Saru - I'm not familiar with your gear, but I am familiar with "humming and then patting your chest -- what should be a smooth sound is disrupted by unnatural vibrations"
In my case it was the simple fact that I was overdriving the room. I was putting too much sound (volume) in there, and the bass interferred with the midrange, mainly vocals.
I fixed it by changing speakers and putting acoustic treatments in the room. That distortion is a distant memory.
Since you have a $0 budget, I suggest that you put some bulk in the room to help diagnose the problem: Blankets, pillows, boxes of stuff, even an extra piece of furniture (cloth). If this helps or eliminates then you know what the problem is. Then you might look for more permanent solutions that look good.
The fact that you rearranged the room and added blankets and got improvement leads me to believe this is your problem.
But do remember that there are limits with any system. You won't be able to play as loud as you want.
In my case it was the simple fact that I was overdriving the room. I was putting too much sound (volume) in there, and the bass interferred with the midrange, mainly vocals.
I fixed it by changing speakers and putting acoustic treatments in the room. That distortion is a distant memory.
Since you have a $0 budget, I suggest that you put some bulk in the room to help diagnose the problem: Blankets, pillows, boxes of stuff, even an extra piece of furniture (cloth). If this helps or eliminates then you know what the problem is. Then you might look for more permanent solutions that look good.
The fact that you rearranged the room and added blankets and got improvement leads me to believe this is your problem.
But do remember that there are limits with any system. You won't be able to play as loud as you want.