How loud is loud, What DB is actually loud?

more to it then it's sensitivity :) Some of the best sounding speakers are in the 80-90db efficiency area

I think it depends on the person on what DB is loud. I prefer loud music.... & movies my brother doesn't like it anywhere close to as loud as I like it. Never put a SPL meter to my stereo to know how loud it is.... did years ago in my car audio days.... 135-140db is all I would do since it was a SQ setup

I agree with the Klipsch comment! Very good speakers for the money, and very efficient.....easy to push! I personally have spent much cash on my system over the years, and also love to rock out! That being said, when sitting in the listening chair, with the volume cranked up, and I mean helicopter in the room with you loud, it's still only 90 to 95db, in the listening chair.

I don't know how rock concerts come up with these big numbers, think it must be because they are pumping out pure distortion. At 90 to 95db in my listening room, you swear you could pound nails into the wall with the bass, incredible!

As for what type of speaker to buy, I don't think electrostatic or planar are the way to go for you! Both can be great speakers, but generally like lots of power to get the bass working well, which all starts to cost you money. For a reasonable amount you can get some nice Klipsch.......and get the volume bug out of your system!

I would think a Quad would NOT be an ideal speaker for you at all and your likely to regret it quicky.
If you like that sort of presentation Martin Logans are a better choice as they have that magic but dynamic woofers and will play louder but again when you consider the music you likely will favor they can be ruthless with the average at best majority of recordings your probably gonna listen to.
Klipsch is a good idea, KEF, BW, Legacy would all probably be better places to look, I also would say VMPS offers a good line to explore but I own them for the record.
As always take all this with a grain of salt and trust nobody as you just need to listen for yourself from either a store to maybe even a member around here who can give you some time in their seat for a trial.
Post where your at here and under clubs tab and see what may be close to you............might be a real game changer for you and ya might make a friend in the bargain.

I suspect you've already damaged your hearing. 135 dB is above the threshold of pain.

I have a friend that listens to his musics very loud at times. In high school he put in ear plugs in his car to "feel" bass and actually got a nose bleed out of the deal. When we shared an apartment he had the system in his room cranked up so loud that a lady from the next building (about a 30 foot air gap) came over to complain. I requested that she wait while I got him since he wouldn't believe the complaint if he didn't hear it from her. In any case, we used a dB meter once to check the listening volume because he wanted to see how it compared to OSHA recommendations for hearing damage. I don't think he even exceeded 95 dB (probably not the loudest he ever turned it up) on the meter. We were both surprised as we expected a higher number. Concert volume is stupid in my opinion.