Ranked: The 4 Best Phones for Music Lovers — Under $400

One of the most popular usages of modern-day smartphones is listening to music. It doesn't matter if you download or stream your tunes, you are part of a massive group of users who do exactly the same. While statistics are a bit foggy on how many smartphones users download music, we do know that over 68% of American smartphone owners stream music on a daily basis.

According to a study by Park Associates, most of this streaming is done by T-Mobile and Sprint customers (over 70% of subscribers for both providers participate in this day-to-day activity). In fact, streaming music is an activity done by more users for a longer period of time than most other audio-related tasks like video streaming (which is only about 40% of smartphone owners, in case you were wondering).

If listening to music is something you spend most of your day doing, then you'll probably want a phone capable of outputting eargasm-level audio quality. Hardware and software work in tandem to produce superior sound, which is exactly what we were looking for during the selection process for the phones in this list. Our test results are available for viewing in the chart below, with a breakdown of each phone underneath it.

To make this list, all phones had to be one generation old or newer, and they needed to cost less than $400, so their hardware and audio quality isn't necessarily top-of-the-line. But if you do have money burning a hole in your pocket, check out the link below for the top-shelf smartphones capable of outputting unbelievable audio quality. Otherwise, let's continue onto how the comparison points in this chart helped us find the top four sub-$400 phones for listening to music.

Key Comparison Points

• Headphone Jack Location: Depending on factors like the headphones you use and how you place your phone in your pocket, the 3.5 mm jack may or may not sit nicely when plugged into your phone. There is no clear-cut winner in this section since everyone has their own opinion on the best headphone jack placement, so this data is meant to be informative more than anything.
• Headphone Amplifier: Once the DAC (see below) converts the audio into an analog signal, it's amplified before being sent to your headphones. With a more powerful amplifier, louder output volume can be pushed to your headphones, so you want higher numbers in both fields here. The wattage numbers listed here were sourced from the manufacturer's spec sheets for each phone, but we did our own tests to determine the voltage.
• Expandable Storage: Expandable storage is extremely useful when it comes to downloading higher quality music for offline listening. For folks who maintain their own music library, the extra potential space afforded by expandable storage can allow you to save your entire MP3 library on your phone.
• DAC: A digital-to-analog converter, or DAC, converts the phone's digital audio into an analog signal before sending it to the headphone amp. A 32-bit DAC is better than a 16-bit DAC because it allows for higher bit rates. However, a more powerful DAC can lead to additional battery drain while playing music.
• Hi-Fi Playback Capability: Hi-Fi playback is tied in with the phone's DAC, so what we want is high numbers for both bits and frequency. The lowest quality accepted as Hi-Fi is 16-bit, 44 kHz — also known as CD Quality.
• Supported Audio File Formats: These are the different types of audio files that each phone natively supports. Third-party music players can use additional software to bring support for more formats, but native processing is preferred, as it means there's one less layer between you and your music.
• Stock Equalizer/Quality: We made sure that every phone in this list offered a system-wide audio equalizer so that you'll be able to fine-tune your music's overall sound. Some of these equalizers have more features than others, so keep an eye out for more information on that front below.
• Overall Audio Accessibility: How easy is it to make use of these phones' awesome audio hardware? Ultimately, the software on a phone will determine exactly how the hardware is used, and depending on the device, this can be relatively simple or slightly complex. Considerations that impacted this rating were how easy or hard it was to toggle the DAC and amp on or off, enable features like HTC's BoomSound or Dolby Atmos, and access equalizer presets.
• Background Audio Processor: Think of this as a hardware equalizer, working silently to modify the audio signal before it gets processed by your music app and/or the software equalizer. The background audio processor is fine-tuned by the OEM to the most suitable settings for the device's hardware.
• Maximum Decibel Output: This is simply a measure of how loud the signal sent through the 3.5 mm headphone jack is, listed in decibels (dB). We gathered these numbers ourselves; to see how, check the methodology section below.
• Signal-to-Noise Ratio: The level of the desired signal compared to the level of background noise. In other words, the level of music versus the amount of hiss you might hear. The higher the ratio, the less obtrusive the background noise is, and the more enjoyable your music will be. While the word "ratio" may throw you off, this is measured in decibels, so higher numbers are better.
• Stereo Crosstalk: This represents any bleeding that might occur between the two audio channels of the device (left and right). The lower this value is, the less interference there will be between the two channels. To check this yourself, listen to a song and see if you notice the stereo effect. If not, it's probably because there's a lot of crosstalk, which causes the two channels to seemingly condense into mono sound.
• 3.5 mm Jack Voltage: A measurement of how hot the signal being pushed through the 3.5 mm jack is, which is closely tied to the device's maximum decibel output. The higher the voltage, the louder the music, so we're going with bigger is better here as well.
• Frequency Response: This is a measurement of how accurately the amplifier is able to reproduce the audio after converting it. What we want is to be closer to zero in this case, which would represent a perfect replication of sound output across the frequency range of human hearing. But, of course, no audio equipment is absolutely perfect in this regard, so each of these devices fell in a range between two-decibel values when we tested them (a positive and a negative number). The numbers listed here are the highest deviation from zero after multiple tests on the devices. In other words, the closer these numbers are to zero, the better the frequency response of the device.

Testing Methodology & Analysis

In addition to simply taking time to listen to the music output from each of these phones, we also had to get some precise numbers to see how they stacked up against one another. To do that, we hooked the phones up to FuzzMeasure on an iMac Pro by running them through a Focusrite Scarlett 18i20. The Focusrite Scarlett is capable of processing and breaking down the highest quality audio playback from all smartphones, and FuzzMeasure gave us readings on these measurements.

With all of the phones in the chart capable of Hi-Fi playback, we loaded them up with our favorite variety of high-quality FLAC files, then used the stock music apps to see how each phone performed. To ensure that the test would be as fair as possible for all phones, we used 24-bit, 44 kHz files.

High-quality audio should have a high signal-to-noise ratio, low stereo crosstalk interference, and an accurate frequency response, so these measurements made it into our chart. There are a few other things that can be looked for, such as dynamic range, harmonic distortion, and intermodulation distortion, but we didn't include these results, as they aren't exactly noticeable to the human ear when listening to certain genres of music.

The starting price was sourced from the OEM and Amazon, with each phone showing the cost of the unlocked variants of these devices. The DAC, amp, and background processing data was either found on the manufacturer's website or dug out from the background running processes. As for the voltage check, we rigged up an oscilloscope to a voltmeter, then used an auxiliary cable to get a reading while having the stock players play a song for us with the volume cranked up to the max.

How We Picked These Phones

To make sure our list was as future-proof as possible, we only considered phones that were available for sale in the US and no more than one generation old.

They also needed to have a dedicated DAC, a 3.5 mm headphone jack, and a built-in equalizer. Another requirement was that they were capable of storing at least 100 GB of music, either as a base storage option or via an expandable SD card slot.

But the biggest requirement was, of course, money. All phones in this list can be had for less than $400, so you won't have to pay top dollar to get a great audio experience. So without any further ado, here are the four best phones for listening to music without breaking the bank.

1: ZTE Axon 7

The ZTE Axon 7 is a midrange phone, but it packs more high-end audio hardware than the rest of the phones on our list. There haven't been any figures released on how well the phone is selling, but the general sentiment amongst developers and music lovers seems to be extremely positive. This is mostly due to the Axon 7 packing a 32-bit dedicated DAC, as well as an extremely loud headphone amp.

The Axon 7 pushes out an extremely hot signal of 84 dB, which is almost as loud as a lawnmower, but this is only if the Headset HiFi option has been set to "Super." Set it to "Standard" and you get a 64 dB signal pushed to your headphones. Either way, it's by far the loudest phone we were able to find under the set requirements, but the ZTE Axon 7 Mini does get pretty close (more on that below).

The audio quality is quite full when listening through a pair of headphones, but is missing that crisp and fresh feeling. Most notably, it has a dedicated DAC and amp combo, as well as a Dolby Atmos background audio processing, which are all used in conjunction with one another to output loud and deep Hi-Fi audio.

To expand on that last point, the ZTE Axon 7 is capable of playing Hi-Fi files up to 32-bit at 192 kHz. This puts it in a completely different ballpark than the HTC 10 or the iPhone SE, but it comes with a severe restriction: Hi-Fi audio files can only be played through ZTE's stock music player.

To make matters worse, the stock ZTE player is extremely limited in terms of functionality — it is literally capable of little more than playing and pausing your audio files. Couple this with a fairly powerful but limited stock equalizer (Dolby Atmos) that includes four presets, and it makes the Axon 7's overall audio accessibility rather restrictive.

Other notable testing results included a high signal-to-noise ratio and a 1.8-volt headphone jack output, which both ranked first. Though the ZTE Axon 7 Mini got pretty close in maximum decibel output, and that's a phone that costs about half as much and has a much lower headphone jack voltage output.

When listening to music on the Axon 7, there seemed to be noticeable stereo crosstalk, though nowhere near as much as on the iPhone SE. You can't exactly max out the volume since it'll get uncomfortably loud, but when you listen at a lower level, the crosstalk becomes more noticeable, so it's hard to find the perfect volume level. However, the ZTE Axon 7 still outputs an audio quality far superior to that of the iPhone SE — just avoid the first and last three volume steps.

2: HTC 10

The HTC 10 was released back in May 2016 and is HTC's fifth audio-oriented flagship. The first audio-oriented phone released by HTC was the HTC One X back in 2013, so sound quality has been something we can usually count on from the Taiwanese phone maker for a while now. While HTC hasn't released any concrete sales figures on the HTC 10, we do know that they had a 42% revenue increase in September 2016 and a 31% year-on-year rise to a 15-month high of $297 million.

From Beats to BoomSound, HTC has always been known for its headphone audio quality, and the HTC 10 doesn't waver from that tradition. BoomSound was introduced as the replacement of Beats Audio once HTC's partnership with Beats by Dre came to an end. BoomSound is a background audio processor, best described as an audio profile which enhances the three main components of your music for an exceptional playback sound: Crystal-clear highs, smooth vocals, and deep bass. You might not have too much control over it, but it will do its job if turned on.

In addition to BoomSound, the HTC 10 comes with a secondary background audio processor called Dolby Atmos, and the two work in tandem to make sure you get the best audio quality possible. Dolby Atmos also serves as a profile that tailors itself to your listening preferences after making you sit through a sort of pop quiz. This setting can easily be turned on and off, and it works with more than just the stock music player. In general, using the HTC 10 is very simple, there aren't a lot of options to get confused with, and it still delivers amazing audio quality.

My biggest gripe with the HTC 10 is its stock music player — the incredibly basic Google Play Music, which we can't even uninstall. Google Play Music is your only choice if you want to listen to locally-stored music files using HTC's proprietary BoomSound processing, as every third-party player is forced to use generic software instead. However, if you stream music, then everything works perfectly, so it's not a complete deal-breaker.

In our testing, the HTC 10 yielded some impressive stats. It had the lowest stereo crosstalk and the best frequency response of any phone on this list, and its headphone jack voltage ranked second. Decibel output and signal-to-noise ratio were about average, so overall, it's a great bang for your buck now that prices have dropped in the wake of HTC's brand new flagship, the U11.

3: ZTE Axon 7 Mini

Released in September of 2016, the ZTE Axon 7 Mini can be described in one word: budget. If affordability and music quality are your top two priorities, this is the phone to get, because it doesn't get cheaper or better than this. The ZTE Axon 7 Mini might be a smaller variant of the ZTE Axon 7, but the audio output and quality aren't exactly second to the ZTE Axon 7 (or the HTC 10, for that matter).

The ZTE Axon 7 Mini does not have a headphone amplifier, but it's almost as loud as its bigger brother. Capable of pushing out 79 dB, the Axon 7 Mini sounds pretty nice. It's about as loud as a running shower and feels as though pure power is being pushed out because the bass is pretty heavy, but it's not so overwhelming that the treble and mids get lost.

Since the Axon 7 Mini was released after the Axon 7, it comes with an upgraded DAC, which fixes some of the things we didn't like on the Axon 7. The Mini has a slightly better frequency response while retaining an above average signal-to-noise ratio. The stereo crosstalk, on the other hand, seems to have gotten just a tad worse, but only on the first three to four volume levels. There's absolutely no audible hissing or static once the Axon 7 Mini has been cranked up.

Like its bigger brother, the Axon 7 Mini ranked poorly in the audio accessibility category. This is mainly due to the fact that Hi-Fi audio files can only be played at their full quality if you use the stock music player. We wouldn't count this as much of a knock, except the stock player is incredibly basic with limited controls, so it gets frustrating quickly.

But sharing software with the Axon 7 means the Mini also comes with Dolby Atmos as the stock equalizer. Dolby Atmos comes with a few dope presets, including my favorites, Deep and Rich. The equalizer and Dolby Audio background processor work with third-party apps as well, which makes for an overall sweet listening experience, especially if you like rap and hip-hop.

4: iPhone SE

Last but not least, the iPhone SE comes in pretty close to most of the other devices on our list. The SE was released in March 2016 and targeted at people who wanted a smaller iPhone without sacrificing hardware advancements. The SE comes with two undisclosed Cirrus Logic chips, which makes the phone pretty loud. Overall, it has almost the same exact audio hardware as the more expensive iPhone 6s.

The iPhone SE is a solid choice overall, but bass is practically non-existent on Apple's lone midrange phone. This is fine if you're allergic to bass (like a couple of my family members), but it's something the average listener could struggle with. This is slightly offset by the fact that the iPhone SE has an equalizer which works very well with Apple Music, however, it's not compatible with third-party apps.

The SE's frequency response didn't test to be all that, causing the device to lack that dynamic feeling, part of why the bass is close to non-existent. While the audio sounds crisp and precise, it fails to portray the mids all that well. This might have something to do with its low signal-to-noise ratio, but on the bright side, the SE does have pretty solid stereo crosstalk numbers.

The biggest downside with the iPhone SE is the fact that it does not include expandable storage. This is typical of Apple devices, as no iPhone has had an SD card slot to date. However, if you prefer to stream your music, this shouldn't be a factor. Plus, a 128-gigabyte model is available if you need that extra space.

With solid decibel output, the iPhone SE proves that not all phones need a headphone amp to be capable of pushing out sound — I could hear music bleeding from multiple different sets of headphones. And despite the muddled bass and mids, Apple really should be given a big thumbs up for the quality of treble and higher notes.

Conclusion

Even though these devices ranked closely in our testing, each one stood out in its own way. The Axon 7 for being ridiculously loud, the HTC 10 for its two background audio processors, the Axon 7 Mini for holding its ground at half the cost, and the iPhone SE for having the most prominent treble I have ever heard in my life.

My personal favorite was the HTC 10, though this was mainly because I love its physical design. From a pure audio perspective, though, the Axon 7 eked out the win, thanks in large part to its measurables.

Which of these phones would you go with? Do you have any recommendations for cheaper phones that would be an audiophile's dream? Make sure to share your thoughts with us in the comment section below.

• Follow Gadget Hacks on Facebook, Twitter, Google+, YouTube, and Instagram
• Follow WonderHowTo on Facebook, Twitter, Pinterest, and Google+