Good Stereo Speakers for outside use during BBQs, evening pot luck dinners etc

Get a pair of Used Mackire Srm 450’s.  Mount them on the adjustable pole mounts with the 3 legs...

The pole on the stand is height adjustable and you can lift the speakers up high so that the sound isn’t blocked by people standing in front of the speakers.  They have a horn waveguide on the tweeter and therefore a very wide dispersion pattern.

buy something like a parasound z dac; something with balanced outputs.  Plug an i phone or ipad into the zdac streaming soundcloud or spotify or tidal, whatever.  Plug the z dac into the speakers with xlr cables.  All in, speakers, dac, stands, i pad, you will spend $1500 but will have a system worthy of a serious dance party!

Tci rock speakers are best...10 years and going strong...

Seriously, check out some Cerwin Vega speakers in the XLS line.  Absolutely voiced perfectly for outdoor situations like you are describing.  I’ve  had an older set of the dual 15” models for years and they absolutely rock outside for parties and surprisingly smooth and subdued when played quietly.  

On the large side of things, I bought a cheap PA setup from monoprice for outdoor events and karaoke. Two self powered 15" plastic boxed PA speakers, stands, cables, a wireless mic set from Amazon. I have under $400 into everything (less than my last cable upgrades for the main rig). I hook up a phone or a laptop for the source and everyone loves it. I can host or take the whole thing to a friends house. Plenty of sound.

On the small side of things, the weather proof JBL Charge bluetooth speakers are fantastic. Link two of them together and use a phone as a source and you can fill any room with sound. My dad puts a set on his deck for outside listening and small gatherings. You can pair up to 100 speakers if I remember correctly (running in mono) so you can always add another one for more sound.

Both good options depending on what you are trying to achieve.

Another vote for Altec Voice of the Theatre. ROCK ON!!!!!