Improve Airplay quality?

[Fietsbel]

Setup

• iMac 2012
• Airport Express 2013 - connected to the reciever with tulip plugs
• Apple TV 2013 - connected via HDMI
• Sony DN-550 - no network support
  
  Everything is wired via UTP

Problem:
Whenever i stream music to the reciever it sounds a bit dull and not crisp at all.

The quality is the same whenever i use the Airport express or Apple TV.
I have tried to use different cables and another reciever but the quality does not improve. Tried to find a setting in iTunes to increase the bitrate but i couldnt find it.
One person suggested that i should buy a different reciever with built in airplay, but im sceptic about that.

Anyone got a suggestion for me to improve the quality?

 

[JTToft]

Well, I can say this much: Your problem isn't with AirPlay itself, since it's completely lossless (hence why there's no setting to improve it).

 

[McScooby]

Qi

http://www.mcelhearn.com/how-apples-airplay-streams-audio/

 

[mcarvin]

Stumbled on this completely by accident trying to solve your problem earlier this week. It had nothing to do with the Airplay settings. I had to switch my receiver from PLII to Stereo. Hope this helps.

 

[Fietsbel]

Thank you all for the answers, i'll try more settings on the reciever