disclaimer: I borrowed the IMR Aten from another head-fi member to review in trade while he tried out my LZ A7 beta. I have no financial interest in IMR or any of its affiliates and having lived through some of the Trinity fiasco personally understand those who are leary of wanting to deal with IMR as a result. I’ll admit to mixed feelings myself in that respect but this is a product review and as such lets leave the politics in this section and move forward with the product. If you have an interest in IMR, check their website. Also a lot of IMR products have found their way to Drop so it is probably wise to check there before spending more elsewhere.
Unboxing / Packaging:
I received the carrying case with all elements packed neatly in it so cannot speak to the original packaging, but the case is well thought out with plenty of room for the accessories and even a spare cable. The one caveat is with all three cable options, that compartment is a bit cramped so you may want to limit it to a single cable at a time. The kit contains the earpieces, cable, tips, shirt clip, tubes, filters, leather cable ties, 6.3 to 3.5 adapter, and carrying case. Filtering the Aten is a 2 stage proposition with tubes screwed into the earpieces and then a filter screwed into the top of the tube to complete the ensemble. The filters have striped edges to also operate as the lip for tip retention. The Unit ships with 5 sets of tubes and 6 sets of filters. As a side note, the filters from my older Trinity Icarus III also fit the Aten so this expands the filter options for those that have Trinity in-ears still in their collections.
Build/Fit:
Defining the shape of the Aten is a bit difficult as it doesn’t follow any of the typical shapes we normally see. With a 14mm driver, the bulk of the shell is round with a vertical tube at the rear edge for the connectors. Shells are 3 pieces with a gold face plate held on with screws, and outer shell and inner of gunmetal colored aluminum with a large threaded stub for the tubes and filters that form the nozzles. Nozzles have a distinct upward rake when installed and the combination of fairly shallow insertion and open back lead to limited isolation. I found the Aten comfortable for extended wear once a proper tip size was found.
Internals:
The Aten utilizes a 14mm dynamic driver with a beryllium composite diaphragm for its lows and mids. The driver uses updated Neodymium motors for faster response compared to older IMR models. The top end is handled by a piezo ceramic driver giving the Aten a listed range of 10Hz-50kHz. Nominal impedance is listed as 32Ω with a sensitivity of 106 dB/mW. This puts the Aten in a class that can be driven by a phone or tablet, but make no mistake, these like a bit more power than those are likely to provide and they do scale considerably both qualitatively and quantitatively with better sources. I found the bass tightened up and became cleaner and better separated with moving from phone to Tr-amp for example.
Cable:
The cables that came with the Aten are all exactly alike except for the differences in terminations at the south end. The 3.5 Single ended and 2.5 balanced cables have 90º jacks in translucent plastic and brushed aluminum housings while the 4.4 uses a straight jack in a similar housing. All are gold plated for corrosion resistance. All cables have short strain reliefs before exiting the jack. Cables are oxygen free copper in a clear casing that shows the strands clearly in each twist. The cables are 2 strands in a twisted pair up to the splitters which are brushed aluminum barrels of the same color as the jack. A clear rubber chin slider sits above the splitter and then 2 single strands exit headed north to pre-formed ear-hooks and knurled gun-metal housings containing the 0.78mm bi-pin connectors. Admittedly the switch from brushed silver to the matte gun-metal seems a bit odd at first but the pin housings do match the body of the Aten well and it makes a bit more sense in that context. All three cables are well made, didn’t show a propensity to kink or tangle, and microphonics are kept to a minimum by the ear-hooks.
Filters:
Filters can be a good tool to help the user shape the sound to their liking or they can be largely a gimmick to entice those that like gadgets. I’ve had both in my collection as some like the FLC8s made great use of the filters to allow tuning while others were more for show as they offered very little in the way of appreciable difference. The filters on the Aten fall somewhere between the two. Starting with the tubes, the black and red tubes are inside each others margin of error on my measurements so realistically pick the one you think looks better of the two. The purple offered the best compromise in my opinion with the green removing too much low end (remember the filter cannot put back what the tube removes so once gone, its gone). The Gold I have trouble figuring out the use for as the mids are so scooped. I guess if you wanted to remove all vocals it might be a starting point but for me realistically the choice is between the black/red for bass boosted or purple for a more linear signature.
When we get to filters we have a bit of the same with the red/green overlapping nearly entirely and changes made by all of them fairly minimal. If you look at the stacked graph below you quickly realize that changes due to the filter are all above about 2kHz and are fairly small incremental changes. The 2nd graphs has curves separated for easier reading. Here again we have some that overlap entirely and other that the changes are so small many will be hard pressed to hear them.
Overall, I like the idea of tunable iems, but the design here is a bit clunky as the tubes and filters are difficult to remove from the aluminum storage blocks without using a needle nose plier or some other tool (Something I didn’t feel comfortable with using a borrowed IEM). Once you do have them removed they are tiny parts that are easily lost and I wouldn’t dream of attempting to change these while traveling or outside the home for fear of losing them. I would have preferred fewer options with more distance between them rather than a lot of overlapping options. Good idea, less than great execution.
Sound:
My sound notes are with my preferred combination of purple tube and gold nozzle. This provided the closest to neutral signature in my measurements.
Bass:
Bass is emphasized on the Aten as expected with a 14mm driver, but it is fairly linear throughout its range without a pronounced lift of drop between sub-bass and mid-bass. Roll-off at the low end is evident below the mid-40Hz range (purple tube) but still provides enough rumble to satisfying. Speed is fairly good with slightly slower decay than attack giving a bit of warmth to the overall, but also contributing a bit of thickening. That thickening seems to be inherent to the purple tube as does the roll-off. The Black offers less thickening to the mid-bass and a roll-off in the 20s but pushes the bass considerably further forward which was a trade I wasn’t happy with. Mid-bass shares those same qualities with good definition and texture if a bit slower decay than absolutely realistic. Mid-bass steps back as you reach the lower-mids and their is some minor mid-bass bleed, but not so much as to obstruct lower vocals or cello details. Know that even with the most neutral tuning option, the Aten cannot be made linear and your options are to change the depth of the V in the signature at most. Bass will always be a star in the Aten’s show.
Mids:
Lower mids do have some bleed from the mid-bass that adds a bit of warmth. Lower vocals have good weight and texture and guitar growl is satisfying. Strings are well rendered as well but lack just a touch of texture needed to sound completely natural. I found the mids lacking the level of detail of some of the better hybrids in its class, but still detailed enough to be an enjoyable listen. Upper-mids are pushed forward and female vocals step forward in the mix as a result. This is the first place that one of the issues with the Aten rears its head. The issue being that the Aten is not forgiving at all and any flaw in source is at very least displayed and at times seems accentuated. Sibilant, strident tracks will be sibilant and strident and this is especially so with some filter combinations.
Treble:
Lower treble starts out a bit forward as it follows the upper-mid lift, but drops back a bit fairly quickly above that initial peak. The Aten delivers good clarity and detail throughout the treble but does little to attenuate any harsh or rough edges. I found the treble very source dependent as poorly recorded tracks are on full display and get strident, sibilant, and downright peaky and ugly at times. Likewise, well recorded tracks have great detail level, textures, and good sparkle and air at the top end. I can see how opinions of the treble on the Aten could vary quite wildly depending on which filter was in use, what source, and what source material was used during testing. With good source material, snare rattle is quite good with enough edge to sound natural. Cymbals are also quite good if the other factors are accounted for. Final roll-off is above the limits of my hearing.
Soundstage / Imaging:
I expected a good stage out of an open-back iem and the Aten did not disappoint. Stage has good depth, width, and height with width only mildly larger than depth but it maintains a good sense of proportion. Seating the orchestra is straight forward with instrument separation being above average as well. Layering is good as well with minimal thickening as the tracks get overly complex. For this I tried the Black tube as the purple seems to introduce a bit of distortion of its own and may not be a good example of what the driver is capable of. Imaging is good with movements easy to track and positions fairly tightly defined in space.
Thoughts / Conclusion:
The Aten is well made, good looking, sports a 14mm dynamic and a piezo driver, and comes with 30 possible tuning options. That seems like a lot of pluses to chalk up, but it is not with out it down-side. A few of the filters (Gold tube) are basically unusable and others are so closely related that any difference is likely beyond the range of human hearing (Red/Black tube). Even what I felt was the best option to try and tame the V a bit (the purple tube) introduced a higher than normal roll-off at the low end and some mid-bass distortion. Those looking at the Aten should know going in that it is at its best as a fairly deep V using the black tube (lack of any low-end filter) and either the blue or green filter for top-end. Those looking for a more reference tuning will find it is not possible with the Aten. Another thing to keep in mind is the Aten is unforgiving of poor source so if you have a lot of questionable material in your collections like many of us do, you may want to consider other options. For those with predominantly well recorded material of genres that a big V suits are rewarded with a revealing fun in-ear that is comfortable enough to wear for extended listening sessions. It is a niche player, but at the price of the current drop offering, it deserves a look if you fit the niche. Special thanks to Pod who loaned me the Aten for this review.