the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
icon

How Does a Fibreglass Enclosure Work w/Sub Facing Inwards?


Post ReplyPost New Topic
< Prev Topic Next Topic >
rhysem123 
Member - Posts: 3
Member spacespace
Joined: December 23, 2006
Location: Australia
Posted: December 23, 2006 at 5:31 PM / IP Logged  

Hello all,

I was wondering how a fibreglass enclosure works when the sub is facing inwards.  Is there a certain amount of room needed inside the enclosure? Is it less than a sealed rectangular enclosure?

If you do not know what kind of box i am talking about, this is quite similar.

How Does a Fibreglass Enclosure Work w/Sub Facing Inwards? -- posted image.

Thank you

djdowdell 
Copper - Posts: 60
Copper spacespace
Joined: December 07, 2005
Location: Kentucky, United States
Posted: December 24, 2006 at 6:49 PM / IP Logged  
It works the same as a woofer normally mounted. Sealed enclosures are pretty forgiving of miscalculations of sizes, up to 30% if I'm not mistaken, so just build it to the specs of the sub and it should work just fine. Go for it!
Pure Noize
jlord16 
Silver - Posts: 322
Silver spacespace
Joined: September 08, 2005
Location: Australia
Posted: December 24, 2006 at 8:16 PM / IP Logged  
Works exactly the same as a normally mounted sub, this is becuase when you have the woofer basket mounted outwards (inverted) you wire the sub backwards ( ie + becomes - and - becomes +).  The airspace is simliar to that of a normal box but rember the sub dusnt displace any airspace like it would in a conventional box.  Good to see another aussie on here
Clarion DB36MP
Infinity Kappa Perfect 10"
Respone 800w Mono
ALPINE MRP-F250
*Custom fabrications*
otto34 
Member - Posts: 36
Member spacespace
Joined: May 01, 2006
Posted: December 27, 2006 at 10:33 PM / IP Logged  
I just got done with this one, this sub is going to be reverse mounted also.
How Does a Fibreglass Enclosure Work w/Sub Facing Inwards? -- posted image.
How Does a Fibreglass Enclosure Work w/Sub Facing Inwards? -- posted image.
ricoshay 
Copper - Posts: 67
Copper spacespace
Joined: March 23, 2006
Location: United States
Posted: December 29, 2006 at 12:14 PM / IP Logged  
that mountng style is often used when enough air space isn't available.  doen't make much difference in sound.
torquehead 
Copper - Posts: 144
Copper spacespace
Joined: January 15, 2006
Location: United States
Posted: December 30, 2006 at 10:50 PM / IP Logged  

The concept of the speaker working in that type of enclosure is all the same.  When the cone/magnet end of the speaker is inside the enclosure, it takes away from the internal volume, which is the reason its a good idea to have the specs around when building an enclosure.  So, if you poke the speakers rear end (magnet/basket) out of the enclosure, the enclosure can be smaller...a little.  So, when the speaker is inverted like this, the cone actually contains air specific volume also.  It should be figured as additional volume with the enclosure volume. 

So now there is 2 ways of figuring:  The enclosure can be smaller because it no longer contains the speaker magnet, basket, and the rear airspace of the cone.  Additionally, the enclosure can be even a little smaller because the cone is reversed, which adds to the overall internal air volume....regardless of the type of enclosure. 

djdowdell 
Copper - Posts: 60
Copper spacespace
Joined: December 07, 2005
Location: Kentucky, United States
Posted: January 02, 2007 at 12:41 AM / IP Logged  

otto34 wrote:
I just got done with this one, this sub is going to be reverse mounted also.
How Does a Fibreglass Enclosure Work w/Sub Facing Inwards? -- posted image.
How Does a Fibreglass Enclosure Work w/Sub Facing Inwards? -- posted image.

Oh......I see. From the first picture you posted I assumed you were using a sealed enclosure, but what you are building is a ported one so the 30% rule does not apply. Ported boxes are not as forgiving. I am not sure how far off you can be on a ported box...it depends on the tuning frequency you are shooting for, especially if you are going for spl or just an overall uniform sound. That brings in a lot of factors like roll of frequency, resonant frequncies of the interior and sub, etc.. If anyone can chime in with a more clear answer help me out, otherwise I gotta dig out my notes!How Does a Fibreglass Enclosure Work w/Sub Facing Inwards? -- posted image.

Pure Noize
otto34 
Member - Posts: 36
Member spacespace
Joined: May 01, 2006
Posted: January 04, 2007 at 2:00 PM / IP Logged  
It was mainly to save room with the box, its going in an extended cab sonoma so I needed all the room I could get. And I am sure the dimensions on a ported box have to be damn near dead on for the box and the port rather than a sealed where you can be off a tad and it wont matter.....
domnic 
Member - Posts: 1
Member spacespace
Joined: December 03, 2006
Location: India
Posted: January 15, 2007 at 9:19 AM / IP Logged  

hi guys

will anyone let me know is the sub encloser is only the fiber glass or is the mdf also in it is there any cal for the encloser

domant
crazyjim 
Member - Posts: 5
Member spacespace
Joined: January 05, 2007
Posted: January 15, 2007 at 1:02 PM / IP Logged  
jlord16 wrote:
Works exactly the same as a normally mounted sub, this is becuase when you have the woofer basket mounted outwards (inverted) you wire the sub backwards ( ie + becomes - and - becomes +). The airspace is simliar to that of a normal box but rember the sub dusnt displace any airspace like it would in a conventional box. Good to see another aussie on here
You're joking right? Are you telling someone to reverse the polarity of their sub?
Page of 3

  Printable version Printable version Post ReplyPost New Topic
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 Follow the12volt.com on Facebook
Wednesday, September 28, 2022 • Copyright © 1999-2022 the12volt.com, All Rights Reserved Privacy Policy & Use of Cookies
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.

Secured by Sectigo
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
Support the12volt.com
Top
the12volt.com spacer
the12volt.com spacer