The RMAA (RightMark Audio Analyzer) Source and Audio Device Measurement Thread [Overview of Measurements in Post #3, Tutorial in Post #2]

Discussion in 'Sound Science' started by hifichris, Mar 1, 2016.
  1. macky112

    I read through this thread twice trying to figure out how each graph relate to sound and music. But I am still very confused. Is there a guide I can look over? For example, if unloaded is flat but loaded is like a rollercoaster then is it going to sound bad for all headphones?

    I was very curious about the Zishan because of its spec and features, but after looking over its charts on this thread, I am not sure if it's going to sound good
     
  2. castleofargh Contributor
    if unloaded is flat but loaded isn't with some IEMs, then the information you have is that different IEMs/headphones may alter at least the signature(added to the obvious fact that IEMs and headphones aren't flat ^_^). it will usually be a matter of impedance ratio over frequencies and you need to have a look at the impedance graph of your IEM to make an educated guess as to what may happen if plugged into the device.
     
    depending on the load and the result you can also diagnose for other potential problems, but all in all it's still only frequency response into a few different situations, more measurements may reveal a lot more.
     
  3. macky112

    @ruben123 brought up a good point in another thread

    So basically I am hearing what he is hearing, which is the Ruizu X02 has a noticeable amount of bass roll off comparing to my x3ii and m20, however, the rmaa chart is not showing what i hear. Did I do something wrong during my setup or measurement?
     
  4. castleofargh Contributor
    well you're not listening to it unloaded are you? [​IMG]
    this all topic is basically to show that depending on what IEM you plug, the resulting signature can change from unloaded measurements because of impedance variations or capacitors at the output or something really wrong in a device. 
     
    macky112 likes this.
  5. h1f1add1cted
    M-Audio Micro DAC 24/192
     
    Spectrum1-no-ifi.png
     
    Very good 100 buck DAC/AMP combo with very low output impedance. I measured with multimeter ~ 0,6 ohms output impedance, which is just right if you see the RMAA result with my very senstive 12 driver CIEM. Only a bit much hiss, but still a great little DAC/AMP combo.
     
    hakuzen likes this.
  6. macky112
    ah, thank you for the clarification!
     
  7. Samueru Sama
     
    Can you measure its max output power into the 32 Ohm load? Just set up everything as if you were going to run a RMAA test with the load in parallel, generate a 0dB 1 KHz tone in audacity, hit record only in RMAA (and don't go any further, you can use the RMAA's calibration to determine if the device is clipping), and play the 1 KHz tone. increase the volume with the load in parallel until you see clipping and check the voltage which the device starts clipping or until you hit 0dBFS.
     
    Obviously you have to make sure that you're not clipping your line in, your FiiO X7 AM1 max outputs 1.8 Vrms without load, you can use it to make sure that your line input doesn't clip up to 1.8 Vrms.
     
  8. h1f1add1cted
    Sorry but I have no glue from what do you talk here. How do you think I own a FiiO X7 and why you talk about this gear which I have never mentioned in my posting above o.O
     
     
    I have already measured the outputpower of the M-Audio Micro DAC 24/192 with my multimeter which is 2,001 V @ no load and 1,964 V @ 33 ohms load.
     
    Samueru Sama likes this.
  9. music4mhell
    How many hours did you burn-in your Walnut before taking this test ? Please share !
     
  10. hakuzen
    maybe 1 hour? :p
    but don't worry: output impedance is not going to change after 3000 hours burn-in. and unloaded and loaded frequency responses aren't going to change either (i can test it again after 400 hours, if you feel better with this)
     
  11. Samueru Sama

    Thanks a lot. I know you have (or had) a FiiO X7, because I checked your profile (you have a review of it). xD
     
    ~2 Vrms 33 Ohm, very nice, that's even more than what the dragonfly red can output at that load (it clips @1 Vrms with 32 Ohm load).
     
    https://www.seeko.co.kr/zboard4/zboard.php?id=m_device&page=1&sn1=&divpage=1&sn=off&ss=on&sc=off&select_arrange=headnum&desc=asc&no=69
     
    Hopefully you checked that M-audio wasn't clipping (you can't do that with just the multimeter alone).
     
  12. bartzky
    You're not hearing wrong. Here are my results with a RME ADI-2 Pro:

    screencapture-file-E-Desktop-RMAA-Adobe-20Audition-Ruizu-20X02-RME-24-20Bit-Comparison-htm-1485960319991.png

    The RME ADI-2 Pro's ADC is absolutely solid, so you can trust noise, THD and so on measurements as well. Btw: The X02's output impedance is 2.54 ohm, and it puts out 7.96 mW into 30 ohm.
     
  13. HiFiChris Contributor
     
    How does the ADI-2 Pro perform with super sensitive low impedance multi-driver in-ears in terms of hissing and output impedance?
     
  14. bartzky
    It's a beast. No hissing and an output impedance only slightly above 0 ohm.
     

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