[Galaxy S I9000 Android Development] studiominal:
Hello, I am studiominal from Korea. I’m going to explain what ‘Voodoo sound by supercurio’, and ‘Galaxy Tuner by dowkim10’ actually are, plus how to use these solutions to brighten your music life for users using Galaxy S as their MP3 playback device. Please be sure that I’m not an expert in this area, but I managed to get pieces of information regarding sound stuff, so I’d like your patience and also welcome your criticism (plus my English).

What are ‘Voodoo sound’ and ‘Galaxy Tuner’?

First of all, two of them both have the same goal to improve the sound quality of Galaxy S by tuning some systematic parameters within Wolfson WM8994 chip. Before describing differences between them, I’d like you to have a look at this.

1/ Mic sensitivity

2/ True line-out

3/ Headphone amplifier gain

4/ 5-band Hardware Parametric EQ

5/ Radio Noise

6/ iPhone headset support

7/ Call through headphones

8/ General sound quality

9/ Bluetooth gain & A2DP streaming issues

10/ Specialization effect for headphones & Crossfeed

11/ Multi-track recording support and VOIP fixes

Yes. These are the small objectives that supercurio mentioned which will be available on final Voodoo sound solution. It seems that overall progress doesn’t go exactly in the order of the list above, but I think it’s definitely going in the right way. As most of you might have noticed, the first release of voodoo sound has feature #3 and #5, and #1 and #8 are expected to be coming in the next version.

Let’s take another look at Galaxy Tuner by dowkim10 then. In this app, feature #4 and #10 are available, which means you can alter the native equalizer as you wish. (The most-wanted feature for me yay :)) This app, however, doesn’t have full features of * parametric EQ because the developer didn’t have the proper datasheet for WM8994. Nothing to worry though, a full parametric EQ will be available in supercurio’s release. So today I’m going to let you know how to set your EQ using Galaxy Tuner. What if supercurio releases it so fast? Hmm.. let me think about it later then 

* What is Parametric EQ?

Equalizers in poweramp, or default Samsung music player are called band Equalizers. It has several bars with fixed frequencies tagged, and the only control we can have is called ‘gain’, which we can alter in the direction of plus or minus. Parametric EQ is literally an EQ with several parameters: Center frequency, Bandwidth(Q-factor), and Gain.

Center frequency : The center of frequency you would like to emphasize or diminish. By adding some gains, you’ll see a peak formed at the center frequency. Of course you can change this center frequency in parametric EQ in an allowed range.

Bandwidth(Q-factor) : There comes a slope when you alter the gain of a band, and this parameter determines whether the slope should be steep or gentle.

‘Gain’ is just what you know already. (Degree to which a band is emphasized or diminished)

It is said that the more number of bands, the better the EQ is. With 5-band parametric EQ, however, I don’t think that’s always true. You can make a bunch of graphs by changing 3 parameters of each band. OK. These were for people who might not know what the parametric EQ is, and let’s get the real deal started.

Prerequisites

1. You must have ‘voodoo sound kernel’ and ‘voodoo app’ installed.

2. Your device must be rooted.

3. You also must have ‘Galaxy Tuner’ installed.

How to set Voodoo sound : Headphone Amplifier Analog Gain

Underneath is a screenshot of VoodoApp by supercurio. As many of you may have noticed, all the settings are reset upon rebooting. So the bar you see now is the default gain of headphone amplifier on Galaxy S.

You don’t have to think for a single second in this dialog, which means dragging it to the right means you’ll get louder volume, and left will result in quieter volume. I think I read a tip from supercurio and would like to let you know what that was by announcing in this post. (Cannot exactly remember where your tip was at, sorry supercurio :D)

1. Lower your amplification level in VoodooApp below the default level.

2. Maximize the volume bar in your music player (Android system)

3. Finally change the amplification level in VoodooApp again to fit your ears.

“By performing these procedures, you’ll get both lower noise and satisfactory volume.” I think this is similar to what supercurio said. However, there’s one major caution when using this technique I think, which might blow your ears. PLEASE KEEP IN MIND THAT HARDWARE AMPLIFICATION LEVEL WILL BE RESET WHEN THE DEVICE IS REBOOTED AND MEDIA VOLUME WILL NOT. Maybe there will be a solution coming automatically when ‘set on boot’ option becomes available.

So I won’t recommend this method for all of you, but only a few who are using receivers with low impedance(16ohms) or receivers of high sensitivity. This is because not only the volume but also the noise level will increase by increasing analog amplification gain. Of course, the SNR is very good for a phone in this class, and you might not notice a big difference of noise level though you have altered it a bit to the right. And for those who are using receivers with 32 ohms of impedance or higher, it’ll be of no problem.

In addition, I’m one of those who think that quantitative ways won’t always work, so I’d recommend you alter it without any annoying figures or formula 

How to set Galaxy Tuner : Sound (3D, HW EQ)

Finally we’re here. You can see 6 bars after you launch Galaxy Tuner. Let me start with the one in the top, the 3D effecter. By turning this feature on you will feel as if the stereo sound is expanded wide. Be sure that if you set it too high, it’ll result in a lot of distortion. Personally I set it at the maximum of 7.

5 bars are the bands for hardware equalization(B1~B5), each of which has a 100, 300, 875, 2400, and 6900 label. These correspond to the notion of center frequency I mentioned above. (100Hz and 6900Hz are called cut-off frequencies, not center frequencies)

The picture above is describing the results I recently measured with RMAA with ALC889A codec. (I’ve got a PCI one, but there seems to be a problem especially in line-in jack) Here you can see each graph drawn when each band was altered by 3 dB. See the peaks around 20Hz, 300Hz, 800Hz, 2500Hz, and 17000Hz? And some of you (including me in the past) might notice that it’s different from what is displayed in the Galaxy Tuner application. (like “What happened to 100Hz and 6900Hz?!”) I thought the datasheet was wrong, but I came to know that I was wrong. (How shame :o)

Now that we have an idea how the graph is altered when using this app, we want to know how to set it! Seeing many people who love listening to music, I thought some of them prefer the FLAT graph and others prefer their own tastes. Of course I’m one of the latter, so that’s why I’m writing this. It is said that most men can sound from 100Hz up to around 8000Hz, and women/children 200~9000Hz. Instruments, of course, have much wider a range of frequency bandwidth. Looking at the graph I posted right above, the peak for B1 forms around 20Hz, which is very hard to hear for a human, and the shape is so gradual that it might have a negative effect on other frequency bands. I think 50~60Hz will be just fine for people who seek for dense and powerful bass. (And this will come true with supercurio’s awesome next release I suppose)

Personally I love strong deep bass and emphasis on string instruments, which leads to a V-shaped eq setting. So mine is like +4, 0, +1, +1, +3 from B1 with Sony EX-600 earphone. The results are shown in the pic right up there (the one in the bottom, green)

~130Hz : MEGA BOOST!

~5000Hz : nothing special

5000Hz~ : Boost

That’s what I’ve done for my taste. Of course you might have your own tastes that might be different from mine. For example, if you wish to hear the vocal more clearly, just alter B2, B3, and B4 and you’ll notice the voices got boost. And for special cases like Triple fi used with Galaxy S which is known to be a mismatch because of attenuation in high frequencies, Galaxy Tuner will do the work 

Thanks to ‘Voodoo sound’ and ‘Galaxy Tuner’ anyway, I came to convince that every user of galaxy S has a potentially good MP3 player. For those who seek for frequency bandwidth of other instruments, please refer to the address below.

http://www.independentrecording.net/irn/resources/freqchart/main_display.htm

Galaxy Tuner *unlocked version for GT-I9000* by dowkim10

http://xdaforums.com/showthread.php?t=909801