Springs under turntable

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. 

Yep. I do know what I am missing, and I don't miss it.Even when electronic manipulation of the system response is "transparent" (and I will believe that when I hear it), the subjective impression of the listeners I have been around is that they are not pleased with the SQ, compared to using no equalization on the very same system in the very same room.  Measurements do not coincide with the sense of verisimilitude that is after all what we are all ultimately seeking. I have attended several such demonstrations, and the net impression of other listeners and me is turn off the EQ. On the other hand, in your particular room with your particular equipment, etc, perhaps the results are different; I can hardly say otherwise. You can go your way, and I will go mine.  It would behoove you to recognize more often that you are expressing your opinion based on your own experiences, rather than to speak as if you are presenting the gospel.  This is not to say I don't advocate and implement room tuning to get the SQ I am after.  But I am sure that my room that satisfies me would not measure perfectly flat across the audible spectrum.