The FutureSonics Atrios are a nice set of phones. They're very warm (which I like) and have a very full low end (which I also like), but their midrange is weak and I have struggled with the murkiness of the treble for some time now (which is improved in the newer mg7 drivers!). In hopes of getting these phones to keep their warmth but improve clarity, I decided I'd try out a range of different tips for these phones and see which could get me the sound I wanted. I was hoping for a nice, full, clear bass response with precise treble and at least reasonable representation of the midranges. I've tried out five different sets of tips, and posted my impressions below. Many of these tips are quite sensitive to correct placement and seal in the ear, therefore your results may vary tremendously from mine, but I invite any comments/dissenting opinions! I did all my listening either on my Cowon D2(+) or on my Palm Pre, and the type of music I was listening to included Them Crooked Vultures (which is a VERY difficult album to make sound good on the Atrio's), Bullet for my Valentine, The Black Keys, The Raconteurs, 30 Seconds to Mars, and a spattering of John Coltrane, Miles Davis, Cannonball Adderley et al (think hard bop). I wear these phones with the cable "over the ear."
1.) FutureSonics ComfortFit Foams (large):
I'm gonna come right out and say these are my least favorite of the group, but not because of their sound; they are just impossible to get in my ears the way I like. Once they are in my ears, they sound pretty good though. They deliver clean and full bass, ok midrange, and half-decent treble although the soundstage could be cleaned up a bit. I probably should try out the small foams, which I have...somewhere...
2a.) FutureSonics EarFills Silicone Sleeves (medium):
These go in my ears two different ways: part of the way in such that the first flange is in and sealed but not the second, and aaaaaaall the way into the ear canal. With the more superficial insertion, these sound a little sharper than the FS Foams in terms of dynamic range, but the soundstage isn't as clean. This gets you slightly more treble then the foams. Inserting these all the way, the sound quality is improved in terms of soundstage, but the bass because muddled and the treble falls apart; the cymbals lose all their definition. Yuck.
2b.) FutureSonics EarFills Silicone Sleeves (small): (added 3/17)
Typically it would be odd to include the small tip but with two different sizes, as one would immediately ask "why not just write up the one tip that fits?" The train of thought is why I never bothered to even try the small tips when I started this review, especially given that I use medium tips in virtually all other styles of eartips. But in this case, they both fit, just differently. While the medium-sized tip can be inserted either halfway or all the way in and achieve a seal both ways, the small tips, for me, can only be inserted all the way. Unlike the medium sized tips, the sound quality improves substantially when inserted completely.
To stop the verbosity and cut to the chase, the small FS silicone sleeves are the best sounding tips I have tried yet on the Atrios. They bring out the treble much better than any of the other tip options presented here, are the most dynamic, and don't achieve this improvement at the expensive of the beautiful Atrio sub-bass. They also isolate wonderfully, giving me arguably the best isolation on any IEM/tip combo or headphone I've ever had the opportunity to try. The only downsides are in comfort. While these are easier to insert into my ears than any of the foams or the other double flanged tips, they still require a bit of technique to get in and can make the ear canal quite sore if you insert and remove them several times (as often happens if you're wearing them in an environment in which you periodically need to hear something or communicate with others around you.) Sometimes I find my ears tolerate them well, and I am able to wear them for several hours without discomfort; other times I can't stand them for more than half an hour.
3.) Shure Gray Soft Flex Sleeves (medium): The good news here is that these are, by far, the easiest to get in your ears. They pop right in, seal almost immediately, and quickly establish the sound you're going to keep getting. The bass is slightly weaker and doesn't punch as hard, but my biggest critique is that the sound just isn't as dynamic. I'm not sure how to describe it, as the treble is there and sounds good, but I just keep finding myself going to crank up the volume because I'm not getting the livelihood I'd like. I have a hard time isolating what I don't like about the sound until I've listened for a couple minutes and everything just seems flat.
4.) Shure Black Foam Sleeves (medium):
In terms of fit and isolation, I like these a lot. They're a little more effort to get in than the Shure grays but are probably easier than FS silicones and way easier than the FS foams. The foam stays cleaner, is easier to squish down, and is more comfortable in my ears. These sleeves have a very nasty Achilles heel though; they utterly wreck the soundstage. The treble and midrange would probably sound great if you could hear it over the constant rumbling coming out of the bass section. If you're a bass-head and prefer quantity over quality when it comes to boom, these might be for you, but for me, all I hear is *THUMP RUMBLE THUMP*.
5.) Alpine Double-Flange Silicon Tips (one size fits all, apparently):
And now, the sleeves responsible for this review. IanD over on anythingbutipod.com sent me a pair of these (discussed here) to try out after dfkt recommended them. In my opinion, these are the best sounding of the sleeves listed here. They're punchier than the other sleeves across the frequency spectrum and are the most dynamic. On particular tracks, the FS silicones or foams can match their quality, but these in general have the best sound. They've got the most well-represented treble and have the most balanced soundstage. However, they are the worst isolators and aren't great to get into your ears. These are much softer than silicone sleeves packaged with the Atrios, which makes them squish and fold when you try to push them into your ears. The shaft of these needs to be cut before you want to use them (they're very long) and I found cutting them all the way down to the base of the 2nd sleeve to help with inserting them into the ear canal. It's possible that doing this hurts the isolation because they don't go as far into your ears, but I couldn't get them in much further anyway without a hell of a lot of effort. They feel ok once they're in your ears (the FS foams, FS silicones, and sometimes the Shure foams make my ears sore after awhile) and you've found a seal. Also, whoever decided to make these white must have really clean ears...mine are already starting to yellow.
6a.) Klipsch Double-Flange Silicone Tips (small):
Klipsch boldly claims that their oval-shaped tips are far superior to everyone else's circular tips, and went so far as to score a patent on the idea. When I heard that they could fit the Atrios, I decided to give them a try. It's worth noting that these are a total pain in the ass to buy as it seems that no one retails them except directly through Klipsch, who stubbornly refuses to sell them any other way than one size at a time at $14 a pack. Obnoxious.
First I tried the small double flanges, hoping that since I typically wear mediums and am not a particularly large fellow, they would fit. Wrong. First off, they are much too short to work on the Atrios. The stem is so short that you can't fit them into your ears hardly at all. So, I lengthened the stem (if you're really curious, ask about it) then tried again. When I get these deep into my ears, they'll seal, but barely. They just don't fit. These tips shouldn't be called "small", they should be called "pediatric". Unless you're absolutely diminutive in size, forget it, these don't work on the Atrios.
6b.) Klipsch Double-Flange Silicone Tips (large):
After awhile, I couldn't help myself and had to try out the bigger size. Klipsch's large double flanges are about the same size as the FS small silicones, which is stupid, but so it goes. The stem on these is long enough for them to work on the Atrios, although they are still slightly more shallow than I would prefer and I might make an attempt at lengthening them eventually.
In terms of sound, they actually aren't overly dissimilar from the FS small silicones. I need to do a bit more listening to accurately detail the differences, so I'll get to that later. They don't isolate as well, but are easier to get in and out of my ears. Sometimes they are more comfortable, and sometimes not. They don't insert as deeply into my ears and aren't as bad to insert and remove repetitively as the FS silicones, but they sometimes press into the side of my ear canal at the tip which feels awful. I can't figure out why this only happens sometimes, but when it isn't, these are reasonably comfortable.
7.) JAYS single flange silicones (medium):
These are the tips found on my JAYS earphones. To keep it short, these have one and only one pro: they are comfortable. However, they sound absolutely terrible; they are a muffled, veiled mess. They don't isolate much, and don't really fit the stem of the Atrios very well; you have to be careful when removing them or else you'll have to dig the tips out of your ears. I don't see any compelling reason to use these ever, as the Shure single flanges outperform them in sound, isolation, comfort, and actually fit the stem of the earphone.
8.) Modified Shure e2C tips (medium):
User shotgunshane suggested using Shure e2C tips on the Atrios, which he did by using the cores from a pair of FS foamies as an adapter of sorts for the larger nozzle of the e2C tips. He reported great results, so I thought I'd have a try. I de-cored a pair of Shure Olives and added them to a pair of e2C sleeves I happened to have sitting around:

The fit is actually pretty good, aside from the fact that the Olives cores fit a little tighter than I'd like on the Atrio nozzles. Leaving a little bit of foam left on the cores helps the e2C sleeves fit snuggly. I like how the Olive cores have that base on the bottom; it really helps them fit nicely onto other sleeves as an adapter (I don't think the FS foamies have this base.)
I should be writing my thesis right now, so I'm gonna keep this brief. In terms of isolation, these aren't as good as the Shure flex sleeves or FS silicone sleeves, but they're no slouch either. Expect middle-of-the-road isolation, which may vary for you depending on your ear shape. The most important thing to note here is sound. These aren't as good as the FS silicone flanges, but don't lag far behind and are FAR more comfortable. If you're willing to sacrifice a little bit of soundstage for comfort, these really may be the choice for you. They handily outperform the Shure flex sleeves, Olives, JAYS tips, and probably beat the Alpine and Klipsch double flanges in terms of sound quality. If you have a pair of e2C tips sitting around, pull out a knife and de-core a pair of the included FS foam sleeves; you won't regret it.
Conclusion
As an early conclusion (see below for update), I think my favorite of these are probably the Alpine sleeves, although I may switch over to either the Shure soft flex sleeves or the FS silicones when I need more sound isolation. I wouldn't advocate any of these tips aside from the Shure soft flex sleeves if you are going to be popping the phones in and out of your ears a lot, although the Alpines are probably the second best in that regard due to the softness of their silicone.
UPDATE: My current favorite sleeves are either the FS small silicones or the large Klipsch double flanges. They sound so much better than everything else that I deal with the discomfort of using them. I'm still breaking in my new Atrios with mg7 drivers, and perhaps some of these conclusions will change, although I doubt it.
UPDATE 2: The Shure e2C sleeves are great. I still prefer the FS small double flanges because they sound a bit better, but when my ears get sore or if I anticipate doing a lot of listening in a day, the modified e2C sleeves go on my Atrios without much hesitation.
Best treble: FS silicones (small size only!)
Best midrange: FS silicones (small)
Best bass: FS foams
Best isolation: Tie between Shure foamies and FS silicones (closely followed by Shure soft flex)
Worst isolation: Alpine (might be better if I didn't cut the shaft so short)
Most comfortable: Shure soft flex/Modified Shure e2C
Least comfortable: FS silicones (medium, followed by small)
Best sound overall: FS silicones (small)
Best mix of comfort/sound: Modified Shure e2C
1.) FutureSonics ComfortFit Foams (large):
I'm gonna come right out and say these are my least favorite of the group, but not because of their sound; they are just impossible to get in my ears the way I like. Once they are in my ears, they sound pretty good though. They deliver clean and full bass, ok midrange, and half-decent treble although the soundstage could be cleaned up a bit. I probably should try out the small foams, which I have...somewhere...
2a.) FutureSonics EarFills Silicone Sleeves (medium):
These go in my ears two different ways: part of the way in such that the first flange is in and sealed but not the second, and aaaaaaall the way into the ear canal. With the more superficial insertion, these sound a little sharper than the FS Foams in terms of dynamic range, but the soundstage isn't as clean. This gets you slightly more treble then the foams. Inserting these all the way, the sound quality is improved in terms of soundstage, but the bass because muddled and the treble falls apart; the cymbals lose all their definition. Yuck.
2b.) FutureSonics EarFills Silicone Sleeves (small): (added 3/17)
Typically it would be odd to include the small tip but with two different sizes, as one would immediately ask "why not just write up the one tip that fits?" The train of thought is why I never bothered to even try the small tips when I started this review, especially given that I use medium tips in virtually all other styles of eartips. But in this case, they both fit, just differently. While the medium-sized tip can be inserted either halfway or all the way in and achieve a seal both ways, the small tips, for me, can only be inserted all the way. Unlike the medium sized tips, the sound quality improves substantially when inserted completely.
To stop the verbosity and cut to the chase, the small FS silicone sleeves are the best sounding tips I have tried yet on the Atrios. They bring out the treble much better than any of the other tip options presented here, are the most dynamic, and don't achieve this improvement at the expensive of the beautiful Atrio sub-bass. They also isolate wonderfully, giving me arguably the best isolation on any IEM/tip combo or headphone I've ever had the opportunity to try. The only downsides are in comfort. While these are easier to insert into my ears than any of the foams or the other double flanged tips, they still require a bit of technique to get in and can make the ear canal quite sore if you insert and remove them several times (as often happens if you're wearing them in an environment in which you periodically need to hear something or communicate with others around you.) Sometimes I find my ears tolerate them well, and I am able to wear them for several hours without discomfort; other times I can't stand them for more than half an hour.
3.) Shure Gray Soft Flex Sleeves (medium): The good news here is that these are, by far, the easiest to get in your ears. They pop right in, seal almost immediately, and quickly establish the sound you're going to keep getting. The bass is slightly weaker and doesn't punch as hard, but my biggest critique is that the sound just isn't as dynamic. I'm not sure how to describe it, as the treble is there and sounds good, but I just keep finding myself going to crank up the volume because I'm not getting the livelihood I'd like. I have a hard time isolating what I don't like about the sound until I've listened for a couple minutes and everything just seems flat.
4.) Shure Black Foam Sleeves (medium):
In terms of fit and isolation, I like these a lot. They're a little more effort to get in than the Shure grays but are probably easier than FS silicones and way easier than the FS foams. The foam stays cleaner, is easier to squish down, and is more comfortable in my ears. These sleeves have a very nasty Achilles heel though; they utterly wreck the soundstage. The treble and midrange would probably sound great if you could hear it over the constant rumbling coming out of the bass section. If you're a bass-head and prefer quantity over quality when it comes to boom, these might be for you, but for me, all I hear is *THUMP RUMBLE THUMP*.
5.) Alpine Double-Flange Silicon Tips (one size fits all, apparently):
And now, the sleeves responsible for this review. IanD over on anythingbutipod.com sent me a pair of these (discussed here) to try out after dfkt recommended them. In my opinion, these are the best sounding of the sleeves listed here. They're punchier than the other sleeves across the frequency spectrum and are the most dynamic. On particular tracks, the FS silicones or foams can match their quality, but these in general have the best sound. They've got the most well-represented treble and have the most balanced soundstage. However, they are the worst isolators and aren't great to get into your ears. These are much softer than silicone sleeves packaged with the Atrios, which makes them squish and fold when you try to push them into your ears. The shaft of these needs to be cut before you want to use them (they're very long) and I found cutting them all the way down to the base of the 2nd sleeve to help with inserting them into the ear canal. It's possible that doing this hurts the isolation because they don't go as far into your ears, but I couldn't get them in much further anyway without a hell of a lot of effort. They feel ok once they're in your ears (the FS foams, FS silicones, and sometimes the Shure foams make my ears sore after awhile) and you've found a seal. Also, whoever decided to make these white must have really clean ears...mine are already starting to yellow.
6a.) Klipsch Double-Flange Silicone Tips (small):
Klipsch boldly claims that their oval-shaped tips are far superior to everyone else's circular tips, and went so far as to score a patent on the idea. When I heard that they could fit the Atrios, I decided to give them a try. It's worth noting that these are a total pain in the ass to buy as it seems that no one retails them except directly through Klipsch, who stubbornly refuses to sell them any other way than one size at a time at $14 a pack. Obnoxious.
First I tried the small double flanges, hoping that since I typically wear mediums and am not a particularly large fellow, they would fit. Wrong. First off, they are much too short to work on the Atrios. The stem is so short that you can't fit them into your ears hardly at all. So, I lengthened the stem (if you're really curious, ask about it) then tried again. When I get these deep into my ears, they'll seal, but barely. They just don't fit. These tips shouldn't be called "small", they should be called "pediatric". Unless you're absolutely diminutive in size, forget it, these don't work on the Atrios.
6b.) Klipsch Double-Flange Silicone Tips (large):
After awhile, I couldn't help myself and had to try out the bigger size. Klipsch's large double flanges are about the same size as the FS small silicones, which is stupid, but so it goes. The stem on these is long enough for them to work on the Atrios, although they are still slightly more shallow than I would prefer and I might make an attempt at lengthening them eventually.
In terms of sound, they actually aren't overly dissimilar from the FS small silicones. I need to do a bit more listening to accurately detail the differences, so I'll get to that later. They don't isolate as well, but are easier to get in and out of my ears. Sometimes they are more comfortable, and sometimes not. They don't insert as deeply into my ears and aren't as bad to insert and remove repetitively as the FS silicones, but they sometimes press into the side of my ear canal at the tip which feels awful. I can't figure out why this only happens sometimes, but when it isn't, these are reasonably comfortable.
7.) JAYS single flange silicones (medium):
These are the tips found on my JAYS earphones. To keep it short, these have one and only one pro: they are comfortable. However, they sound absolutely terrible; they are a muffled, veiled mess. They don't isolate much, and don't really fit the stem of the Atrios very well; you have to be careful when removing them or else you'll have to dig the tips out of your ears. I don't see any compelling reason to use these ever, as the Shure single flanges outperform them in sound, isolation, comfort, and actually fit the stem of the earphone.
8.) Modified Shure e2C tips (medium):
User shotgunshane suggested using Shure e2C tips on the Atrios, which he did by using the cores from a pair of FS foamies as an adapter of sorts for the larger nozzle of the e2C tips. He reported great results, so I thought I'd have a try. I de-cored a pair of Shure Olives and added them to a pair of e2C sleeves I happened to have sitting around:
The fit is actually pretty good, aside from the fact that the Olives cores fit a little tighter than I'd like on the Atrio nozzles. Leaving a little bit of foam left on the cores helps the e2C sleeves fit snuggly. I like how the Olive cores have that base on the bottom; it really helps them fit nicely onto other sleeves as an adapter (I don't think the FS foamies have this base.)
I should be writing my thesis right now, so I'm gonna keep this brief. In terms of isolation, these aren't as good as the Shure flex sleeves or FS silicone sleeves, but they're no slouch either. Expect middle-of-the-road isolation, which may vary for you depending on your ear shape. The most important thing to note here is sound. These aren't as good as the FS silicone flanges, but don't lag far behind and are FAR more comfortable. If you're willing to sacrifice a little bit of soundstage for comfort, these really may be the choice for you. They handily outperform the Shure flex sleeves, Olives, JAYS tips, and probably beat the Alpine and Klipsch double flanges in terms of sound quality. If you have a pair of e2C tips sitting around, pull out a knife and de-core a pair of the included FS foam sleeves; you won't regret it.
Conclusion
As an early conclusion (see below for update), I think my favorite of these are probably the Alpine sleeves, although I may switch over to either the Shure soft flex sleeves or the FS silicones when I need more sound isolation. I wouldn't advocate any of these tips aside from the Shure soft flex sleeves if you are going to be popping the phones in and out of your ears a lot, although the Alpines are probably the second best in that regard due to the softness of their silicone.
UPDATE: My current favorite sleeves are either the FS small silicones or the large Klipsch double flanges. They sound so much better than everything else that I deal with the discomfort of using them. I'm still breaking in my new Atrios with mg7 drivers, and perhaps some of these conclusions will change, although I doubt it.
UPDATE 2: The Shure e2C sleeves are great. I still prefer the FS small double flanges because they sound a bit better, but when my ears get sore or if I anticipate doing a lot of listening in a day, the modified e2C sleeves go on my Atrios without much hesitation.
Best treble: FS silicones (small size only!)
Best midrange: FS silicones (small)
Best bass: FS foams
Best isolation: Tie between Shure foamies and FS silicones (closely followed by Shure soft flex)
Worst isolation: Alpine (might be better if I didn't cut the shaft so short)
Most comfortable: Shure soft flex/Modified Shure e2C
Least comfortable: FS silicones (medium, followed by small)
Best sound overall: FS silicones (small)
Best mix of comfort/sound: Modified Shure e2C