They want to hear dog-music that humans cannot hear.
What can I do? My dogs will bite off my testicles if the
sound system is not good.

I assume this is a troll, but...

Regular CDs do not have any significant audio energy above 22kHz. DVD-A and SACD
recordings might, but it depends on the mics used, etc, etc, etc.

Electrostatic speakers or systems with ribbon tweeters will likely get up 30kHz
or so, as will some metal-dome tweeters. But there's nothing in most recordings
for your doggies to appreciate.