[tattoou2]

  Before I got the GMP 400 I found a few reviews online (not on head-fi) and I'm really surprised that none of them mentioned the bass. These are commonly compared the DT880 and HD600/HD650 and I'm surprised that I never heard it mentioned that they have more bass than either of those cans do. They also have more bass than the K712. It isn't too much bass but I consider the bass on those 3 'phones to be quite neutral so in comparison the GMP 400's bass definitely sounds north of neutral. I actually expected them to be a bit bass-light based on the descriptions I've read and the fact that there is virtually no clamping force and the cups are attached to the headband via elastic strings. Yet there's a remarkable amount of bass impact! If you want something similar to an HD600 or HD650 but you need more bass, the GMP 400 should be right up your alley.

Nice to hear since I just ordered a GMP400.  Hoping this can will help curb my chronic obsession about comfort an attribute which,  for me,  can be elusive.

 

[devhen]

 
Nice to hear since I just ordered a GMP400.  Hoping this can will help curb my chronic obsession about comfort an attribute which,  for me,  can be elusive.

 
Nice! Congrats on the purchase. They are VERY comfortable. I'd love to hear what you think of them. The impressive amount of bass quantity and impact that I'm hearing on mine makes me wonder if there is some driver variance and others are getting slightly less bassy versions. But I doubt it.
 
The center image of the soundstage on the GMP 400 is more congested than on the HD600/DT880/K712 but they are otherwise right up there with those cans. I really think you will like them. I highly recommend them to anyone who likes the laid back nature of the HD600/HD650 but feels like they don't provide enough bass quantity or slam.
 
Good luck with the GMP 400, I hope they solve your comfort issues! Please let us know what you think!
 

 

 

[tattoou2]

Thanks!  I am very fond of my HD600, but there are times when I expect more bass impact and it's just not there.  I'll be checking back later after a little time with the 400.

 

[devhen]

  Thanks!  I am very fond of my HD600, but there are times when I expect more bass impact and it's just not there.  I'll be checking back later after a little time with the 400.

 
Right on. Looking forward to it.
 
That's exactly how I felt about my HD600 initially. In the last 2 years I've come to appreciate and even prefer neutral, un-emphasized bass but 2 years ago I would have most likely preferred the GMP 400 and considered them "better." I'm optimistic that you will be pretty pleasantly surprised by them.

 

[kkl10]

   
Nice! Congrats on the purchase. They are VERY comfortable. I'd love to hear what you think of them. The impressive amount of bass quantity and impact that I'm hearing on mine makes me wonder if there is some driver variance and others are getting slightly less bassy versions. But I doubt it.
 
The center image of the soundstage on the GMP 400 is more congested than on the HD600/DT880/K712 but they are otherwise right up there with those cans. I really think you will like them. I highly recommend them to anyone who likes the laid back nature of the HD600/HD650 but feels like they don't provide enough bass quantity or slam.
 
Good luck with the GMP 400, I hope they solve your comfort issues! Please let us know what you think!
 

 

 
There is indeed some variantion with the GMP 400/450 drivers and the most affected areas of the spectrum are the bass and upper treble.
I have three pairs of drivers and all of them sound different, quite significantly I must say, not necessarilly in tone but rather in frequency balance. According to German Maestro it's due to the way how the drivers are manufactured. Tolerances cannot be so strict that drivers will have exactly the same physical properties and as result they can sound slightly different from each other.
I have looked at the naked drivers myself and noticed they all have some slight color and coating differences between just them below the diaphragm layer, probably manufacturing artifacts or residues...
 
But I doubt that differences can be so large that some units will sound bassier than the HD600 and some units will sound relativelly basslight, so it's possible German Maestro has changed something in the headphone... but I don't know.
In my experience the stock GMP 400 had a natural tone relativelly similar to the HD600 yet maybe slight warmer, but the bass had less punch than the Sennheiser and sounded lighter.

 

[devhen]

 
There is indeed some variantion with the GMP 400/450 drivers and the most affected areas of the spectrum are the bass and upper treble.
I have three pairs of drivers and all of them sound different, quite significantly I must say, not necessarilly in tone but rather in frequency balance. According to German Maestro it's due to the way how the drivers are manufactured. Tolerances cannot be so strict that drivers will have exactly the same physical properties and as result they can sound slightly different from each other.
I have looked at the naked drivers myself and noticed they all have some slight color and coating differences between just them below the diaphragm layer, probably manufacturing artifacts or residues...

 
Interesting. But not surprising. As I understand it, its something that happens for all manufacturers but depending on their processes some of them can afford to scrap a much larger percentage of the most widely varying drivers which results in more consistency from one headphone to the next. Some people get this confused with driver matching. Driver matching is matching the two drivers in a single headphone and its extremely important and headphones that are known to have a lot of variance (the DT770 comes to mind) don't necessarily have poor driver matching. FYI the drivers in my GMP 400 appear to be perfectly matched.
 

 
But I doubt that differences can be so large that some units will sound bassier than the HD600 and some units will sound relativelly basslight, so it's possible German Maestro has changed something in the headphone... but I don't know.
In my experience the stock GMP 400 had a natural tone relativelly similar to the HD600 yet maybe slight warmer, but the bass had less punch than the Sennheiser and sounded lighter.

 
That's interesting because I completely agree that the GMP 400 has a natural tone similar to the HD600 but is slightly warmer. But my GMP 400 definitely has both more bass quantity and more bass impact than my HD600 (though not by a whole lot). I'm interested to hear how tattoou2 finds his pair.

 

[tattoou2]

Hopefully I will get them by Tuesday and I plan to check them out over the holiday.  There's nothing quite like a new hp for Christmas!    

 

[Tiemen]

I just went through the The 2013 Head-Fi Winter Gift Guide.
Every headphone company, obscure as they may be, are mentioned.
But none German MAESTRO at all, which is a shame!
 
Still love my GMP 250 and GMP 8.300 D.

 

[TrollDragon]

Still waiting for my 8.300 D's, must be coming by an old U-Boat from Mein Vaterland...

 

[Tiemen]

Still waiting for my 8.300 D's, must be coming by an old U-Boat from Mein Vaterland...

 
Nice. Then I won't be the sole owner of the GMP 8.300 D anymore, but the two of us

I'm curious how they perform with your Little Dot. I never got a good match with the 8.300 and tube amps. As if they hate them.....

 

[TrollDragon]

Nice. Then I won't be the sole owner of the GMP 8.300 D anymore, but the two of us
I'm curious how they perform with your Little Dot. I never got a good match with the 8.300 and tube amps. As if they hate them.....

Well that doesn't sound too good, the main reason I chose the 8.300's over the 350's was for use with the LD as it is my main amp. My LD doesn't like low impedance cans as it has a bit of a hum in them. I haven't had the urge to take it apart again as it is a PiTA to do so and I believe heater wire routing is causing the hum. I can use a 100 Ohm impedance adapter I built, but I don't really want to if I don't have to.

Hopefully the 8.300's will pair up nice with some nice cheap Soviet tubes from the E17/E09K combo's Line Out.

Your gear is a lot higher end than mine so possibly it is a lot more revealing in the 8.300's, fingers crossed they sound sweet through the tubes, if not the E09K will drive them nicely, for my ears anyway.

If they block TV / Wife on telephone chatter and sound almost as good as the DT880's I will be a happy man. Findings will be posted when they arrive.

 

[devhen]

@tattoou2: FYI, the GMP 400 has been slowly going down on Amazon every day or two and is down to $222 currently. Within 7 days of receiving yours you can ask Amazon to refund you the difference in price so I recommend you do that now or keep an eye on it to see if it goes down even further during your 7-day window.

 

[dahoo]

German Maestro released a white version of GMP435s
http://www.german-maestro.de/US/gmp435swhite.htm

 

[tattoou2]

  @tattoou2: FYI, the GMP 400 has been slowly going down on Amazon every day or two and is down to $222 currently. Within 7 days of receiving yours you can ask Amazon to refund you the difference in price so I recommend you do that now or keep an eye on it to see if it goes down even further during your 7-day window.

Thank you.
 
I received my GMP 400 yesterday and had a brief listening session last evening.  For me, the GMP 400 is rather a unique sounding hp.  It really is extremely linear and neutral.  Bass is present when the music insists upon it, but the GMP 400 seemingly lacks that certain punch and impact.  The bass lets one notice it and analyze it without much fanfare.  Treble, to me, is slightly dry while the midrange is just a tad forward and a little less fuller sounding than what I am used to.  It has an open and spacious sound, but imaging, depth, and overall detail seemingly suffer a bit using my Burson HA-160D.
 
Build quality is generally good and comfort reminds me of my AT's with even less clamping force which makes the 400 very comfortable indeed.
 
Of course, this is a very initial impression straight out-of-the-box.  I'm going to give the 400 some burn-in, and try it with my ALO Continental and Woo Fireflies.  For me the GMP 400 is a sound signature to which I will have to become accustomed.  Because of its almost absolute neutrality, it may be an acquired taste for some, including me.

 

[DefectiveAudioComponent]

I wish GMP would start selling those with orthodynamic drivers again - they quit making them in the late 70s / early 80s, but the headsets appear to be about the same still.
 
Just compare that GMP 435 to this (magnat-branded) 70's headphone (nevertheless most likely made by PMB / GMP), with a 55mm orthodynamic driver. If they could just produce some more of their old orthodynamic drivers and put them into that GMP 435 headset...