[Joe Bloggs]

Stumbled across this app thanks to this post
http://www.head-fi.org/t/671936/how-i-turned-a-bass-iem-into-a-balanced-clearer-iem
 
In which Viper4Android is mentioned almost as an afterthought, with a vague explanation of it making things sound "clearer".  The description given made it sound like a gimmick, but upon further exploration...
http://forum.xda-developers.com/showthread.php?t=2191223
 
I was floored by what the app promised to do--and on testing it out I find that it pretty much delivers everything it promised and more!

 
1. It is a system sound processing module--intercepts all system sounds (apart from phone calls).  I confirmed this works with, e.g. Poweramp and KKBOX (streaming music service)
2. It is NOT just like a wrapper for MusicFX, unlike dozens of wannabe system DSP apps.  A brief read of the feature list should convince you of that.  And I haven't tried them all, but I can certainly confirm that there is a working 10 band EQ (unlike the 5 band of MusicFX).
3. Most importantly, there is a Convolver function, which lets you take a recording of almost any sound processing effect as an impulse response (there are dozens of stock effects but I think it's better for you to record effects yourself) and use it on your phone.
 
People have been using this feature to record the various bass boost, EQ and spatialization effects of different players and devices (the spatialization effects probably with limited success, since the convolver doesn't yet support cross-channel processing), but as seen in this post
http://www.head-fi.org/t/671936/how-i-turned-a-bass-iem-into-a-balanced-clearer-iem#post_9609650
and the OP's response following it, I think the greatest potential of this feature is headphone compensation EQ a la Accudio.  You can take the headphone measurements of various headphones from various sites like goldenears, take their frequency response relative to the site's target curve, and apply the inverse EQ with arbitrary level of precision using your EQ of choice (I choose Electri-Q), tweak the resulting curve to taste (e.g. I apply a subbass boost below 100Hz to compensate for the loss of bass in noisy environments), record an impulse response with this EQ, and put the result into Viper4Android and your phone will be able to play music through the same precision crafted corrective EQ that you have on your computer.
 
Edit:  I have my own thread dedicated to these headphone compensation EQs now:
http://forum.xda-developers.com/showthread.php?t=2372750

 

[jump3r]

Stumbled across this app thanks to this post
http://www.head-fi.org/t/671936/how-i-turned-a-bass-iem-into-a-balanced-clearer-iem

In which Viper4Android is mentioned almost as an afterthought, with a vague explanation of it making things sound "clearer".  The description given made it sound like a gimmick, but upon further exploration...
http://forum.xda-developers.com/showthread.php?t=2191223

I was floored by what the app promised to do--and on testing it out I find that it pretty much delivers everything it promised and more! :eek:

1. It is a system sound processing module--intercepts all system sounds (apart from phone calls).  I confirmed this works with, e.g. Poweramp and KKBOX (streaming music service)
2. It is NOT just like a wrapper for MusicFX, unlike dozens of wannabe system DSP apps.  A brief read of the feature list should convince you of that.  And I haven't tried them all, but I can certainly confirm that there is a working 10 band EQ (unlike the 5 band of MusicFX).
3. Most importantly, there is a Convolver function, which lets you take a recording of almost any sound processing effect as an impulse response (there are dozens of stock effects but I think it's better for you to record effects yourself) and use it on your phone.

People have been using this feature to record the various bass boost, EQ and spatialization effects of different players and devices (the spatialization effects probably with limited success, since the convolver doesn't yet support cross-channel processing), but as seen in this post
http://www.head-fi.org/t/671936/how-i-turned-a-bass-iem-into-a-balanced-clearer-iem#post_9609650
and the OP's response following it, I think the greatest potential of this feature is headphone compensation EQ a la Accudio.  You can take the headphone measurements of various headphones from various sites like goldenears, take their frequency response relative to the site's target curve, and apply the inverse EQ with arbitrary level of precision using your EQ of choice (I choose Electri-Q), tweak the resulting curve to taste (e.g. I apply a subbass boost below 100Hz to compensate for the loss of bass in noisy environments), record an impulse response with this EQ, and put the result into Viper4Android and your phone will be able to play music through the same precision crafted corrective EQ that you have on your computer.

i hv htc one will it work on that too?

 

[Joe Bloggs]

I guess you just do this extra bit before starting the installation proper?
"1.Open up /system/build.prop (If you can't find this line, you have to solve in other way)
2.Change the line lpa.decode=true to lpa.decode=false"

 

[Joe Bloggs]

http://forum.xda-developers.com/showthread.php?t=2372750

I have created a handful of headphone correction filters for specific headphone models running viper4android; the idea is similar to accudio or audyssey audio player on for apple players

 

[SpiderNhan]

I run Cyanogen mod on my Galaxy Note i717 and I can't get Viper to work with PowerAmp, so I'm now using the stock Cyanogen mod player, Apollo. What phone(s) do you use and is there anything I can do to get PowerAmp functionality on my phone?
 
Edit: Nevermind. I found the solution.

 

[Kaffeemann]

Joe, thanks a lot for your guide on xda!
 
Basically, with Viper4Android we get a free parametric EQ for Android. Cheers

 

[zzffnn]

Nice find, thank you Joe. I will get this for Samsung Galaxy S3.
 
Do you happen to know a system level parametric EQ for iPhone (3GS with ios 5.0.1)? 
 
BTW Joe, I see that you also like parametric EQ and you work for Fiio. Would you please take a look at our thread here and let James know:
http://www.head-fi.org/t/677571/poll-parametric-eq-on-fiio-x3
 
We would love to have parametric EQ on Fiio X3/X5. So far 75 Headfiers have voted and 85%/64 of those want parametric EQ on X3. 

 

[Kaffeemann]

I just noticed that unchecking "ReaFir 0.x compatability mod (low quality)" completely ruins the sound. Mids start to sound distant and hollow and the bass is extremely exaggerated.
 
So just leave it checked.

 

[Joe Bloggs]

  Nice find, thank you Joe. I will get this for Samsung Galaxy S3.
 
Do you happen to know a system level parametric EQ for iPhone (3GS with ios 5.0.1)? 
 
BTW Joe, I see that you also like parametric EQ and you work for Fiio. Would you please take a look at our thread here and let James know:
http://www.head-fi.org/t/677571/poll-parametric-eq-on-fiio-x3
 
We would love to have parametric EQ on Fiio X3/X5. So far 75 Headfiers have voted and 85%/64 of those want parametric EQ on X3. 

Yes I will!

 

[zachgraz]

I love this APP !
 
Can somebody tell me if Viper4android remains functional when I use an external DAC via USB OTG or does it get surpassed then ?
 
Thanks
 
Edit: I found and answer myself. It does work, only is the DAC not recognised as "headset". Therefore in the menu "effect mode" needs to be locked to headset OR the settings need to be made for the phone speaker according to a member in a different forum.

 

[jared basshead]

I'm on custom ROM, MIUI v6, it has viper4android integrated in the os. Let me tell you, this is pretty shocking, my mh1c has turned to true balance monitors, i have no idea how they achieved this but i might have just hit the sweet spot.
I would donate the viper4 dev if the app works on other ROMs but i havent tried yet and instead i donated to the ROM dev.
Also, it does work with USB DAC

 

[Lostinspace]

i've tried Viper on my rooted S3 with Boefla and, well, meh. Its a massive battery drainer and doesnt improve the already excellent sound when using Neutron music player.

Strikes me as a bit gimmicky really.

 

[SpiderNhan]

i've tried Viper on my rooted S3 with Boefla and, well, meh. Its a massive battery drainer and doesnt improve the already excellent sound when using Neutron music player.

Strikes me as a bit gimmicky really.

I use it on my Galaxy Note and it does put extra strain on the battery but, I do notice a significant gain in audio performance. Compared to the stock sound using PowerAmp, Viper4Android is livelier, more spacious and more dynamic. I also prefer its equalizer to PowerAmp's built-in EQ, though I don't use EQ very often. Haven't had much experience with the S3, so maybe the sound gains aren't as significant with the S3 DAC.

 

[jared basshead]

I use it on my Galaxy Note and it does put extra strain on the battery but, I do notice a significant gain in audio performance. Compared to the stock sound using PowerAmp, Viper4Android is livelier, more spacious and more dynamic. I also prefer its equalizer to PowerAmp's built-in EQ, though I don't use EQ very often. Haven't had much experience with the S3, so maybe the sound gains aren't as significant with the S3 DAC.

That's what I think too, the dac of the soc indirectly or directly affects the performance of Viper. Mine is qualcoms 16/44 dac and Viper has more than significant effects. It is just as you said more lively and spacious and again the eq is more than decent too. While am just lucky with no battery drain, maybe the reason is it's integrated with the ROM am using.
Hats off to the Dev.

 

[SpiderNhan]

Just a comparison I've noticed while using my two phones.

I have an old Samsung Infuse 4G with a Wolfson DAC that is rooted so I can use this hack called Voodoo Sound. Basically Voodoo Sound unlocks the built-in restraints Samsung put on the Wolfson DAC and allows the AUX port full access to the DACs processing capabilities. Using Viper4Android with my Infuse 4G actually sounds WORSE than using it with Voodoo Sound alone. Every setting I tried: gain, bass boost, treble boost, virtual surround, tube simulator, Cure tech, EQ, etc. reduced the sound quality of my device. I have uninstalled it from that phone.
 
However, on my Galaxy Note, which uses a Yahama DAC, it makes a huge difference and allows me to tweak it so it almost sounds as good my Infuse 4G. I used to carry both phones around, the Infuse 4G as a music player only, but Viper4Android has eliminated the need for me to lug around both devices.
 
Not every phone will benefit from using it, but when it works, oh boy.