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Audiofly AF-33 In-Ear Headphones Review

technologyEdward KiledjianComment

Who is Audiofly?

The website says Audiofly is an Australian company that is comprised of musicians trying to deliver the best possible headphones to consumers. 

The headphones

Audiofly sent me a pair of AF-33 (AF33) headphones for testing and review. As always, I only commit to testing and writing the review. My reviews are always honest and impartial. 

The testing process

I consider myself an audiophile and own over a dozen in ear monitor (IEM) style headphones and a handful of over the ear large headphones. For this test, I decided to compare the AF-33 to the following headphones:

For the audio source, I use:

  • iphone 4s
  • Nexus 7
  • Cowon iAudio 7

Audio Formats

  • I used MP3 music in formats of (kbit/s) 128, 192, 320
  • on the iPhone I tested with ALAC (Apple Lossless Codec)
  • on the cowon I tested in FLAC

Audio Tracks

Before I even test with actual music, I first test the headphones with special sound files built for:

  • Test track #1 - test for frequency response
  • Test track #2 - dynamic range testing
  • Test track #3 - deep bass test
  • Test track #4,5,6,7 - testing wiring for left and right sound + center and twisted

I then use high quality 3d holographic audio tracks from NatureSpace to test the 3d generation qualities of the headphones. For this test, I used Ice Wind, Infinite Shore, Night at lake unknown.

Last but not least, I use different songs to "see" how music is reproduced. For this test, I used:

  • Dark Side of the Moon
  • J.S. Bach - Partita No.2 in D minor BWV 1004
  • Toto - Africa
  • Yeke Yeke - Mori Kante
  • K'naan - Wavin Flag
  • Shakira - Waka Waka

None of these headphones require a headphone amp so none were used.

As recommended in the manual, I first used a burn-in process to "prepare" the headphones. For this test, I used an app called Burn in tools to prep the headphones. I ran 120 minute cycles and let the headphones rest 60 minutes in between cycles. I completed 40 hours of burn-in.

The results

I was surprised at the sound quality these sub $35 headphones produced. Overall, they are decent producing average but clean sound. The Triple-Fi are my go to reference when comparing in-ear-monitors because they offer a clean neutral canvas. 

The AF-33 performed very well on all my first round test tracks. The center and twister tracks were the ones where I found the headphone lacking. In the center test, the 3D sound should "feel like" it is coming from the center of my head wereas it pulled noticeably more to the left hand side.

The twisted 3D track should take the sound from he left side, to the center then to the right and back. When I say left or right, I am not talking about the sound coming from one earphone or the other but rather it should feel like the sound is moving fluidly in 3d space around me. This too showed the weakness of the headphone and it was unable to reproduce this tough 3D effect with any level of credibility.

Lows : These are not bass heavy headphones (which I like). They have clean low reproduction with very little distortion. The lows were cleanly separated from the mid and high tones. I found the low reproduction average and was wanting just a little more oumph...

Mids: The mids are clean too with very little bleed from the lows. I did find that the low and highs overwhelmed the mids a little but the mids were still clear. I found the mids relatively thin and sometimes a little "canny"

Highs:  I was surprised at the quality of the highs. They were fairly clean, well separated from the other tones with good detail. As I expected (and similar to other headphones in this range) the highs were a little too bright and a little too loud compared to the mids and lows.

As described earlier in the test section, the headphones failed the center and twist tests which are basic 3D sound reproduction tests (most headphones in this price range fail these tests). It is no surprise therefore that the headphones were not able to properly reproduce the 3d holographic sounds from the NatureSpace recordings. As I sit there and close my eyes, the location of the various 3D sounds wasn't clear and this is due to the limited soundstage provided by these headphones. Instrument imaging is good with clean separation but within a limited soundstage. 

After all my testing, the sound quality is average with a slightly unateral tone and very tin like feeling.

Using 128 or higher quality tracks yielded the same reproduction (FLAC, ALAC, 192 or 320 music didn't provide additional reproduction benefits beyond the base 128 kbits track.)

Build Quality

The build quality is nothing to write home about and they compare to the other competitors in this price range. For the price, I find the Zagg Smartbuds much more solid. 
The audio cable is thin. The earbud plastic casing feels light and cheap.
Overall I would say the build quality is average for this category of headphone.


So what's my verdict? These are better than any stock headphones provided with any device. They were also better than the skullcandy headphones and slightly better than the Monoprice ones but nothing to write home about. If you are looking for a "not too expensive" set of headphones that will deliver "good enough" sound then this is a good buy. If your expectations are higher, you will likely be disapointed. This is certainly not for the audiophile. 
The provided medium headphone tip fit nicely and held the headphone fairly well. Because of the type of type, the shape of the tip, the material and the way it is only slightly in the ear canal, it doesn't provide any important level of noise isolation.