You shouldn't definitely go T50RP route. Even the most basic mods yields the good results.

The value for money is astounding. Even just a pad change and blocking of vents makes them into something more preferable for hi fi enthusiasts.

I haven't been able to take them off. Relaxing sound that gets you into the 'room' so well and cleanly at high volume too.

I'm not even getting the 'honk' that you can get from closed in types of headphones. (Although this is semi-closed)

In UK, they are a bit more expensive than the USA but still incredible value.

I did all of the walls and even lined the ceiling! When I'd finished, I did wonder if everything had become rather 'dry' sounding though.

I had heavy curtains on a patio door and even experimented by moving the curtains sllghtly to expose glass surfaces in order to tart the sound up!!!

I'm not certain a 'fully damped chamber' is always the best thing at home in spite of the way that speakers get 'tuned'.

Good speaker sound is more rife with problems in many ways than a headphone I suppose. The massive variations in rooms must account for an awful lot of bad sounding systems.

UK homes tend to be small as well so furniture is crowded in etc, so I have no idea how good sound is achieved in them other than to use shelf monitors or near field monitors. Ceilings can also be quite low. Therefore there will be wonderful room resonances that will interact beautifully with your 'flat' speakers.

Doing a frequency sweep from speakers in a room shows surprising amounts of reverberation/ringing of frequencies and not many people take that into consideration when buying speakers.

Not too many of us can afford to build an anechoic chamber in our houses!! They're ugly but a little bit of treatment and care can really help a lot. Identifying key reflection spots is useful and a mirror could be used to identify where they are.  Moving a mirror down the side walls and sitting in the listening position will show where sound gets reflected - when you can see the speaker in the mirror from the seated position. That's where the padding can be critical to cut down room reflections. Not many people actually do this though.

On the key areas, dampening can really cut room revererations down quite well and still leave some room 'liveliness' to keep that 'musicality' there. (For want of a better word)

I guess headphones and 'flat response' have a slight edge since speakers are rife with in room problems and furniture.

To generate a nice clean 20 Hz, a room size bigger than about 17 meters would theoretically be needed as well. A room to dream for.

I guess it's easier to change a headphone than change a room. Standing waves are also a problem in rooms.

Have you ever measured what is going on in your room with a frequency sweep? It can be very revealing. Speakers aren't measured by factories in a normal room. Then again what's a normal room? In the UK, it tends to be smaller than the USA so the little shelf speakers tend to be more popular over here than in USA. They don't really give the low end grunt though.

Likewise, popular speakers emanating from USA don't tend to sound quite so good in UK homes. It's all to do with room sizes and proximity of furniture.

"Good speaker sound is more rife with problems in many ways than a headphone I suppose."

Not at all.  Everyone overstates the affect rooms have and I have to constantly repeat this so my apologies to those who have read this before.  At least compared to what we see in headphones.  You'd have to specifically design a room to create teh kind of resonances you see in most headphones.  I will say again, that I have no room treatment, one of my speakers is 4 inches in front of a glass wall and they are cleaner than almost all headphones ever made (maybe cleaner than anything ever made).  Maybe some kind of sealed cement chamber with specific shapes on the wall could create something nasty.  I'm still doubtful. 

The affect of rooms has more to do with changes in FR.  And the biggest impact is on bass.  It's more like EQ than it is resonance.  And the affects on dynamics, clarity, detail is more akin to upgrading to a better amp with the same headphone. 

The way my speakers change between rooms is more like HD600 vs HD650 plus the variations introduced by various amps plus a bad sub thrown in sometimes. 

Maybe you could say that rooms have a big effect on resonance in the bass region with speakers and decay rate overall.  But headphones have serious resonance problems in the much more problematic midrange-treble area that cannot be fixed, it's in no way comparable.

Are you listening near field or further away?

The side wall/floor/(possibly) ceiling reflections will be more critical if you're further from the speakers. My listening distance is slightly over 3 m.

So I agree that it's not as hyper critical as resonance in headphones (they're also sitting inches from your ear), but dampening the reflections in speakers still makes a significant improvement. Far bigger than sources, proper (ie not under powering or clipping) amps, etc.

The treatments also aren't something that easily lends itself to quickly adding and removing. But when I removed all my side wall treatments there was a significant difference in the amount of smearing I was hearing leading to low level resolution loss. Also it was generally more unpleasant to listen to at the same volume as before.