Review: German Maestro GMP 400

Firstly I would like to thank Thomas at German Maestro for sending me this sample, I will write as honest a review possible. These received over 50hrs of burn-in before review, no differences were noted.

Gear Used:
Asus M50vm > iFi iDAC > iCan/JDS Labs O2 > GMP 400

Frequency Response: 14 - 24.100 Hz
Nominal Impedance: 300 Ohm
Type: Open back, circumaural, dynamic driver.
Average Pressure on the ear:  ~3 N
Weight Without Cable: 240g
Connector: Gold plated 3.5mm with 6.3mm screw on adapter.
Cable Length: 3m

Packaging, Build Quality and Accessories:
The packaging is standard across the German Maestro range, a black and red box, with a picture of the model on the front with specifications below. It has Made In Germany in bold letters on the box as they develop and make all their products in Germany. Inside this the headphones are held securely around a triangular piece of cardboard. Well packaged with no frills, pure function.

Build quality is not luxurious, but they are light and also German Maestro put more in to the sound than how they look. The headphones are mainly plastic with grey metal grills, and an adjustable headband. They don’t look special, but the plastic keeps weight down and I have no problems with any of the stress points, the plastic is of high quality, the cups are held in a suspension type mechanism by rubber bands which means they conform perfectly to your head shape and don’t exert much pressure. The pads are Velour and comfortable, the cable is 3m long with a small coiled strain relief  below the y-split. The cable is sufficiently thick, and well relieved on the jack and housing, it is terminated in a 3.5mm jack with a 6.3mm screw on adapter included. Overall no problems with the build quality, these are definitely more function over form.

Accessories are not any really apart from a 6.3mm screw on adapter, a small fabric carry bag would be nice. 

Comfort and Isolation:
Comfort is very good, the headphones are light and the headband is not tight, the adjustment mechanism is similar to AKG and helps distribute weight evenly. The pads are velour and deep, they soften up with time also, the suspension mechanism of the cups is very good and they conform perfectly to any shape of head, the comfort is something they have taken great care to make good.

Isolation is pretty much none as these are open back, full size headphones.

Split in to the usual categories with a conclusion at the end.

Lows: The lows on the GMP 400 are very accurate and also extends low not having abundant peaks in any part of it. Tight punch and full body when called for, but not in huge quantity, these are designed as studio reference headphones, that is what they are. Very linear bass, I remember reading a review saying that these don't have fast lows, but I would say the lows are tight and quick, and excel in comparison to some thicker sound cans like the Sennheiser HD650. These handle bass boost very well too, the boost on the iCan really gives you some extra body and weight without taking away detail from the mids or highs, the lows are well separated and never become boomy or congested. Some will consider these a little bass light, but I don’t think that. Amping is key (more on this later)

Mids: Again very linear and well placed, excellent detail retrieval from the lows, both male and female vocals sound realistic, when you have multiple vocals in one track it is easy to differentiate between them, being well separated and also having good placement and air. There is a little dip in the upper mids which means no sibilance but they lack a little energy.  On the whole the mids are very clear and detailed and spaced.

Highs: The highs have good extension and air, but do lack a little energy sometimes, they don’t have the brilliance and sparkle of some other open back models. They do however have more presence than the Sennheiser HD650 which is relatively dark in comparison. It is very dependent on the recording also, some sound overly thin sometimes (A Skylit Drive) yet with other  well recorded tracks (The White Stripes) they sound detailed yet a little behind in the mix. The highs have enough detail and extension and they sound balanced overall, not dark or warm.

Amping: Well these are 300ohm headphones, I could not find the sensitivity rating but it must be quite low as these are quite hard to drive and require an amp. The O2 and iCan both handle these very well, the O2 having a slight edge in detail retrieval and soundstage width and the iCan being slighly smoother overall. Adding the iTube to the system makes them sound even more natural (especially with the 6db buffer setting). But I found these to sound the best out of the Bravo Audio Ocean valve amp, it gave them a bit extra body (which they can use) and didn't take away the essence and detail of them. Dynamics were reduce by a small amount, a small trade-off for the gain in musical enjoyment.

These have a wide soundstage, not as immersive as the Sennheiser HD650 but still nice and wide. I suppose it is similar to the SoundMAGIC HP200 in the regard that it is an open back headphone that doesn’t have the widest/open soundstage but still does imaging very well (excluding Grado, which are completely different).

These are quite revealing headphones, playing low bit rate MP3's you will notice a difference going to FLAC or other lossless files.

Overall I really enjoy these headphones, in essence they are neutral and detailed, but with amps you can tailor the sound, the iCan is perfect with the 3D sound on max and also bass boost on max as it gives them extra body and soundstage but an overall very enjoyable sound. The comfort is great, the looks are typical German Maestro, function over fashion. Lows are tight and fast, yet warm and full when needed. Mids are clean and spacious as are the highs.

As you can see in the photos I recabled them, with some flexible copper from Toxic Cables, sound differences are not obvious, maybe a tad more body and smoothness, but overall very small. I just prefer the feel of my own custom cable over the stock.

Headphone Stand courtesy of Oscar's Audio:

Sound Perfection Rating: 8.5/10

Tracks Used:
Skrillex – First Of The Year (Equinox) (320kbps MP3)
Paramore – Franklin (320kbps MP3)
Diana Krall – The Girl In The Other Room (FLAC)
Deolinda – Passou Por Mim E Sorriu (live) (ALAC)
Suicide Silence – Unanswered (FLAC)
Massive Attack – Angel (ALAC)
Eat Static – Dzhopa Dream (ALAC)
The XX – Crystalised (FLAC)
Funeral For A Friend – Bend Your Arms To Look Like Wings (ALAC)
Mumford & Sons – Little Lion Man (FLAC)
The Scene Aesthetic – Humans (259kbps MP3)
A Hero A Fake – Swallowed By The Sea (254kbps MP3)
Vivaldi – The Four Seasons, Spring Allegro (ALAC)
Johnny Craig – Children Of Divorce (161kbps MP3)
Deadmau5 + Kaskade – I Remember (Caspa Remix) (320kbps MP3)
Black Uhuru – Utterance (ALAC)
We Are The In Crowd – Never Be What You Want (226kbps MP3)
Silverstein – Discovering The Waterfront (320kbps MP3)
Concept Of Thought – Our Thought (FLAC)
Nirvana – Something In The Way (Unplugged) (ALAC)