RMAA of Android Tablets

2014-05-29 20:32:22

Original thread: HERE

Asus TF201 (eee pad)

Inter-modulation distortion 44.1k 16bit
[attachment=7915:imd.png]

[attachment=7916:imdswept.png]

RMAA of Android Tablets

Reply #1 – 2014-05-29 20:38:17

Nexus 7 (2012) (100+ ohms, I forget), loaded with Denon AH-D2000 headphones (25Ω) and Shure SE425 IEMs (22Ω).

RMAA of Android Tablets

Reply #2 – 2014-05-29 21:37:41

Those look absolutely wonderful compared to this asus tablet skamp

This one of noise was particularly troubling. It was so bad that I was convinced I was doing something wrong in the software or playback and so repeated and double checked everything many times. Amazingly there were no procedural errors found and this was the actual input received by the line in (configuration was tablet playing RMAA test waveform, head phones out to PC sound card line in). Soundcard line-in is not perfect, but good to -100dB so plenty good enough for this test.

Eventually I realized that the phones output on this tablet must be unstable (or only marginally stable) into a high impedance load and added a set of headphone in parallel. At least that damped the noise down to an ok level, but you certainly wouldn't want to use this as a line out source to drive a amplifier input. Overall I was very surprised at just how bad the sound hardware is on this thing for what was originally a relatively expensive tablet.

[attachment=7917:noise.png]

RMAA of Android Tablets

Reply #3 – 2014-05-29 21:47:34

For comparison here are the results from a very cheap supermarket brand (aldi) tablet that I also tested. Nothing spectacular, but very much better than the Asus.
Freq response
[attachment=7920:fr.png]


Noise
[attachment=7922:ns.png]


Dynamic range
[attachment=7919:dr.png]


THD
[attachment=7923:thd.png]


IMD
[attachment=7921:imd.png]

RMAA of Android Tablets

Reply #4 – 2014-05-30 05:30:42

Lumia 520 and HTC One SV, recorded by X-Fi Titanium HD
[attachment=7924:LumiaHTC.7z]