spare tire box questions

[Bossman150]

I am in the early phases of planning a spare tire fiberglass box build for my 2012 Maxima. I have seen another build thread on one of the Maxima forums and the box ended up being 3.5 ft, which is more than enough for either 1 or 2 JL 10w6 subs. I currently have one in a crappy prefab .75 ported box and it sounds really fantastic despite the crappy prefab.

I am fairly certain I could do a simple sealed box without much issue. I think however I would like a ported box and I'm not sure how to go about that with this type of build. What type of port would be best so I can do some research? With this type of build would sealed be better?

I know I don't have my measurements and I should before I ask, but I really don't want to take everything out of my trunk until I have to. I am just looking for some ideas or direction. I was planning on waiting until winter to do this, but I really hate looking at the stupid box in my trunk so I would like to do this sooner rather than later.

Also, can I build it in such a way that I can just use the one w6 I have now and add another down the road if I decided I need it? I am a total noob when it comes to box building...

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[bubbagumper6 5,000+ posts]

Sealed will be your easiest option as it's difficult to calculate the volume of a fiberglass enclosure (not impossible though). You'll definitely want to look at aero ports for this. If it were me I would through together a rough design of a ported enclosure (just size and tuning) that I'm aiming for then build the fiberglass enclosure to be approximately the right size for the gross volume. Then measure the actual volume, refine the port tuning/length and install the port. However if all of this sounds over your head you may want to just go sealed. You'll definitely have less output but also less chance of you f***ing it up...

As for building an enclosure that would allow you to add another sub later, that's easy with sealed, much more difficult with ported.

 

[Bossman150]

Sealed will be your easiest option as it's difficult to calculate the volume of a fiberglass enclosure (not impossible though). You'll definitely want to look at aero ports for this. If it were me I would through together a rough design of a ported enclosure (just size and tuning) that I'm aiming for then build the fiberglass enclosure to be approximately the right size for the gross volume. Then measure the actual volume, refine the port tuning/length and install the port. However if all of this sounds over your head you may want to just go sealed. You'll definitely have less output but also less chance of you f***ing it up...
As for building an enclosure that would allow you to add another sub later, that's easy with sealed, much more difficult with ported.

Thanks, it sounds WAY over my head lol. I think I will have to go sealed, I am pretty sure the output will be plenty especially if I have the option of adding a second sub. So for keeping the option open for a second, is it just as simple as dividing the enclosure in half and sealing them separately?

 

[CSCStang]

Yes

 

[Bossman150]

Yes

Thanks. CSCStang is it even feasible to build an MDF box that would fit in a spare tire spot, so I could hire you for instance to build one so I could go ported? I have only seen the fiber glass ones so not sure if this is a dumb question or not. I don't know the exact dimensons but I could get them, but I do know my car has the round kind, so I would guess I would lose a lot of space trying to go MDF instead of fiberglass.

 

[bubbagumper6 5,000+ posts]

Thanks. CSCStang is it even feasible to build an MDF box that would fit in a spare tire spot, so I could hire you for instance to build one so I could go ported? I have only seen the fiber glass ones so not sure if this is a dumb question or not. I don't know the exact dimensons but I could get them, but I do know my car has the round kind, so I would guess I would lose a lot of space trying to go MDF instead of fiberglass.

Yes, it's entirely possibly to build one however you will lose some airspace as it will not fit the space as perfectly as fiberglass will. Also keep in mind ported enclosures need more airspace than sealed.

 

[budahbuddy803 10+ year member]

I agree with bubba. Build your spare tire enclosure, sealed. Find the volume of your enclosure. If the interior is all glass you can do this by filling it with water, then measuring how much water it held. If the volume is enough for a porter enclosure, check the amount of port area you need for that size enclosure. Get an aeroport and cut it to the desired length. Cut a hole in the top baffle and mount the aeroport. I would love to do a spare tire enclosure, but I drive pretty long distances relatively often and would be SOL on the side of the road if I get a flat.

 

[CSCStang]

Thanks. CSCStang is it even feasible to build an MDF box that would fit in a spare tire spot, so I could hire you for instance to build one so I could go ported? I have only seen the fiber glass ones so not sure if this is a dumb question or not. I don't know the exact dimensons but I could get them, but I do know my car has the round kind, so I would guess I would lose a lot of space trying to go MDF instead of fiberglass.

Pm me

 

[Bossman150]

Ok I just spent a couple hours listening to some of my favorite songs first in the .75 ported box. Then I moved the sub to a sealed 1.2 box(first removing and then installing 10 drywall screws into 3/4inch MDF by hand blows!!), which is a better made box then the ported one, but it's also more than double the size that JL recommends for 1 10w6. I listened to the same songs over again. I don't know if I am correct on some of these observations, but the ported box was louder, but maybe sloppier sounding? It was overwhelming in a few songs. It sounded wonderful for rap and good for the rock and country songs, other than the couple it overwhelmed. When I switched to the sealed box it was not as loud, but felt more powerful and precise. One thing I noticed is it seemed to take more power? I noticed my headlights dimming with the sealed a bit at idle and I don't remember seeing that with the ported box. I much preferred the sound of the sealed box for the rock and country songs, but it was a bit diminished in a couple of them. It was not as loud with the rap but still sounded great.

First off am I going to hurt the sub playing it in a box that is much bigger then JL recommends? I think I might have to go with the above idea and do a sealed box, listen and see if I am happy with it. If not I can fill it with water to determine the size and add a port.

Between these two boxes the sealed wins bar far, but the ported box is a piece of sh*t and I have no idea what it's tuned at or if its even properly done, I highly doubt it is.