H2O Audio Interval 3G - Marine case for digital player - iPod shuffle (3G)

I have used (consumed) 6 of these during the past year and a half. They have gone through, I would estimate, about 300 cumulative hours of use in the pool. They have also gone through about 50 hours of use in a sauna. Each of the six ended up not working. Three of them failed during the warranty period and were replaced. One of them was repaired and is currently in use. The remaining two were thrown out.

When they work, the headphone system is great. It attaches easily to the goggle strap and there are no long cables to deal with. The music makes swimming much more pleasant. The earbuds also act as earplugs and keeps the water out. I would give it five stars for the conceptual design.

The problem is that they are not reliable. The most common failure is one of the headphones not working. With use, they start to fail by producing diminished sound volume. Then, over time, they simply fail and produce no sound. Another mode of failure is the buttons not working.

I have taken apart a couple of them, and this is my finding. The main unit is basically a waterproof housing with three push buttons. There are some resistors and capacitors that replicate the function of the original Apple headphone push buttons, but there are no active components. The headphone cables enter the housing through a compression fitting that seals out the water. The earlier units simply had a knot in the cable to prevent it from slipping out. One mode of failure is that the cable is free to rotate and since the connections are made through hand soldered contacts onto a small printed circuit board, the contact point can break. The guys at H2O audio must have figured this out, since the units produced later has the connections potted inside a heatshrink tube with a sturdier pair of wires being soldered onto the PC board. The cable connections to the buttons are also hand soldered (some of them quite poorly). The cables are very thin and fragile and even small movement can cause the solder joint to come apart. The main design issue here is that the four conductor connector inside the box is allowed to move (rotated and pulled). This motion tugs on the thin cables, and over time, one of the weaker solder joints would fail.

The earbud consists of a housing and a speaker unit that is about quarter inch in diameter and about eighth inch deep. The cable in the earbud is sealed with a potting compound. The speaker membrane is a clear material that can be seen directly when you look through the orifice in the earbud. I think much of the failure of the earbud comes from this thin membrane having have to hermetically seal the magnet and coil assembly inside. The air pocket would experience pressure changes as the wearer swims under water (e.g. when doing flip turns). My guess is that the pressure cycling causes the membrane to fail. Out of curiosity, I poked the membrane on one of the defective earbuds, and it ruptured readily. Interestingly, the units came with an explanation on how air pressure changes during freight could affect the initial performance of the headphones and that the earbuds would need to somehow equalize the pressure. Still can't figure out what this means... My experience is that units that were bad out of the box ended up being the ones that got sent back.

The unit I am currently using had one of the push button joints come off. This was repaired by a simple solder connection. I 'repaired' a defective earbud by taking a working earbud from another unit that also had one defective earbud. Hopefully these battle-hardened earbuds will work for some time. These were the earbuds that have gone through real-life pressure cycle testing. H2O audio should sell 'military spec' versions of the earbuds that are subjected to actual 'burn in' tests so that the ones destined fail early are removed from the lot. I, for one, would pay a premium for this enhanced level of reliability.

I think the next set of underwater music player I would get would be the ipods that are sealed using a potting compound injected directly into the ipod units. I think this is the more elegant solution. Amazon carries this also. What we then need are waterproof earbuds with short cables... This should be easy enough to modify from one of the existing headphones, though.

I saw an ad for this product and requested that my son to get it for me for Christmas when he asked what I wanted. It was the best present I received! I love this product! I do triathlon training year round, and lap swimming in the winter gets boring. This product makes the time fly by. The sound is great and the case is so lightweight, I don't even know that it is hooked onto my goggles. The controls are easy to use. I can't wait to try it for long lake swims this summer.

I find swimming to be great exercise, but extremely boring. I was hoping to pass the time better with this device, however, it was a disappointment. Two problems with the device. I had a hard time keeping the headphones in my ears during swimming. I was partially able to overcome the difficulty after a lot of laps and trying the different size ear fittings provided. However, even after numerous trials, the head phones continued to pop out. What they need is an ear strap of some sort that forces the buds to stay in/near the ears. The other problem with these is the sound amplitude is not high enough to overcome the ambient sound made during swimming. Compared to my normal headphones, the sound coming from the waterproof ones is diminished. Hence swimming a crawl and being able to hear through the headphones is poor at best. It wasn't worth the $100 for this version of the device.