Smartphones and tablets are the best music players ever in many ways, but their sound quality can leave a bit to be desired. They simply weren’t built from the ground up solely for the playing of music.

Sub-par headphones or speakers, signal noise from compact designs, and other factors can disturb the smooth flow of music from ones and zeros to your headphones. With a little experimentation, you can often make specific headphones, speakers, or specific aural situations sound better by applying equalization, surround sound simulation, and other digital signal processing (DSP) to the music on your smartphone, using the following apps and hardware. We focused on the iPhone this time around, although similar apps exist for Android.

Hardware first

The standard earbuds that come with listening devices generally cannot reproduce bass well, lack definition at other frequencies, and let in outside noise, which not only makes your music sound worse, but requires you to listen to it louder than would otherwise be necessary.

Upgrading headphones improves matters significantly (to over-the-ear or sound-isolating headphones), because in any audio chain, the speaker or headphones are the biggest factor in sound quality. You can also augment the pint-sized power of the internal headphone amp with an external headphone amp, but only truly dedicated audiophiles would want to carry one of those.

5 Sound-Processing iPhone Apps + 2 Bonus Ideas

As with many things, when it comes to sound quality, there’s an app for that — several, in fact, listed here alphabetically. Most include some EQ functions for shaping songs based on what your ears like to hear (or for fighting imperfect hardware), and a few go beyond that:

Simple 10 Band EQ App Can Improve iPhone’s Sound for a Dollar

Elephant Candy’s EQu Unites Form, Function to Alter iPhone’s Sound

Fabio Policarpo Player+ Adds Crossfades, EQ to iPhone

Honorable mention: SRS Labs Improves Music Apps’ Sound at the Hardware Level

Bonus round: Get Better Sound from YouTube