KZ AS10 hiss

Discussion in 'Live Sound [BG]' started by il_mix, Mar 16, 2019.

  1. il_mix


    Dec 15, 2017
    Hi, everyone!
    I've just bought these in-ear headphones after reading/viewing several positive review about the good price/quality tradeoff. They arrived yesterday... and I'm quite unhappy with one thing: the background hiss.
    I've tested them with:
    - the PC stereo output
    - an MP3 player
    - Rolls PM351 (that's the device I'll use them with)
    - RME Babyface Pro audio interface
    In all of the tests, I can clearly hear a background hiss (louder or quiter depending on the device used, but clearly audible on all devices) even when the output volumes of these device are at minimum.
    I've read someone else that has this problem, but it looks like they are less annoyed then me.
    Are here anyone that has these in-ear monitors and have experienced the same problem? (or haven't experienced it) Is it possible that I've got some faulty ones? Notice that the noise is on both left and right buds.
    I've read people talking about the fact that these have a really low impedance (around 13 Ohm). I've tested all these devices with Beyerdynamics Byron (18 Ohm) and never experienced any hiss (some stranance noises with the Rolls PM351, but I suppose it is due to the 4 poles jack connector of these headphones)

    When listening to some music the hiss doesn't seems noticeable. But it is still a noise floor that for sure ruin the overall signal. And my main concern is that, when using them on stage when not playing, I'll hear this hiss and start panicking that maybe it is my amp that is noisy or there is some problem on stage or whatever.

    I can still return them (as said, they arrived just yesterday), but damn, I was so confident that I will get some good price in-ear monitors... Returning them means that I'll need to buy more expensive ones.
  2. JKos


    Oct 26, 2010
    Surprise, AZ
    Passive headphones cannot create hiss.

    I'll say it again, passive headphones cannot create hiss. That would basically be like saying that they could hiss while unplugged.

    They can only reproduce hiss created by the source.

    - John
    frnjplayer likes this.
  3. il_mix


    Dec 15, 2017
    I agree. But it happens...
    I understand your point; the problem are not the headphones but the sources. The headphones are too sensitive and amplify the source small noise floor. But to have suche floor noise with an RME interface...
  4. Spectre1966

    Spectre1966 Striving For Mediocrity Supporting Member

    Jul 4, 2014
    Wallingford, CT
    I use the same headphones with a Rolls PM55P and they sound fine. The only hiss I ever get is from a device farther down the line like a pedal.
  5. il_mix


    Dec 15, 2017
    I've tested on the Rolls without anything connected. And the Rolls was powered by a Palmer Power supply.
  6. mrufino1


    Aug 2, 2005
    Nutley, NJ
    You mentioned the 4 pole connector, did you buy a version with a trrs plug and a microphone on the cable? That could be the issue. I don’t know if that model is available with mic but they have other models that are.
  7. il_mix


    Dec 15, 2017
    The 4 poles connector is the Beyerdynamics' one. The KZ have 3 poles (no microphone on the cable).
  8. il_mix


    Dec 15, 2017
    Update on the topic.
    I've brought home a pair of Shure SE425 in-ear for testing. What happened is:
    - on the MP3 player the hiss is really low, but still there
    - on the Rolls the hiss is lower than the one I hear with the KZ, but still quite loud
    Also, I have to say that I can actually hear a really low hiss with the Beyerdynamics Byron earphones too on the MP3 (lower than the one I hear with the Shure). I was also able to test the Beyerdynamics on the Rolls bypassing the noise due to the 4 poles connector; simply touching the screws on the case removed it (I became the mass). Long story short, I can hear the hiss with the Beyerdynamics, too. A little lower than the one I hear with the Shure.
    Now, this "noise scale" (KZ > Shure > Beyerdynamics) is consistent with the relative impedence (14 Ohm for the KZ, 22 Ohm for the Shure, 23 Ohm for the Beyerdynamics).
    The MP3 player is a SANSA Fuze+; not your typical audiophile player, but still a good player. Anyway, the point is that the noise I hear on this player with the Beyerdynamics and Shure is beareable (not the one I hear with the KZ, tho).
    The noise I hear on the Rolls with the Shure is not beareable for playing, IMHO. And the noise with the KZ is even louder.
    The point now become;
    - the KZ are maybe too sensitive and catch too much noise
    - maybe my Rolls has some problems (and that's the worst case scenario. I'm from Italy and bought it from USA; returning it without guarantee that it is really faulty ... will be a nightmare journey, I'm sure...)

    Whats your thoughts?

    Also, on monday I'll take the Rolls with me at work. There I have some labs power supply; using them I will exclude any problem with the power supply. We'll see (hear) what happens...
  9. The AS10's probably are capable of clean, clear high frequency reproduction in a way that your not used to, and are accurately reproducing the hiss inherent in your other gear.

    My experience with Rolls equipment has not been positive and I suspect that with a better quality monitor solution the ear buds would sound fine.
    s0c9 likes this.
  10. il_mix


    Dec 15, 2017
    Back from the lab. Connecting a 1500+ € power supply to the Rolls didn't change the floor noise at all.
    On the bright side, this means that the problem is not my pedal power supply, so I don't need to change it.
    On the other side... man, this sucks...
    I think I'll try to contact the seller. As said it can be quite problematic since I bought it from USA and I'm in Italy. Also, the Rolls works ok with other phones, like Beyerdynamics DT770 (high impedance headphones), so I don't know if they will actually declare it "faulty".
    I think I will probably end up openening the device and see what's inside and how I can improve anything. The schematic is on their site, so it can be quite easy to spot the noise source (oscilloscope at hand). I'll avoid the warranty, but as said it will probably cost me more to return it.
  11. il_mix


    Dec 15, 2017
    Finally, found a solution. I've hacked the Rolls PM351 to work better with these IEM (actually, I've "aligned" it for CCA CA10, but I've also got better performances with AS10).
    Since it's Rolls related, not really KZ AS10 related, I preferred to start a new thread: Rolls PM351 improvement for IEM