It may be beneficial to EQ 1500 to 3000Hz down something like -3 to -6dB and use +6 to +10dB high shelf from 3000-4000Hz upwards for the DH1A, depending what horn is used.
DL15X has 3rd harmonic distortion peak around 600Hz, eq it down some -3 to -6dB depending taste. This should help to...