Seeking advice/tips on improving sound quality


Greetings fellow audiophiles,
Lately I have gravitated towards streaming music from my iMac to a Audioengine B1 bluetooth receiver just for the sake of convenience and the ability to play the same music in my main listening room as well as the patio/backyard (which is extremely convenient when we have large gatherings) The primary system comprises of Mcintosh C27 preamp + Mccormack DNA .5 + Vandersteen 2CE and Vandersteen 2WQ. It's a modest system and works very well. 90% of my audio files on the IMac have been ripped from original cds to Apple lossless format. Although this setup sounds very good, I was curious to know what else can be added to this chain that would bring about significant improvements to the sound quality, i have no experience with any software packages that claim to enhance the sound quality and have occassionally used an Arcam rDAC which has not sounded any better than the dac that's in the Audioengine. 
uditnaik
#1 improvement will be to upgrade the Vandersteens to 3's or higher and work on placement & room treatments (or patio treatments)

#2 is to got back to those original CDs and find better sounding ones - better mastering - esp. important if they are older releases

if the bluetooth is older see if you can move to WiFi - did the Arcam unit use WiFi?

Mcintosh has a "house sound" and many feel it is rather dark - so...


Of course going up the Vandy line will yield better reproduction, but I think the OP wanted to ugrade sound quality for his networked system.
I, too, have been working on this. 
Just last week I bought Fidelizer and have been wowed by the difference in my system. Since you are using a Mac, I am sure there are other programs that do the same thing (optimize OS for music reproduction).
A quick Google brought up something called Museeks. I don't run Mac, so I can't say if it is good or not, but maybe worth a try.
Bob
Bluetooth is newer and am using AptX protocol. Vandersteen 3 might be too big for the room, besides the 2CEs are the signature ii editions (3 yrs old)... so not sure if all that hassle of swapping speakers will be justified in sound improvement. The Arcam is the non wifi one. Guess, experimenting with another preamp might not be a bad idea if there are any recommendations.