General SPL General discussion of Sound Pressure Level topics.

Subs inverted vs. Inside the box

Old Nov 12, 2010 | 03:12 PM
  #31  
Dukk's Avatar
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^ So you invert the sub and now the motor gets in the way of the air flow and changes how the air/pressure flow moves in your cabin.

Manufacturers generally go to great lengths to design a basket and motor assembly that impedes the wave off the back of the driver as little as possible. As mentioned, if you compensate for the volume difference inside the box with the motor outside, there should be no difference in output either way.

There is no pressure in space, i.e. 0 psiA, it is not negative.
Old Nov 12, 2010 | 05:53 PM
  #32  
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Space is a vacuum, that's negative pressure from atmospheric

Oh and livin louder, btw air does not flow in the box, air flows throughout the port

Last edited by Lessy; Nov 12, 2010 at 06:01 PM.
Old Nov 17, 2010 | 01:05 AM
  #33  
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Originally Posted by jonesbrooklyn
Ok, I've been thinking about this one for a while now and was wondering what type of input anyone can give on this as this is something I would like to try.
What would be the pros and cons of the subs being inverted as opposed to being mounted inside the box and, is there a possibility of one's spl score being louder. I'd like to hear what the vet splers think about this as I know that they may have thought about it as well.
Assuming the that you`re using a ported box alignment, with the subs installed as a wall mounted array etc and have no less than 1800 cubic inches of SD - The following shifts are likely to occur:

1. The Fb of the box will drop
2. The F3 of the box will drop
2. The box efficiency will increase
3. The velocity off the back side of the drivers is less than the front - reasons: cone shape and driver bias - most SPL subs have a positive bias...
4. The basket and Magnet will change the phase characteristics of some frequencies – perhaps for the better – perhaps not!

What this adds up to is some recalibration... as your center frequency will change and negatively or positively affect your transfer function... the arrival time and location of your primary center frequency of each driver many vary more and become defused... There will be less force coming off the back of the drivers, but depending on box design and wave management that may be a good thing...

You will need to tweak things up a bit and in the end you may find that you hit harder - it is quite possible and cost only your time...

If I was to bet 5.00 bucks though, I`d say that in the end, you`ll probably drop, however, if you were starting your design from scratch, inverting your subs, loading into an area port type design can have some advantages.

In the end, driver selection is paramount as it dictates the enclosure type and adjustments etc...

I hope this helped.

If you can provide me with more insight about your system, I might be able to narrow my assumptions...

Last edited by dogbaker; Nov 17, 2010 at 01:08 AM.
Old Nov 17, 2010 | 02:56 PM
  #34  
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^ A real answer. Nice.
Old Nov 17, 2010 | 10:24 PM
  #35  
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If you can provide me with more insight about your system, I might be able to narrow my assumptions...[/QUOTE]

My system??? There's a couple of ways to describe it so here goes......
1. LOUD!!!!!!
2. TF ONE FTW !!!!!!!!!
3. Check it out for yourself...
http://www.youtube.com/#p/u/36/SFD-11dNLGo

Last edited by jonesbrooklyn; Nov 17, 2010 at 10:34 PM.
Old Nov 17, 2010 | 10:30 PM
  #36  
fresh1's Avatar
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Originally Posted by jonesbrooklyn
If you can provide me with more insight about your system, I might be able to narrow my assumptions...
My system??? There's a couple of ways to describe it so here goes......
1. LOUD!!!!!!
2. TF ONE FTW !!!!!!!!![/QUOTE]

BO! BO! BO! BRAPPPPPP!!!!! lol sorry DJ, it just felt right hahaha
Old Dec 5, 2010 | 08:14 PM
  #37  
Newguy's Avatar
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Originally Posted by Dukk
^ A real answer. Nice.
I agree
Old Dec 9, 2010 | 06:59 PM
  #38  
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Originally Posted by dogbaker
Assuming the that you`re using a ported box alignment, with the subs installed as a wall mounted array etc and have no less than 1800 cubic inches of SD - The following shifts are likely to occur:

1. The Fb of the box will drop
2. The F3 of the box will drop
2. The box efficiency will increase
3. The velocity off the back side of the drivers is less than the front - reasons: cone shape and driver bias - most SPL subs have a positive bias...
4. The basket and Magnet will change the phase characteristics of some frequencies – perhaps for the better – perhaps not!

What this adds up to is some recalibration... as your center frequency will change and negatively or positively affect your transfer function... the arrival time and location of your primary center frequency of each driver many vary more and become defused... There will be less force coming off the back of the drivers, but depending on box design and wave management that may be a good thing...

You will need to tweak things up a bit and in the end you may find that you hit harder - it is quite possible and cost only your time...

If I was to bet 5.00 bucks though, I`d say that in the end, you`ll probably drop, however, if you were starting your design from scratch, inverting your subs, loading into an area port type design can have some advantages.

In the end, driver selection is paramount as it dictates the enclosure type and adjustments etc...

I hope this helped.

If you can provide me with more insight about your system, I might be able to narrow my assumptions...
Finally.. +1
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