Airport Extreme (new) with bridge

Hello!

I am a college student and am having some wireless speed issues. My ISP provides me with 50-55MB down, however, that is restricted on some of my devices because they have to operate on the 2.4 GHz frequency. My router is the new AC wireless Apple Airport Extreme.

Here's the breakdown: I, along with a roommate, live in an apartment, where WiFi is horrid on the 2.4 GHz frequency. The signal strength isn't too horrific, but that's not the issue. Here's an example - devices on the 5GHz signal always receive over 50MB down (like my Macbook Pro), but devices on the 2.4GHz signal, regardless of channel, get less than 2MB down, sometimes less than 1...

I am writing this because I just recently purchased a PS4, which only operates on the 2.4 GHz signal. I receive unbearably slow connection, again, less than 2MB down. I would like to fix my network so that those devices, via some sort of bridge, could connect via ethernet at the full speed (or at least improved).

I do have the last-gen Airport Extreme (N-wireless), in which I was using as an extender, followed by ethernet to those devices. The signal strength on Airport Utility regarding the signal between the router and the extender was listed as excellent, however, the speed was still less than 2 MB down on any of those devices including my Macbook Pro.

Is there anything I can do? Third party bridge? I would hopefully like to avoid purchasing another AC wireless Airport Extreme...

Thank you!

-Nick