They are external dimensions. The 4912's are listed as 23" wide, yet are only like 19" wide on the inside. You can stagger it, but remember you have to account for the hump in the back there. You wont get full use of the bottom space, only the front 2/3rd's or so. You would lose some space to the shelves in the front... unless they were remoed. Also, you will be on your own with drilling the hole...the sanyo's are documented on where to drill. (and they look better  )
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