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Placement. As only one of the drivers can fire in the direction of the LP, and the other....somewhere else thought of as "less" favorable. This can be a "percieved" disadvantage as well.
 

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If one has two drivers in the same enclosure, whether they are side by side or an opposing baffles, the drivers "see" the same internal volume, so size is not an issue.


At 80 Hz, the wavelength is appx. 14 feet long, and all one needs to do is make sure either subwoofer is properly situated in the room properly.


The main advantage of dual opposed drivers is they cancel out the cabinet vibrations.
 

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Quote:
Originally Posted by craigsub /forum/post/18130260


If one has two drivers in the same enclosure, whether they are side by side or an opposing baffles, the drivers "see" the same internal volume, so size is not an issue.


.

does this hold true for the sub1 and sub2 6 drivers in the same enclosure?
 

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Quote:
Originally Posted by craigsub /forum/post/18130260


If one has two drivers in the same enclosure, whether they are side by side or an opposing baffles, the drivers "see" the same internal volume, so size is not an issue.


At 80 Hz, the wavelength is appx. 14 feet long, and all one needs to do is make sure either subwoofer is properly situated in the room properly.


The main advantage of dual opposed drivers is they cancel out the cabinet vibrations.

If the drivers are not moving, the see the same volume, but once they start moving, they work against each other....right?
 

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Quote:
Originally Posted by osofast240sx /forum/post/18130390


does this hold true for the sub1 and sub2 6 drivers in the same enclosure?

Correct. Let's take, for example, 6 of the 10 inch drivers for the Sub2 ... when the designers worked on the internal volume, let's say that they determined 20 liters per driver was the right amount of net volume based on the eq curve, power, etc ... then the unit would have 120 liters for the six, and all 6 would "feel" the same load as a single would in a 20 liter box.
 

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Quote:
Originally Posted by cschang /forum/post/18130683


If the drivers are not moving, the see the same volume, but once they start moving, they work against each other....right?

The drivers "work" against the internal "air spring" at the same "rate" regardless whether they are on opposing baffles or the same baffle.


Think of it this way, if the drivers are moving, say, one liter of air when moving out, they will compress one liter of air while moving in, and will do so whether on the same or opposing baffles.
 

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Dual opposed drivers are the best for canceling even-order distortions, which many folks say are the most "objectionable" type. The box is normally about twice the size of the single driver enclosure. The design is neither new, nor particularly innovative, but it can sound very good when executed well.
 

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Quote:
Originally Posted by TnTBigman /forum/post/18129898


Placement. As only one of the drivers can fire in the direction of the LP, and the other....somewhere else thought of as "less" favorable. This can be a "percieved" disadvantage as well.

But if sound below 80hz is non directional, would this matter? Or is that why you're putting the "perceived" in quotes?
 

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Having a Epik Tower with one front firing 15" driver, the best results I got from it was always with the driver (and thus port) firing in the direction of the LP ie energy directed at the LP. I thought placement of my Empire would be a problem becasue one driver can be position to the LP at a time. Not so. Both driver's are now perpendicular to the LP and it sounds great.
 

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Quote:
Originally Posted by craigsub /forum/post/18130260


If one has two drivers in the same enclosure, whether they are side by side or an opposing baffles, the drivers "see" the same internal volume, so size is not an issue.


At 80 Hz, the wavelength is appx. 14 feet long, and all one needs to do is make sure either subwoofer is properly situated in the room properly.


The main advantage of dual opposed drivers is they cancel out the cabinet vibrations.

Forgive the question but, you're not saying that if a particular driver required 1sq ft of volume that you could put 2 drivers each requiring 1sq ft of volume into a 1sq ft box and all would be well?
 

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^^^

No, per this quote he is not recco'ing that at all ...

Quote:
Correct. Let's take, for example, 6 of the 10 inch drivers for the Sub2 ... when the designers worked on the internal volume, let's say that they determined 20 liters per driver was the right amount of net volume based on the eq curve, power, etc ... then the unit would have 120 liters for the six, and all 6 would "feel" the same load as a single would in a 20 liter box.
 

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Quote:
Originally Posted by craigsub /forum/post/18131329


The drivers "work" against the internal "air spring" at the same "rate" regardless whether they are on opposing baffles or the same baffle.


Think of it this way, if the drivers are moving, say, one liter of air when moving out, they will compress one liter of air while moving in, and will do so whether on the same or opposing baffles.

Yes...I realize it doesn't matter if the drivers are opposed or not.


Looking at your other posts, I think we are in agreement.
 

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Quote:
Originally Posted by zora /forum/post/18132055


Dual opposed drivers are the best for canceling even-order distortions, which many folks say are the most "objectionable" type. The box is normally about twice the size of the single driver enclosure. The design is neither new, nor particularly innovative, but it can sound very good when executed well.

I have never heard that even-order harmonic distortion is more "objectionable" than odd-order harmonics.


I know that in the world of amplification odd-order harmonics are clearly more objectionable. I can only surmise that the same thing applies to subwoofers.
 

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One of the only cons is enclosure weight.


Two drivers plus twice the box all in one can rise in weight quickly.


You can help mitigate the inconveniences by using casters and designing the proper height to width ratio for ease of movement.
 

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Quote:
Originally Posted by jpmst3 /forum/post/18134139


One of the only cons is enclosure weight.


Two drivers plus twice the box all in one can rise in weight quickly.


You can help mitigate the inconveniences by using casters and designing the proper height to width ratio for ease of movement.

This has nothing to do with the drivers being dual opposed vs. two side by side drivers - the cabinet would need to be twice the size regardless.


In fact, it's quite possible that dual opposed would be lighter than with two on the same baffle, as the dual opposed arrangement requires less bracing, due to the "cancelling of vibration" the drivers exhibit when on opposite baffles.


I am pretty sure, though, that you were thinking in terms of dual drivers period vs. a single drive - but check the opening post.
 
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