Kicker Hideaway weird noises

I just finished the install of my hideaway under the driver seat and while tuning it, it made some weird noises. For clarity, the hideaway is taped into the front L and R speakers ahead of my Key amp behind the dash. I was able to set the gain just fine while using a constant 40Hz tone, no problem there. However, when using test tones, or listening to music you can hear a knocking noise. FYI I tried tuning it with the bass knob and without.

No Bass Knob using test tones.

No Bass Knob, good 40Hz gain adjustment

W/Bass knob at center adjust, gain set, playing music

In the first and last video, that knocking you hear above the tone is what I'm concerned about. I don't think this is normal, though I've never had a compact sub/amp before. Just curious if I should be reaching out to Amazon for an exchange?

I can't really hear the knocking when the rest of the speakers are in play, but I'm sure it's happening. And if it's happening at the beginning, I'm concerned it will get worse and I won't be able to exchange it down the line...