  We demonstrate that, for the case of quasi-equipartition between the velocity
and the magnetic field, the Lagrangian-averaged magnetohydrodynamics
alpha-model (LAMHD) reproduces well both the large-scale and small-scale
properties of turbulent flows; in particular, it displays no increased
(super-filter) bottleneck effect with its ensuing enhanced energy spectrum at
the onset of the sub-filter-scales. This is in contrast to the case of the
neutral fluid in which the Lagrangian-averaged Navier-Stokes alpha-model is
somewhat limited in its applications because of the formation of spatial
regions with no internal degrees of freedom and subsequent contamination of
super-filter-scale spectral properties. No such regions are found in LAMHD,
making this method capable of large reductions in required numerical degrees of
freedom; specifically, we find a reduction factor of 200 when compared to a
direct numerical simulation on a large grid of 1536^3 points at the same
Reynolds number.
