[slowstatic]

Understand that the QP400 is 300ohms. Which amp you using to drive the QP400 ?
 
How's the SQ compare to the GMP435S (32ohm) ?
 

 
Quote:

Just got the QP400 in.
 
I think this headphone will suit your needs much better.
 
Given you love the GMP 450 PRO except for the fact that it is indeed closed, the QP400 sounds perfect - the driver is identical, the clamping force is slightly greater, and the soundstage is quite large.
 
To be honest, it lost a little resolution and speed, but the open design really livens up the vocal ranges.
 
More on this as I A/B with more tracks.
 
My roomate and I plan on posting something, as mentioned before.
 

 

[yupoet]

Really good review. I am having a GMP450pro as well and loving it.
I can say, in China ,there are a lot of people (who is considered as senior head-fiers) who loves GMP450 or QP450 as well.
 
It's also of good reputation when it's used in MIDI / professional zone. A very faithful headphone to the recordings and tracks in Cubase / Protools / Nuendo I used.
 
Now I am wondering if it can be modified to be a real balanced headphone? So that I can use Audio-GD ROC or Phoenix to drive it.

 

[kkl10]

 
If anyone is thinking about opening their GMP 450 Pro, do not!
 
After comparing for several days the open configuration with closed, it turns out that my inexperienced ears were initially fooled by the sonic changes.
Afterall the open configuration does not sound better, it actually degrades the sound!
What I have wrongly identified as improvements over the sound of the closed configuration were actually signs of sonic degradation made by underdamping.
Bass became quite uncontroled and infested the midrange, the upper midrange and treble lost clarity and definition as if "veiled".
Lower bass clarity seemed to have greatly improved but it was just more upfront.
The ressonance and strange coloration of the closed configuration seemed to have gone but tone and timbre were not really better... worse and lacking due to the degraded sound quality and tonal balance.
 
Still, with the open configuration, the realism of sense of space and immersion were better due to superior low bass ambient information perception... but not worth anymore since the sound quality was inferior.
 
Man I feel an idiot now!
I apologize for all wrong information about the sonic changes made by this modification!
 
So forget about opening your GMP 450 Pro, unless you are able to get an open enclosure with which you can dampen appropriatelly the transducer...
 
Back to stock closed configuration... for now.
 
Regarding the earpads:
 
The round perforated velour pads boost up the higher frequencies and recess the lower ones, they give the larger sense of space but the sound ends up being to thin and bright.
In stock configuration these are the earpads with which the ressonance and coloration are less prominent, and I think that's because they are deeper and put the driver further away from my ears.
With the open configuration I prefered them to the stock ones because the sound in that situation was fuller and somewhat darker...
In stock configuration the GMP 450 Pro doesn't need these earpads, the sound is to thin and bright, much like I remember the MB Quart QP 400 to sound.
 
The stock earpads are the bassier, darker and most closed in and claustrofobic sounding from all the ones I got yet they work well with the GMP 450 Pro in stock configuration making for the better balanced sound than the round velour ones...
However, my issues with the ressonance and coloration of the stock GMP 450 Pro are worse with these earpads since they are the thinner ones and put the driver closer to my ears.
 
So the oval perforated are my favorite because they are just at the middle in sonic character and closed sonic shortcomings prominence.
I think they offer the best overall sound resolution and clarity, with reasonable sense of space and a tonal balance almost as good as the stock oval ones with a bit less prominent ressonance and coloration.
Good earpads with the GMP 450 Pro.
 
I still maintain my issues with the sonic shortcomings made by the closed configuration, but for now there is one simple thing I can do to minimize those issues and actually improve sense of depth and width of space, clarity, and definition, which is to simply place the oval perforated earpads over the stock earpads and wear it like that. (Thankfully my head is not to large and the seal is as good as wearing the headphones with just the oval perforated pads)
 
By doing so, I note that ressonance is almost completely gone while the strange coloration still remains but in a less aparent way. Tonal balance remains roughly the same and the claustrofobic sound of the stock earpads is replaced by a much more open and spacious sound, there's almost no honk/bathroom feeling now.
The tone of the instrument is slightly better now and timbre has improved more since the ressonance was degrading it.
I also note that the sound is less coarse becoming smoother with better definition.
The sense that the sound comes from within the headphones is greatly reduced, realism of sense of space and immersion are almost as good as the open configuration, but not quite and in a different way...
 
It almost seems now that a great part of the ressonance I was percieving was being created between my ears and the driver and not so much within the enclosure of the GMP 450 Pro (which is massively damped, with almost no air inside), while the coloration does indeed come from within the enclosure... not sure if this makes any sense but that's the idea that I'm getting...
 
I'll post a picture when I can just so that you guys can visualize what I mean.
 
The round perforated velour pads do not work this way, at least with the stock ones... if I put them over the stock ones the sound quality degrades despite the improvement in width of space...
I think it has to do with the combination of shapes and sizes of the earpads openings.
I'll try other combinations...
 
The sound quality I'm getting now is definitely the best I have heard from the GMP 450 Pro.
Now I can really say that the GMP 450 Pro sounds like my initial expectations, almost like an open headphone... if only I had some open enclosures... ; )
 
Will post some pictures when I can...
 
Some conclusions:
 
The open configuration, afterall, degrades the sound quality!
In stock configuration and with the stock earpads, the further away my ears are from the driver, the better and more open it sounds!
 
This is not my final write-up.

 

[kkl10]

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.
 

 

[svyr]

I received my pair today.

I'm not sure if I'm driving them OK (MD11 can't handle them for classical, neither can my 3ch cmoy, nor can the low geared impedance jaycar amp...). These seem very hard to drive, especially for non-vol leveled recordings.

On my Bravo tube amp (the only thing that seems to have enough juice for these), it sound like there's a rather sharp peak in the lower mids (some sort of distortion and coloration you get from mids starting to sound like a wind insturment lol). Maybe even stretching to upper bass.
That's simply %(#*%# but maybe I'll have better luck when my audio-gd NFB-10WM arrives

So far it seems like money well wasted.

Now back to DT48e

 

[R-Audiohead]

A Charteroak SP-1 or GMP 450 PRO?

 

[svyr]

A Charteroak SP-1 or GMP 450 PRO?

GMP 450 PRO.

 

[kkl10]

Quote:

I received my pair today.

I'm not sure if I'm driving them OK (MD11 can't handle them for classical, neither can my 3ch cmoy, nor can the low geared impedance jaycar amp...). These seem very hard to drive, especially for non-vol leveled recordings.

On my Bravo tube amp (the only thing that seems to have enough juice for these), it sound like there's a rather sharp peak in the lower mids (some sort of distortion and coloration you get from mids starting to sound like a wind insturment lol). Maybe even stretching to upper bass.
That's simply %(#*%# but maybe I'll have better luck when my audio-gd NFB-10WM arrives

So far it seems like money well wasted.

Now back to DT48e

You ended up following my advise, didn't you? Hehe
I'm very interested on how the GMP 450 Pro compares sonically against your other headphones - specialy against the Beyerdynamic T5p and your upcoming FA-002w.
 
Regarding amplification, I remember to have read somewhere that the QP/GMP 450 Pro should be mated with a sonically neutral and balanced gear to take the most of it, so your upcoming NFB-10WM might give better results.
Strange the sharp peak at lower mids... from the experience you are reporting it seems that the 450 Pro is somewhat picky... but isn't this normal on tube amplification anyway?
On my Yuolong D100 the GMP 450 Pro sounds pretty flat, there's just a bit of fluctuation (not much really) between 3000 - 9000 and a nasty sharp peak around 9700Hz. The bass rolls-off smoothly from 50Hz below and the treble from 16000Hz up and I can hear it until at least 18000Hz.
 
Can you discern different sound signatures from your different amps and sources with the GMP 450 Pro? Do you find the GMP 450 Pro a transparent headphone in this regard?
 
Out of the box the GMP 450 Pro sounded very strange to me, but after the initial hours it became more coherent on my ears.
Still it is giving me some serious challenge to fully understand it's sound... I should warn you that this might be a very difficult headphone to deal with.
It is at least to me.
 
How can you describe this headphone sound signature, for now?
 
By the way, I want to say that I got my hair shaved recently... since then I have a much better seal on my ears and my sonic impressions on this headphone are somewhat different from what I have been stating until now.
For example putting the oval perforated earpads on top of the stock ones now makes the sound slighly darker and bassier due to the seal...
I'll try to cover this and other subjects about tweaking on my upcoming GMP 400/450 Pro review/guide.

 

[svyr]

>Strange the sharp peak at lower mids... from the experience you are reporting it seems that the 450 Pro is somewhat picky... but isn't this normal on tube amplification anyway?

does it on MD11 as well and the SS 3ch cmoy amp.


>Can you discern different sound signatures from your different amps and sources with the GMP 450 Pro? Do you find the GMP 450 Pro a transparent headphone in this regard?

none of my amps are currently able to drive them properly, so the question is mostly moot.


>I'm very interested on how the GMP 450 Pro compares sonically against your other headphones - specialy against the Beyerdynamic T5p and your upcoming FA-002w.

so far it's isn't comparing to them at all. Sounds dull and underamped and peaked/distorted mids are annoying. Need to wait for a proper amp to do that. and 002w should be shipped today (well, should've been yesterday).


>How can you describe this headphone sound signature, for now?

f#*#**#* ?


Since I have nothing better to do while waiting for other HP/amps, I'll put it to burn in on my MD11 24h/day over a few days and we'll see what happens

 

[svyr]

Interestingly, the MD11 amp is a lot more juiced than the D100 amp (pretty sure it's around 260mw into 300 ohm...2x the Yulong one), so I have no idea how you can drive the HP from D100, when even @ max volume for MD11 for some classical is too low. (especially older classical music DVDs). For modern music it's mostly ok at around 50% volume. Which is I think around the max D100 would do.
MD11 + GMP 450 still sounds veiled (+ the mids/upper bass problem) regardless of the 2x power out.

 

[kkl10]

 
Quote:

>Strange the sharp peak at lower mids... from the experience you are reporting it seems that the 450 Pro is somewhat picky... but isn't this normal on tube amplification anyway?

does it on MD11 as well and the SS 3ch cmoy amp.

 

 
 
 
Quote:

Interestingly, the MD11 amp is a lot more juiced than the D100 amp (pretty sure it's around 260mw into 300 ohm...2x the Yulong one), so I have no idea how you can drive the HP from D100, when even @ max volume for MD11 for some classical is too low. (especially older classical music DVDs). For modern music it's mostly ok at around 50% volume. Which is I think around the max D100 would do.
MD11 + GMP 450 still sounds veiled (+ the mids/upper bass problem) regardless of the 2x power out.

That lower mids, upper bass peak is something that doesn't happen on mine even if driven by my Sansa Clip+ portable player...
Do you really mean upper bass, lower mids range (200 ~ 500Hz)?
Don't you mean upper mids (3000Hz up) instead? (probably not since you say that it sounds veiled...)
 
My Yulong D100 can't drive them louder than my ears can tolerate and, often, I feel that there is some lack of grip on the drivers indeed, but it sounds right and energetic to me, nothing like veiled nor distorted...
 
Did you check that the included 6,3mm jack adapter is well screwed?
Hope that your unit isn't faulty...
 

 

[svyr]

Checked on my D2 - same story. (3.5mm jack)


>Hope that your unit isn't faulty...

Probably not, but I'd hate to send it back and wait for a replacement, since getting this one took > 1 month.


>Do you really mean upper bass, lower mids range (200 ~ 500Hz)? Don't you mean upper mids (3000Hz up) instead

about 600hz - 1.5khz is peaked and somewhat distorted (a sort of a 'ringing' quality to it).


>, but it sounds right and energetic to me, nothing like veiled nor distorted...

compared to what might I ask? Aside from the mids/bass thing, they sound near dead compared to the DT48e.

 

[kkl10]

Quote:

Checked on my D2 - same story. (3.5mm jack)


>Hope that your unit isn't faulty...

Probably not, but I'd hate to send it back and wait for a replacement, since getting this one took > 1 month.

If you bought your from German Maestro itself you can expect good customer service.

>, but it sounds right and energetic to me, nothing like veiled nor distorted...

compared to what might I ask? Aside from the mids/bass thing, they sound near dead compared to the DT48e.

 
The GMP 450 Pro is very fast and sounds better to me compared to pretty much every other headphones I've heard (not much really)... look, I know it sounds good, lol.
Probably it won't compare to the DT48 (which I'm quite interested to know for sure) but, if working properly, you should find the GMP 450 Pro sound signature to be the oposite of what you have been describing untill now, dull, veiled, dead (OUCH!).
Energetic, engaging, nimble are terms I (and others) use to describe it's sonic signature.
 
I don't want to alarm you, but you could ask German Maestro by mail about your issue to know if it's normal or not.

 
 

 

[R-Audiohead]

It is very interesting that you find them peaky.  I can't remember where I saw a printout of the frequency response (not that I am suggesting this is tell-all because it certainly isn't) but I remember even the response line to appear extremely flat and roll off in the lower frequencies right around 50Hz.
 
They're definitely made for studio mixing purposes and carry an analytical sound with them... a sound some audiophiles find accurate and detailed while those who prefer a "rich" or "juicy" sound find it boring or bland.  I think the flat response seems to make them a tad bright, given that on many high end loudspeaker systems you'll find the treble ranges to seem more recessed because those frequency ranges dissipate faster over a set distance.  It is this rationale that caused Sennheiser to put a small "dip" in their treble ranges for their HD 650 to mimic this effect.  The unbias and flat GMP450 may be perceived as a little bright as a result.
 
I'm familiar with MB Quart sound as a whole, and peaky midranges are not normal.  It could be perception difference, but I would not be surprised if something was wrong with the unit.  I find my Charteroak SP-1 extremely fast, detailed, a little bright and pretty flat (in a good way).  Traditional sound from the MB/German Maestro guys.  I'm driving mine from a pretty simple e7/e9 solid state setup and they're powered just fine on high gain... anything passed 1 oclock is painfully loud.
 
I also read somewhere that these prefer an RMS of 100mW at 300 ohms....  Your amps should have plenty of juice. 

 

[R-Audiohead]

I'm with kkl10 on this one... VERY nimble and energetic.  I would definitely not consider these to be dead and even more so not consider them veiled.  I'm convinced that if you're finding these semi-bright headphones to be veiled something is wrong with the unit... German Maestro will take care of you.
 
Quote:

 
The GMP 450 Pro is very fast and sounds better to me compared to pretty much every other headphones I've heard (not much really)... look, I know it sounds good, lol.
Probably it won't compare to the DT48 (which I'm quite interested to know for sure) but, if working properly, you should find the GMP 450 Pro sound signature to be the oposite of what you have been describing untill now, dull, veiled, dead (OUCH!).
Energetic, engaging, nimble are terms I (and others) use to describe it's sonic signature.
 
I don't want to alarm you, but you could ask German Maestro by mail about your issue to know if it's normal or not.