Subwoofer Project

[catacon]

Hey guys!

I just received the driver and port for the subwoofer I am planning to build. I'm using the Dayton RSS315HF-4 12" Hige Fidelity Subwoofer and an 18" x 4" flared port and a 250W amp (which I still have to buy). I'm using this design (http://www.rogues-guild.com/sub plans.pdf, Hi Ho used this design and has been helping with it). I just have a few questions.

1) The port length thing is confusing me. The equation that comes with the port:

Lv = [8466.4r^2 / (Vb)Fb^2] - 1.463r

Vb = 6.162
Fb = 23Hz
r = 2

gives me a port length of 9" if I tune to 23 Hz (which is the low end of the subwoofers response range). That doesn't seem right. Should I be tuning lower (16Hz) or am I doing the equation wrong?

2) I need to biscuit joint everything, right? I don't have a biscuit joiner and am trying to get one, but was just making sure I actually needed it.

That's it for now. I might have more questions later.

Thanks!

 

[3x10^8]

Your link does not work.

 

[catacon]

It should now. Sorry.

My neighbor has a biscuit joiner so I got that answered.

 

[catacon]

Bump......

 

[catacon]

Well, I redid the equation and got a length of like 17" so I guess I just leave the port at 18", can't hurt, can it? One more question, do I need to secure the wires going from the amp to the driver, or is it OK to let them dangle? If so, what is the best way to do that?

Thanks!

 

[catacon]

Anyone at all...

 

[annunaki]

Which enclosure volume are you using? That will dictate your port length for tuning.

In the large 142.5L enclosure (4.3 of the linked document), I believe they said a 4" flared port with the full length center tube (12"), plus the ends, for a total near 18" would be all that is necessary for an 18hz tune.

 

[catacon]

I think the volume is 6.6 cubed ft. (22.5 x 22.5 x 22.5) When I said 18" I meant the entire length, including the ends.

 

[annunaki]

That is what I am saying as well. You cannot go by external dimensions either. The internal dimensions less the bracing and woofer displacement will get you true internal volume.

 

[catacon]

I guess the internal volume is like 5.95 ft^3. If I did the equation right, that give me an overall length of like 15.5" (internal piece is 9").

 

[annunaki]

That sounds about right for an 18hz tune with a 4" diameter port.

 

[catacon]

Do I need any gasket tape?

 

[catacon]

So I still don't know, do I need any gasket tape? And is it necessary to secure the wires?

Thanks!

 

[annunaki]

Gasket tape for the sub woofer would be fine. You could also put some around the port where it attaches to the outside of the enclosure. Securing the wires is optional. Most do it to avoid any possible issues.

 

[catacon]

Can I get gasket tape at a local store? I'd rather not make another order to PE. Two more questions: How do I secure the wires? and I was looking a the joints on the port and on the inside, there seems to be a lip. I was wondering if this was normal or should that not be there?

Thanks a lot!

 

[seattle_ice]

If you get gasket tape at the hardware store, make sure it is the high density closed cell type, not the open cell foam.

I just built a similar subwoofer, using the shiva plans, an Assasin 12" and the remote controlled 250 watt plate amp from parts express. I cut 1" from the full length port, and used gasket tape under the port and speaker.

That thing shakes the room watching movies. It feels like the wind is blowing my hair on the pod races.

It is a little 'loose' on the music for my taste, but some of that is undoubtedly the room and the positioning of the sub.

Now I need to make a couple of those Eros MkII speakers, and get rid of the crappy pioneers I have for my front speakers.

 

[catacon]

Well I finally got this subwoofer done. It took about 2.5 weeks (more like 1 because I was out of town and work got in the way). This thing is amazing. It fills the room with bass and has a rich, full sound. It works very well for movies and music (and an end table).

Thanks for all the help everybody!

Here are the specs:
Dayton RSS315HF-4 12" High-Fidelity Subwoofer
250W plate amp with remote
18" x 4" port
3/4" MDF, biscuit joined

I'll get some pics up soon.

 

[catacon]

Alright, here are the pics.

http://s100.photobucket.com/albums/m4/catacon/Subwoofer Project/

 

[Hi Ho]

Hmmmm... That looks familiar. Great job! That looks really nice! Are you going to keep that nice MDF finish for a year like I did?

 

[catacon]

I will veneer it, I just don't know when. I am going to build some speakers soon, so when I get those done I will veneer and stain everything. I'm thinking mahogany with a redish stain, should look pretty cool.