Polyphonicwinter Blog

ProblemSolving

Unwanted Distortion

The SE215's from Shure are fantastic in ear monitors however like all things they break. Specifically the cable and after it broke. I ordered a replacement, however after I plugged them into my computer for testing I heard a horrible crackling. Damn dodgy cable! Well that's what I thought...

Testing

After testing a different set of headphones (Beyerdynamic DT770's) I quickly realised it was coming from the left channel but the crackling was following the same pattern as the audio file. I tested WAV files, MP3 and Vorbis OGG files. Same thing. Perhaps it's only that specific track or maybe it's the program I am running the file through? Nope! I tried VLC, Spotify and Rhythmbox. Same thing.

Hmm... Maybe it's not the cable and due to my first test I can tell it's not an issue with the left driver in my SE's. Maybe the solder is loose on the headphone jack port? Well I can test that by plugging in my external sound card/audio interface and then my phone, trying both headphones through that. The crackle has gone through the phone but I can still here it through the interface at a high volume.

Drivers

So now I know that it is coming from the laptop not just the port. It must be a software issue. Okay cool, that means I can fix it! Let's think I recently converted from Ubuntu to it's older brother Debian so it's probably whatever audio drivers are installed by default in Debian. Quick search. ALSA and PulseAudio.

ALSA

Is the backbone of the audio in Debian systems. By typing alsamixer into the terminal brings up a terminal “GUI” with a single audio meter but with a searching you are greeted with lot's of meters for: Master, Headphones, Speaker to name but a few. It also gives control of the sensitivity of the input as well (microphone). Alsamixer is very nice but missing a few features in my opinion.

PulseAudio

PulseAudio is what my laptop has defaulted to. It's basically the newer version of ALSA and is very user-friendly with a GUI and the ability to adjust individual programs volumes and routing.

After spending a little while playing with the settings it seems the problem is due to distortion rather than a “crackle”. By turning the audio down it goes away but I like listening loudly ;)

Fixed!

So what to do? By using either the PulseAudio mixer or alsamixer I can see that the headphones output is set to 100% but the main output is only 55%. Aha... So I am causing the headphone to be above 100% causing distortion. So a little more tweaking and the best setting appear to be Headphones set to 100% and Main set to 0 – 35%. These parameters provide enough room to crank it but very little to crackle.

After a little more searching this SOLVES the issue!

#Linux #Debian #Audio #AudioEngineering #ProblemSolving #ALSA #PulseAudio #Fixed


NOTE: THIS POST IS NOW OUT OF DATE! Please refer to this one: WhatsApp: the solution?

I think I joined Facebook when I was 14 years old. I posted pictures of everything. From my friends, food, travel photo's to even some images of myself as a baby. I loved it! I was obsessed. Farmville. All day. Everyday. Constant invites to other games, funny memes, I had loads of friends and (from what I could see) everything was good in the world

Then I found out about the Snowden leaks. I was horrified, scared but above all angry. How could I have been so stupid?! You get nothing for free and yet I just blindly gave Facebook all my data. After reading maybe 3 articles/study's I was convinced that I HAD to delete Facebook. But even as I filled out the deletion page I felt a lump in my chest. Would my friends think I had abandoned them? I organised everything on this site, everyone did. The more I thought about this the worse and worse I felt about deleting my account. But luckily for me my hate for unnecessary hierarchy was more than a match for my guilt. DELETE.

In the coming days I was conflicted. I had lost so many friends from such a simple act. However it opened up a opportunity... how good a friends where they? Some people immediately just asked for a email address or a phone number so we could stay in touch. However most didn't blink an eye at it. My group of friends shrunk from 60 'online friends' to 5 really good friends, friends I'm still in touch with to this day.

It was definitely worth it.

I noticed my concentration improved, my grades went up and overall I felt better. The more I researched the treachery of Facebook and other internet giants the more I felt empowered about what I had done. I felt smart. Ahead of the curve. I started trying to convince other that their cyber footprint mattered, digital hygiene was huge and not to trust anything at face value. My interest in technology grew and I realised above all that I wanted to be an engineer. I didn't feel controlled, I felt free...

Which is why I am so confused about what I am doing. I'm seriously thinking about CREATING a Facebook account.

Why?

I hate Facebook!

I like feeling free!

Answer: The convenience of others.

Let me explain...

I am involved with a lot of group work at University and almost all of that group work is organised over Facebook. Group chats, Pages, you name it are all on Facebook. Now if someone let's me into their group they can no longer use those tools. They have to text, email or God forbid... call. This is “so much” hassle that no one wants to work with me. I have Twitter, Reddit, Signal, XMPP, email, phone numbers, Hell I'll even build my own chat application but NO Facebook. No one is particularly a dick about it they just sort of accept it and move on. Normally in these circumstances I would say fuck'em. We all have email and text. Create a group in that, Setup your phone so you get Uni email. Sorted. Right?

But in this case, wrong. If I can't work in a group then I will struggle to get good grades and at this point in my life that is vital. Vital enough to sacrifice my online freedom a bit?...

Probably, Yeah. (UPDATE: NO!)

Okay if I'm gonna create a Facebook account lets do it as anonymously as possible. So question 1...

Torify

When you think of anonymity, one of the first things that comes to mind should be Tor. Nicely for us Facebook (ironically) has it's own Tor hidden service facebookcorewwwi.onion which is even certified by Digicert, so using this a must. On a PC/laptop we can access this with the brilliant Tor Browser Bundle. On a mobile device you can either use Orbot and Orfox combo for android (Available from both Google Play Store and F-droid) or either Red Onion or VPN + TOR Browser Private Web on an apple device (although the android is considerably better and has actually been verified by torproject).

UPDATE: The Tor Project has released it's own Tor Browser for Android (Available on: Playstore/F-Droid (Preferred)). Use that instead of Orbot and Orfox.

But...

What device am I going to use to access Facebook? Well I need it specifically for group pages and group chats, so it would be preferable to be on my phone. There's no point have it if I don't get notifications at decent speed. Let's look at some Android apps.

Application Choices

  • Regular Facebook app The app that most people are talking about when they say Facebook. It allows me to use Facebook messenger for group chats and also access Facebook pages. However it is a big application and I would prefer to work with the minimal amount of scripts as possible to avoid as many Facebook trackers as possible. On the subject of trackers unlike if we ran Facebook though a browser we can't use plug-ins to control what it can and can't see and do. Because of this I don't want to use this option.

  • Facebook messenger (FML) A sleek alternative to the regular Facebook app you can simply sign up with a phone number and we are golden. We CAN route it through Tor (all though not natively) and we can get the LITE version, which is only 9 MB and has less bloat. It even tests (at the time of posting) clean with Exodus!

UPDATE: It NO LONGER reads clean!

  • SlimSocial Is a Facebook wrapper, meaning it runs in it's own browser so as not to gather data from my normal browsing. Nice! It has the ability to receive messages and I can see a nice slimed down version of the timeline. Group chats work! Looks like we have a winner

Hmm...

So SlimSocial should be our winner but after testing for a few weeks. Sadly it isn't meant to be. At the time of posting it has major flaws in consistency in receiving and notifying me of messages and updates. I tried multiple wrappers and apps from F-droid (Frost, Tinfoil for Facebook, Faceslim) to no avail. So what to do but claim the winner as...

Facebook Messenger Lite!

Okay so route FML through Tor (Orbot) and access the main page/s with Tor Browser Bundle and Orfox Tor Browser for Android!

WAIT!

We are not done yet! Unlike the wrappers from Lite still collects data from our device and asks for all sorts of permissions I don't want to give. Damn! If only there was a application that isolated 'big brother' apps...

Enter SHELTER!

Isolate

Shelter is an open source version of Island by OsasisFeng and “leverages the “Work Profile” feature of Android to provide an isolated space that you can install or clone apps into.”[1] Awesome we can simply install Shelter, install FML into our Shelter profile and we are good to go.

UPDATE: It is important to install Orbot or a VPN in the Shelter profile as well. Set it to 'Connected, Always-on active'. You will be running two VPN's at once. It will eat you battery life, but the privacy is worth it!

Closing remarks

Hopefully you can replicate these steps and have at least a 'slightly' more private time using the parasite that is Facebook. Enjoy!

Liam

[1] https://f-droid.org/en/packages/net.typeblog.shelter/

#Facebook #Privacy #ProblemSolving #Tor #TorProject #Shelter