  When a gravitational wave (GW) passes through a DC magnetic field, it couples
to the conducting wires carrying the currents which generate the magnetic
field, causing them to oscillate at the GW frequency. The oscillating currents
then generate an AC component through which the GW can be detected - thus
forming a resonant mass detector or a Magnetic Weber Bar. We quantify this
claim and demonstrate that magnets can have exceptional sensitivity to GWs over
a frequency range demarcated by the mechanical and electromagnetic resonant
frequencies of the system; indeed, we outline why a magnetic readout strategy
can be considered an optimal Weber bar design. The concept is applicable to a
broad class of magnets, but can be particularly well exploited by the powerful
magnets being deployed in search of axion dark matter, for example by DMRadio
and ADMX-EFR. Explicitly, we demonstrate that the MRI magnet that is being
deployed for ADMX-EFR can achieve a broadband GW strain sensitivity of
$\sim$$10^{-20}/\sqrt{\text{Hz}}$ from a few kHz to about 10 MHz, with a peak
sensitivity down to $\sim$$10^{-22}/\sqrt{\text{Hz}}$ at a kHz exploiting a
mechanical resonance.
