On technical progress, including the science of materials - and you are all for science, as I am, I believe there is no denying that there have been major improvements in the last 40 years, and so, again, some context is probably needed and only you can provide it since you know your speakers. In particular, I didn't like the PM1s either.
I love my Oppo cans. They're the best headphones I've ever heard. It's just that headphones don't come close to matching the experience of a good speaker system. Headphones can't match the important aspects of directionality or the visceral impact of sound pressure all around your body.
There have been a lot of advances in speaker technology in the past twenty years. The average mid priced speakers of today are better sounding, better designed and more compact than the average mid priced speakers of the 70s and 80s. And the top of the line modern speakers are much more accurate than the best speakers back then. But that's only part of the story. I know a lot of people around here ascribe to the lofty goal of
accuracy and nothing else, but I feel a little differently. There is no such thing as perfect accuracy with speakers. There are always compromises dictated by the room, the design of the speakers and the way you listen to them. Accuracy to me is a general goal, it isn't my ultimate destination.
The reason I love my old JBLs is partially because of accuracy... they're pretty close to the pinnacle of accuracy that was achievable in the 1970s. Even compared to modern speakers, they're no slouch. Sure there are more accurate speakers today, but not by that much. However, their design gives them some added impact that may not be completely accurate but still is highly desirable. Modern speakers perform spectacularly at normal listening levels, especially in clarity and balance. My JBLs can't match that. They still sound great, just not quite as spectacular in that context. But at high volume levels, my speakers wipe the floor with more polite modern speakers. I can crank the volume so you can hear the music six blocks away and there's still no distortion- amazingly clear and balanced. It's almost impossible to overdrive them. Also, they pack a solid dynamic punch. When you push them, they put out astounding dynamics, especially in the upper bass through the mids. It's relatively easy to do good sub bass if you have a good subwoofer, and upper mids and treble is easy with the very sophisticated designs on modern speakers. But the bread and butter upper bass and mids are usually presented accurately in modern speakers, but without the huge impact and lifelike presence that classic JBL drivers give them. Today, audiophiles worry about frequency extension a lot. That's great, but the sound in the middle is what really counts to me.
Inside the classic Fender guitar amps that rock musicians cherish are the same speakers that are inside my 70s box speakers. So when my speakers produce the sound of bass or lead guitars, it's going through the exact same transducer that originally produced the sound at the recording session. Vocals, especially baritone voices are extremely dynamic. You can feel the power of vocals better. Upper mids and treble are handled very well because my brother had the presence of mind to spend a fortune on buying super high quality bullet tweeters with an exponential horn design. They are very directional and don't have very good off axis performance compared to modern tweeters, but if you sit in the right place, they are fantastic. I've solved that in my room by backing up my mains with the highly directional and dynamic sound with a pair of modern JBL towers that have great high frequency dispersion and super clear upper mids. Cake and eat it too.
My approach may be anachronistic, because I don't follow the rules of accuracy strictly. I realize that I inevitably have to rob Peter to pay Paul, so I do that in a way that gives me what I want most. For me, I want a huge sound that is balanced and detailed. It may not be perfect off axis, but I can fudge that. The overall presentation may not be quite as accurate on paper, but when you listen to it, it is alive and you can feel the power behind it... kind of like the difference between realistic color in a film and vivid Technicolor. A recording is already an approximation, and any sound engineer worth his salt will tell you a sound mix is never intended to be a completely accurate representation of a live performance. If sound mixers can apply sweetening techniques to make a recording sound better than real, I don't feel guilty doing that on playback. Better sounding is better than accurate to me.
