  Double-peaked Balmer-line profiles originate in the accretion disks of a few
percent of optically selected AGN. The reasons behind the strong low-ionization
line emission from the accretion disks of these objects is still uncertain. In
this paper, we characterize the X-ray properties of 39 double-peaked Balmer
line AGN, 29 from the Sloan Digital Sky Survey and 10 low optical-luminosity
double-peaked emitters from earlier radio-selected samples. We find that the
UV-to-X-ray slope of radio-quiet (RQ) double-peaked emitters as a class does
not differ substantially from that of normal RQ AGN with similar UV
monochromatic luminosity. The radio-loud (RL) double-peaked emitters, with the
exception of LINER galaxies, are more luminous in the X-rays than RQ AGN, as
has been observed for other RL AGN with single-peaked profiles. The X-ray
spectral shapes of double-peaked emitters, measured by their hardness ratios or
power-law photon indices, are also largely consistent with those of normal AGN
of similar radio-loudness. In practically all cases studied here, external
illumination of the accretion disk is necessary to produce the Balmer-line
emission, as the gravitational energy released locally in the disk by viscous
stresses is insufficient to produce lines of the observed strength. In the
Appendix we study the variability of Mrk 926, a double-peaked emitter with
several observations in the optical and X-ray bands.
