Best way to play audio wirelessly from Android to home theater system?

Chromecast? I did this when I was fiddling around with my Android 4.4.4 (OnePlus) phone and a new chromcast dongle. Although I have not done it in a while, instead of casting straight from an app such as YouTube, cast the screen and it will cast whatever app is in use. (Note: I am no expert on this.) Also, if your phone is rooted and you can run https://play.google.com/store/apps/details?id=com.bubblesoft.android.bubbleupnp&hl=en I think it does this. It works with Chromecast too.

I use the Amazon Basics Bluetooth Receiver for this and it works fine as long as the distance isn't too big. Caveat: I have it hooked up to a stationary HP android slate mounted on the wall and not my phone that walks around with me in my pocket. I don't know if this impacts the bluetooth connection or not.

I have two methods (separate speaker systems in separate rooms). I have a belkin bluetooth receiver in one. All of the reviews pointed out a large bit of metal in the device apparently just for weight which impaceted receiving/distance. Sure enough, when I got it, if I was even 10 feet away with LoS I would get cut outs, and 20 feet through one wall was my max distance. I opened it and removed the metal weight, and 20 feet, through one wall, is absolutely fine and I only get a few sputterings if I'm about 35 feet away through two walls (and possibly a fridge). Perhaps your device also has something in for weight (if it's too light, apparently it doesn't feel "premium" and they consider it better to make a low quality product that might be perceived as better quality) that might impact the connection? Secondly, for another set of speakers I have a media system. I run http://www.musicpd.org/ and our android devices can connect as remote controls. But that's a separate media library, unrelated to the phone.

As long as you have HDMI in on your receiver, chromecast seems like the obvious choice. I do this with my home theater system. It's super easy to set up, very cheap, and the sound quality seems fine. Both apps you mention seem to have built in chromecast support.

DLNA is a protocol that links data server, renderer and control nodes. Controllers can request that a chosen renderer plays music from a chosen server on the same network. Servers, controllers and renderers all find each other automatically via a service discovery protocol. As a concrete example, I have a DLNA server (a Linux box running in a corner somewhere) with all my music on, and I can use a DLNA app on my phone to either play that music on the phone itself (perhaps sending the audio output via bluetooth to the speakers in the kitchen) or I can have the DLNA app control the renderer in the amp under the TV to play music on the speakers in the living room. If you can connect all your devices to the same network (wired or wireless) then it all works fairly seamlessly.

Is your television hooked into your audio system? If so, I'd say get a chromecast and use that to play audio from your phone through the TV and into the audio system.

Sounds like, yeah, maybe it's just that my Bluetooth receiver sucks, and a different one is the first thing to try. The Satechi is pretty light so I don't think it's the specific issue of extra metal added just for weight that nobeagle suggests, but his story does add further evidence in support of the notion that some Bluetooth receivers are decidedly better than others. My audio system actually is pretty old and doesn't have an HDMI input (I am almost pathologically incapable of replacing outdated technology as long as the old stuff still works—that's also why I still have only SD TVs), so Chromecast is only an option if I also add in an HDMI to RCA converter, which puts the cost up above what I was hoping to pay, but I'll keep it in mind as a possibility if the other Bluetooth receivers don't work out. Thanks also for the DLNA explanations—I understand now that it would require a player that supports DLNA, it can't just take aribtrary audio output and stream it, and http://gonemadmusicplayer.proboards.com/thread/572/wi-fi-streaming-using-dlna, so that's that. Thanks for all the responses, and I'll report back on what I try out.

I just ordered a http://www.myrocki.com/ today after looking for a DLNA/wifi audio receiver. Clocks in under $50 with a coupon from RetailMeNot. Reviews indicate it still has a few bugs that will need to be worked out, but I hoping it'll work well enough for my purposes. It might work for you if you end up going the DLNA route..

I got the Amazon Basics bluetooth receiver (not as cool looking as the Moto Stream, but notably cheaper) and am happy to report that it's working much better than the Satechi did. Thanks, everyone!