Wall_Breaker

I need some of you guys to make sure my calculations are good and that this box will work out. This is the first box I have designed to be as critical as needed. I am wanting to try a subs back and port into the cabin approach. This should work out to 6.75 Cu Ft after port displacement and after the 15 " BL's it should have 6.39 Cu Ft at about 32 hz. I am wanting to try to make it bigger and get maybe close to 4 cubes per sub. I have about 7 or 8 more inches to work with to make it a little bigger. But I figured I would make sure I am doing this correct before I go and design another one.

I thought the loudest sound possible in our atmosphere is around 190db? I may be wrong but I always heard that once you reach that point the air in our atmosphere can't be compressed any more. I'm sure at a higher altitude more db's would be possible since the air is thinner but nowhere near 1000db's.

What he means is by having the flush baffle it seals all the sound in the trunk. Which means it will rattle all to hell with no deadener and it will be less audible inside the car. You don't have to have a port going inside the car just pointing toward the cabin will make a big difference. This is if you are looking for sound quality. In the SPL circuit then every car is different and it's almost impossible to know what will be louder until you build many boxes. What you have to decide right now is having it flush like that and looking petty more important to you than the performance of the subs? I would also recommend you install a front stage as soon as possible because this is gonna be loud enough you won't hear anything but bass.

I am looking to build my first system and I am a full believer in saving money but not at the expense of diminished quality. I want to get 2 15" BL's. This is in an every day driver, I want it loud but it doesn't have to be insane. I know that install is 90% of it so I am wondering how much of a difference am I really gonna see if I have Sundowns 1500 powering them or the 3000. Saying the encloser and every other factor is the same. I am thinking that since I am not looking to compete I would be spending way too much money buying the 3000 and all the extra electrical upgrades that are needed and not have that much of a noticeable difference. So if anyone who has experience with doubling the power in their system can help me by telling me what the difference to the ear would be I would be thankful. Some day I wouldn't mind upgrading but right now I am just finishing my senior year and trying to save as much money as possible. Also if I were to just get one 18" BL would I notice that much of a cone area difference in a trunk car? Also what does everyone think of running MP3 players on their system? I have so much music on that little device it will be hard changing over to cd's if I have too.

I don't use norton but I am pretty sure you can scan them using Norton. But I don't see why you would have a problem unless you have reason to think your jpegs are infected. But I am over cautious so I would scan the disk before you rip anything onto your computer.

You should use MDF, probably half inch, depends on the application. I won't recommend anything else because I've never used anything else but that's what 90% of enclosures are made of.

Yeh I would love to see this set up. Damn good numbers too.

Well lets just say lows and home depot are over an hour away from me, what something to use other than MDF then?

In doing that how would I place the 1x1's? just glue them to the peices of MDF to help make it heavier or would I make them standing up like pillars. This is going to be top firing ported towards cabin. So the double baffle is going to be on the top.

The problem is I want a way that I can easily find out the displacement of my bracing because it's going to be ported.

Would I need metal bracing or maybe like swiss cheese bracing or what? basically I am looking for the best way to brace it using the least amount of space.

I am using CAD right now to try to make a 3d design of my box. My question is if it is an 8 cu ft. box before displacement with external aeroports, what kind of internal bracing am I going to need even with a double baffle? This is getting a fully loaded 18" BTL by the way, with a Sundown 3000d. If I use 3/4" MDF will I have a problem with too much flexing? Also one question this is my first build, first system and I want to know what your guys preference is on MDF from different suppliers. All I really have around here is a Menards and I work there so I can get a small discount on it there. I just wondered what you guys think of the quality of Menard's MDF compared to other. Also I have seen a lot of guys just use bolts instead of terminals and they swear by it. Your not gonna be able to see it in my trunk setup anyways so I'm thinking about doing that.

Also one othe thing real quick, whats a good way to keep the box secure without putting any bolts through my car or anything. If it's the only way I guess I can but I would rather not.

Well it won't matter if the tire is in there or not really because the box is gonna be over it and impossible to get out. Also the cover for the tire well is a big sheet of plastic pretty much. Will the weight of the box be enough to hold it down so that it won't vibrate it?

I sm trying to get my trunk ready for everything but before I start deadening I need to decide what to do with my spare tire well. I know I cant leave everything in there cuz it will vibrate like a mother. But if I take everything out there is just a big hole so what can I do to cover this that won't cause any noise?

Ok I have seen boxes with the ports sticking out of the boxes, how does this work? Wouldn't his still give the same port length but without sacrificing box space?

Yes it is going to be a fully loaded 18" BTL. I want the sub to be firing up with the ports back.

What are the disadvantages of this? It seems like an easy way to make a port without sacrificing so much box space, so if it was as flawless as it seems then everyone would do it.

Ok I was looking at my trunk and if I want to make a 8 cubic foot box the only way I am going to be able to do it is make an odd shaped box ported, or do aeroports. I am just wondering how I would tune a 8 cubic foot box after displacement for 32 hz with aeroports. I am kinda new to these and I was looking at info on how to use them and I am just majorly confused.

Ok I hav e one question how do you do ports like this? I have been thinking about it and I think this is the only way that I will be able to egt a 8 cu f.t box in my trunk. Can someone help me do the math on tuning for something like this. I don't mean to jack the thread or anything but it looks like you guys could help me.

Ok one last question where can I find the specs for these, like the RMS rating, mounting depth, cutout diameter, everything. I have looked all over the website and can't find a thing. Also is the 100.4 sundown the only thing I need to run them active? Or do I need a HU with certain capabilities?

Well I do like quality, and I if I turn it up that loud I can't expect the BTL to blend in any way very good with any set of speakers. But I want to be able to turn down the sub, put on some zeppelin and and just be blown away. If I have to find a way to make 6.5's work then I will. Also if nessicary I will get the legatia series and more power if needed, i don't wanna half ass this.

I am trying to come up with a good design for a ported box for a 18" BTL. Now it is going to be in my trunk but I am going to try to get a full 8 cubic feet. It can be 41" wide, 29 inches deep, and the tallest it can be is 18.5" and that is exactly right size for a 18" BTL. The only problem I have had is that I know it is going to need some kind of bracing and since I have no idea how to go about that I don't know how to calculate in the displacement of the extra bracing, and I don't know how to figuire out how big I will have to make my port to be at about 30hz. If it is under 8 which I'm sure it probably will be I'm fine with that I guess, but I need some help on how to get this started.

Wow that really sounds good, especially since I had always been told that I would be pretty much screwed for finding good midranges in a 5.25, thanks a lot. one other question how do you think these will react running on the 100.4 if I am going to have a 18" BTL running on a sundown 3000? I'm confident in that they will sound great but will they be powerful enough not too be too drowned out if I want to crank up the bass?

Thats kinda what I wanted to do I just didn't know if mixing up batteries like that would cause any problems. Also my battery is under my back seat and it is a 3.8 so I could fit another inch taller if I needed the extra power.