I usually am on motorcycle forums but as we all know crossover happens. Based on another forum member's praise of the JVC Marshmallows, because they don't fall out when putting on his motorcycle helmet, I purchased them and am impressed. My other earbuds and in-ear headphones wouldn't work with my helmet (either too uncomfortable or would fall out), so I gave up on listening to music while riding, but after stumbling upon this guy finding the perfect in-helmet headphones I got excited. i listened to them inside my motorcycle helmet (Shoei RF1000) for a bit and they worked great. Due to it not being riding season for me, it's freezing, I haven't had a chance to actually take them for a ride.
I used them yesterday while snow blowing and they blocked out a sufficient amount of noise (they are very good ear plugs) and are very comfortable. I had no issues with the sound quality, but I don't usually expect much from the music coming straight out of the jack of my iPod?
The sound was actually unusually good coming out of the old iPod Nano with the Marshmallows sounding like what I expect 160kbps mp3s to sound like. As I was listening while snow blowing I was questioning whether or not the cashier got the right price on these, $20 headphones? The bass was spot on, if not a tad heavy (which is fine when there's a lot of background noise to drown it out). The middle frequencies seemed a bit recessed, but with background noise to drown out some some of the bass, I'm guessing the middle frequency recession would seem less pronounced. The highs were there and seemed to have better than average resolution, but also seemed slightly recessed relative to the bass. I was curious to how good they sound hooked up to my reference system. Naturally, I wasn't expecting a miracle, but I was expecting an improvement.
After the first few tracks of the Marshmallows hooked up to my Headroom Maxed-Out Home Headphone amplifier, is when I realized the genius of the people at JVC. In my opinion, the Marshmallows sound better powered by the iPod than by my $1000 reference level headphone amplifier. The accentuation of the bass frequencies was too much when connected to the headphone amplifier. The bass seemed to be so powerful that it sounded like one of those stereo systems that the kids have where all you can hear is the bass. Listening to some organ, I felt like I could feel the organ notes moving my outer ear.
The recession of the middle frequencies made female vocals sound unnaturally deep, almost male. And then where most other headphones sound much bigger and have a vastly more spacious sound, the Marshmallows clammed up to where I could clearly hear their soundstage compress to something smaller than what I heard straight from the ipod.
My impression is that these things are perfectly tuned to their application, and that by using reference level equipment with them just exposes their flaws, which are actually engineered compensations for the low powered portable player market, specifically the ipod since they are color coordinated with their colors.
Connecting the $20 marshmallows to the $1000 amplifier (connected to other reference level equipment) is probably not going to be a common occurrence, so I'm pretty sure that this is not a problem in general.
As a side note, I had to get out my pricier Ultimate Ears (in-ear style headphones that wouldn't fit in my ear with the helmet) to compare, and as usual they sounded amazing with the headphone amp and average from the ipod. I actually prefer the JVCs straight from the iPod over the Ultimate Ears for the overall sound. The Ultimate Ears have better resolution, but the JVCs have a more pleasing sound. Of course once the Ultimate Ears are hooked up to a quality amplifier with Headroom processing I undoubtedly prefer them.
I looked at reviews on JVC's website and found some reviews that confirmed my review of these headphones. One reviewer in particular said they sounded better than his $200+ in-ear systems of the past.
I can definitely recommend these as in-helmet/ yardwork/ exercise headphones. I'll keep the Grado SR325s or Sennheiser HD650s for my reference system.