Help design ported box

Home / the12volt's Install Bay / Car Audio / Help design ported box (

Topic Closed)

Welcome Guest :)

Members

< Prev Page < Prev Topic Next Topic >

DYohn

Moderator - Posts: 10,741

This member has made a donation to the12volt.com. Click here for more info.

This member has been recognized as an authority in Electrical Theory. Click here for more info.

This member has been recognized as an authority in Mobile Audio and Video. Click here for more info.

Joined: April 22, 2003

Location: Arizona, United States

Posted: February 06, 2005 at 10:03 AM / IP Logged

You could design an arrangement with four woofers in the same airspace facing different directions. It's called a "push-pull" setup. My M&K home theatre subwoofer uses this kind of arrangement (M&K MX-350 MKII if you want to look it up.) The basic theory is to wire one out of phase with the other so that both cones move in the same linear direction at the same time. I'm not sure your design would work well as there are many other factors to consider other than simple air space, including precise damping, matching the woofers physical and electrcal performance (they must have the exact same compliance and displacement behavior) and using the correct amplifier and crossover. Also, many push-pull setups use customized electronic controls to ensure the subs move in precisely the same amounts (like Community Sound's servo subwoofer series.) So yes, it could be done. Do I recomend it? No.

Your next question is would 4 sealed woofers be "better" than 2 ported? What do you mean by "better?" Louder?

Support the12volt.com

tmorefi

Member - Posts: 31

Joined: October 01, 2002

Posted: February 06, 2005 at 1:22 PM / IP Logged

yes, louder. 4 in a sealed enclosure would be louder then 2 in a ported enclosure, right? That push/pull thing is way too over my head. I have a Hifonics bx1500d so i think if i wire 4 in parallel I should have enough power for them all..

DYohn

Moderator - Posts: 10,741

Joined: April 22, 2003

Location: Arizona, United States

Posted: February 06, 2005 at 1:36 PM / IP Logged

No. If you look at the graph on the ID technical information page for this woofer, it shows that in a ported alignment the woofer produces about +3-4db above the SPL of the same woofer in a sealed alignment (around the tuning frequency of 34Hz.) So 4 sealed (which will produce on average +3db more SPL than 2 of the same woofers sealed) would produce about the same SPL as 2 in the proper vented enclosure. If "loud" is what you're after, I recomend using a single 12" in a ported enclosure which should produce more SPL than 2 of those 8's.

Support the12volt.com

tmorefi

Member - Posts: 31

Joined: October 01, 2002

Posted: February 06, 2005 at 4:34 PM / IP Logged

unfortunately, i can't fit a 12 in the location. i am using the top of the box as a step to get into the boat. i previously had 2 10's firing down but that didn't work all that great so i'm want to go with 8's. so, 2 ported 8's will be equivalent on the spl side with 4 sealed... i guess that tells me which way to go.. i attached a pic of the 10's firing down and the location i need to put the box for clarity.

Help design ported box - Page 2 - Last Post -- posted image.

DYohn

Moderator - Posts: 10,741

Joined: April 22, 2003

Location: Arizona, United States

Posted: February 06, 2005 at 4:40 PM / IP Logged

And why do you think those 8's will produce more SPL than two 10's? All else being equal, in general more cone area = higher SPL.

Support the12volt.com

tmorefi

Member - Posts: 31

Joined: October 01, 2002

Posted: February 06, 2005 at 9:57 PM / IP Logged

Just having the 10's firing down didn't sound very good at all in my opinion. I was hoping to have the 8's fire into the hull of the boat. People who have done both said it helped drstically. I can't go high enough to have the 10's firing out to the side..

< Prev Page

Sorry, you can NOT post a reply.
This topic is closed.

Printable version

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

Search the12volt.com

Follow the12volt.com

Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

Help design ported box

Sorry, you can NOT post a reply.This topic is closed.

Sorry, you can NOT post a reply.
This topic is closed.