If you plan outdoors, then you would want pa speakers. Those mackie’s will probably give you everything you would want then, albeit at the top of your price range. You could go smaller, but might end up wanting a sub.
Another thing to consider is what you would use as your source. You would just have to get some cables to connect it to phone/laptop or rca in
Source is likely to be a headphone adapter cable from a phone or a cheap bluetooth receiver, which will again be from the phone. Either way, that’s cheap enough I won’t count it against the rest of the budget.
Also something that I forgot to mention about the mackies is that they have built in profiles that can modify frequency response and optimize the sound for what you are using them for, which is nice
These should fit the use you want, powered, portable,big ,and 220w of power with Bluetooth for garage use.https://www.parts-express.com/american-audio-els-15bt-15-2-way-powered-bluetooth---usb---mp3-pa-speaker--244-4331
Just a thought. I don’t know if it would be enough, but the JBL Partybox 300 is 450$ on Amazon (well, pretty much everywhere).
@ 8m50:
In the same (eh, “loudest bluetooth speaker evar”) category, there’s the “Soundboks”… but they’re basically 1000$, overpriced PA speakers with bluetooth. Same for the JBL Partybox 1000.
Otherwise, this 80$ gadget changes speakers into bluetooth speakers (RCA outs):
Or this one, 100$ (available soon), but better for PA systems because it has XLR and 1/4 inch outs and it’s also a volume knob… and it supports AptX! (Man, maybe I should have waited a bit before buying the Bludento…)
I check these out for garage use because they should rock a 2+ car garage to the point your neighbors will hate you and for less than $200 each. All the hookups you should need and the Bluetooth is a plus.https://www.parts-express.com/american-audio-els-15bt-15-2-way-powered-bluetooth---usb---mp3-pa-speaker--244-4331
HAAAH!!!
There is a nice label with that ELS 15": WARNING: Cancer and Reproductive Harm 
That is just hilarious a 15" BT speakers and ~200$.
They probably sound like crap but in garage, does not really matter. Just loud.
Maybe someday i’ll get something similar and Big speakers for my garage.
Got small Mackies studio monitors now but they have worked ok for 2 years with the dust and humidity there is sometimes. They are kinda in a test to see how long they last.
Almost put a pair Genelec’s there also but my brain finally woke and was like “NOOOOOOO!!!” 
Haha, hmm, Genelecs all use DSP, huh? I wonder what DSP can… and cannot, fix. For sure, in a garage, that would test its limits, lol.
Yea, basically.
Newer Studio monitors have GLM system and older ones have dip switches.
G series is more home use, have dip switches also.
Had extra pair of 8330’s laying around that almost had place in garage. 