Springs under turntable

Mijo
I KNOW the windows are having a huge effect, hence the semi treatments to all of them.
Wood blinds on all of the side and back windows usually at 2/3 closed position.
Recent addition of heavy blackout curtains behind my gear and speakers on the large glass doors that open into the room, that had an even bigger impact than I expected.
But no I have no intention of getting any type of room control unit for this room atm.
I can live with ignorance is bliss because right now my listening experience is pure bliss!
Could it be better?
I am positive it can but small steps.

Every electronically-based room equalizer that I have ever heard does far more damage to the sound than it does good for the sound. So I agree with your strategy of altering the room, rather than the signal to give you your desired response at your listening seat.

Traffic though the tunnel created very low frequency rumble exciting the panels cracking them.

The failure was in the epoxy holding the panels. They didn't crack due to rumble. 

Every electronically-based room equalizer that I have ever heard does far more damage to the sound than it does good for the sound. So I agree with your strategy of altering the room, rather than the signal to give you your desired response at your listening seat.

Tonal timbre accuracy is too complex to be measured by computer program for sound....It takes ears to correct the room...

I correct mine with an astounding success on all counts by ears on a many months of experiments listenings, with TONAL TIMBRE accuracy, not frequencies of the bass... Now my bass are so intense and clear you will not believe what i take to reach that....(7 inches driver i hear with my stomach)

The important point, no ready made formula correcting frequencies can beat your ears to establish the best room possible for perception of timbre....

The same room is different for different ears, then also the fact that it must be FOR YOUR EARS that you work a room treatment not for a program or for another person.... 

All people speaking about bass are beside the point for me....

I dont need a woofer nor bass traps....Not even a program...

All treatment and controls cost peanuts....

:)

« The room is the third ear »-Groucho Marx

Lewm, you have no idea what you are missing. The really good units like My TacT and the Trinnov Amethyst do all their processing at 192 hz 48 bit
It is totally transparent. The power of these units is amazing. You not only get automated room control ( they automatically generate filters that bring each speaker individually to flat) but an incredible subwoofer crossover and bass management. I can independently change the frequency and slope of either the high pass or low pass filter on the fly. I can use slopes up to 10th order. I have dynamic loudness compensation. It changes its corrective slopes automatically with volume. The balance between bass treble and mid range stays exactly the same regardless of volume. I can program filters to adjust frequency response any way I want with 0.5 Hz precision. I can delay individual speakers so the the sound from each hits your ears at exactly the same time. Using this capability I can put the sweet spot anywhere in the room! This capability also matches the subwoofers in phase and time to the satellites. I can hold 9 different frequency response curves in memory and I can switch back and forth on the fly. As an example one has the BBC or Gundry dip programmed in so if things get harsh I activate that curve. All the programming is done on a PC and all the filters and curves are displayed in graph form. Everything that this unit does is done without any distortion. It is invisible. 
Talking about unbelievable differences, if I switch the system to bypass my wife will even ask me what happened. 
Once you use something like this you never look back. Back is the stone age. If you think you do not need it get a calibrated microphone and measurement program and check your system out.