[oqvist]

Well just buy them always work for me

 

[joelpearce]

Quote:

man I wish someone would buy me pair of GMP450 Pro

.... Been FSing them for ages now

Mine took a long time to sell, too.  Having had both the 450 and the QP805HS, I still think that they are a hugely underrated brand on head-fi.

 

[kkl10]

 
Quote:

I guess the difference between QP400 and QP450 is similar to the difference between dt770 and dt880. The closed versions (qp400 and dt770s) are using a different earpads with the open versions. The velour skin of the earpads of dt770 covers a layer of leather, while there is no leather layer inside the earpads of dt880/dt990. The effect of the leather layer is significant, which brings a huge sense of bass and compressed soundstage. I guess it is the same structure with the original velour eapads of QP450, which makes the most different sound signature between QP400 and QP450. 

QP 400 and QP 450 do not sound the same as their GMP counterparts.
The QP 400 is the open version, QP 450 is the closed one.
What dictates the fundamental difference in sound signature between GMP 400 and GMP 450 Pro are the enclosures and damping scheme, not the earpads.
The GMP 400 with the brightest and thinner sounding earpads I have here (the round velour perforated back), still has more weight and thickness (great balance though!) to it's sound than the GMP 450 Pro with the darkest and bassier sounding earpads, which are it's stock ones.
 


Quote:

Mine took a long time to sell, too.  Having had both the 450 and the QP805HS, I still think that they are a hugely underrated brand on head-fi.

joelpearce, how did you like the QP805HS?
 
 
I FORGOT TO CLARIFY ONE THING!
 
The EQ graphs of the GMP 400 and GMP 450 Pro, I last posted, do not represent the absolute differences in amplitude (dBs) through the frequency spectrum between those two headphones!
Those graphs only represent each headphone's FR curve to my ears, nothing more!
 
It's just that when I equalized the GMP 450 Pro I was trying to cut much more than boost, but when EQing the GMP 400 I I used both methods equally.
 
Just so that nobody interpret those graphs the wrong way...

 

[punkplayer]

Quote:

 

QP 400 and QP 450 do not sound the same as their GMP counterparts.
The QP 400 is the open version, QP 450 is the closed one.
What dictates the fundamental difference in sound signature between GMP 400 and GMP 450 Pro are the enclosures and damping scheme, not the earpads.
The GMP 400 with the brightest and thinner sounding earpads I have here (the round velour perforated back), still has more weight and thickness (great balance though!) to it's sound than the GMP 450 Pro with the darkest and bassier sounding earpads, which are it's stock ones.

Interesting findings! Have you tried putting the GMP 400 drivers into the GMP450 enclosures with 450 earpads (or the other way around) to see if there are any change in the sounds, they should sound the same if they share the same drivers. 

 

[R-Audiohead]

I'm almost certain the drivers are identical

 

[kkl10]

The drivers are exactly the same!
 
You can see what I have from a previous post of mine.
 
Quote:

I bought a new headphone to compare the GMP 450 Pro with...
Does somebody recognize it?
 

 
 
SURPRISE! SURPRISE!
I bought some spare parts for the GMP 400, that's the headphone with which I will measure the GMP 450 Pro against.
I hope to be able to improve even more the sound quality I'm getting out of the 450 Pro right now.
 
According to German Maestro the only differences between the GMP 400 and the GMP 450 Pro are the enclosures and the dampening materials used inside them, so I bought the respective spares parts used on the GMP 400 :
 
As you can see on the explosion drawing sent to me:
 

 
This explosion drawing is representative of the GMP 2 and 4 series.
As you can see on the first photo, the GMP 400 uses diferent dampening materials from the GMP 450 Pro, I also bought the stock earpads of the GMP 400...
 
So now I have:
4 sets of earpads;
several different dampening materials (which I'll try to use in different configurations besides stock ones);
1 pair of closed enclosures;
1 pair of opened enclosures;
and 1 pair of lightning fast transducers with which I'll be making all my experiments and comparisons.
 

 
PHEW!!
I feel tired already!
I'm probably going to write a comprehensive review/guide about these two headphones on a(nother) new thread.
Won't be able to cover higher end source and amplification performance and scaling themes because I'll only use my Yulong D100.
Not complainig though... it's a very good Dac/Amp solution.
 
Now the real work begins!
 
For those interested on my findings posted above about using the perforated oval earpads over/on top of the stock ones... here's a photo:
 

 
This is how I'm wearing the GMP 450 Pro right now and the sound is superb!
The enclosed sonic character of the stock oval earpads is replaced by the more open and spacious and resolute character of the perforated earpads with a major attenuation of the ressonances and coloration I was perceiving before.
It maintains pretty much the same tonal balance but soundstage, overall resolution and refinement improve greatly to my ears.
Since all the frequency spectrum is less upfront the bass can be a bit to light sometimes but it's still quite satisfatory for anyone who already likes it in stock comfiguration and I don't mind it at all because the overall sound is just so good.
 

I had bought the GMP 450 Pro headphone first, then I bought the enclosures and damping materials of the GMP 400.
The enclosures and damping materials are essentially the only thing that differ between the two headphones and are what make them sound different because the driver is the same on both.
 
There is another phisical difference, however, which might affect the sound between the two headphones:
if you check the pictures of the driver assembly structures from Headfonia's review, you'll see that the layer of felt covering the grill in front of the drivers has a bigger opening on the GMP 400 than on the GMP 450 Pro... that might take some part on the differences between both headphones fundamental sound signature...
 
Since I only have the GMP 450 Pro driver assembly structure which has the smaller opening, my impressions of the GMP 400 sound might not be absolutely accurate (taking as point of reference a perfectly stock GMP 400) but I dont think that the opening makes a very important difference in sound...
 

 

[R-Audiohead]

Since I've recently been spending a lot of headtime with my newly acquired Shure SRH-940s I am finding that I agree the SP-1 is midcentric.  It is also making me think even less that the SP-1 is bass light (although certainly far from bass heavy).

 

[r31t0]

which of the gmp will u all recommend for orchestra music? the 400 or 450?

 

[kkl10]

Well, that mostly depends on what kind of sonic signature or presentation you are looking after...
 
The GMP 400 and 450 Pro do give quite different presentations:
 
the stock GMP 400 does gives me a more enveloping (feeling of being on stage with the musicians) experience with a dark, warm and lush sound, the instruments and vocals placement on the soundstage is closer to me than on the GMP 450 Pro, the GMP 400 might also have a slightly better dynamic range (might need to check this);
 
the stock GMP 450 Pro takes a brighter and more analitical approach to it.
Instead of trying to make me feel engolfed by the music like the GMP 400 does, it tries to put a distance in between so as to give me a better perspective from which "observe and evaluate" the sound, it's still an engadging listening experience but in a differen way... with the right mind-set, this approach might be preferable.
 
Despite this sound presentation differences between the two headphones, however, it is the GMP 450 Pro the one which gives a higher and more coherent tonal perception of instruments and voices because of it's midrange emphasys and linearity, detail retrieval is similar on both but the GMP 450 Pro emphasize mids - highs and the GMP 400 mids - lows frequencies.
 
Frequency extension is similar on both ends on both headphones.
Both need some amperage behind them. The GMP 450 Pro is slightly harder to drive...
 
If what you want is accuracy and realism on equal measures ( I'm finding out that a more accurate sound doesn't always correlate to higher realism), then I highly recomend the GMP 400 with the GMP 450 Pro earpads, because, despite being the darkest sounding configuration, this is the most linear and coherent sounding configuration,... assuming that you're not interesting on double-padding nor equalization.
 
 
 
 

 

[svyr]

Well, that mostly depends on what kind of sonic signature or presentation you are looking after...
 
The GMP 400 and 450 Pro do give quite different presentations:
 
the stock GMP 400 does gives me a more enveloping (feeling of being on stage with the musicians) experience with a dark, warm and lush sound, the instruments and vocals placement on the soundstage is closer to me than on the GMP 450 Pro, the GMP 400 might also have a slightly better dynamic range (might need to check this);
 
the stock GMP 450 Pro takes a brighter and more analitical approach to it.
Instead of trying to make me feel engolfed by the music like the GMP 400 does, it tries to put a distance in between so as to give me a better perspective from which "observe and evaluate" the sound, it's still an engadging listening experience but in a differen way... with the right mind-set, this approach might be preferable.
 
Despite this sound presentation differences between the two headphones, however, it is the GMP 450 Pro the one which gives a higher and more coherent tonal perception of instruments and voices because of it's midrange emphasys and linearity, detail retrieval is similar on both but the GMP 450 Pro emphasize mids - highs and the GMP 400 mids - lows frequencies.
 
Frequency extension is similar on both ends on both headphones.
Both need some amperage behind them. The GMP 450 Pro is slightly harder to drive...
 
If what you want is accuracy and realism on equal measures ( I'm finding out that a more accurate sound doesn't always correlate to higher realism), then I highly recomend the GMP 400 with the GMP 450 Pro earpads, because, despite being the darkest sounding configuration, this is the most linear and coherent sounding configuration,... assuming that you're not interesting on double-padding nor equalization.
 
 
 
 

for GMP450, if I want to get rid of the mids peak, will modding them with any of the spare parts you used above (pads, etc) help? or EQ only?

 

[stokitw]

Both of them are good.
 
If you have a system designed for low impedance phones, think about GMP435s.
Overall, GMP400/435/450 have very good detail but the very low end is somewhat lacking compare to the higher level (GSK/PSK, T1, HD800) phones.
The foam pad GMP400 used gives it a slightly more volume low, but somewhat sacrifice the detail.
The closed back GMP450 has a outstanding hall presentation, yet you cannot listen on it for extended period of time.
The opened back GMP435s uses the same pad as GMP450, so the presentation is very similar.
Thanks to its opened back design, it can be used for long period of listening as GMP400.
 
Personally, I like the sound of GMP450/435s better since they are not as lay-back as GMP400.
But it's just my view.
 
Quote:

which of the gmp will u all recommend for orchestra music? the 400 or 450?

 

 

[svyr]

Both of them are good.
 
If you have a system designed for low impedance phones, think about GMP435s.
Overall, GMP400/435/450 have very good detail but the very low end is somewhat lacking compare to the higher level (GSK/PSK, T1, HD800) phones.
The foam pad GMP400 used gives it a slightly more volume low, but somewhat sacrifice the detail.
The closed back GMP450 has a outstanding hall presentation, yet you cannot listen on it for extended period of time.
The opened back GMP435s uses the same pad as GMP450, so the presentation is very similar.
Thanks to its opened back design, it can be used for long period of listening as GMP400.
 
Personally, I like the sound of GMP450/435s better since they are as lay-back as GMP400.
But it's just my view.
 


 

depending on how sensitive you are to the mids sharp peak/what HP you've listened to before, you may get listener fatigue after only 5-10 mins (I can't stand my GMP450Pro for longer )

 

[kkl10]

Quote:

for GMP450, if I want to get rid of the mids peak, will modding them with any of the spare parts you used above (pads, etc) help? or EQ only?

Yes, since replacing the earpads on the GMPs significantly changes their tonal balance, you can easily get rid of that midrange peak by swapping the stock earpads by one of these two:
 
The 41-6049 black velvet/velour with perforated back, this earpad is deeper than the others and puts your ears further away from the drivers, it will require a little boost in volume...
   
Since this earpad puts a distance between the ears and the drivers it the less fatiguing listening experience to me, it is the brightest one with an emphasys/peak on the lower treble region, the mids no longer dominate the rest of the spectrum they are fairly in line with the rest, this earpad has the least bass - much less than the stock ones.
 
 
If you want my recomendation, I'll say the 41-6050, oval soft foil earpad,
   
To my ears, this earpad has an emphasys/peak on the 4000 - 6000Hz region and is not as bright and lean as the 41-6049 nor as midcentric and warm as the stock ones - 41-6086, it's somewhere at the middle regarding sonic signature and  tonal balance. It has a more linear bass - midrange response than the stock earpads and therefore provides the slightly better perception of lower bass, it sounds somewhat similar to the stock earpads with a brighter sound, less forward midrange and a leaner, but more linear bass.
 
Both of these two earpads improve spatial, clarity and detail perception. If ordering some of these earpads make sure to order also the dust protectors 18-6052.
You could also try some Beyerdynamic, or other manufacturer earpads just to see what they do...
 
But why do I really recommend the 41-6050 earpads?
Because of the double-padding possibilities they bring to the table.
What I'm caling double-padding is the simple act of placing one set of earpads on top of another which is already attached to the headphone.
You can see it on one of the pictures above - the pile of videogame boxes wearing the double-padded GMP 450 Pro (disregard the reference to it's tonal balance below the picture).
 
Doublepadding the stock GMP 450 Pro with the 41-6050 earpads can have one of several possible sonic outcomes depending on fit and seal (to which this configuration is highly sensitive):
 
It can go from very bassy and dark with a perfect seal, to slightly bright and lean with a not so perfect seal (if you wear glasses or have some hair around your ears like me).
This means that it can get very balanced and neutral with the right fit in your head, which I have managed to do:
 
My EQ curve for the doube-padded GMP 450 Pro with the 41-6050 earpads,

 
As you can see tonal balance is much better when double-padded, equalization here is serves more to eliminate coloration than to correct balance issues.
The sound quality as no comparison to the non double-padded configuration, it's a true lip forward at every aspect in my opinion.
 
Double-padding the other way around, placing the stock 41-6086 earpads on top of the 41-6050 also improves tonal balance and overal sound quality, the difference is that it generally sounds darker and warmer, very pleasing, laid-back and non-fatiguing. this configuration is less sensitive to seal and fit.
 
I'm really looking forward to see someone experimenting this configuration on the GMP 450 Pro... it deserves some hype activity.
Since I'm not much of a hyping person somebody else will have to do it for me!
 

 

[svyr]

Thanks,
how about inside the cups(damping?)
Also where did you buy the spares?

 

[kkl10]

Playing with the damping materials inside the earcups of the GMP 450 Pro won't yield any significant changes in tonal balance nor coloration.
I won't recommend to, since there isn't any benefit in doing so, at least with the materials I have here.
Playing around with damping materials inside the GMP 400 open enclosures is much more interesting.
 
It is possible, however, to combine those damping materials with the 41-6049 or 41-6050 earpads to create less bright and flatter sounding variations of those earpads.
For example placing a layer of thin foam under one of those earpads will tame down upper mids and lower treble peaks providing a more linear response at those frequencies, like the stock earpads 41-6086 do.
 
To be honest double-padding gives me such a big gain in sound quality that it renders any damping material mod to irrelevance.
Beware, that if you have a very big head and find the GMP 450 Pro very small and if you have to adjust it's fitting range to close to max to fit it in your head, wearing it double-padded might not be possible for you. I think it's deffinitely worth a try anyway.
 
You can order spare earpads and dust protectors on the German Maestro online shop (freight charges on the bottom of the page), if you also want damping materials or other spares or have some kind of custom requirement you'll have to contact them by mail:
info@german-maestro.de
 
I think that the 41-6050 earpads and dust protectors are all you need...
German maestro sell other earpads besides the ones I have but I don't know how they will change the sound...