\begin{tikzpicture}
\begin{axis}[
name=plot1,
%at=(plot1.below south east), anchor=above north east, xshift=1cm,
axis lines*=middle,
enlargelimits = upper, clip=true,
scale only axis,
axis line style={->,>=stealth, shorten >= 0pt},
xlabel={$\omega$},
ylabel={dB},
every axis x label/.style={
	at={(ticklabel* cs:1)},
	xshift=-0.2cm,
	anchor=north,
},
every axis y label/.style={
	at={(ticklabel* cs:1)},
	xshift=0.4cm,
	anchor=south,
},
every outer x axis line/.append style={white!15!black},
every x tick label/.append style={font=\color{white!15!black}},
xmin=0, xmax=1,
ymin=-40, ymax=0,
xtick={0, 0.25, 0.5, 0.75, 1},
xticklabels ={$0$, $\pi/4$, $\pi/2$, $3\pi/4$, $\pi$},
xticklabel style={yshift=0.6cm},
ymajorgrids,
every outer y axis line/.append style={white!15!black},
every y tick label/.append style={font=\color{white!15!black}},
legend style={draw=white!15!black,fill=white,legend cell align=left, at={(axis cs: 1.05, -5)}}]

\addplot [smooth, color=blue2, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_butterworth.dat}; \addlegendentry{Butterworth};
\addplot [smooth, color=red2, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_chebyshevI.dat}; \addlegendentry{Chebyshev I};
\addplot [smooth, color=green2, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_chebyshevII.dat}; \addlegendentry{Chebyshev II};
\addplot [smooth, color=orange, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_elliptical.dat}; \addlegendentry{Elliptic};
\addplot [smooth, color=Qpurple, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_bessel.dat}; \addlegendentry{Bessel};

\only<2|handout:1> {
\draw (axis cs: 0, -1.5) rectangle (axis cs: 0.55, 0.6);
\draw (axis cs: 0.25, -1.5) to[shorten >= 1cm] (axis cs: 0.2, -7);
}
\end{axis}

\onslide<2|handout:1> {
\begin{axis}[axis background/.style={fill=white},
name=plot2,
at=(plot1.south), anchor=north, yshift=5.5cm, xshift=-3.2cm,
axis lines*=middle,
enlargelimits = false, clip=true,
%scale only axis,
every outer x axis line/.append style={white!15!black},
every x tick label/.append style={font=\color{white!15!black}},
xmin=0, xmax=0.55,
width=7cm, height=4cm,
ymin=-1.5, ymax=0.6,
restrict y to domain=-1.5:1,
xtick={0, 0.25, 0.5},
xticklabels ={$0$, $\pi/4$, $\pi/2$},
ytick={0, -1},
xticklabel style={yshift=0.5cm},
ymajorgrids,
execute at end axis={
	%        execute at end axis={
	\draw (rel axis cs:0,0) -- (rel axis cs:1,0)
	(rel axis cs:0,1) -- (rel axis cs:1,1);
	\draw (rel axis cs: 0.999, 0) -- (rel axis cs: 0.999,1);
},
every outer y axis line/.append style={white!15!black},
every y tick label/.append style={font=\color{white!15!black}}]

\addplot [smooth, color=blue2, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_butterworth.dat};
\addplot [smooth, color=red2, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_chebyshevI.dat}; 
\addplot [smooth, color=green2, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_chebyshevII.dat}; 
\addplot [smooth, color=orange, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_elliptical.dat};
\addplot [smooth, color=Qpurple, solid, line width=2pt] table[x index=0,y index=1] {figs/data/classic_filters_mag_bessel.dat}; 
\end{axis}
}
\end{tikzpicture}