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What is the point of the USB audio out feature for smartphones?

post #1 of 5
Thread Starter 

My understanding is that USB audio allows you to pass your music data to an external portable DAC.

 

But why do I want to do that if my DAC can already store songs? Shouldn't I just store my songs in my portable DAC and play from there and ignore my smartphone?

 

Disclaimer: I am completely new to portable DAC. I've never tried to set up USB audio out. So please bear with me if what I said is a bit off from the reality.

post #2 of 5

Sometimes phones can have a very bad sounding DAC. All DAC's are not made equal. Having a phone that has USB OTG enabled in the kernel and allows for USB audio will help when a lower quality DAC is present in the phone. 

post #3 of 5

It's not only a matter of the quality of the internal DAC, but also the implementation at the software level and other factors like power supply, interference from other internals etc. There is usually a degree of compromise inherent in convergence devices like mobile phones, so things typically aren't that well optimised for sound. An external USB DAC takes all of that away from the phone, and will typically give you better sound quality. Most USB DACs are also combined with an amp section too, which also helps since it circumvents the (usually) too-low volume output in mobile phones for those who are not listening via sensitive IEMs.

 

If you're happy with having a standalone DAC and it does what you need, then there is no particular need to use USB audio from your smartphone. For those of us who prefer to use our smartphones as our primary portable music players, the option to have higher sound quality is welcome.

 

Also, just a point of clarification - I think in most of the instances where you are using the acronym DAC (which means digital to analog converter) you actually mean to say DAP (digital audio player).


Edited by NZtechfreak - 1/15/13 at 7:58pm
post #4 of 5
Thread Starter 
Quote:
Originally Posted by NZtechfreak View Post

It's not only a matter of the quality of the internal DAC, but also the implementation at the software level and other factors like power supply, interference from other internals etc. There is usually a degree of compromise inherent in convergence devices like mobile phones, so things typically aren't that well optimised for sound. An external USB DAC takes all of that away from the phone, and will typically give you better sound quality. Most USB DACs are also combined with an amp section too, which also helps since it circumvents the (usually) too-low volume output in mobile phones for those who are not listening via sensitive IEMs.

 

If you're happy with having a standalone DAC and it does what you need, then there is no particular need to use USB audio from your smartphone. For those of us who prefer to use our smartphones as our primary portable music players, the option to have higher sound quality is welcome.

 

Also, just a point of clarification - I think in most of the instances where you are using the acronym DAC (which means digital to analog converter) you actually mean to say DAP (digital audio player).

 

Thanks for your detailed reply. 

 

You are right that when I was talking about DAC, I mean DAP.

 

I think maybe the point of using USB audio is that some high end DAC doesn't have audio player software or their software is not as good as the one on smartphones (e.g. poweramp). Is that right?

post #5 of 5

Not exactly...

 

The [in this case] phone's software (music player app) still does the decoding of the 1's and 0's that the audio files contain, but - where generally speaking there are better electronics in the external DAC, when those 1's and 0's are converted into audio, it is generally heard in a better way for the reasons cited by NZTechFreak above... 

 

Think of it like a CD player, that the music file in the phone is the CD, and the app that plays the music is the laser - you still need a DAC in both cases to make the 1's and 0's into music, and on full sized players as well, it is generally desirable to have an external DAC for 'ultimate' playback...

 

...Although, not all phones (and CD players) are born equal, and - in some cases, it is perfectly fine to listen to the one box approach... 

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