Speakers with separate woofer columns, why?

[TitaniumTroy]

I was wondering what are the advantages and disadvantages of 4 piece speakers systems, that have a full separate woofer column. The Infinity Reference Standard would be the originator or close to it I would think. YG Acoustics has it in their statement system as does, Wilson Audio, Magnepan and Gryphon.
http://www.gryphon-audio.dk/products/loudspeakers/kodo.aspx
http://www.theabsolutesound.com/articles/tas-legacy-the-infinity-reference-standard-irs-loudspeaker/

Advantage's would be I assume, a lot more bass, floor to ceiling bass, can be put in a location to maximize room nodes and boundaries, lower distortion, can play louder, better for larger rooms.

Disadvantage's might be, harder to integrate with the rest of the system, best crossover point to use, more complex overall system, more amplification is needed, and loss of floorspace.

Do these woofer column's act the same as subwoofer's, or is their is some difference's? Like if used for two channel audio, what is the best point to set the crossover point similar to subwoofers? Also on placement, do you shove these towers in a corner or place them more out in the room?

 

[MakeMineVinyl]

I would think they function essentially as a subwoofer that just goes higher up in frequency, with the advantages/disadvantages of that. The Infinity would be gigantic if it was all in the same cabinet (not that its not already gigantic).

 

[malsackj]

The mids and tweets are also along the line of line array and limiting how much of the sound is reflecting from the floor and ceiling.
The larger curved panel / front baffle removes edge diffraction.
The 12's or bass module removes the high pressure back waves from the back of the other speakers. Not a big problem there.

The 12's being in a separate box can create a problem with time alignment however. Along with the distance and comb filtering between the bass and the mids, on the crossover frequencies. The help of using some DSP processing could reduce this some.

 

[Flint]

With proper placement and crossover settings (including phase or delay capabilities), this is not an issue. The law of quarter wave comes into play when it comes to the distance between drivers. If the distance from the acoustic center of a speaker is less than a quarter wave of the crossover frequency, placement is less of an issue in terms of phase alignment and a simple digital delay can address delay response between the distance of the driver from the listener. This really isn't a complicated process, but it does have to be taken seriously when designing and installing a speaker.

So, for a crossover at 150Hz, the acoustic centers of two speaker sources should not be more than 22.5 inches apart. That's quite a bit of wiggle room.