A continous time signal $x(t)=4cos(200\pi t)+8cos(400\pi t)$, where $t$ is in seconds, is the input to a linear time invariant (LTI) filter with the impulse response

$h(t)=\left\{\begin{matrix} \frac{2sin(300\pi t)}{\pi t},\: t\neq 0\\ 600,\: t=0 \end{matrix}\right.$

Let $y(t)$ be the output of this filter. The maximum value of $\left | y(t)) \right |$ is _________.