  We present an update on the meson mass spectra calculation with the
light-front quark model constrained by the variational principle for the
QCD-motivated effective Hamiltonian. By smearing out the Dirac delta function
in the hyperfine interaction, we were able to avoid the negative infinity that
one encounters when using variational principle for the entire Hamiltonian. We
obtained a better fitting for the mass spectra of ground state pseudoscalar and
vector mesons from $\pi$ to $\Upsilon$, compared to the previous calculation
that handled the hyperfine interaction as a perturbation rather than including
it in the parameterization process. Our new parameters are further tested in
decay constant calculation. We showed that by taking a larger harmonic
oscillator basis in our trial wave function, the decay constants calculated
from our model can be improved to agree reasonably well with the experimental
data.
