Linux Mint

So my big questions are :

is there a way to get an equalizer installed.

Is there a way to fix the audio so the player Rhythmbox doesn't try to create a surround effect in music during playback? It seems like the music system is trying to "shove" the music from the left and right speakers further out to the left and right. Kind of an artificial surround sound.

I have 2 speakers and sub plugged into the computer via a usb cable that runs directly to the sub with the speakers plugged into the sub.

I'm running linux mint. it comes with rhythmbox preinstalled. I used the software manager to install

Rhythmbox-plugin-alternative-toolbar

but didn't see any real change to the interface of rhythmbox .

When I go to the 3 lines on the upper right corner (which I assume is the menu) and click that it shows (view) (tools) (preferences)

When I click preferences and then the plugins tab it doesn't show the plug in that i just installed ..

I was hoping that the plugin might give me some control for how the audio is played (some sort of equalizer)

i tried going to the package manager to see if there is an equalizer that i could add to this program. doesn't seem to be any.

any help is appreciated.