In my quest to search for the best closed, non-noise-cancelling headphones that will do a satisfactory job of isolating the engine rumble of the bus that I take to and from work, I found that the choices are very few. I ultimately decided on purchasing two pairs, the Sennheiser HD 380 pro and the Shure SRH840. Prior to testing the differences between these two headphones, I ran both of them through my home audiophile stereo system at high volume for over 50 hours each plus another 20 hours each of casual listening to and from work.
First, the dimensions of each can. The Senn's are bigger and more oval shaped than the Shures. The Senn's cans measure approximately 4 9/16 inches by 3 7/16 inches, while the Shure's is more roundish, although still oval, measuring about 4 2/16 inches by 3 1/2 inches. The longer length of the Senn's may bother people like myself who suffer from TMJ syndrome (jaw problem due to clenching), which may also be further induced by its vice like pressure. The Shure's are not long enough to reach my jaw, and they fit more loosely but still snug enough to keep firmly on my head. The depth, the length of the outside of the leather that covers your ears to the felt of the inside of the can, is 1 1/16 inches in the Senn's and only about 3/4 of an inch for the Shures. This is a huge difference. My normal size ears actually touch the inside felt of the Shure's, but this rarely bothered me. This vast difference led me to believe that the Senn's will have a better soundstage; however, I was not able to detect any difference. The Senn's have a very thin and porous felt, and it is easy to see the speaker. However, the Shure's felt is thicker and far less porous, and therefore, it is not possible to see the speaker. Perhaps the speaker in the Shure's is further recessed, which may be the reason that I was not able to detect a difference in the soundstage.
I like the fact that the Shure's wire is a screw on, so if the wire breaks, it can be replaced. I believe that the Senn's wire is a permanent fixture, but I am not certain; however, I do know that they are not the screw on type. Although they both come with a case, I much prefer the Senn's case. It is a somewhat hard case, but at the same time somewhat soft - difficult to explain. Anyway, it is very cool. It even has a strap like handle - very cool. It fits very easily in my briefcase. The headphone case has a zipper and can be completely enclosed. The Shure's case is leather with a draw string, but it cannot be completely enclosed, and takes up a lot more space in my briefcase, and is not nearly as cool. I was not impressed.
In my subjective casual listening to these headphones during my commute to and from work, I felt that the Senn's isolated the outside sounds of the engine rumbles of the bus perhaps 10%-20% better than the Shures. I did a more objective test in my house, as I put the headphones on without music and listened to my air conditioner. The Senn's clearly isolated better. Still, the Shure's did a satisfactory job.
Now it was time to test the sound. First, I wanted to know if the headphones would sound different through an mp3 player (320 bit rate) compared to through my stereo system. I did a blind test. The difference was clear - it took me only between 5 and 10 seconds to know which sounded better. I came up with the same results time and time again. The headphones sounded superior, much cleaner and sharper, when connected to my home stereo. I am not sure how much of the difference was due to the mp3's compressed sound of the copy or to the huge difference in the quality between my audiophile stereo amplifier to the low quality amp of the mp3 player. However, my test may lead me to one day buy a portable amplifier for my headphones, if a company ever comes up with a high quality amp that uses a rechargeable battery instead of a 9v battery lasting only a week or two.
I wanted to know which is more efficient ( obtaining more headphone volume at the same amp volume setting.) I raised the volume in my amp until I was able to hear something. This test proved to me that the Senn's are efficient but only sightly. I used music with only midrange in this test.
Now I wanted to see which headphones sound better - at least to my ears. To me, better means more faithful frequency response, extended bass, and crisp and open sound. I used my audiophile stereo system as the reference. I listened to songs that I am very familiar with - Stevie Wonder, Frank Sinatra, Count Basie, Chicago, Elton John, Melissa Manchester, Kelly Clarkson, Steely Dan, Donald Fagen, George Winston, and Johann Sebastian Bach. I listened for many hours. I listened at high volumes and at very, very, low volumes. There is definitely a huge difference in the sound. By far the biggest difference is in the middle to high part of the bass, such as sounds produced by the bass guitar, bass drums, and synthesizer bass. I am completely convinced that the Senn's have an exaggerated mid to high bass. The Shure's mid to high bass always sounded far closer to the faithfulness of my reference. The difference is staggering. The only reason that I still listen to the Senn's with music with a lot of mid to high bass is that the rumble of the busses dampen the exaggerated bass; however, once I step off the bus, I always wish that I was listening to the Shure's. So, when I listen to say Stevie Wonder, Steely Dan, and Chicago, I much prefer to listen to the Shure's.
I must say, however, that although the Senn's mid to high bass is definitely exaggerated, its mids and high are impressive enough and the bass is tight enough, that the whole music spectrum can still be appreciated. However, the whole music spectrum is more appreciated with the Shure's, as it too has a tight bass and has mids and highs that are even more impressive than the Senn's.
Listening to music having a deeper bass than mentioned above, for example the plucking of the bass fiddle in Count Basie's CB Express and Satin Doll, the Senn's were a little more impressive than the Shure's. Going still deeper in the bass, the bowing (you know, when the musician uses the bow in the string instrument) in Bach's concertos, I was surprised to find out that the Shure's went equally deep as the Senn's. With bass this deep, it is nearly impossible to exaggerate the bass, so ultimately the headphones with the more powerful bass is the one with the better deep bass. I found that sometimes the Senn's sounded slightly better and at times the Shure's sounded slightly better. At one part of the music, I decided to listen at the lowest possible volume to find out at what volume would I not be able to hear the bass anymore. The Shure's actually did slightly better than the Senn's during this test. However, at a different part of another concerto, I felt something in the bass with the Senn's that I felt less of with the Shure's. Consequently, my impression with the deepest part of the bass is a mixed conclusion and the differences only slight.
When I tested the mid range to high ends, I found that the Shure's made this musical spectrum sound more separated from the bass than the Senn's, but I was not certain if it was due to the exaggeration of the mid to high bass of the Senns's. However, when I listened to Bach, which mostly lacks mid to high bass, the mids and highs still sounded more separate from the bass with the Shure's. Cymbals in every music that I listened to almost always sounded more crisp and clear with the Shure's. Still, they never sounded too bright or tinny.
All the other closed, non-noise cancelling headphones that I tested at the stores simply could not match the noise isolation of the Shure's and Senn's. However, I think that the Sony MDR 900's came the closest. I did not buy the Sony's because they were too loose fitting on me. If you want headphones that have high quality sound but you are a little less concerned about isolation from outside sounds than I am, I would consider the Shure's SRH840 and the Sony MDR 900. If you are not concerned about isolation at all, then there are many, many more choices. The Denon's 2000's is just one example of a solid choice for those who want high quality sound and do not care less about isolation, but, as I mentioned, there are many, many other choices. I just wish there were more choices for folks like myself who want to enjoy listening to music while being in the middle of a raucous of a big city. For now, the Sennheiser HD 380 pro and Shure SRH840 may be the two best choices available for those who need the very best of noise isolation, without the noise-cancelling technology.