speaker box
Le Mans Master
Joined: Apr 2004
Posts: 7,106
Likes: 38
From: Newark DE
stoly
the KEY to making the subwoofer sound good is proper enclosure design. The airspace inside the enclosure must be correct for the sub choosen or even the best subwoofer on the market will sound like crap. I have never measured the air space inside the well behind the seats but that would be the very first thing that i'd recommend you do. Only than, based on the air space inside would I than choose the correct subwoofer to go into that space. With the amount of air, it may be perfect for one model 10" over another model 10" because of the different specs of the different models......or you may find that two 8' work out better in that space, or you may have to devide off one section of the well from the other section to actually make the airspace inside smaller to match up to a choosen sub.
The easies way to maesure the airspace inside an odd shaped area such as the well is to fill it with water, than measure the amount of water inside.
As mentioned previously, I usually recommend a sealed enclosure for subs rather than a ported enclosure. This is for a couple of reasons.
1. better power handling. A sealed enclosure offered a higher power handling ability for the sub
2. a tighter, more accurate, harder hitting bass response.
this is because the air inside the sealed enclosure act as an air suspension for the subwoofer and helps to control the subs movements. A ported enclouse doesn't offer this and a sub can easily sound loose and sloppy.
A sealed enclosure is typically smaller than a ported one because of the way the air works with the subwoofer.
In our car especially where room is very limited, just the smaller enclosure is reason enough to go with a sealed design.
When I say SEALED, i really mean completely and totally airtight with no leaks what-so-ever.
that means that if you cut an MDF board as a new cover and to mount the sub(s) on, the cover than must be sealed with silicone to make it airtight. Are you willing to make that modification to your car? it also means you have absolutely no other use in that well such as to store your jack, etc.
If you are willing to give up your well for use as your enclosure it is the easiest way to go though.
another option would be to line the well with a protective plastic, and make a mold of the well with fiberglass for the sides and bottom. Remove this "shell" than use your MDF to make a mounting plate for the top and fiberglass that on to your new subbox shell. This would allow you to have an excellent subbox (fiberglass is great for boxes because it won't resonate) plus it is molded exactly to the shape of your well so you know it fits perfect, and it's not permantly adhered to the interior so you can remove it at any time and return your car to stock without damage.
If you measure the airspace correctly and choose the correct sub to work in that available space, you may even be able to make it work with only needing a fiberglass subbox that fits on one side of the well and the other side is still available for your jack, tools, whatever. just make the top cover the size and shape to stretch all the way over the well and it will look good, cover everything, and yet the sub is only on one side. You may be able to design that top cover so it hinges up on that one side only to give yo easy access to your tools and not disturb the subbos side itself.
Regarding dynamat: The main purpose of dynamat is to reduce resonation which is particually troublsome with metal body panels on cars. i'm sure you hear these kids with big subs in the trunk and the whole truck lid of the car is resonating like crazy. Fiberglass typically won't do that which is why it's an excellent material for subboxes. Many installers even take a standard wooden enclosure and will line the interior in fiberglass for this very reason. Because of that, installing dynamat on the inside of a fiberglass well is a bit useless. You are trying to use the dynamat to eliminate a problem which shouldn't crop up anyway because the material you are applying it to (fiberglass) does not usually exhibit the problem the dynamat is designed to stop.
the KEY to making the subwoofer sound good is proper enclosure design. The airspace inside the enclosure must be correct for the sub choosen or even the best subwoofer on the market will sound like crap. I have never measured the air space inside the well behind the seats but that would be the very first thing that i'd recommend you do. Only than, based on the air space inside would I than choose the correct subwoofer to go into that space. With the amount of air, it may be perfect for one model 10" over another model 10" because of the different specs of the different models......or you may find that two 8' work out better in that space, or you may have to devide off one section of the well from the other section to actually make the airspace inside smaller to match up to a choosen sub.
The easies way to maesure the airspace inside an odd shaped area such as the well is to fill it with water, than measure the amount of water inside.
As mentioned previously, I usually recommend a sealed enclosure for subs rather than a ported enclosure. This is for a couple of reasons.
1. better power handling. A sealed enclosure offered a higher power handling ability for the sub
2. a tighter, more accurate, harder hitting bass response.
this is because the air inside the sealed enclosure act as an air suspension for the subwoofer and helps to control the subs movements. A ported enclouse doesn't offer this and a sub can easily sound loose and sloppy.
A sealed enclosure is typically smaller than a ported one because of the way the air works with the subwoofer.
In our car especially where room is very limited, just the smaller enclosure is reason enough to go with a sealed design.
When I say SEALED, i really mean completely and totally airtight with no leaks what-so-ever.
that means that if you cut an MDF board as a new cover and to mount the sub(s) on, the cover than must be sealed with silicone to make it airtight. Are you willing to make that modification to your car? it also means you have absolutely no other use in that well such as to store your jack, etc.
If you are willing to give up your well for use as your enclosure it is the easiest way to go though.
another option would be to line the well with a protective plastic, and make a mold of the well with fiberglass for the sides and bottom. Remove this "shell" than use your MDF to make a mounting plate for the top and fiberglass that on to your new subbox shell. This would allow you to have an excellent subbox (fiberglass is great for boxes because it won't resonate) plus it is molded exactly to the shape of your well so you know it fits perfect, and it's not permantly adhered to the interior so you can remove it at any time and return your car to stock without damage.
If you measure the airspace correctly and choose the correct sub to work in that available space, you may even be able to make it work with only needing a fiberglass subbox that fits on one side of the well and the other side is still available for your jack, tools, whatever. just make the top cover the size and shape to stretch all the way over the well and it will look good, cover everything, and yet the sub is only on one side. You may be able to design that top cover so it hinges up on that one side only to give yo easy access to your tools and not disturb the subbos side itself.
Regarding dynamat: The main purpose of dynamat is to reduce resonation which is particually troublsome with metal body panels on cars. i'm sure you hear these kids with big subs in the trunk and the whole truck lid of the car is resonating like crazy. Fiberglass typically won't do that which is why it's an excellent material for subboxes. Many installers even take a standard wooden enclosure and will line the interior in fiberglass for this very reason. Because of that, installing dynamat on the inside of a fiberglass well is a bit useless. You are trying to use the dynamat to eliminate a problem which shouldn't crop up anyway because the material you are applying it to (fiberglass) does not usually exhibit the problem the dynamat is designed to stop.
Intermediate
Joined: Mar 2003
Posts: 26
Likes: 0
From: Vancouver BC
Barry,
Thanks for the comments. I have measured it and just meets the recommended cubic volume. I will only be using the one side, the other will be for storage. I like the idea of creating its own fibreglass box but thought I would try it this way first. I'm going to attach a foam/rubber seal around the top MDF panel to help seal the enclosure.
And as for the Dynamat, I was simply going to use it to make the fibreglass more rigid as it seems flimsy compared to a wooden enclosure. I'm not sure that sonically it sould be that flexible or lacking in density. Building the slip in enclosure would certainly help, but I'll try without the matting first.
Thanks for the comments. I have measured it and just meets the recommended cubic volume. I will only be using the one side, the other will be for storage. I like the idea of creating its own fibreglass box but thought I would try it this way first. I'm going to attach a foam/rubber seal around the top MDF panel to help seal the enclosure.
And as for the Dynamat, I was simply going to use it to make the fibreglass more rigid as it seems flimsy compared to a wooden enclosure. I'm not sure that sonically it sould be that flexible or lacking in density. Building the slip in enclosure would certainly help, but I'll try without the matting first.
