Sub box question.

[talonation777]

I've decided what kind of box I want to build for my 2g with the help of someones thread on here.
I have a few questions and need the help of an experienced audio installer, or someone knowledgable in this particular area. I think it'll be easier if I list and number my questions so people can answer certain ones, or all of them if their experience allows them.
Here is the link with the picture that shows the sum box I wish to build. Refer to pictures 2 and 3. (numbers can be found in the top right corner)

Questions:

1. What thickness of MDF wood should I use? 1/2", 5/8" or 3/4"?
2. Should I construct the box so it's sealed around the subs, or should I just make a piece to bolt the subs to and allow them to sit in my spare tire well and have that act as the box?
3. If I build a box around the subs, should I use fiberglass to seal it or wood glue?
4. How big of a box to subs need? Is there a certain capacity that the sub will preform best in, or will any capacity do?
5. Is it better to have the box ported as in the last picture? Or is a sealed box more beneficial?
6. Is MDF wood able to be painted? Or would it be better to just have the box carpeted?

Are there any other things I should consider before I attempt to build this box?
Any tips or advice will be helpful. Thanks alot.

 

[Taylor3180]

1. I'd recommend the 3/4 I workd for circuit city a little while installing systems and I myself used that to build my own
2. I'd seal it around the subs when you use your spare tire area it just tends to rattle alittle more usually somethin is down in there that you just can't find.
3. I would use wood glue on all ## joints and it can't hurt to go that extra mile and fiberglass all the corners up.
4. Some subs have recomendations hence why there is different size sub enclosures alot of times it depends on the sub size.
5. Alot of people argue the port no port option. I myself have had both and not really noticed any difference in the sound quality. Nor how hard the bass hit.
6. MDF Can definetley be painted as long as you use a good primier first I use it all the time as I am a carpenter now. But as far as your box goes I would just go ahead and carpet it because the carpet rubbing on carpet tends to hold the box from sliding around to much.

Just make it your own box. Can never hurt to get creative with shape and such. Also think about adding an amp rack if you don't want it to look like everyone else's setup where you just mount the amp to the back of a seat.

 

[DGajre777]

Box volume
This measurement, listed with each component subwoofer, tells you the recommended interior volume in cubic feet that an enclosure should have to get the best performance from the sub. A variation of 10-20 percent is generally acceptable.

Enclosure types

* Sealed box — A sealed box is an airtight enclosure housing your subwoofer. A sealed box is best for any music that demands tight, accurate bass. Expect flat response, deep bass extension, and excellent power handling. Since a sealed enclosure tends to require more power than a ported box, use an amplifier with ample wattage for optimum performance.

* Ported box — A ported box uses a vent (called a port) which allows movement of air in and out of the enclosure chamber. This additional air movement reinforces low bass response. You get more output from a ported box than you would from a sealed box at any given level of amplifier output. Some people simply prefer the sound of ported boxes for rap, techno, or any hard-driving music because they play louder than comparable sealed boxes.

http://www.crutchfield.com/learningcenter/car/subwoofers_glossary.html#enclosure_types


How to build a sub box - http://www.crutchfieldadvisor.com/S-uDZVwwzl8gA/learningcenter/car/subwoofers/box_building.html and

http://www.crutchfieldadvisor.com/reviews/20030701/customize_box.html

 

[RedTurboEclipse]

I have always been preferring sealed boxes because thats all I had personal experience with so I was biased. I sweeten my case by saying the already typical characterisics of sealed boxes with "quality" bass.

I have tried bandpass boxes too and I absolutely hated it. it was loud but the quality was very noticeably inferior.

Not until recently I said hey lets try a ported/vented box. After I finally experienced one I have changed the other box in my other DSM to a vented box. Not only does it hit harder and louder than my sealed boxes prior to the switch, the quality was still very good. This is now currently my choice. I listen to all types of music.

 

[DGajre777]

I agree, bandpass boxes suck! I had a bandpass box on my last car, then went to one 12" sealed. My Talon has a 2 x 12" sealed box. I've never heard a ported box in a DSM before.

 

[cbassgsx]

I would either a.. do it right and glass a REMOVABLE spare tire box
or b... buy or build a sealed box
ported and bandpass require knowledge of volume and port tuning to sound correct. Please don't just baffle your spare tire well its like the equivelent of venting to atmosphere using a fcd and running a stock boost gauge. Spooge boxes like that stopped being made buy professionals like 15 yrs ago. besides a fiberglass box only costs like $80 to build and a spooge box done correctly needs like $100 in dynamat alone

 

[turkeyman87]

I've had a sealed box, and a ported in my eclipse. I prefer Ported, because it had harder bass, and I don't think the guy who first replied to this had a hard hitting system, because when i went to ported, holy cow I noticed a HUGE difference.

 

[roadrunner2176]

1. use 3/4 mdf
2. Seal it with wood glue.
3. Unless you plan on going show fiberglass isn't worth it.
4. Depends on the speakers, porting, and displacement. Read the volumetric requirements for the speakers before building the box.
5. Ported will cause more wind noise, thrushing sound, and be more responsive. Sealed will be more clear and deep.
6. MDF can be painted just fine. But a roll of auto carpet for 10.00 is a longer better looking alternative in my opinion.

To offer some better information I would have to see what you are trying to build. All I ca tell you is the more solid it is the better it will be. Secure everything and recess the speaker rings for a better appearance. Have an idea of where you want things to go and how you want wires to be run.

 

[Talesin]

As an audiophile, I can only argue for the sound quality that a sealed box provides... if all you're after is rattle and thump, a ported box is the way to go, to make the most of the wattage you (and your drivers) can provide.
But for audio clarity and quality (of highest importance to me), nothing can surpass a properly done sealed box. You'll get more response and crisper hits, rather than the 'flabby' bass that most ricers trend toward. You could also theoretically do a hybrid box... the rear sealed to preserve clarity, and a front ported segment for acoustic resonance. There are formulae for how to build the port properly, though I don't have them handy... Google is your friend.
But with the amount of space that we have available in the back of a DSM, I'd say that a sealed box would give the best result for those actually inside the car... rather than the cars around you.

 

[gotgrip666]

the best sounding boxes are honestly store bought, unless you are exstremely well with fiberglass and would then do not make your own it will sound like complete but and the bass will muffle so much

 

[roadrunner2176]

Store bought boxes will not sound any better than a home made box. Its how you load them that makes them sound good.

Pre-built boxes usually come tuned to the speakers in them. If you build a box to the specs of the speaker your using, it will respond how its supposed to. Just putting a speaker into any ordinary box isn't going to produce quality sound.

Build you box for the speakers your using or buy a box with the recommendations your speakers require.

Fiberglass has nothing to do with the sound a box produces unless your using the insulation as a sound baffle. Fiberglass is purely for looks and custom installs. Most boxes are still produced with a wooden structure and covered with fiberglass to look better, cleaner.

 

[totalazneclipse]

If I remember correctly, most sub companys tell you what's recommened for the sub to get the most out of it. So I would consider that also. For example: http://mobile.jlaudio.com/pdfs/8-12W2_BDS.pdf gives you normal recommended enclosure dimensions.

That's IMO of course