AM demodulation

Hi,

I've been working on a gnuradio AM broadcast receiver, and have found
that the tuning is very critical to obtaining clear audio. My flowgraph
can be seen at https://wiki.gnuradio.org/index.php/File:FunCube_AM.png.
Are there any alternate demodulation methods which are not so sensitive
to exact tuning?

Thanks,
--
Barry Duggan KV4FV