Results 11 to 20 of 28
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01-05-2010, 02:41 PM #11
David,
Thanks for the response. If I go free air, is the JL Audio 10W3v3-2 the one I want? Since it's a 2 ohm sub, the Kicker will deliver 420w instead of 210w so will that be enough to adequately drive this sub? If I go the free air route, do I still have to seal the top hole and the hole below the footbox that leads to the under floor pipe/cable chase?
Also, the footbox is actually stouter than you think - it's at least 1/2'" thick, maybe even 3/4" - it's not just thin fiberglass. I'll measure it the next time I remove the sub.
Do you have a recommendation as far as some good songs to use for tuning/testing a stereo system? Something with a wide range of sounds and some good bass segments?
Thanks,
AlLast edited by cab13367; 01-05-2010 at 02:49 PM.
Al
2006 Mobius LSV
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01-05-2010, 02:44 PM #12
Phil,
I'll remove the drop cloth and see how it sounds. I think you're right, ultimately, sealing the footbox is probably my best bet. Then I can use the equipment I have and will have the clean look I like. I do plan to install a heater in the boat though and the water lines will have to run through the underfloor pipe chase, thru the footbox, and out the hole on top so I need to do that first before I seal it with the expanding foam.
Phil, David,
Thanks a bunch for your input. It's so generous of you to share your knowledge with me and others on this forum. You guys are the best.
AlAl
2006 Mobius LSV
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01-05-2010, 02:48 PM #13
Joe,
I thought you were happy with the bass out of your system? I thought maybe your footbox is better sealed than mine.
If I buy another sub, it will be a 2 ohm sub to get more output out of the amp. Also, I've looked at that Boston sub but the fact that it has a foam surround (instead of more durable rubber) is a show stopper for me. Don't know why they spec'd such a nice sub with a foam surround.
Thanks anyway,
AlAl
2006 Mobius LSV
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01-05-2010, 03:14 PM #14
Al,
I am happy but this thread certainly has me thinking??
then the Jl is probably the sub for you.
David,
What is the song on the youtube video on the 2009 super air nautique? i love that video.
When i get enough cash i be upgrading to the HLCD, hopefully you''l be able to ship to western NY.Last edited by jmvotto; 01-05-2010 at 03:50 PM.
A Day at the Lake...Priceless
A Day in Powder...Endless
Joe V
2012 Möbius XLV~ Loaded & Exiled
2007 Outback V ~ sold
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01-05-2010, 05:25 PM #15
cab,
Acoustic suspension for a sealed box woofer is a fixed relationship. So you can't approximate it with a quasi-sealed or aperiodic enclosure and have predictable results. Go with free-air (infinite baffle) or acoustic suspension (small sealed). One or the other. But no combination or mixing your schemes.
The JL Audio 10w3v4-2 is not a free-air sub and should not be used in your floor. Its just for enclosures whether sealed or bass-reflex. The appropriate JL sub is the M10IB5-SG-TB and its only avaiable in 4-ohms.
If you are 'free-air' it means an infinite and unobstructed volume of air (the entire bilge for example). A free-air 10-inch sub usually requires a 3 cu. ft. enclosure or larger so that the woofer's 'Q' is unchanged which is the basic qualifier for free air. You cannot have too large of an enclosure. However, it should be sealed or isolated front to rear by a 1/8 wavelength 'to' and 1/8 wavelength 'from' the nearest large opening, for a total round-the-world path equal to a 1/4 wavelength of the lowest frequency you're expecting to reproduce, which would be approaching the woofer's free-air resonsance. And the resonance is higher on a free-air driver. From this you can deduce that a.) the hole in the top of the starboard hump must be sealed and b.) the hole in the port hump or other distant openings do not matter.
In contrast, if you go sealed then it should be at or close to the optimum displacement (averages .65 internal net on most 10-inch drivers) and that means absolutely air tight in the strictest interpretation.
David
Earmark Marine
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01-05-2010, 05:30 PM #16
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01-05-2010, 06:44 PM #17
jmvotto,
We're happy to ship anywhere in the states.
As for the music in the video, I had to ask someone. I'm more of the technical and application spokesman.
I believe the artist is 'Akon', the album is 'freedom' and the song is 'keep you much longer'.
David
Earmark Marine
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01-05-2010, 07:27 PM #18
I really don't think you'll be happy with a free air sub. In my opinion free air subs are throwing good money after bad. If you're going to upgrade, I'd recommend either 1.) a small sealed enclosure and put it on the other side (or on top of) of the drivers footwell (simplest option) or 2.) cutting out some of the front of the footwell and inserting a sealed enclosure with a larger front panel that covers the face of the existing footwell. (harder to do, and even harder to describe, ill see if i can put together a quick diagram.) Again, this is just my opinion as I've yet to hear a free air sub that would make me happy.
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01-06-2010, 03:58 PM #19
So it appears that even if I decide to go "free air" I still have to seal up two of the three holes in the footbox - the one on top and the one under/in front of the woofer than leads to the pipe/cable chase under the floor of the boat. And I have to invest in a free air subwoofer.
So I got to thinking about pre-fabbed sealed enclosures and ran across an ad in the local craigslist for the sealed enclosure below, brand new, for $20. Apparently, he bought a stock of them at a closeout somewhere. I checked the dimensions and it will fit just fine under the dash - I can just screw it directly to the face of the footbox. It's not too deep so it won't take up a lot of the room down there. I know that it's not water proof but this is more of an experiment, to see how my sub would sound in a sealed enclosure and I'm only spending $20. The dimensions are stated as 20.25"W x 13.88"H x 5.88"D but I don't know if that is interior or exterior. If interior, then the interior volume is 0.96CF which is 50% more than the recommended volume of 0.66CF for my sub. I supposed I can just screw in a few lenghts of 2x4 inside the box to get to the desired volume. BTW, does the recommended volume of 0.66CF include the volume displaced by the sub or not?
So Phil and David, do you think this enclosure would work okay with my sub? Is the shallow rectangular shape a concern vs a square box shape? Should I reduce it's volume a bit or just try it as is? My sub has a top mount depth of 5-1/2" so it should fit depth wise.
If it turns out that the sub sounds worlds better in a sealed enclosure, then I may have to build a custom one after all.
Thanks,
Al
Al
2006 Mobius LSV
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01-06-2010, 04:32 PM #20
Top mount depth for your sub is 5 3/4", and I'd bet the stated box dimensions are external measurements. So if it fits it will be very very close. Ideally you'd have an inch or more behind the magnet, so I'd keep looking. Also the recommended sealed box volume of .66 does not include the sub displacement. Good luck, I think you'll be amazed by the sealed box improvement over factory.