John Buchanan
1000+ Head-Fier
This is a comparison between the Stax Sigma low bias headphones run from a Stax SRM 1 Mk 2 Pro amplifier and the Stax Lambda Nova Signature (or LNS) headphones run from a Stax SRM-717 amplifier.
1.Physical comparison of the headphones.
The Sigmas (see my avatar) are large and very box-like enclosures with a relatively flimsy head band (or arc assembly) supporting the drivers. The drivers are mounted in front of and perpendicular to your ears, unlike any headphone previously and with only the AKG K1000 having used a similar principle since. The "semi-panoramic" LNS have much shallower cases than the "panoramic" Sigmas with the drivers angled out approximately 10 degrees from parallel to your ears, instead of 90 degress as per the Sigmas. The LNS arc assembly and case holders are much more substantial than the Sigmas and exert more pressure against your head. Instead of the sound bouncing off the enclosure itself and into your ear canals (as per the Sigmas), the LNS virtually inject the sound straight into the ear canals. It is worth mentioning at this point that all listening should be done with the middle of the drivers centred on your ear canals. Both headphones are quite comfortable, but I give the nod to the Sigmas for several reasons – they don’t clamp as tightly around your head as the Lambdas and because the drivers and their netting covering (of the Lambdas) are so close to your ears, they can cause some mild irritation of the pinnae that the Sigmas avoid. My ears can start to sweat whilst wearing the LNS, whilst the Sigmas are much more bearable in warmer weather. This is important in Perth, although we do have air conditioning.
The cables and drivers have been “improved” over the years between the release of the Sigmas and the LNS – the cables are now PC-OCC for the LNS, whereas the Sigmas had no special claim for cable quality as far as I know. The cables themselves are much wider in the LNS for lower capacitance. The drivers were also changed to the later high bias system enabling a louder peak level and increased bass excursion.
2.Sound
a.Deep bass
The very bottom end of the frequency response of the LNS is much more apparent – in particular bass kick drum has more impact and is rendered better than the Sigmas (the difference is that the Lambdas really kick at you, whereas the Sigmas produce a more muffled thud). This should be the case, as the LNS go down to 7 Hz, whereas the Sigmas only reach 20 Hz. The same Sigma drivers were used in the Lambda headphones and went as low as 8Hz, so this deep bass roll off must be more a function of the headphone enclosure and is probably less due to the differences in cabling and drivers.
b.Mid bass
The Sigmas have a pleasant exaggeration of the mid bass region compared with a slight recession from true (IMHO) in the LNS. This makes the Sigmas sound very nice on music that has been recorded live, as it seems to replicate the mid-bass (i.e electric/acoustic bass) emphasis that one hears at a live venue. This often seems to be lost in translation to recorded sound. On occasion, if the bass is mixed louder than it should be, this can be overwhelming on the Sigmas , whereas in that example, the LNS would be about right. I prefer Cream’s “Live At The Royal Albert Hall 2005” on the LNS for that reason, whereas the Grateful Dead’s bass sound is much more “live” on the very well recorded “Fillmore West 1969” 3xCD set using the Sigmas. To recapitulate, on a CD where the bass is a little recessed, the Sigma will restore it perfectly: if the CD is a bass monster, phase up the LNS instead. Generally, I prefer the Sigmas - I suspect most albums were originally cut so the average stylus of the time could track them. This translates as rolled bass. CD reissues usually replicate the sound of the vinyl (otherwise audiophiles rightly complain), so I guess that we get stuck with the bass roll off. Sigmas correct this to some extent - indeed I prefer them to the LNS on older analog recordings, not only because of the mid bass emphasis, but also because of the sibilance de-emphasis. The latter seems to be more problematic in analogue recordings IMHO. See later for more on this.
c.Mid and upper-mid range
This area of the frequency spectrum is where the Sigmas really shine – human voices simply sound more real on the Sigmas. There is none of the Lambdas lack of force, nor is there any sibilance – they just sound great. There is a slight loss of consonant clicks in vocals, but the lack of sibilance is so impressive, that this loss is not really noticeable. The LNS, on the other hand, seems to thin out the mid-range and makes vocals a little 2 dimensional, trebly and sibilant in my opinion. They are not as enjoyable and don’t sound like they should as reproduced live. Again, using the Grateful Dead Fillmore West example, Pigpens vocals simply sound live on the Sigmas and thinner and more sibilant on the LNS. This is a great album by the way - I have only just started to get into the Dead.
d.Treble
The Sigmas roll the top end quite a bit compared with the LNS – this makes tape hiss and recorded crowd applause sound different than in the LNS. I think the Lambda is closer to the truth, but the adjacent frequency band elevation (e.g the emphasis on sibilance) is too much of a price to pay. Still, if we could have the lack of sibilance and the frequency extension at both ends (and this may be attainable with the Sigma/LNS hybrid I am thinking about), I suspect I may have the perfect phone.
3.Dynamics.
Although there was much trumpeting of the increase in dynamics allowed by changing the bias voltage and the inter-electrode spacing when upgrading to the high bias system, the dynamics of the two headphone systems seem to be about the same (i.e. excellent). I hear minimal evidence of superior dynamics, with the exception of the frequency extremes. The LNS can play louder without stress, but I don’t want to listen at those levels anyway, so this is a moot point. Ed cites increased ambience with the Sigmas as evidence of this, but the treble roll off on my pair mitigates against that. I know what he means however, it's just I don't hear it on my pair.
4.The Future.
According to other Head-Fiers (thanks Edstrelow), the Sigma/LNS hybrid could be what I am looking for – a Sigma that retains the positives and corrects the negatives. There is also the bonus that I could use the superior SRM-717 for the phones with its balanced inputs. An Omega 2 is on its way in June sometime, so after that a hybridization may occur, if the Omega 2’s aren’t just so overwhelmingly good that Sigmas pale in comparison. Further reviews will be coming.....
1.Physical comparison of the headphones.
The Sigmas (see my avatar) are large and very box-like enclosures with a relatively flimsy head band (or arc assembly) supporting the drivers. The drivers are mounted in front of and perpendicular to your ears, unlike any headphone previously and with only the AKG K1000 having used a similar principle since. The "semi-panoramic" LNS have much shallower cases than the "panoramic" Sigmas with the drivers angled out approximately 10 degrees from parallel to your ears, instead of 90 degress as per the Sigmas. The LNS arc assembly and case holders are much more substantial than the Sigmas and exert more pressure against your head. Instead of the sound bouncing off the enclosure itself and into your ear canals (as per the Sigmas), the LNS virtually inject the sound straight into the ear canals. It is worth mentioning at this point that all listening should be done with the middle of the drivers centred on your ear canals. Both headphones are quite comfortable, but I give the nod to the Sigmas for several reasons – they don’t clamp as tightly around your head as the Lambdas and because the drivers and their netting covering (of the Lambdas) are so close to your ears, they can cause some mild irritation of the pinnae that the Sigmas avoid. My ears can start to sweat whilst wearing the LNS, whilst the Sigmas are much more bearable in warmer weather. This is important in Perth, although we do have air conditioning.
The cables and drivers have been “improved” over the years between the release of the Sigmas and the LNS – the cables are now PC-OCC for the LNS, whereas the Sigmas had no special claim for cable quality as far as I know. The cables themselves are much wider in the LNS for lower capacitance. The drivers were also changed to the later high bias system enabling a louder peak level and increased bass excursion.
2.Sound
a.Deep bass
The very bottom end of the frequency response of the LNS is much more apparent – in particular bass kick drum has more impact and is rendered better than the Sigmas (the difference is that the Lambdas really kick at you, whereas the Sigmas produce a more muffled thud). This should be the case, as the LNS go down to 7 Hz, whereas the Sigmas only reach 20 Hz. The same Sigma drivers were used in the Lambda headphones and went as low as 8Hz, so this deep bass roll off must be more a function of the headphone enclosure and is probably less due to the differences in cabling and drivers.
b.Mid bass
The Sigmas have a pleasant exaggeration of the mid bass region compared with a slight recession from true (IMHO) in the LNS. This makes the Sigmas sound very nice on music that has been recorded live, as it seems to replicate the mid-bass (i.e electric/acoustic bass) emphasis that one hears at a live venue. This often seems to be lost in translation to recorded sound. On occasion, if the bass is mixed louder than it should be, this can be overwhelming on the Sigmas , whereas in that example, the LNS would be about right. I prefer Cream’s “Live At The Royal Albert Hall 2005” on the LNS for that reason, whereas the Grateful Dead’s bass sound is much more “live” on the very well recorded “Fillmore West 1969” 3xCD set using the Sigmas. To recapitulate, on a CD where the bass is a little recessed, the Sigma will restore it perfectly: if the CD is a bass monster, phase up the LNS instead. Generally, I prefer the Sigmas - I suspect most albums were originally cut so the average stylus of the time could track them. This translates as rolled bass. CD reissues usually replicate the sound of the vinyl (otherwise audiophiles rightly complain), so I guess that we get stuck with the bass roll off. Sigmas correct this to some extent - indeed I prefer them to the LNS on older analog recordings, not only because of the mid bass emphasis, but also because of the sibilance de-emphasis. The latter seems to be more problematic in analogue recordings IMHO. See later for more on this.
c.Mid and upper-mid range
This area of the frequency spectrum is where the Sigmas really shine – human voices simply sound more real on the Sigmas. There is none of the Lambdas lack of force, nor is there any sibilance – they just sound great. There is a slight loss of consonant clicks in vocals, but the lack of sibilance is so impressive, that this loss is not really noticeable. The LNS, on the other hand, seems to thin out the mid-range and makes vocals a little 2 dimensional, trebly and sibilant in my opinion. They are not as enjoyable and don’t sound like they should as reproduced live. Again, using the Grateful Dead Fillmore West example, Pigpens vocals simply sound live on the Sigmas and thinner and more sibilant on the LNS. This is a great album by the way - I have only just started to get into the Dead.
d.Treble
The Sigmas roll the top end quite a bit compared with the LNS – this makes tape hiss and recorded crowd applause sound different than in the LNS. I think the Lambda is closer to the truth, but the adjacent frequency band elevation (e.g the emphasis on sibilance) is too much of a price to pay. Still, if we could have the lack of sibilance and the frequency extension at both ends (and this may be attainable with the Sigma/LNS hybrid I am thinking about), I suspect I may have the perfect phone.
3.Dynamics.
Although there was much trumpeting of the increase in dynamics allowed by changing the bias voltage and the inter-electrode spacing when upgrading to the high bias system, the dynamics of the two headphone systems seem to be about the same (i.e. excellent). I hear minimal evidence of superior dynamics, with the exception of the frequency extremes. The LNS can play louder without stress, but I don’t want to listen at those levels anyway, so this is a moot point. Ed cites increased ambience with the Sigmas as evidence of this, but the treble roll off on my pair mitigates against that. I know what he means however, it's just I don't hear it on my pair.
4.The Future.
According to other Head-Fiers (thanks Edstrelow), the Sigma/LNS hybrid could be what I am looking for – a Sigma that retains the positives and corrects the negatives. There is also the bonus that I could use the superior SRM-717 for the phones with its balanced inputs. An Omega 2 is on its way in June sometime, so after that a hybridization may occur, if the Omega 2’s aren’t just so overwhelmingly good that Sigmas pale in comparison. Further reviews will be coming.....
