This is a review of Zero Audio DuoZA dual dynamic driver IEMs. http://www.zeroaudio.jp/product_ZH-DWX10_01.html
It has been awhile since a set of IEMs made me go WOW! the second I put them in my ears, literally “out of the box”. Obviously, my definition of WOW might be different from yours since everyone has a unique taste and hear things in a different way, but if you have been craving a full body sound with a warm organic tonal characteristics and excellent retrieval of details topped with a bass that going to make you feel its presence while you submerge yourself into a deep and wide soundstage – you are in for one smooth ride with these dual balanced driver headphones from Zero Audio. And if this intro description of DuoZA sound signature is not convincing enough for you, then continue reading to find out why I am so excited about these IEMs.
Packaging.
With a basic plastic packaging and see-through display setting of DuoZA, there is not much to talk about it since Zero Audio didn’t waste any of their resources on fancy boxing. As a matter of fact, packaging is very similar to Tenores and Doppios I looked at in the past. The same goes for the included accessories. You have a rather unique cotton drawstring pouch, and three sets of silicone narrow bore eartips – very modest selection of accessories. Personally, I ended up using a pair of JVC spiral dot tips since I find these particular wider bore eartips to open up mids and treble while still keeping bass under control. Plus, with a rather shallow insertion of DuoZA you probably would want to use a bigger size eartips for a more secure fitment and a better seal. Either way, I always encourage experimenting with tip rolling, going through your collection of eartips to see which one fits you better, gives you a better seal and isolation, and shapes a sound to your preference.
Design.
Considering the packaging and accessories are not the focal point of these headphones, their actual design really makes up for this shortcoming with a rather bold look! Starting with 3.5mm gold plated plug, it’s a right angled connector with a slim rubbery molded housing extended into a strain relief. Cable is thin and soft, with a rubbery coating and enough flexibility to assist in cable management while still keeping it tangle free. Y-splitter is also short, rubbery, slim, and with a lack of strain relief. Chin slider is present, and it slides nice and smooth. The part of the cable from y-splitter going to earpieces is a bit thinner in comparison to a common part of the cable going to the connector. Also worth mentioning, there is hardly any noticeable microphonics from the cable. So far up to a strain relief of earpieces I found the cable to be identical to Tenore and Doppio, and that’s where the similarity ends!
Housing of the shell is cylindrical and rather large, measuring approximately 30mm in total length including a short nozzle and about 14mm in diameter to accommodate its large drivers. The housing is bi-colored and separated by a ring in the middle which extends into a strain relief of cable connection. Furthermore, the part of the shell toward the nozzle is color coded with Black on the left side and Red on the right side, where L/R marking also printed on the housing. The back chrome part of the housing has a single air vent, impressive considering such a wide and airy soundstage of these IEMs. I assume Zero Audio engineers intentionally used a large cylindrical housing for an improved acoustics of sound shaping. Overall, when you first look at DuoZA you feel like they are too big, but surprisingly they fit really well and feel quite comfortable in your ears. But you do have to keep in mind these are shallow insertion IEMs, so a selection of correct eartip is important to keep these snugly in your ears. Also, earpieces could be worn wire up or down, but I found a wire down to provide a deeper insertion with an improved perception of the bass.
Another quick comment, I did find some driver flex in my right earpiece. Perhaps a combination of large shell design, a single pinhole air vent, and large Spiral dot tips created a strong enough seal to put some air pressure into the housing causing a driver flex. At the same time, when I'm slightly twisting DuoZA while inserting them in my ear, this driver flex never reoccurred again. And since I'm on a subject of earpieces, gotta mention they provide an excellent isolation – in combination with spiral dots it felt like earplugs in my ears!
Sound analysis.
Of course, I saved the best for last – sound description! Here is more to elaborate on my intro where I gushed about “smooth ride” you take putting DuoZA in your ears.
DuoZA has a smooth full body sound signature with enhanced bass. The sound is very clean and clear with an excellent retrieval of details, and great layering and separation of instruments and vocals. The soundstage is airy, wide, and deep with an impressive sense of imaging and position in space. They do need a bit of a volume boost to drive them to a proper sound level due to lower sensitivity (had to raise volume on my N6, X5, and Note 4 versus average level I use with other IEMs), but I found amping was not really necessary to bring them up to a full potential. At the same time, extra juice never hurts to make that bass sizzle!
In more details after 50hrs of burn in, bass is tight with an excellent balance between crispy sub-bass rumble and punchy mid-bass attack. It’s very articulate and well controlled without spilling into lower mids, though you could get a wrong impression at first since lower mids already have a thicker body to begin with. Another thing I noticed, with a warmer source (like X1) bass could get a bit overwhelming for those who are fans of neutral low end quantity. For me personally – this is a quantity and quality of the bass I have been craving for a long time! Moving on to mids, they are warm and have a nice body (thanks to lower mids), and sound smooth and clear. Upper mids are slightly recessed which becomes more apparent with a bass heavy tracks, but they are still very detailed and not too bright or harsh. Vocals delivery is exceptionally smooth and organic without losing a sparkle of details. Treble is crisp, extended, and has a pleasant sparkle but not harsh or sibilant or fatigue – a delight for an extended listening period.
Next to some of my other IEMs, I found the following in comparison to Zero Audio DuoZA:
- CKR10 has a little less sub-bass, same mid-bass punch, mids more forward and a bit brighter while still being very similar in nature, treble is brighter, soundstage is similar but less airy, and overall slightly better retrieval of details with a leaner sound.
- B3P1 has a lot less sub/mid bass in quantity, sound is leaner and more neutral in comparison, retrieval of details is close but not as high, and soundstage is wider/deeper.
- A71 bass is more bloated with some spillage into lower mids, mids itself are smoother and warmer, treble is warmer and with less sparkle, soundstage slightly narrower, not the same level of detail retrieval, and overall sound is a bit thicker.
- IM50 has more aggressive mid-bass, mids are more forward, warmer and smother, treble has a bit less extension, soundstage has less depth, and overall sound is smoother and not as detailed.
- UM Pro 30 has a more aggressive mid-bass, mids are more forward and sound warmer and smoother, treble has less sparkle, soundstage is smaller and more intimate, and overall sound is a bit more congested in comparison.
Summary.
In conclusion, I think Zero Audio delivered one fantastic set of headphones which stacks up really well against competition to reach a level of sound performance comparable to other IEMs that cost almost twice as much. And speaking of price, I was fortunate enough to get these through a friend of mine since at the current moment DuoZA is only available directly from Japan through their Amazon (using forwarding service for outside purchases) or from eBay. I hope that soon it will be available from Japanese retailers on Amazon US as well, just like it is now with other Zero Audio products. One thing for sure, if you are a fan of smooth detailed full body sound with a bass that won’t let you down in both quality and quantity and prefer a wide airy staging – DuoZA should be at the top of your list! It might not be for everybody if you are fan of neutral or reference sound and prefer a brighter sound signature, and perhaps if you need IEMs with a smaller shell and deeper insertion – these will not fit you well. But otherwise, when you have a dual dynamic driver budget gem that can challenge a performance of ATH-CKR10, you know that you are looking at (and listening to) something very special! As long as it fits your sound signature preference, go for it! You will not be disappointed!
Here are the pictures.
It has been awhile since a set of IEMs made me go WOW! the second I put them in my ears, literally “out of the box”. Obviously, my definition of WOW might be different from yours since everyone has a unique taste and hear things in a different way, but if you have been craving a full body sound with a warm organic tonal characteristics and excellent retrieval of details topped with a bass that going to make you feel its presence while you submerge yourself into a deep and wide soundstage – you are in for one smooth ride with these dual balanced driver headphones from Zero Audio. And if this intro description of DuoZA sound signature is not convincing enough for you, then continue reading to find out why I am so excited about these IEMs.
Packaging.
With a basic plastic packaging and see-through display setting of DuoZA, there is not much to talk about it since Zero Audio didn’t waste any of their resources on fancy boxing. As a matter of fact, packaging is very similar to Tenores and Doppios I looked at in the past. The same goes for the included accessories. You have a rather unique cotton drawstring pouch, and three sets of silicone narrow bore eartips – very modest selection of accessories. Personally, I ended up using a pair of JVC spiral dot tips since I find these particular wider bore eartips to open up mids and treble while still keeping bass under control. Plus, with a rather shallow insertion of DuoZA you probably would want to use a bigger size eartips for a more secure fitment and a better seal. Either way, I always encourage experimenting with tip rolling, going through your collection of eartips to see which one fits you better, gives you a better seal and isolation, and shapes a sound to your preference.
Design.
Considering the packaging and accessories are not the focal point of these headphones, their actual design really makes up for this shortcoming with a rather bold look! Starting with 3.5mm gold plated plug, it’s a right angled connector with a slim rubbery molded housing extended into a strain relief. Cable is thin and soft, with a rubbery coating and enough flexibility to assist in cable management while still keeping it tangle free. Y-splitter is also short, rubbery, slim, and with a lack of strain relief. Chin slider is present, and it slides nice and smooth. The part of the cable from y-splitter going to earpieces is a bit thinner in comparison to a common part of the cable going to the connector. Also worth mentioning, there is hardly any noticeable microphonics from the cable. So far up to a strain relief of earpieces I found the cable to be identical to Tenore and Doppio, and that’s where the similarity ends!
Housing of the shell is cylindrical and rather large, measuring approximately 30mm in total length including a short nozzle and about 14mm in diameter to accommodate its large drivers. The housing is bi-colored and separated by a ring in the middle which extends into a strain relief of cable connection. Furthermore, the part of the shell toward the nozzle is color coded with Black on the left side and Red on the right side, where L/R marking also printed on the housing. The back chrome part of the housing has a single air vent, impressive considering such a wide and airy soundstage of these IEMs. I assume Zero Audio engineers intentionally used a large cylindrical housing for an improved acoustics of sound shaping. Overall, when you first look at DuoZA you feel like they are too big, but surprisingly they fit really well and feel quite comfortable in your ears. But you do have to keep in mind these are shallow insertion IEMs, so a selection of correct eartip is important to keep these snugly in your ears. Also, earpieces could be worn wire up or down, but I found a wire down to provide a deeper insertion with an improved perception of the bass.
Another quick comment, I did find some driver flex in my right earpiece. Perhaps a combination of large shell design, a single pinhole air vent, and large Spiral dot tips created a strong enough seal to put some air pressure into the housing causing a driver flex. At the same time, when I'm slightly twisting DuoZA while inserting them in my ear, this driver flex never reoccurred again. And since I'm on a subject of earpieces, gotta mention they provide an excellent isolation – in combination with spiral dots it felt like earplugs in my ears!
Sound analysis.
Of course, I saved the best for last – sound description! Here is more to elaborate on my intro where I gushed about “smooth ride” you take putting DuoZA in your ears.
DuoZA has a smooth full body sound signature with enhanced bass. The sound is very clean and clear with an excellent retrieval of details, and great layering and separation of instruments and vocals. The soundstage is airy, wide, and deep with an impressive sense of imaging and position in space. They do need a bit of a volume boost to drive them to a proper sound level due to lower sensitivity (had to raise volume on my N6, X5, and Note 4 versus average level I use with other IEMs), but I found amping was not really necessary to bring them up to a full potential. At the same time, extra juice never hurts to make that bass sizzle!
In more details after 50hrs of burn in, bass is tight with an excellent balance between crispy sub-bass rumble and punchy mid-bass attack. It’s very articulate and well controlled without spilling into lower mids, though you could get a wrong impression at first since lower mids already have a thicker body to begin with. Another thing I noticed, with a warmer source (like X1) bass could get a bit overwhelming for those who are fans of neutral low end quantity. For me personally – this is a quantity and quality of the bass I have been craving for a long time! Moving on to mids, they are warm and have a nice body (thanks to lower mids), and sound smooth and clear. Upper mids are slightly recessed which becomes more apparent with a bass heavy tracks, but they are still very detailed and not too bright or harsh. Vocals delivery is exceptionally smooth and organic without losing a sparkle of details. Treble is crisp, extended, and has a pleasant sparkle but not harsh or sibilant or fatigue – a delight for an extended listening period.
Next to some of my other IEMs, I found the following in comparison to Zero Audio DuoZA:
- CKR10 has a little less sub-bass, same mid-bass punch, mids more forward and a bit brighter while still being very similar in nature, treble is brighter, soundstage is similar but less airy, and overall slightly better retrieval of details with a leaner sound.
- B3P1 has a lot less sub/mid bass in quantity, sound is leaner and more neutral in comparison, retrieval of details is close but not as high, and soundstage is wider/deeper.
- A71 bass is more bloated with some spillage into lower mids, mids itself are smoother and warmer, treble is warmer and with less sparkle, soundstage slightly narrower, not the same level of detail retrieval, and overall sound is a bit thicker.
- IM50 has more aggressive mid-bass, mids are more forward, warmer and smother, treble has a bit less extension, soundstage has less depth, and overall sound is smoother and not as detailed.
- UM Pro 30 has a more aggressive mid-bass, mids are more forward and sound warmer and smoother, treble has less sparkle, soundstage is smaller and more intimate, and overall sound is a bit more congested in comparison.
Summary.
In conclusion, I think Zero Audio delivered one fantastic set of headphones which stacks up really well against competition to reach a level of sound performance comparable to other IEMs that cost almost twice as much. And speaking of price, I was fortunate enough to get these through a friend of mine since at the current moment DuoZA is only available directly from Japan through their Amazon (using forwarding service for outside purchases) or from eBay. I hope that soon it will be available from Japanese retailers on Amazon US as well, just like it is now with other Zero Audio products. One thing for sure, if you are a fan of smooth detailed full body sound with a bass that won’t let you down in both quality and quantity and prefer a wide airy staging – DuoZA should be at the top of your list! It might not be for everybody if you are fan of neutral or reference sound and prefer a brighter sound signature, and perhaps if you need IEMs with a smaller shell and deeper insertion – these will not fit you well. But otherwise, when you have a dual dynamic driver budget gem that can challenge a performance of ATH-CKR10, you know that you are looking at (and listening to) something very special! As long as it fits your sound signature preference, go for it! You will not be disappointed!
Here are the pictures.
