[jamesjames]

I think removing the resistor will leave the signal from the source, to the voice coil unchanged. Whatever the signal has to get through, and get to the voice coil. In theory, all are reduced or changed. My source is my phone. I even removed the original 3 meter cable, replacing it with another one that was only 80cm meter and smaller. What about paper, when removing the ma900. I found that it's not really an open back headphone. To be exact, it's only open about 50%.

Everyone can see that on its back, the area of the holes only for about 50% of the back area. I lined it with paper to increase this ratio to ~70%. The types of paper I use are quite tight. If brought into the dark using a light, the tiny holes are as sparse as the starry sky. Paper lining has made the ma900 a semi-open headphone. That still makes it retain the low frequencies, and the high frequencies are still bright enough. That kind of paper makes the sound full. It continues to resonate and doesn't disappear too soon...the most suitable type of ear cushion I think is the type with no holes or few holes, 20-25mm thick.

I think I follow that. It had occurred to me that the MA900 could probably be described as semi-open - much like the T1. Do I understand correctly that you've reduced the openness by using tighter weave paper? With a slight boost in lower frequencies? The large opening at the back, of course, differentiates it from the Beyer (and most other phones). But I'm surprised in my listening by the extent to which the semi-open nature of the driver housing still seems to result in low-frequency 'fullness' - much greater, for example, than the MySphere (or the ADX5000). That said, I suspect the HD800S and ADX5000 both have greater low frequency extension. I had been thinking that the semi-open structure of the MA900 also tended to produce the slight 'boxiness' that sometimes intrudes. Your point about ear cushions with no openings, and leaving more space for resonance, is interesting too. I find this hard to predict, myself. The HD800S - with relatively low-profile cushions, is famously spacious - although the same can't be said for the ADX5000. The MySphere is probably more spacious than the ADX in my experience but has less audible low-frequency extension than the others.

 

[buidoimiennui]

I think I follow that. It had occurred to me that the MA900 could probably be described as semi-open - much like the T1. Do I understand correctly that you've reduced the openness by using tighter weave paper? With a slight boost in lower frequencies? The large opening at the back, of course, differentiates it from the Beyer (and most other phones). But I'm surprised in my listening by the extent to which the semi-open nature of the driver housing still seems to result in low-frequency 'fullness' - much greater, for example, than the MySphere (or the ADX5000). That said, I suspect the HD800S and ADX5000 both have greater low frequency extension. I had been thinking that the semi-open structure of the MA900 also tended to produce the slight 'boxiness' that sometimes intrudes. Your point about ear cushions with no openings, and leaving more space for resonance, is interesting too. I find this hard to predict, myself. The HD800S - with relatively low-profile cushions, is famously spacious - although the same can't be said for the ADX5000. The MySphere is probably more spacious than the ADX in my experience but has less audible low-frequency extension than the others.

We can see that. Many holes, and mesh. Is different. I once heard somewhere that the z1r is an open back hp. And its back has so many microscopic holes. And it still helps keep the high frequencies bright, but retains the bass. On the ma900 we have to deal with driver membrane distortion. So leaving the back 30% exposed I think is ideal.

 

[jamesjames]

We can see that. Many holes, and mesh. Is different. I once heard somewhere that the z1r is an open back hp. And its back has so many microscopic holes. And it still helps keep the high frequencies bright, but retains the bass. On the ma900 we have to deal with driver membrane distortion. So leaving the back 30% exposed I think is ideal.

Yes, I follow that. Interesting point re Z1R - which I've never heard. Have you?

 

[buidoimiennui]

Yes, I follow that. Interesting point re Z1R - which I've never heard. Have you?

Sorry, I don't own a z1r to mod yet!

 

[jamesjames]

Sorry, I don't own a z1r to mod yet!

I look forward to reading about your efforts when you do!

 

[jamesjames]

I look forward to reading about your efforts when you do!

A final brief thought here, based on some more recent listening - I've been lucky enough to have some time recently to test some of my own long-held prejudices and assumptions! I'm inclined to think that, as good as the MA900 is, it doesn't quite match the HD800S when it comes to the very best recordings - by which I mean the highest quality. To put it another way, I think the MA900 is at its best when the recording quality is not at the very highest level, in which case it nevertheless achieves a presentation that's remarkably realistic to my ear. However, with the best recordings (in my opinion), it can seem just a little crude in comparison with the HD800S (and perhaps one or two others). It doesn't seem quite as transparent to the gossamer-light, transient information delivered by the best recordings - and I'm persuaded this effectively renders some fine spatial cues inaudible. I'm inclined to think also that this might be relevant in relation to Hertsens' general observations above re the relevance of distortion to a spacious presentation. The limitations (as I see them) of the Utopia, for example, don't seem to me to be a consequence of its undoubted clarity and low distortion. For what it's worth, I'm inclined to think they're simply a function of design parameters carefully implemented - which trade-off some space for warmth. It's a family trait with Focal in my view, and one not shared, for example, by the HD800S.

 

[buidoimiennui]

A final brief thought here, based on some more recent listening - I've been lucky enough to have some time recently to test some of my own long-held prejudices and assumptions! I'm inclined to think that, as good as the MA900 is, it doesn't quite match the HD800S when it comes to the very best recordings - by which I mean the highest quality. To put it another way, I think the MA900 is at its best when the recording quality is not at the very highest level, in which case it nevertheless achieves a presentation that's remarkably realistic to my ear. However, with the best recordings (in my opinion), it can seem just a little crude in comparison with the HD800S (and perhaps one or two others). It doesn't seem quite as transparent to the gossamer-light, transient information delivered by the best recordings - and I'm persuaded this effectively renders some fine spatial cues inaudible. I'm inclined to think also that this might be relevant in relation to Hertsens' general observations above re the relevance of distortion to a spacious presentation. The limitations (as I see them) of the Utopia, for example, don't seem to me to be a consequence of its undoubted clarity and low distortion. For what it's worth, I'm inclined to think they're simply a function of design parameters carefully implemented - which trade-off some space for warmth. It's a family trait with Focal in my view, and one not shared, for example, by the HD800S.

I'm back. These past few days, I checked my eq. Oh no. it's crazy, my eq is V-shaped, at the same time I have Dolby mode on. wearing ma900 on my head. I tried turning off EQ, and turning off the Dolby effect. Oh. I just want to throw away the ma900. so sad. The ma900 is probably more suitable for watching movies, and it needs eq to be fine. I would like to withdraw my comments on hd800.