The custom ear plugs (no sound/speakers) I use under my helmet while motorcycling are essentially the silicone ear impressions that are made as the precursor for molding custom IEMs. Once the silicone is trimmed, they are relatively easy to insert/remove. I don't know the level of db reduction...

I will second the Yuin recommendation:  either the PK3 or the slightly more expensive PK2. In my opinion, and those to whom I've loaned them for a trial, these earbuds have remarkably good sound for the price. I use the PK3s (with the foam "doughnut") during walks/runs and have no issues with...

Quote: Another vote for the Yuin earbuds. I have the a set of the Apple EarPods and while they are comfortable, the sound quality (to me), is *not* up to the marketing hype. On the other hand, the "plain Jane" Yuin PK3 buds, for about the same money, offer much better SQ from an unamped...

I have a pair of the JH5 Pros and agree that they offer terrific value and excellent sound for the dinero.   YMMV.

I have given SWMBO an Ety HF set AND an MC set for use with her iPhone 4. (She tends to be VERY tough on all things electronic and optical...) She likes the slightly larger size and perceived durability of the MCs; however, she has noted that the sound of the HF set is FAR better. (FWIW, she...

While I don't have any particular comfort issues with triple flanges, I do have a set of the custom tips on my Ety HF2s...have worn them comfortably on numerous 12+ hour international flights and only take them out when eating. (And yes, the custom tips will also fit the ER4-P.)   For added...

FWIW, when shipped, Ety provides two sizes of the triple flanges for different size ear canals. My wife uses the smaller flanges on her HF3s with good success while I use the larger size on my ER4-Ps. (I've also experimented with the Comply foam tips, but none of the three sizes provided the...

I visited the Dallas Best Buy listening station a couple of weeks ago. They had 4 - 6 headphones nicely displayed; however, during my visit, there was no player/amp attached to any of them. When I finally got the attention of the nice, but clueless sales person, he initially tried to demo the...

I've been using the PK1 (amped with a Super Mini Moy) for about 3 years and the PK3 (unamped) for two years. I've been VERY happy with both 'buds and totally agree with the original reviewers comments that they sound great and are amazing bargains. In fact, I've helped "sell" a few sets of PK3s...

Another vote for ACS tips purchased via Ety...super comfortable, excellent seal and no change in the SQ (for me). YMMV

I would love to get a set of these to use underneath my motorcycle helmet...so far, I haven't found anything that is small enough to stay put under the helmet AND block the ambient noise around me.

Interesting issue...I find that the ER4Ps and HF2s  with the triple flanges fit/seal exactly the same for me. Perhaps you could try switching the ER4P flanges to the HF2s and see if it makes a difference??   FWIW, I recently upgraded to the ACS custom tips on my HF2s and am a VERY happy...

Just a personal thumbs up for the ACS tips. I received mine about a week ago (process took about 3 weeks total) and I am extremely pleased with the result. I normally use the silicone triple flanges and had no major issues; however, for my ear canals, the isolation and comfort of the ACS tips is...

Quote: Yes, you are correct. I wear a snug fitting Arai and there is no way that my ER4Ps or HF2s would fit under there. =8-0     

I wear a fairly snug fitting Arai and even with deep insertion, the HF2s stick out too far to be usable with my helmet. One of my riding buddies uses the tiny, dual driver "S Plug" http://www.bikebone.com/page/BBSC/PROD/motorcycle-headsets/S22SP however, I haven't listened to them and have no...