Speaker Guru's needed....

JayMan · 11-20-2002, 07:41 AM

Hey all, just need an opinion/advise on something to do with speakers.

Its not really PC related at all either.... So feel free to move to community if thats where it should be....

Basically its for my car, i currently have a sub box in my car with 2x 10inch pioneer 400watt subs. I'm not sure on the volume of the enclosure.....

The thing i want to know is, the box is currently fully sealed, would i get a better sound by porting the box? Also i heard that if you filled the encloser with a dampening material it will help to give a "deeper"/"richer" sound.....

What does everyone think???

Thanks

JayMan

OuTpaTienT · 11-20-2002, 07:54 AM

You should definitely have dampening material in there no matter what.

As for ported or not, that depends on if the speakers are designed to be ported or not. Some speakers can't handle being ported because it allows for too much movement of the cone. And some speakers aren't well suited for a sealed enclosure because it takes too much power to drive them.

There is a specific formula to figure out what the volume of the enclosure should be. Let me see if I can find it.

OuTpaTienT · 11-20-2002, 07:57 AM

Speaker Enclosure Volume Calculator

crazyray · 11-20-2002, 10:57 AM

JayMan, I ASSUME that the current enclosure was properly designed for the subs that are in it. If that is true, it is HIGHLY unlikely that a ported version of the same box would improve the sound you are getting. This stuff is (fortunately) no longer an area ruled by trial and error or "witchcraft". Science can actually help!

Subs should have specifications with them. The key ones for our purposes are Vas, Fs, Qts, and Qes. You can plug the specs into this free windows program and get an idea what a suitable box type and volume would be...

http://www.mobiledynamics.com/main/t...special.html#F

If not available there, try here:

http://www.nightstormer.com/software.htm

Look along the left side of the page for free box design software. For car audio, a sealed box is usually designed for a system Q of about 0.8 to 0.9.

Using dacron polyfill inside a sealed sub box is likely to help. Use about 1 pound per cu ft of internal volume. Be sure to place it in the box in such a way that it does not impinge on the speaker cone.

woodbutcher · 11-20-2002, 11:22 AM

Both Out and cr are on the money.
The only thing I would add is from my exp. in home theatre installs (having built custom enclosures for subs) companys such as boston acoustis will have actaul specs on enclourse size for each type of sub as well as port size recomendations.
I don't know if pioneer offers this.

WB

JayMan · 11-20-2002, 05:38 PM

I'll checkout the specs when i get home, but i'm pretty sure the sub aren't designed for a sealed enclosure.

The box & subs were actually just thrown together, not really designed specially for each other.

JayMan

crazyray · 11-20-2002, 09:20 PM

A quick look at Pioneer's website shows they do indeed recommend certain types and sizes of enclosures for their current line of subs. Check it out.

JayMan · 11-21-2002, 02:16 AM

Speaker Model: TS-W254F
Revc: 3.0
Levc: 0.822
Fs: 39.2
Qms: 6.836
Qes: 0.862
Qts: 0.765
Vas: 36.16
Rms: 2.811
Mms: 78.12
Cms: 2.108x10^-4
Diam: 211
DL: 8.303
Xmax: 8.0

Hehe i've got no idea what all that means! Can anyone explain it all to me??

JayMan

JayMan · 11-21-2002, 02:18 AM

Also, how could i work out the volume of the enclosure they are in??

JayMan

OuTpaTienT · 11-21-2002, 02:29 AM

Hello?

Speaker Enclosure Volume Calculator

The calculator(s) there says this about your speaker:

- This speaker is better suited for SEALED enclosures.

- Total box volume 1.5 cubic feet. For a plain rectangular box that would measure 12"x12"x18" (HxWxD) and that's the measurements of the INSIDE of the box.

There's also a calculator there if you want to make boxes with an angled face.