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Info on Home Subwoofer Enclosure


Allright so I have this 18" 8ohm sub and want to make a boxfor it and use for my surrund sound sub but dont know what size to build the box and how to tune the port.NowI am awoodworker and know exactley how to build the box but not what size.Any info or where to get info would be great,thanks.

Contact the manufacturer of the sub, there should be a spec sheet on it.

Is this for the bass in the background?

[quote]tedro wrote:
Contact the manufacturer of the sub, there should be a spec sheet on it.

Is this for the bass in the background?[/quote]

No its more less just a project,I have it I like building stuff thats about it.

Do a qick Google search, mate. There’s lot of info and formula for this stuff.

It’s actually not as simple as making a box about yay big if you want the sound output to be quality.

How are you planning on driving it? Most subs have internal amps. If you are planning on driving it with a typical reciever it will probably be underpowered.

Check this link, they have everything you’ll need, crossovers, amps etc…

http://www.partsexpress.com/speaker-building.cfm

An 18 inch subwoofer needs at least 1000 watts just to give it some bounce to make it move. Is the surround system in your house or car? In any case, if properly powered, the bass will be so low and loud, it could blow the windows out of a small room, and the vibrations could rattle pictures off the walls.

[quote]Yo Momma wrote:
An 18 inch subwoofer needs at least 1000 watts just to give it some bounce to make it move. Is the surround system in your house or car? In any case, if properly powered, the bass will be so low and loud, it could blow the windows out of a small room, and the vibrations could rattle pictures off the walls. [/quote]

That’s why I asked him if it was for his bass. I figured he was going to use it for a gig. That’s borderline crazy to put in your car or house.

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[quote]Yo Momma wrote:
An 18 inch subwoofer needs at least 1000 watts just to give it some bounce to make it move. Is the surround system in your house or car? In any case, if properly powered, the bass will be so low and loud, it could blow the windows out of a small room, and the vibrations could rattle pictures off the walls. [/quote]

Well thats fine,Its a project I have the speaker and i work in a wood shop so i am gonna build it as a project but still want it to sound good and last.

It’s not trivial to make one that actually sounds good. There’s a bunch of formulas, but you also have to actually do some measurements after that, and tune the box. You need to know how to listen to a speaker (good ears and a sense of what “sounds good”), you need instruments to measure the sound level and put some numbers on what you hear, you need a “dead chamber” to do measurements in, and you need equipment to generate the signal at different frequencies.

Realistically, the only way is to find a plan for a subwoofer made by a good company using the same speaker model, and replicate it exactly. Even then, it probably won’t sound the same without tuning.

Making speaker enclosures that actually sound good is not like slapping a turbo on a Mustang. It’s not something a guy can do in his garage over the weekend.
Yes, there are many people who “build subwoofers”. But then, there are many people who slap some bling on a Miata and call it a sports car. To each his own.

You’re probably better off selling the speaker on eBay, then just buy a 'woofer.
For 'woofers that are cheap yet sound pretty good, one brand that I like is Cambridge Soundworks.

http://www.cambridgesoundworks.com/store/category.cgi?category=spk_subwoofer

I’ve a slightly older revision (before they were bought by Creative) of their Bass Cube 100 in my living room and it actually sounds like a bigger, more expensive 'woofer, provided that the room is rather small (like mine). The sound is full and clean, driven with surprising authority for such a small subwoofer. The low end is 35 Hz - I’ve seen better numbers, but in a small room it’s hard to excite frequencies lower than that.
In a large room it would probably suck, but I’m happy with it in my little house.

AVSforum.com has a DIY speaker and sub section. I was just looking thru it the other day and I thought I saw some plans for an 18" driver box. If I remember correctly you’re gonna have to build a big box for that thing.

link: http://www.avsforum.com/avs-vb/forumdisplay.php?f=155

hope that helps.

J

[quote]bushidobadboy wrote:
I would use a sealed enclosure, with shitloads of foam on the inside to minimise fuzziness caused by sound wave reflection from the inner walls. resonance is something to be avoided at all costs, lol.

You can also minimise resonance/buzzing/loss of sound clarity, by baffling the inside, ising ‘eggbox’ foam, and tapering the cab, so that the backwash from the cone does not hit any surface square on.[/quote]

Ah yes, a sealed box is relatively easy to build correctly.

But then, it has pretty low efficiency - you have to really pump it up to get good volume. It’s also not very good at very low frequencies - it acts as a damper.

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[quote]florin wrote:
It’s not trivial to make one that actually sounds good. There’s a bunch of formulas, but you also have to actually do some measurements after that, and tune the box. You need to know how to listen to a speaker (good ears and a sense of what "sounds good
[/quote]

This is really the most important element. If it sounds good to YOU, no further tweaking is necessary. One person’s noise is another’s music. I like my bass to make the floor jump. My neighbors think otherwise.

Some great advice here. Especially about this being an acoustic suspension (sealed) versus ported sub. It will require more power but have much tighter bass.

One other thing, do not make your enclosure from wood. Cost is not the only reason sub makers use medium density fiber board aka MDF. Wood will have unpredictable resonance giving you vibrations where you don’t want them.

[quote]Testy1 wrote:
Some great advice here. Especially about this being an acoustic suspension (sealed) versus ported sub. It will require more power but have much tighter bass.

One other thing, do not make your enclosure from wood. Cost is not the only reason sub makers use medium density fiber board aka MDF. Wood will have unpredictable resonance giving you vibrations where you don’t want them.[/quote]

What do you suggest,I was thinking about using HDF With lot of bracing.

[quote]horsepuss wrote:
Testy1 wrote:
Some great advice here. Especially about this being an acoustic suspension (sealed) versus ported sub. It will require more power but have much tighter bass.

One other thing, do not make your enclosure from wood. Cost is not the only reason sub makers use medium density fiber board aka MDF. Wood will have unpredictable resonance giving you vibrations where you don’t want them.

What do you suggest,I was thinking about using HDF With lot of bracing.[/quote]

That is a better choice than the MDF I mentioned. Just be sure to include the bracing in the total volume.