Beyer construction. The images on line betray the level of construction and feel of these phones. They are very solid and the stainless is of heavier gauge then expected. The ability to swivel the cups 180 is very convenient. A point of interest though, there is very little action on the headband hinges; I had expected that like the hd25s you would be able to swing one of the cups back off your ear. Also, when split the headbands close very easily, merely dangling the bands on an index finger will do the trick.
Clamping force - using a digital kitchen scale and a stack books to replicate the thickness of my head I got the following clamping force in grams: HDs band closed - 7g and band open 13g. DTs band closed - 7.5g and open 13.4g. Trade specs indicate Senns have ca. 2.5 N while the Beyers show ca. 5.5 N. Personally I didn't sense twice the clamping force with the Beyers. By the way, the HDs weigh 5.7g and the DTs are 7.3g.
Isolation - the packaging specs for the Beyers indicates 23 dBA, couldn't find specs for the HDs but, according to the Beyer rep the DTs have slightly better isolation (clamping force?)
Fit - the HDs have a slightly larger cup (HDs 2 5/8" and DTs 2 3/8") and perhaps as a result seem easier to find the sweet spot quicker. If I had one minor beef with the construction of the DTs it would be the up and down adjustment. While trading the two phones back and forth, and letting family members try them, I found the HDs easier to adjust up and down while on the head. The DTs stainless steel construction is superb but takes some getting used to when adjusting up and down. Since my head tends not to change shape or size all that often this was quickly resolved - don't share them, but if you do - remember your approximate settings, try them, remove, adjust, replace.
A comment about finicky fit and finding the sweet spot for sound. At no time did I have a problem, this may be due to the fact that I'm used to this on ear style. I tried the suggested "hum" technique to confirm that what felt right was a good sonic fit. No problems there. Having read comments that the T50p sound improved by pressing the phones to your head - I tried the same with the DT1350s - no change.
Sound - I'm not going to even spend time describing the Hds sound signature, pretty much everyone here knows it, so I'd rather run-through a bunch of songs and then offer a few general observations.
The setup for this comparison was a first gen iPad. All songs were 320kbps. No amp. No eq. Stock phone cables of course. The HD25 are over 2 years old and my primary phones. The DTs had just over 20 hrs burn in and seem to have settled in.
Corinne Bailey Rae - Like a Star. I listened to this first with the HDs and enjoyed the warm, full, bass forward presentation. With the DTs the detail went up, the bass player tightened up and took a step back, the instruments found a little more room and Corrinne sat down and sang to just me.
Buddy Guy - Baby, Please Don't Leave Me. This one goes to the HDs, their signature really brought the song together.
Cage the Elephant - In One Ear. The HDs had me playing air guitar and having fun. The Beyers were great but I have to admit, I found myself listening and thinking... I didnt realize he tells us to "sshhh" during the song. That being said, the Beyers keep up to the pace and rocked better then expected.
Springsteen - Radio Nowhere. This is included to confirm a personal opinion/suspicion - the song is produced way too load. Yup, I'm a huge Bruce fan, but this song suffers for bad production. So far, the Senns are more forgiving of bad production, which is why so many of us love them. With the Beyers the song is simply noisy.
Miles Davis - Doo Bop Song. The song has an good mix of bass and horns, the HDs added to the bass but at the expense of Miles. Beyers presented a more balanced and engaging performance.
Bruce Springsteen w/ The Sessions Band - Blinded By The Light (live in Dublin). I found myself wanting a combination of both phones. Bruce's vocals are cleaner and more forward on the DTs, but with the HDs the band really showed up. Also noticed with the DTs the stage moved up slightly?
John Melloncamp - My Sweet Love. DTs all the way, the strong mix of bass and drums, jangling guitar, John's vocals and backup singer all get the detail and clarity required. The HDs comparatively presented flat, however, an interesting note, the HDs did separated the backup vocals better.
Kid Rock - Born Free. Tough call here, maybe the HDs by a slight nose for that fun full rock sound, but the upper treble did lose detail and turned to sibilance as the volume went up. The DTs were more fun then expected though.
Jamey Johnson - Lonely at the Top, Guitar Song. Started with the Beyers on track one, was captivated and couldn't stop, listened straight through both albums. The Beyers brought an intimacy to the album that was completely unexpected. The song interludes were a hoot with these headphones, particularly the fly sequence. This brought me back to my first time with Dark side of the Moon.
Rancid - She's Automatic. Probably an unfair song for the DTs, but I included this to confirm a general theory. For me, the HD are more of an on your feet, fist pumping, singing with the band, kinda musical experience. While the DTs inspire you to sit, listen, wait for the song's final note, then jump to your feet and clap til your hands hurt. This song proved the theory. Again the clarity and detail was better with the DTs but this song belongs to the HDs.
I'd like to spend more time on this and give some attention to more jazz and classical, but I think that it won't be long and forum members with a better audio vocabulary then myself will be joining in. My musical tastes lean heavily to singer song writers and from the past few days the DT1350 have proved their worth.
General sound conclusions. As you have probably gathered by now the Beyers show more detail across bass, mids and treble. I'm not sure if its the correct description, but to my ears the Beyers offer better resolution. Compared to the HD25s the DTs are less bass forward and not as warm. With almost every song the DTs brought my attention to the vocals and mids. They are certainly less forgiving of poor production then the HD25s and perhaps a little less musically fun as a result. On some albums from one song to the next I found myself noticing marked changes in production levels.
Sound stage - the Holy Grail. Honestly, overall I didn't observe much of an increase. As mentioned above there is a greater degree of detail and on several songs improved separation between instruments with the Beyers, but not the marked sound stage increase some may be looking for. By and large the music is still inside my head - the room is less crowded - but still a room and not a stage.
Ear fatigue. There's a lot of great things about the HDs, but over time I've found that my ears get tired quicker then I'd prefer. It may be the fact that they're fun to listen with and as a result the volume may creep up, but after a good 3 hours straight with the DTs - no fatigue. I also found myself bringing the volume down a touch with the DTs. According to the marketing info the DTs are more efficient, so, using an SPL app and my iPod touch I ran a comparison. iPad as the source, full volume, Kings of Leon - Sex on Fire: HDs peaked at 92db, Beyers peaked at 93.5db. My personal listening level rarely goes over 60% with either phones, this translated into right around 80db peak with the iPod touch app.
Well, I hope that this helps some of you with your decision regarding the new DT1350.
Cheers and thanks for reading.