Wrong vertical alignment of equations in tabular

Why is the vertical alignment of my equations different resp. how can I correct it?

documentclass{article}
usepackage{amsmath}
usepackage{tabularx}
usepackage{graphicx}
usepackage{environ}

defmm#1{mathbf{mathrm{#1}}}
defscalemath#1#2{scalebox{#1}{mbox{ensuremath{displaystyle#2}}}}
NewEnviron{scaledMatrix}[1]{renewcommand{arraystretch}{1.5}arraycolsep=1.4ptscalemath{0.85}{left[begin{array}{#1}BODYend{array}right]}}

begin{document}
begin{subequations}
begin{center}
begin{tabular}{|m{0.5hsize}|m{0.5hsize}|}
hline 
begin{equation}
mm{A}_{L,2} = mm{I}_{4times4}
end{equation}
&
begin{equation}
mm{B}_{L,2} = 
{begin{scaledMatrix}{cccc}
 frac{1}{12} & 0 & -frac{1}{12} & 0 
 0 & frac{1}{12} & 0 & -frac{1}{12} 
 -frac{1}{12} & 0 & frac{1}{12} & 0 
 0 & -frac{1}{12} & 0 & frac{1}{12} 
end{scaledMatrix}}
end{equation}
  hline
end{tabular}
end{center}
end{subequations}
end{document}