Reddit reviews VIZIO S3820W-C0 38-inch 2.0 Home Theater Sound Bar with Integrated Deep Bass

http://www.reddit.com/r/rocksmith/comments/2iz0qj/tested_successfully_latency_solution_digital_coax/

this might be helpful. You definitely don't need a $700 sound system though.

Thank you!
That's a VIZIO S3820W-C0 soundbar
(https://www.amazon.com/VIZIO-S3820W-C0-38-inch-Theater-Integrated/dp/B00DG6FOV0/ref=sr_1_19?s=electronics&ie=UTF8&qid=1467223526&sr=1-19&keywords=Vizio+soundbar)

This is what I have, there's still a very small amount of lag, but it is absolutely playable.

Amazon Reviews

On Sony receivers it's called "Night Mode," although you can't set your desired minimum and maximum volumes. It just compresses the dynamic range so that everything is closer to a middle volume. AFAIK every Sony AV receiver has it, and basically every major-label AV receiver has a similar function. Of course, it's somewhat of a waste on a good 5.1/7.1 setup since the dialogue is usually very audible anyway with a good center channel speaker.

Also, sound bars are getting really good now. You can pick up a great one that helps a lot with dialogue for $78 used from Amazon warehouse.

http://www.amazon.com/VIZIO-S3820W-C0-38-inch-Theater-Integrated/dp/B00DG6FOV0/ref=sr_1_1?s=electronics&ie=UTF8&qid=1417991609&sr=1-1&keywords=sound+bar

OK, I tried to do it for you on the cheap... I mean who doesn't already have wires running from their stereo to their TV? :-)

Well then here you go: but its going to run you north of $50. You will need one of these kits. The transmitter end will connect to your TV, and the receiving end to your stereo. If your stereo does not have a way to select different audio sources (then you should get a proper stereo... Kidding-kinda) then you will need the audio selector box I recommended in my comment above.

Honestly here's how it should be done:
[Cable box] ---hdmi---> [A/V receiver: HDMI input #1] ---hdmi---> [HD TV]

[PC] ---hdmi---> [A/V receiver: HDMI input #2]

[Chromecast] ---hdmi---> [A/V receiver: HDMI input #3]

Here is a nice 4 HDMI input A/V Receiver under $200.

Here is a solid HD TV under $500.

Don't have room for 5.1 channel speakers? Here's a very decent 2.1 channel sound bar. It's under $100.

It's time to step up your game.