which excels at Rock and Roll

Bose speakers is the best for any type of music, Also SVS and Tekton is amazing 

Just one example: If you want to play AC/DC or The Ramones at 100dB, the QUAD ESL is a bad choice; a pair of them is not going to last very long if you do.

Classical music can easily be at 100dB! What you are talking about here is that Quad ESLs (like the 57 or 63) really aren't suited to play at really loud volumes. 

If you want to do that you need something more efficient. Its not that the Quads otherwise will misrepresent the Ramones. My Classic Audio Loudspeaker T3s can easily play Romones or Verdi's Requiem at 100 dB. 

Next thing you know,..he might claim his 'genre agnostic' tube amps might just work great for every kind of speaker I have and my entire music collection spanning every genre available.

@deep_333 Nope- not gonna do that! If you have the right speaker, they will play any genre equally well though.

Any designer can tell you its impossible for a speaker or amp to favor a certain genre for a very simple reason: musicians, regardless of what kind of music they play, have ears that use the same hearing perceptual rules. So they tend to make music with similar balance, for example bass notes will always tend to consume more amplifier power and thus need greater excursion on the cone of the loudspeaker.

Like I said, for any recording you can come up with that seems to reinforce the myth, there's one out there that will disprove it. This is simply because the idea that speakers can favor a musical genre is a logical fallacy based on a limited sample size. 

In my experience some maybe even most speakers are absolutely suited more for certain types of music. So I totally disagree based on my experience with probably 30-40 sets of speakers.  

For me, the key to great Rock & Roll speakers are the following:

1.  Great Deep Bass
2.  Great low end "Chunk" - think Drop D. or Hendrix on VooDoo child slight return.
3.  Great high end "honk" from the guitars with the treble pot turned down, smooth highs, & vocals that cut through all the distortion.

You can achieve this with Tower Speakers with lots of Bass or adding a subwoofer.  However, item 2 above my suffer with only a subwoofer supplying all the bass. 

Personally, I like towers with bass better than separate subwoofers.  It is easier to achieve the best sound for Rock.  Look for good size towers with two woofers, the larger, the better.  ie. 8" to 10" woofers.  Make sure the reviews "rave" about the bass.    For the high end "honk" like Dire Straits  "money for nothing"  and those smooth highs, think "Ted Nugent - Stranglehold", & vocals that cut through, you will need a good quality tower to achieve that.  This is where the extra money makes a difference - synergy of the tower.  In general, the more you spend within reason, the better synergy you will get and the better you will be able to hear and separate all these great distorted sounds that Rock makes.  I hope this helps you. 

@atmasphere If you want to do that you need something more efficient. Its not that the Quads otherwise will misrepresent the Ramones. My Classic Audio Loudspeaker T3s can easily play Romones or Verdi’s Requiem at 100 dB.

100Db+- 10db   40-10000hz ??