Change fontsize in beamer theme bars

Question

I am creating a beamer presentation and using 10pt fontsize. At that fontsize, the subsection titles that appear in the smoothbars are small. Is there a way to make it larger?

My simple code is

\documentclass[10pt]{beamer}
\usetheme{Ilmenau}

\begin{document}
 \section{Section}
 \subsection{Subsection}
 \begin{frame}
  The first frame
 \end{frame}
\end{document}

My output is

What I want to achieve is enlarge the fontsize and/or the subsection smooth bar. How to achieve that?

Answer 1

One possibility: First change the beamerfont headline and then reset the beamerfont section in head/foot to \tiny.

\documentclass[10pt]{beamer}
\setbeamerfont{headline}{size=\footnotesize}
\setbeamerfont{section in head/foot}{size=\tiny}
\usetheme{Ilmenau}
\usepackage{lmodern}

\begin{document}
 \section{Section}
 \subsection{Subsection}
 \begin{frame}
  The first frame
 \end{frame}
\end{document}