Schedule

Schedule

Sunday, April 19

1429466400 The Tech Guy
1429480800 This Week in Tech

Monday, April 20

1429549200 Tech News Today
1429552800 Triangulation
1429558200 iPad Today
1429565400 Coding 101
1429570800 Tech News 2Night

Tuesday, April 21

1429635600 Tech News Today
1429639200 MacBreak Weekly
1429648200 Security Now
1429657200 Tech News 2Night
1429660800 All About Android

Wednesday, April 22

1429716600 FLOSS Weekly
1429722000 Tech News Today
1429725600 Windows Weekly
1429732800 This Week in Google
1429743600 Tech News 2Night
1429745400 Android App Arena
1429750800 Ham Nation

Thursday, April 23

1429808400 Tech News Today
1429812000 Know How...
1429817400 Marketing Mavericks
1429822800 Home Theater Geeks
1429830000 Tech News 2Night
1429831800 The Giz Wiz

Friday, April 24

1429894800 Tech News Today
1429898400 This Week in Law
1429909200 Before You Buy
1429916400 Tech News 2Night

Saturday, April 25

1429984800 The Tech Guy

Sunday, April 26

1430071200 The Tech Guy
1430085600 This Week in Tech

Monday, April 27

1430154000 Tech News Today
1430157600 Triangulation
1430163000 iPad Today
1430170200 Coding 101
1430175600 Tech News 2Night

Tuesday, April 28

1430240400 Tech News Today
1430244000 MacBreak Weekly
1430253000 Security Now
1430262000 Tech News 2Night
1430265600 All About Android

Most Recent Episodes

The Tech Guy
The Tech Guy 1179 April 18th, 2015

Can I still back up off-site when internet connection is unreliable?

Before You Buy

First looks at the 3DR Solo Drone and Sony HDR 4K Monitors at NAB.

This Week in Enterprise Tech

AT&T suing the FCC, Skype for Business, and Android is ready for work.

Tech News 2Night

What's so great about Slack?

This Week in Law

Co-founder of Invisible Girlfriend Matt Homann and crowd-sourced labor.

Tech News Today

Google now shows Apps in search results, on Android devices.

This Week in Computer Hardware

Intel Skylake Leaks!

The Giz Wiz

Onewheel, ThinkPad Stacks, Epson HD Whiteboard, and more.

Tech News 2Night

The best apps for your messy digital life

Home Theater Geeks
Episode #252: NAB 2015 April 16th, 2015

The latest and greatest from NAB 2015

Know How... 64

Audio Calibration and Wiretapping 101

October 10 2013

Today you'll know how to tap your network using Wireshark, how to fine tune your home theater audio, and more.

Wiretapping Your Home

Step 1: Get a Tapping device

Step 2: Get a device capable of receiving the tap data stream

  • Anything with a WIRED port that is capable of receiving the full speed of your chosen tap
  • USB adapters are fine, but remember that USB 2.0 devices top out at 480Mbps. If you’re using a Gig tap, you’ll drop traffic once the pipe is less than half full.

Step 3: Get Wireshark (www.wireshark.org)

  • Mac/PC/Linux – 32/64bit – Choose the version that is right for you.

Step 5: Choose where to place your tap

  • The tap will capture the traffic going between the two devices on either side of the tap.
  • Tapping the Externals will give you ALL devices on your network.
  • Tapping the Wireless AP will give you ONLY the devices connected wirelessly
  • Tapping a specific desktop/laptop/set-top box will give you ONLY that traffic
  • You choose if you want the outgoing or the incoming traffic.

Step 6: Capture

  • Press the button!
  • Choose the interface on your capture box. Typically it will be labeled "Local Area Connection"
  • Click "Start"

Step 7: Analyze

  1. Looking for Outgoing Streams: Are you a Spambot?
  2. Filter for SMTP: Look for SMTP packets when your computer is supposedly idle
  3. Filter for DNS: look for sites you don't recognize.
  1. Looking for "Top Talkers
  2. "Statistics" – "Conversations" – "IPv4"
  3. Click "Bytes" to sort by Top Talkers
  4. You can see the origin and destination of your traffic
  1. Looking for Usernames/Passwords in the clear
  2. In the "Filter" field, type " – "tcp contains username"
  3. This will give you all the packets that contain the string "username" in the clear
  1. Looking for Network Congestion
  2. tcp.analysis.retransmissions
  1. Here are a few helpful strings to get you started
  2. "ip.addr == 192.168.0.1: – This will give you all packets with 192.168.0.1 as either the source or destination.
  3. "ip.addr==192.168.0.1 && ip.addr==192.168.0.200" – This will give you all packets going between 192.168.0.1 and 192.168.0.200
  4. "tcp contains username" – This will display all TCP packets that contain the word "username" – I think the usefulness of this one is self-explanatory
  5. "tcp.analysis.retransmissions" – This will display all packet retransmissions – VERY useful when you've got a network that is unexpectedly slow.

Audio Calibration Part II with Scott Wilkinson

We've got part two of our audio calibration tutorial with Scott Wilkinson in this episode. In Part I of our audio calibration segment, we allowed the automatic calibration tool take care of our speakers. This time, Scott gives us the techniques we need to tweak our audio to create a great sound field.

Using a Sound Meter
Scott suggests that you pick up a sound level meter from a place like Radio Shack ($40-$50). You can also get an app for iOS or Android that can do the same thing.

AVR Settings
To calibrate your audio, set your sound meter to 70 dB. Then you'll place your sound meter on a tripod in the center of the room. Play the test tone from your audio/video receiver (AVR). Scott calibrates each speaker to 75 dB. To get even better audio, you can tell your AVR how far your seat is from each speaker. You'll need to take out the measuring tape and find out the distances. From there, you can place those values in your AVR.

If you cannot find your AVR's onscreen menu, you might want to connect your AVR to your TV via the composite (or yellow RCA) cable. Scott says that older AVRs feed their onscreen menus through that connection, which may seem counterintuitive to many.

You'll also tell your AVR if your speakers are large or small. The physical size of the speaker isn't what large or small refer to -- those words relate to what frequencies the speaker can reproduce.

Speakers and Subwoofer Tips
Any information that cannot be produced by a small speaker get redirected to the subwoofer. Scott's general recommendation is to tell your system that all your speakers are small. Don't worry about sending your low frequencies to your subwoofer because those low frequencies are non-directional. You'll hear what the director intended.

Where should you place your subwoofer? If you want to find the optimal place for your subwoofer, try the subwoofer crawl method. Place the subwoofer where your seat would be. Then play a familiar piece of music that has plenty of bass. Then crawl around the outside of the room. Wherever the music sounds the most natural is the place you should put your subwoofer.

When it comes to your audio cables, make sure you've got them set right; red to red, black to black. Mixing them up could lead to phase inversion, which causes indistinct audio.

The last step is finding the frequency below which you send audio to the subwoofer. This is also known as crossover. THX suggests 80 hertz. Scott suggests that you look at the specs of your speakers. If your surround speaker goes down to 100 hertz, Scott would set the crossover to 100 for all the speakers to create a consistent sound field.

Scott recommends that your five or seven speakers all come from the same manufacturer and possibly the same line. Individual manufacturers tune their speakers differently and to have a consistent sound from those speakers, it is easier to have speakers from the same manufacturer. Your subwoofer doesn't need to be from the same company.

Quickfire Questions

We got a chance to ask Scott four questions to get more information out the Home Theater Geek. We've given you a summary of the Q&A, but you'll have to watch the video or listen to the audio to find out the full answers.

1. Is there ever a reason to leave motion smoothing on?

Scott says yes, for things shot on video like sports or news.

2. Can you replace your speaker wire with coat hanger and not notice?

Scott said he wouldn't because the hanger isn't insulated nor is it flexible. Sonically, it might not be a problem.

3. Is there ever a good reason to place a TV over a fireplace?

No, the angle's all wrong.

4. Movie theater popcorn: lots of butter or light butter?

Neither. Scott doesn't eat popcorn.

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