I have a mix of old school and new school. I have a 2010 Mac Mini Server running Mountain Lion Server. I am running the Music Cabinet mod. The Mini is in my living room serving as my main HTPC, Web Server, and Subsonic server. Audio out goes to a Music Streamer DAC, then into my Yamaha AV Receiver (840 Watts). Yamaha provides A channel music to my Great Room (7/1 surround) driving 30 year old JBL LX 55 3 way speakers, Orb Woofer and Orb surround speakers. B channel drives smaller 2 way JBLs on top of kitchen cabinets.
The Yamaha has output for 2 separate zones via low level output. One zone runs out to my Screened in porch connected to my 30 year old Kenwood receiver (100 watt per channel). A speakers ceiling mounted on screened in porch, B speakers under the eaves on my deck. I purchased some decent but cheap outdoor speakers, everything stays dry and stays connected year round. Turn the Kenwood to Aux and it plays house system. There is also a TV on screened in porch hooked up to the Kenwood receiver.
The second Yamaha Zone runs upstairs to my Master bedroom. I purchased a refurb Denon reciever ($135.00, 75 watt) and located it in my master bedroom. A speakers are 40 year old 2 way ARs in Master Bed Room and B speakers are 30 year old 3 way Kenwoods located in my office. I have in wall Niles controllers for volume control in bedroom and office. Select Aux and the Denon plays the House system. The Denon in bedroom is also connected to TV.
The Denon passes through to 2 zones while in stand by mode. One Zone runs goes to Sharp 15 watt integrated Amp (located next to the Denon) that I have had since the 70s. This Amp drive single stereo speakers in Master Bathroom and Guest Bathroom. They are in-ceiling mounted and both have in wall Niles volume controllers. Denon Zone 2 runs to my garage work shop. I have an old boom box with audio inputs in the garage driving cheap 2 way speakers ceiling mounted.
I installed most of this before Subsonic came on the scene. Back then there were no Blue Tooth or Wireless options. All told I have 19 speakers that can beat as one. Power up additional amps as needed, turn to Aux and my house rocks!