Free: Aim the speakers straight ahead with no toe in. This will decrease the perceived treble at your listening position, assuming that you sit centered between the speakers.
Free: Position the speakers at the best distance from the front wall behind them to reinforce the bass. I have my GoldenEar speakers at 19.5 inches from the front wall, but your speakers should probably be something like five or six inches from the wall.
Free: Position your listening chair at the best distance from the back wall to reinforce the bass. I have my chair positioned so that my ears are 20 inches from the back wall (and I have a curtain and absorption panels behind me). Experiment to find what works best for your room and speakers.
Low cost: Position a large rug on the floor directly in front the speakers.
Low cost: Place curtains over the windows.
Low cost: Attach a large blanket or curtain on the front wall centered behind the speakers and another one on the wall directly behind you.
As funds permit: Purchase absorption panels and place a few of them on the wall behind the speakers, more on the wall behind you, and on the first reflection points on the sidewalls. You can use two inch thick acoustic foam panels for this because you only need to attenuate the treble and maybe the upper midrange. You don't need to cover the entire walls with absorption panels.
It could be that you find that none of this is enough, but it will help and it costs very little.
I had a new Pioneer receiver in 1980 and would rock out with Led Zeppelin way back then. I did nothing to treat the room and it sounded great. But as funds permit, your old receiver needs to be replaced with a new warm sounding amp/receiver. There are some warm amps/receivers that cost less than $800 new. Some YouTube channels to help find one include the Audiophiliac, Jay soulsik, and Zero Fidelity. All of them review budget gear that sounds great. Jay's YouTube channel also has a video about how he treated his room using items from a very low cost vendor.
You should know that many tube amps run hot and will heat up your entire room. So do most class A solid state amps. One option would be to purchase a class AB receiver that sounds warm. Most class AB amps/receivers run cool.
Let us know how your efforts progress.
Free: Position the speakers at the best distance from the front wall behind them to reinforce the bass. I have my GoldenEar speakers at 19.5 inches from the front wall, but your speakers should probably be something like five or six inches from the wall.
Free: Position your listening chair at the best distance from the back wall to reinforce the bass. I have my chair positioned so that my ears are 20 inches from the back wall (and I have a curtain and absorption panels behind me). Experiment to find what works best for your room and speakers.
Low cost: Position a large rug on the floor directly in front the speakers.
Low cost: Place curtains over the windows.
Low cost: Attach a large blanket or curtain on the front wall centered behind the speakers and another one on the wall directly behind you.
As funds permit: Purchase absorption panels and place a few of them on the wall behind the speakers, more on the wall behind you, and on the first reflection points on the sidewalls. You can use two inch thick acoustic foam panels for this because you only need to attenuate the treble and maybe the upper midrange. You don't need to cover the entire walls with absorption panels.
It could be that you find that none of this is enough, but it will help and it costs very little.
I had a new Pioneer receiver in 1980 and would rock out with Led Zeppelin way back then. I did nothing to treat the room and it sounded great. But as funds permit, your old receiver needs to be replaced with a new warm sounding amp/receiver. There are some warm amps/receivers that cost less than $800 new. Some YouTube channels to help find one include the Audiophiliac, Jay soulsik, and Zero Fidelity. All of them review budget gear that sounds great. Jay's YouTube channel also has a video about how he treated his room using items from a very low cost vendor.
You should know that many tube amps run hot and will heat up your entire room. So do most class A solid state amps. One option would be to purchase a class AB receiver that sounds warm. Most class AB amps/receivers run cool.
Let us know how your efforts progress.