, isn't that what forums are for? sharing lots of imo's'06 Supra Launch 20SSV-gone but never forgotten
06-09-2010, 02:16 PM #7
At $200 you can get a pre-built waterproof enclosure (sealed in Rhino polyurethane) including a 5-way terminal cup. We've used this type enclosure in boats for over 10 years now. It mounts over the hump and rests on an ABS pad and is above view without disrupting the cables entering/exiting the top of the hump. You can even fit a 10-inch with a 10-inch passive radiator in the same spot. That particular location will be challenging to fit in a bass-reflex enclosure.
You can install a 12-inch, even in a bass-reflex enclosure, in a fairly shallow box that rides the front of the angled floor hump. The angles, pads for drainage, bracketry and cover facade will make this approach a more involved project.
In general I'm not too crazy about automotive trunk liners used to carpet a marine enclosure in that it retains rather than repels moisture.
06-09-2010, 02:26 PM #8
***EDIT - I didn't scroll down and read Phil's response, AWESOME INFO!
I love the 2 10" Kicker L7's I have in my boat! Next step for me is more power - running 2 L7's off the 5th channel of my ZX700.5 is weeeakkk, lol.2013 Outback V
06-09-2010, 02:52 PM #9
Just to clarify something I read above. Supra routinely used Kenwood and Exelon acoustic suspension woofers (designed for small boxes) in a free-air application. Furthermore, these woofers were mounted in a compliant HDPE panel that was wide open over the top and did not provide any degree of front to rear acoustic isolation. Moomba has also installed the wrong type of woofer in the floor hump into very thin fiberglass and using the bilge cavity as an infinite baffle.
These factory applications never stood a chance of sounding good and by no means are a representation of what a good free-air subwoofer can do.
There are some boats where a correctly executed and true free-air woofer is the best available option and will actually out-perform a sealed enclosure that is choked by its location or restrictive venting. This might include various cruisers and I/Os. However, I can't think of a single towboat where a free-air sub best fits the application.
Speaking of mis-applications, there are cases where a manufacturer may represent an acoustic suspension woofer as a useable free-air also. These two modes will not be fround in the same driver. A woofer does one or the other. If it was intended to do both then it will do both poorly. So the inverse of using a free-air woofer in a small box is just as flawed.
When you've been exposed to and had the opportunity to listen to and anaylize hundreds upon hundreds of boat audio systems and subwoofers, you learn not to cling so tightly to rigid conclusions. There is alot that is dictated by applicaiton and execution. All too often I see people over-learning an exposure or two to bad execution.
Kind of getting off subject but acoustics is definitly a favorite subject.
And remember that your selection on which brand of peanut butter is best may be influenced by what your having it with whether jelly, pickles, bananas, mayonaise, marshmellow, etc. My dog loves peanut butter too.
06-09-2010, 04:02 PM #10
you are totally correct david. my supra came with the dvc kenwood excelon 10" sub in a free-air design. did not sound good at all. it found a second home in my sis' pontoon boat, but this time in a sealed cabinet based on the specs I found online for that sub. sounds 100% better, although even in a sealed cabinet, it can't begin to hold a candle to the 12's I have heard and they have commented that to do it over, would probably have put in a kicker L5 12" that their neighbor's tooner has on it(sis likes the style of the sub). the kenwood is great for scaring the fish out of the water onto the boat tho and I like jif with my fish fwiw.'06 Supra Launch 20SSV-gone but never forgotten