Secrets of Home Theater and High Fidelity - John E. Johnson, Jr.
I received a pair of HiFiMAN RE400i earbuds ($79) recently, to use with my iPad when I watch movies.

The first thing I noticed was that the sound was very clear and detailed, with no harshness, even with the volume up reasonably high.

However, the bass was lacking.

A bag of various sized rubber tips came with the earplugs, and I wondered if removing the default tips, which were small, and replacing them with the larger ones in the bag might solve the problem.

Secrets Sponsor

In the photo below, you can see the earbuds with the larger rubber tips mounted. The default, smaller tips, are sitting next to the earbuds.

Using Large Earbud Rubber Tips for Better Bass Response

Well, this is one of the quickest fixes I have experienced in a long time. The bass was much louder, matching the volume of the midrange and treble. Now I can experience the full extent of explosions in war movies, and also the bass section of the Boston Symphony Orchestra.

Secrets Sponsor

The explanation is simple. Bass reproduction is best when the enclosure is large. So, using the larger eartips increased the “enclosure” size (space between the driver and my eardrum).

  • Carlo Lo Raso

    Completely agree with this. Every time I get in new earbuds I always, invariably, change the default silicone tip size to the larger size for this reason.

  • I agree that a proper fitting silicone earbud is critical for best performance. However I’m not sure I agree with the explanation.
    A large(r) enclosure is better for a subwoofer, however when considering the “room” size (space outside the speaker, including up to your ear drum) usually smaller rooms have better bass response with less input. A small subwoofer can sound phenomenal in a small room, and completely dead in a large room. Likewise, I’ve noticed that it’s fairly easy to achieve good bass inside a car, with drivers that wouldn’t do didly-squat in a medium sized living room.
    That said, we’re talking about a space ORDERS OF MAGNITUDE smaller than a typical living room. There’s no space for bass-frequency standing waves to get established in between an in-ear driver and your ear drum.
    I’m not sure what the correct explanation is. Maybe John’s explanation is correct, but it doesn’t seem to jive with what I’ve experienced with normal sized speakers. But in such a small space, conventional wisdom may not apply.
    I always assumed that the improved response with a different silicone earbud cap was mostly due to the better seal it achieved with my ear.

  • Carlo Lo Raso

    Yup, getting the seal is the thing. With earbuds I inevitably have to switch to the larger silicone plugs over the ones that are attached, out of the box, because they are always too small for my monstrous lobes. On another note, a couple of earbud companies have told me that the aftermarket Comply memory foam type plugs, while giving a good seal, may not always net you the best sound quality because the earbuds themselves have not been tuned for their use.

  • John Johnson

    Well, the larger earbuds do have more space, and it’s all relative. A large room that is twice the size of a smaller one works better for a subwoofer, so it seems logical that a larger space in the earbud would promote better bass response. The large earbud has twice the space of the smaller one. Even though the wavelength of a 20 Hz tone is very long, I can easily hear the 20 Hz test tone in a good earbud. It’s the only explanation I can come up with.