[YellowSloth]

Hello people from Head-Fi,
 
Yesterday I finally acquired an Android phone, and was really excited with it. I loved it, until I plugged my headphones in, because then I had the feeling as if I had plugged in my headphones in a budget mp3 player from 2004. The Xperia Miro does everything well, except behaving well towards the ears. But this is not supposed to be a phone review thread, so I'll move on to the problem.
 
I don't know how to exactly describe it, so I have been unsuccessful in finding a solution on Google. When I plug in my headphones I hear a sort of squeaking and beeping in the background, all the time. My previous iPod Touch had it too, but really soft and only audible between tracks in the night when there was absolutely no other sound around me, so I usually didn't even notice it. With this cell phone though, it's really loud and audible when playing music even on almost the maximum volume! Like there is some bad techno music mixed through what I'm listening to. I'm no expert on hardware, but I think it has something to do with the device not having a dedicated audio chip, so there is a lot of noise from the system, but I cannot say for sure.
 
Therefore I thought of something, since I'm not completely a stranger to the audio world, and that was an USB DAC. I read here and there some people are using one with their devices, but I cannot seem to read clear answers to my questions. I'm looking for a DAC on a SSB. (Starving Student Budget) I do not need the highest quality, but just something a human can listen to without getting frustrated by the bad sound. It has to work on Android, and preferably on the Xperia Miro. I read that, par example, people use the UD100 with the Galaxy SIII, but I don't see any other Android phone with the same device, which makes me worry that it won't work on other models. I also noticed the HifiMeDiy Sabre, but I cannot find any information at all about it working on Android.
 
I would like to apologize for the large amount of text. Many thanks in advance!
 
TL;DR:
 
I'm looking for an USB DAC which works on Android (Xperia Miro), with a budget of about $50. (Ex shipping)

 

[DanBa]

As far as I know, the standard USB audio feature is not enabled on any Xperia yet.
 
As the USB audio driver for Linux ALSA is already included in the source of the Linux Android kernel, you should request Sony to enable the standard USB audio on your Xperia.
https://bitbucket.org/paulobrien/android_kernel_galaxynexus/src/bc4f9b72a51d/sound/usb/card.c#cl-2
 
A lot of people are lobbying for imposing USB DAC as a standard Android USB device, like a standard USB device for every Mac or PC (i.e. we don’t have to request each individual PC manufacturer to add the USB audio capability).
http://code.google.com/p/android/issues/detail?id=24614&sort=-stars&colspec=ID%20Type%20Status%20Owner%20Summary%20Stars

 

[YellowSloth]

Quote:

As far as I know, the standard USB audio feature is not enabled on any Xperia yet.
 
As the USB audio driver for Linux ALSA is already included in the source of the Linux Android kernel, you should request Sony to enable the standard USB audio on your Xperia.
https://bitbucket.org/paulobrien/android_kernel_galaxynexus/src/bc4f9b72a51d/sound/usb/card.c#cl-2
 
A lot of people are lobbying for imposing USB DAC as a standard Android USB device, like a standard USB device for every Mac or PC (i.e. we don’t have to request each individual PC manufacturer to add the USB audio capability).
http://code.google.com/p/android/issues/detail?id=24614&sort=-stars&colspec=ID%20Type%20Status%20Owner%20Summary%20Stars

Thanks, I voted (starred?) the Google page, added my comment there, and emailed Sony to see if they can do anything for me. I won't be giving up the emailing Sony until I've at least have a reply from a developer.
 
I also rooted my device, isn't it possible to "inject" a driver into the system or something like that?

 

[DanBa]

Yes, vote = click on the star (it appears after signing in).
 
 
You should ask some Android kernel developer to follow the instructions of Tsynik, who has successfully enabled the standard USB audio feature on Android-powered Ainol Novo tablet.
http://www.slatedroid.com/topic/29289-usb-audio-cards-support-drivers-and-libs/page__p__324675#entry324675
 
"We just need 3 base things:
1st: USB Host support in Android kernel.
2nd. USB audio driver, in kernel, or compiled as a module.
3rd. Some logic to switch to USB audio card, or back to internal one." 
 
 

 

[jgray91]

Alternatively, it's probably the format/mastering of your music files that's at fault. Your problem seems like low bitrate mp3 problems to me.

 

[YellowSloth]

Quote:

Alternatively, it's probably the format/mastering of your music files that's at fault. Your problem seems like low bitrate mp3 problems to me.

The "sounds" I hear, as described in the OP, are also there when the music is paused/stopped. The music itself were FLAC files converted to q1.00 VBR AAC for this cell phone. Another user with the same phone already described the same problem. I'm sure this is hardware related, as in low quality components inside the cell phone.
 
EDIT:
 
Just a question, would using an AMP improve the quality, or also amplify the noises too?

 

[jgray91]

Ahh, I missed that. Apologies. WRT the amp question, IME yes it will amplify the noises too if it's straight from the headphone out into the amp, although it's better to wait for someone with more experience than me on this matter. I think it's a given that the quality of the DAC/implementation of the DAC for a relatively budget smartphone is, at best, mediocre.

 

[YellowSloth]

 
I happened to have a song in my library which has a couple minutes of no sound at all, so I thought to use that for a quick test. I do not have superb audio equipment for recording, so when I tried to record the noise and played it back again, it was barely noticeable, but with headphones and the volume turned up high it was still there. In a spectogram it was more visible. (I recorded it with a minijack-minijack cable from the cell phone to the line-in from my netbook, and I think that's why there is something missing.) I exported the WAV file to Windows, and there opened it with Adobe Audition, then took a screenshot of that screen.
 
First I started the record in Audacity, the first part, then I pressed play and the song started with a hum and then went full out. (Notice how there is a line somewhat under the middle in the upper channel already.) In the picture I also showed when I pressed pause where the music stopped. There are some lines which are not from the music still going on for a while, and then disappear. I think that is the time-out for powering the minijack. (After there is no sound playing, Android lets go off the power for the minijack, or so I think.)
 
Then I placed another | in the image where I started to play again, this time the song with the silence at the end. At the "Start Silence", the silence in the song started. Since the application is still playing, the time-out won't happen and the minijack will keep being powered. I think the lines you see there (which I marked with arrows) are the noises I hear from the phone when playing music.
 
I am no expert, and hope I am not making a fool of myself this way. What do you think?

 

[jgray91]

I have no idea, since I'm not familiar at all with the science part of music. Sorry

 

[YellowSloth]

I managed to make a recording in which the noise in audible from a recording. I got the a free MP3 audio book from The Call of Cthulhu and played it at the lowest audible level. Then I recorded it from minijack out on the cell phone to line-in on my netbook. I made the recording level high in the settings, and recorded with Audacity. Here is the file:
 
http://puu.sh/17WVz
 
You can hear the audio book playing just under the noise. I can understand that it might perhaps be unfair to play at the lowest level and record on a high level, but this noise is always audible, playing any song, even at higher volumes. Is is something to notify Sony for?

 

[mechgamer123]

I'm not completely sure, but if you can find an android 4.1 ROM and kernel for your device, it should have USB audio enabled. But I don't have the same phone as you to test...
What headphones are you using? 
Also, have you tried putting the phone in airplane mode when you're listening to music? 

 

[bowei006]

It depends on your phone. The Android device you have MUST have USB OTG(ON the Go) support. AND it must also be able to use cyanogen or anyother software that will take advantage of USB OTG.
 
If your phone does not have USB OTG which supports digital out, then it can not be used with a DAC. 
 
If you clear the conditions above, get everything setup, USB OTG and with software on the phone to support and use it then you need a DAC. A portable one. Portable devices like a phone or tablet with this WILL limit the amount of power USB device can draw at a time. For example, the E17 will not work with most devices. However the E7 will work. The E17 draws OVER 150ma while the E7 at around 70Ma. Most phones or devices have restrictions between 50ma to 150ma depending on device. The iPad has a restriction of 100Ma . 
 
To rectify that FOR home portable use, some use a powered USB hub to offset some of that power and then plug into their device, this generally works. Howver it's not too viable for outdoors use.
 
Like Mechy also said, you sure it's not EMI? i-Devices have decent EMI protection

 

[YellowSloth]

Quote:

I'm not completely sure, but if you can find an android 4.1 ROM and kernel for your device, it should have USB audio enabled. But I don't have the same phone as you to test...
What headphones are you using? 
Also, have you tried putting the phone in airplane mode when you're listening to music? 

I tried using two types of earbuds, one Monoprice and one Sony, and with my "main" headphones the Technics RP DH-1200. With all the noise is noticeable, and switching to airplane mode doesn't change it in the slightest. 

 

[Joe Bloggs]

I would just return the phone citing a broken headphone out...

 

[YellowSloth]

The device is going to RMA today, and I'll see what happens. I talked to another owner of the device, and he said there was nothing wrong (to his ears) so this might be bad shielding or something like that. I don't know why it happens precisely, I never had this issue before.