Speaker Damage/Amp Power/Volume

I believe the upper bass driver on one of my Energy Veritas 2.3i speakers is damaged, as it has started to make a humming/vibrating/distorted sound on certain Lee Ritenour jazz guitar tracks. What is confusing is that I do not hear the vibration on most of the other music in my diverse collection of rock, jazz, female vocals and classical. I drive the Energy's with a Musical Fidelity A5 Integrated rated at 250w into 8 ohms and 400w into 4 ohms. While I never go past the "11:00" position on the volume dial, I have no idea how many db that represents or how many db is required to damage a speaker. My room is 16x30x9. How loud can you go? Energy recommends 50-250w for the 2.3i, not unlike the input suggestions for most of the speakers I browse. How are mega-watt amplifiers of up to 1000 watts paired with speakers whose specs call for up to 200 or 300? What speakers in the 3-4k used range are able to play louder with less risk of damage? I also wonder why more higher end amps don't possess a warning light like my second system Adcom 545 II--I think it says 'thermal protection'--and why speakers don't have built in protection. A bunch of Q's, I know, but I am newer to this great hobby and I'd like some A's before I upgrade my speakers. Thanks.
This is pretty simple, you are playing too loud. 250 watts sounds like a lot of power but it's not, it's only 3db more than 125 watts. An in-wall speaker is limited by it's design, it's not meant to rock the house down. There is a reason that there are really big floor standing loudspeakers. If you want big sound you'll need big speakers.
The only guide for feeding power is, that if it sounds loud, it's probably distorting and you need to turn it down. A good speaker will play really loud but will not distort, you'll just notice you are shouting to talk over the music.
It sounds like your audio designer didn't quite meet your needs. At 91db efficient (in room/per Energy) you are not going to get where you want with this speaker and your amp.
Most in-wall systems are designed specifically to trade sound quality/volume for aesthetics. You might want to re-think your requirements.
Thanx, Russ If I have it wrong, I apologize.
Russ69: The 2.3i's are 40 inch floorstanders with dual 6" woofers, a dome mid, and a dome tweeter. Sensitivity per manual is 90 dB.
Goblue: It is my understanding that the typical "tower" speaker will not be capable of delivering the type of volume that you seem to be interested in. You could consider purchasing a professional grade speaker such as those commonly used to DJ. However, I think most would agree that the SPL you would acheive would come at the cost of sound quality, to put it simply. Otherwise, I think that you will need to go to a much higher price-point to get quality speakers that will gracefully play full-range at extremely loud volumes. Of course, it would follow that you will also need significantly more powerful and expensive amplification - money, money, money.

If you are running your 2.3s full-range, consider integrating a subwoofer or two and easing the burden on your speakers and your amplifier. You may be able to achieve the volume you want and keep your equipment safe.

To answer your second question, I think most would also agree that you can never have too much power. In fact, it is usually better to have an amplifier that can run your speakers with power in "reserve". The most likely culprit of driver damage is insufficient power. In either case, you should listen carefully for signs of distress such as "thinning" of the sound, particualarly on the low end, or distortion. Incidentally, I would think that your amplifier should be more than sufficient to power your 2.3s.

The "Thermal Protection" LED on your Adcom will light when your amplifier has shut down due to overheating. It simply provides explanation as to why the unit has stopped working and lets you know that it needs time to cool down. Hopefully, you have never driven it to that point.
Energy will probably fix it for free.
Also, add a powered sub. Not only will this alleviate a lot of the work for your speakers, it will let you get by with much less power from the amp since bass is where most power is wasted.
Have you checked the driver bolts to see if they have come loose? This IS the most common reason for a driver to buzz.
Steereophile even had a comment about this EXACT thing recently.The reviewer took in the speakers for a problem with buzzing, and the tech just tightened the drivers.
If you have never tightened the drivers, this is certainly the reason..Do IT.
(tighten each screw or bolt a little at a time going alternately around until they are all snug. The screws or bolts will still turn a bit with pressure even if snug. do not make them "tight" where they cannot turn anymore)
Unfortunately, there are no external screws or bolts to tighten--the woofer and surrounding rubber ring are flush to front of cabinet. When I described the situation to Klipsch (now owns Energy), I was told that new bass drivers are available for $280 and that they recommend a shop in western Michigan for installation. Before spending that money and driving 200 miles, I will find a place in suburban Detroit to check the driver. I also will begin to research subs and how to integrate. Regarding sound levels, 95 percent of my listening is at lower to moderate volumes with sound quality being the clear priority. The onset of the buzz, however, has me "gun shy" and resisting the occasional urge to turn it up. Your suggestions are appreciated!

You will find the bolts for the woofers located on the rear of the speaker. You will have two of them, one for each bass driver. They are center mounted. They are easily removed, just be careful not to let them tumble out as you unscrew them - or just try to tighten them and see if that cures your problem, as suggested.