It depends on how you want the speaker to sound. When designing an enclosure, the first thing to do is determine what Q factor you want. The Q factor determines overall sound quality. The lower the number, the deeper and tighter the bass will be. The higher the number, the more "punchy" the bass will be. A bigger box will yield a lower Q factor, and vice versa.

Here are some sample Q factors:

-- 0.9 : general automotive use (very boomy, and weak in the lower frequencies)
-- 0.8 : "high-end" automotive use (not as boomy, and a little richer than the above)
-- 0.7 : all-around home theater and music (not very boomy, pretty tight, and pretty rich)
-- 0.6 : audiophile quality (very tight and rich)

If the Q goes above 0.9, the bass will sound boomy and distorted. And if it goes below 0.6, the bass will sound flat and "dry". Since space is usually at a premium in an automobile, speakers are usually put in high-Q enclosures, with electronic gadgetry (equalization, bass boost, etc) to correct the sound quality.

So for an automotive speaker, stuffing the enclosure and/or using a slightly larger one will definately improve sound quality. It will also reduce (possibly even negate) the need for bass boost and/or equalization to get the desired frequency response. You should still use a crossover, though. Crossovers are critical to sound quality, no matter what size/style enclosure you use.

This website should provide some useful info: The Subwoofer DIY Page

[This message has been edited by Blacktree (edited 04-26-2005).]

Ok, I finally finished the box, here it is with a coat of bondo

Here it is sanded and ready for paint

Here is the terminal from the outside, no air is getting past liquid nails. ( don't mind the random peice of tin foil in the fiberglass, it got stuck to it, I was too lazy to pull it out )

Here is the terminal from the insied

And here is the basicly final product, all painted and ready for install eccept the bracket, and sub.

I only chose to finish off the end of the box because that is the only part that may be seen.

I will have a few more updates as soon as I fab up the bracket, and install the sub.

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[This message has been edited by Golden86 (edited 04-27-2005).]

Very nice

quote Originally posted by Golden86: Just to let you know, I measured the old box I built, the black one in the pics above. the box measured .3 cubic feet empty, and the sub took up only .02 cubic feet. So that gave me a working volume of .27 cubic feet. Its not a ton of space, but it is better than nothing.

I was surprised to take .02 cubic feet and stick it in my convert program and see it's 34.56 cubic inches... I was thinking that had to be a typo and it was just a couple of inches. Hard to wrap my head around the sizes visually.

Fantastic work Golden, you should really market those.

Blacktree, you have a PM.

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quote Originally posted by Scott-Wa: I was surprised to take .02 cubic feet and stick it in my convert program and see it's 34.56 cubic inches... I was thinking that had to be a typo and it was just a couple of inches. Hard to wrap my head around the sizes visually.

Well, it really isnt that much space. If you think of a box that is 3.25" x 3.25" x3.25" it comes out to be around 34 cubic inches. I don't think that is that big at all for a sub.

Golden,

Is there any chance you would make more of these? For sale to me/pennocks?

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Thanks Aus!
More info at: https://www.fiero.nl/forum/Forum1/HTML/043357.html

if he doesn't i'll be happy to copy him at some point this summer

well, everybody wants one of these, but I REALLY don't want to make any more, because of the hassel, and my daily job. I mean, I would have to sell it for some outrageous price like $200 so I can make a profite off of the many hours I put into them. I really appreciate all the comments, and I hope to have it done by today if I can get all the parts for the bracket.

quote Originally posted by Golden86: The tallest point on the box is 10" exactly, and it has and OD of 8.75", and an ID of about 8"

How in the WORLD did you get that to fit? Did you cut off the blue ding thing bracket? Go with low profile 4x10 speakers in the dash? I think max i can fit about 8" of height.....

quote Originally posted by Golden86:I would have to sell it for some outrageous price like $200 so I can make a profite off of the many hours I put into them.

What makes you think you would ANY money from us ungrateful Fiero owners?

quote Originally posted by ryan.hess: How in the WORLD did you get that to fit? Did you cut off the blue ding thing bracket? Go with low profile 4x10 speakers in the dash? I think max i can fit about 8" of height.....

Yes I did have to remove the bracket, and move a few other thing under there. I also have HUGE 4x10 magnets, they are audiobahn, aswell as a crossover under there. I still have room to spare.

hey Golden - what are you doing with your old one?

Pictures are nice, thanks for taking the time to show us your progress- good job! Now it's time to include a sound clip!! Of couse this is only good for those who have a 5.1 speaker set up on your computer and crank up the bass!

quote Originally posted by Kohburn: hey Golden - what are you doing with your old one?

I sold it to a forum member about a year ago

Bump to the top so I can bookmark it....... Also for those of you who are building one of these, and plan to glass the inside of the tube, remove the layer of waxed paper first. Otherwise the glass won't stick to it. Luckily it just peels right off.

quote Originally posted by ryan.hess: Bump to the top so I can bookmark it....... Also for those of you who are building one of these, and plan to glass the inside of the tube, remove the layer of waxed paper first. Otherwise the glass won't stick to it. Luckily it just peels right off.

Good point about the wax paper, mine didn't have wax paper on the inside, but I did make sure to sand the tube before glassing it.

Hey Golden86, just wondering how this sounds and do you have any problems with rattling the dash?

I install for Best Buy, so I hear everything from our Rockford stuff up to JL, Xtant, JBL, kicker, you name it I heard it. To me this is the CLEAREST sub by far I have ever heard. It also hits like a decent 10" sub aswell. The only thing lacking is the low, low bass. but I knew it wasn't going to hit those notes when I first built the box, there just isn't enough room for a larger box.

The ONLY thing that rattle in my car is some coins that fell under my center counsel, the dash is perfectly silent.

Thanks, I think I'll try something similar, I looked under there yesterday and there isn't a lot of room is there.

Haaa, the task of getting a good bass in a sports car...

Hi Golden86, Thanks for the idea. I've made my sub enclosures a while back based on it -

#1 stealth 8" - under the dash 11*8*6 inch (No AC unit) (grille installed later)

#2 Pax side 10" - custom design to fit the curve in the floor

Today I'm running with the 8" only supported by 2 bass transducers in the seat backs

[This message has been edited by Mister (edited 06-10-2005).]

I have been getting a lot of PM's and email's about my enclosure, so I thought it would be a good idea to re-open this thread and kinda give an update. Everything has been installed, and it sounds great. I have a Rockford Fosgate 3001 mono amp pushing around 300 watts RMS @ 4 ohms. A Rockford 4004 4-channel amp is powering my interior spaekers, it is pushing 115 watts RMS @ 4 ohms by 4. My front spaekers are Audiobahn 4x10's with external crossovers for the tweeter. My rear speakers are pioneer 4x6 plate speakers with external crossover for the tweeter. My head unit is an Alpine CDA-9855. I chose most of this stuff because I work at Best Buy, and I get an AMAZING deal on all of it. I am not saying any of this stuff is crap, actually the Alpine is one of the best head units I have ever heard.

Now, people have been asking me how far the sub sticks out, how it has been holding up with just that one bracket, ect, ect. So I took a few pics of it today just to show everybody. I have not had a chance to clean out my car, it looks like crap now.

These next few pics are of the sub from different views




My Alpine 9855

Amps up front

This last pic shows how the deck matches the rest of the dash, it has 512 custom colors. It actually matches perfectly in person, it didn't pick it up in the pic.

[This message has been edited by Golden86 (edited 06-30-2005).]

Looks Great! Hope to hear it at a show someday.

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www.centralohfiero.org
In loving memory of Harold Hummel (PFF 4WHEEL)
1936-2004

Thanks Golden the pictures are just what I needed. I'm going down today and getting the supplies to start building and order the sub today. I' send you pictures of what it turns out like. You can see what the car looks like here http://fieroswest.westcoastfiero.com/events/past/westfest/2005/donjones/index.htm
Thanks
Don

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85GT (twoloud)

bump for Aaron

quote Originally posted by Formula88: Not wanting to veer too far off topic, but what's up with Rockfish? Back in the day, they were awesome. Everyone raved about them. What happened? I'm very interested in getting something like this for my Formula, and I'd most likley go with an RF speaker and amp.

I dont get why people think RF is bad now. They are better than they were before. People have heard rumors, and thats about all there is behind them. I have a friend that works in Grand Rapids, Mi that works at the Rockford Fosgate Building. During his off time he does presentations to colleges about speakers. He recently showed me the difference between the new Rockford Line up and JL Audio line up. Wow is there a difference. He takes brand new subs, (ugh) slices the surround, and then the voice coil and is there a huge difference. JL has RF beat when it comes to low watts per sound. But then again most JL subs are 3ohm instead of 4ohm. But what it comes down to is if you have enough power to actually put the RMS to a RF sub, its gonna pound. Oh yeah there amps are very good too. I cannot find it on there site right now but they published a article on 'Old School vs New School' on there amps. Everytime the new school was beating the old stuff. My opinions might be a little biased

I had a chance to meet "The Golden86 Guy" @ the Michigan show.
We had a "Mini Stereo Show Off" at the end of the official show and I got to listen the setup he's got.
The subwoofer moves quit a bit and thumps pretty hard for such a small enclosure
It sounds good

Thanks again Golden86 for the idea and keep it blasting

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quote Originally posted by Mister: I had a chance to meet "The Golden86 Guy" @ the Michigan show. We had a "Mini Stereo Show Off" at the end of the official show and I got to listen the setup he's got. The subwoofer moves quit a bit and thumps pretty hard for such a small enclosure It sounds good Thanks again Golden86 for the idea and keep it blasting

Not a problem, it was nice to meet you and "Feel" your system. Those bass transducers are pretty cool. I actually added a different amp to my linup, so now the sub is getting about 100 more watts

quote Originally posted by Mister: I had a chance to meet "The Golden86 Guy" @ the Michigan show. We had a "Mini Stereo Show Off" at the end of the official show and I got to listen the setup he's got. The subwoofer moves quit a bit and thumps pretty hard for such a small enclosure It sounds good Thanks again Golden86 for the idea and keep it blasting

??? someone else had a system at the mi show?? i saw 1 or 2 but none with this setup. Did you see me there? i was in the yellow 84 2m4 with the kicker L7 in the center counsel box (not finished) i rode around few times with it up a lil

(Mister) did i talk to you at the show when you were washing your car?

[This message has been edited by Fiero2m41 (edited 08-08-2005).]

Affirmative Fiero2m41, Keep working on that angled center console it sounded good!
Next show we'll have our own SPL contest...something to shake the dust off of the Fieros!

[This message has been edited by Mister (edited 08-09-2005).]

Hi all,

Bump for the newbies, and so'z I can add this to my favorites!................

I have a 12" L7 in my truck that i might be trying to get in my car.....we will see how that goes.
Ross

Is there a build thread on the original box? I would like to see how the other box was built as well.

HI all,

Pm sent to you golden..............

Great thread and information

great thread! It's spawned new life =D
https://www.fiero.nl/forum/Forum1/HTML/057646.html

sweetness!