box building nightmare

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=121320
Printed Date: May 12, 2024 at 11:02 AM

Topic: box building nightmare

Posted By: anthonylecuona
Subject: box building nightmare
Date Posted: April 13, 2010 at 1:12 PM

I am trying to build a vented box for max spl in my 96 suburban. I have 6000 total watts and 4 kicker l7 15 inch subs. Just looking for best ways to build facing up front etc. Any help and or graphs showing how or what way would be appreciated greatly thanks.

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In case of snow drive backwards, instant front wheel drive, then again who needs it when you drive a Scoobie

Replies:

Posted By: j.reed
Date Posted: April 13, 2010 at 4:46 PM

About your only good option is subs up, port back. I would also try for at least 4.5 cu.ft NET, per sub.

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Posted By: anonymous1
Date Posted: April 13, 2010 at 5:06 PM

j.reed im with you on this, but he'll never be able to lift that monster by himself.

If it were me, I would make 4 enclusures with UP mounted drivers and a port on the side. Then be able to secure them together once in place with the ports all firing in one direction, or have one large cube with ports on 4 directions.

They need to be both secured and portable.

Posted By: j.reed
Date Posted: April 13, 2010 at 9:49 PM

anonymous1 wrote:

j.reed im with you on this, but he'll never be able to lift that monster by himself.

Thats what friends are for posted_image

Porting rear will be louder also without the canceling action of side firing ports on each side, as well as the enclosure can have a lower profile to stay below, or close to the window line. By doing side firing you will be losing usable width. Having to leave open space for the ports to work correctly on the side. Thats why I say the only GOOD options would be subs up and port rear.

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Posted By: anthonylecuona
Date Posted: April 14, 2010 at 1:29 AM

Thanks for the help and I am trying to keep the subs at around 6 cubes per. Going to be hard but I love a challenge. Any pointers for making the port how big can I go one port for all four and the box will be all one piece. Fiberglass reinforcement inside and out. I would like to do two and join them in the middle. Butt the bottom line is how big can I go with the port opening being square and rounded off. Kicker recommend 6 cubic ft for max SPL per sub. But if I do get this per sub. how do I do the port I have never had such a large scale enclosure to tune. I would like to ask if anyone has a recommended tuning freq also. Thanks again for all the help.

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In case of snow drive backwards, instant front wheel drive, then again who needs it when you drive a Scoobie

Posted By: j.reed
Date Posted: April 14, 2010 at 12:43 PM

you realize at 6 cube thats 24 cubic foot net, plus port displacement, driver displacement and any bracing. Seeing as your looking for max spl your going to want a large port area which is going to add to the cubic foot really fast. Also if you are looking for MAX spl. I have found best results between 4.5-5cu.ft net with these subs. If you have 6k watts. I assume around 3k rms. You wont need to go that large anyway. Im running 2 of these in 13 cu.ft. GROSS. They in are only in 5 cu.ft net per. It doing over 151.xdb on the TL. Trust me ive tried 6cu.ft. Use my homework.

Measure out your space and we can go from there.

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Posted By: anthonylecuona
Date Posted: April 17, 2010 at 1:31 PM

ok i have a total of 60"x48"x20" usable space 29.12 cubic ft. internal. Minus bracing and sub displacement. What do you think I can do?

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In case of snow drive backwards, instant front wheel drive, then again who needs it when you drive a Scoobie

Posted By: j.reed
Date Posted: April 18, 2010 at 7:51 PM

I assume the 60" is from the seat backs to the back wall. Is this correct or have you left room there?

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Posted By: anthonylecuona
Date Posted: April 19, 2010 at 12:16 AM

No there is room left for the ports on the back side.

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In case of snow drive backwards, instant front wheel drive, then again who needs it when you drive a Scoobie

Posted By: j.reed
Date Posted: April 19, 2010 at 3:13 PM

How much room is left? If say your port is 8" wide you will want right at about 8" from the box to the wall at a minimum. If you have that room, I would look at 5cu.ft net per sub. 240sq.in of port area. I would start tune in around FB=34-35Hz range. That should get you peaking around 45-48Hz range and should yield pretty good numbers as well as still have a fairly good musical, street beat quality.

-NET = 20cu.ft

-Port 30" x 8" x 13.75" Fb=35Hz = 1.09cu.ft(internal volume, walls not takin into account.)

-Driver displacement all (4) subs = 0.64cu.ft.

-Internal bracing not figured.

21.73cu.ft Gross internal is what you need, but you will also need pretty extensive bracing to keep from flexing the enclosure. DO NOT forget to add volume for the additional bracing.

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