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Skype Journal: How I Skypified a conference room on a budget

May 11, 2006 10:25 AM

by Stephen Klosky, Director, Federal Systems Engineering, Dataline, Inc.

I often demonstrate Skype and its capabilities to business associates. Crowding around a monitor is sometimes awkward. At my desk, I have a laptop, a docking station, and a second monitor which works well for me and one or two guests. For larger groups, I needed a better setup, so I decided to "Skypify" the nearby conference room.

Before

The typical setup in conference room before the upgrade was to take a portable LCD projector and connect it to any of the laptops in the office. The projector pointed at a whiteboard or a blank wall. This setup was functional, but had some drawbacks. Cords ran across walkways, image quality took some time to tune and setup correctly, there was no audio support, and there was no pc based VTC support.

I did have some gear available for the project. The IT department had purchased a Polycom ViewStation H.323 station with a TV for a monitor. This setup was on an A/V cart. This was attractive because the remote controllable camera could be used for the video part of Skype. Also, the mic pod could be used for the Skype microphone.

There were several network drops - 100baseT Ethernet ports available in the room. Additionally, there was a spare Windows XP Professional workstation available as well.

Shopping on a $510 budget

So, there were definitely some areas for improvement. My plan was to add a stereo for sound reinforcement, a USB video capture device for the video support, a ceiling mount kit for the projector, a wireless keyboard and mouse setup, a ceiling mount kit for the stereo speakers, a manual pull down screen for the projector, cables, mounting hardware and power strips.

I was on a non-existent / small budget, so, after a brief eBay session, I found the items I needed. Fortunately for me, I work for an office with quick approval processing and was able to get the upgrade approved in about an hour or so. After getting the approval, I went back to eBay and ordered up the gear. Here is a spreadsheet I used to track the gear.

Upgrade Conference Room		Status	Notes
Stereo with Speakers	$ 155.00	Ordered	to be shipped around 2/13
Speaker Mounts	25.00	Ordered	shipped 2/12
Cabling from Stereo to Speakers	14.00	Ordered	shipped 2/12
Cabling from PC to Stereo	6.00	Ordered	shipped 2/11
Power Strip	4.00	Ordered	shipped 2/10
CPU	-	In Hand
Video Capture Board / USB device	35.00	Ordered	shipped 2/11
Cabling from PC to Network (need 3)	15.00	Ordered
Cabling from PC to Projector	20.00	Ordered	to be shipped around 2/13
Cabling -- Power for Projector	27.00	Ordered	shipped 2/10
Cabling from PC to Microphone	4.00	Ordered	shipped 2/11
Cabling from PC to Video	4.00	Ordered
Wireless keyboard and mouse	30.00	Ordered
Ceiling Mount for Projector	30.00	Ordered	shipped 2/13
Screen for Projector	85.00	Ordered
Gaffer Tape	15.00	Ordered
Plywood	20.00	to be purchased
Fasteners	20.00	to be purchased
Total	$ 509.00

Putting it together

After a few days, the items started arriving and I began installing.

I moved the workstation to the conference room and put it on the bottom of the cart. I wired it to the company's network. I installed the wireless keyboard and mouse. One note is that the wireless range is very limited with the current wireless keyboard and mouse I'm using. On my "to do" list is to extend the range of this setup so that the keyboard and mouse can be used anywhere in the conference room. My plan it to ceiling mount the receiver over the center of the conference table and use long keyboard and mouse extension cables to reach the PC on the cart.

The next step was to install the stereo and wire it to the PC. That was straightforward.

Ceiling mounting the speakers was fairly simple as well. For each of the speakers, I removed a ceiling tile, I put a 1/2" x 12" x 12" piece of plywood on the top side of the ceiling tile. I put the mounting bracket for the speaker on the bottom side of the ceiling tile. I screwed the whole "sandwich" together using "zapper" screws (a.k.a. drywall screws). I drilled the appropriate size hole to allow the speaker wire to pass through the "sandwich." I secured the speaker to the whole setup, then returned the ceiling tile to its original location. I then ran the speaker wire from the stereo amplifier to the speaker. I did this by removing the appropriate ceiling tiles and fishing the speaker line down one of the interior office walls. After a brief sound check (using Media Player and a local radio station), this part of the project was complete.

The next step was to install the manual pull down screen for the video projector. This was straightforward, after modifying a few ceiling tiles and using the appropriate fasteners (wire ties, a.k.a. zip ties), the screen was up and operational.

Next step, input audio support. I wired the audio output from the ViewStation to the mic input on the PC sound card. Note that the ViewStation puts out a line level signal, so I initially went to connect to the line input on the sound card. This was a mistake, because Skype seems to actively manage the microphone input, not the line in input. No biggie, I just had to adjust the input channel on the PC so that the level was correct. Note that I have used the voice audio setup wizard in Windows XP several times with good results. You might try this if levels and settings are difficult to get your arms around.

Next step, video support. To accomplish this, I used the USB video capture device and connected it to the PC. I connected a composite video feed from the ViewStation to the USB video capture device. Then I loaded the support software for the USB video capture device. This went well, and quickly I was bringing up the Skype Video Test dialog box and seeing the appropriate video.

Currently, I have the video projector and the ViewStation mic pod on the center of the conference table. On my "to do" list is to ceiling mount these two units.

Cancelling Echoes

After all of this configuration and setup, how did it work? Well, Skype-to-Skype the system worked well. But I ran into a big problem with SkypeOut calls. There was major echo happening. When the person on the other end of the call spoke, they heard their words echoing back from the open microphone. This was embarrassing when I was demonstrating the system to my boss shortly after setting up the rig. We had dialed into an important conference call, and his boss was like - what's that major echo? We quickly reverted to the old speakerphone . . . And I felt like Wile E. Coyote who had just been beaten by the Roadrunner again. Back to the drawing board.

To combat the echo, I started on the Skype forums. It was clear from the forums and other Skype documentation that Skype has Automatic Echo Cancellation (a.k.a. AEC) built into the product. Several configuration settings can be adjusted to get the most out of the native AEC engine. After many adjustments, I concluded that the built in engine was not able to provide the echo cancellation I needed. So, it was back to the Skype forums to find more info on this topic. Surprisingly, I didn't find much. So, it was off to Google for me. After some research, I found that most business conference rooms have big challenges for echo cancellation.

• Ambient noise,
• distance from mic to stereo speakers,
• distance from mic to human speakers,
• loudspeaker volume,
• human speaker volume, etc.

All these factors make it difficult to provide a "one size fits all" AEC. So, I started researching available AEC units.

The three main units I found were the Gentner AP800, the Polycom Vortex and the Wideband Solutions WC-300. From my limited research, the Gentner is an old, discontinued model. The Polycom Vortex is a premium solution used by high end conference rooms. The WC-300 is a unit developed for use with conference rooms, Skype and other VOIP applications in mind. The Wideband Solutions unit is approximately half the price of the Polycom unit.

Given my non-existent budget, I went on eBay, and found a pre-owned (not certified . . .) AP800. I picked it up for about $250.00 including shipping. The installation and setup of this unit took a good amount of time. It took me about three hours to build the cables and insert the unit into the inbound and outbound audio paths. It took me about six hours to tune the unit for optimum performance. In the end, the purchase and the configuration effort paid off, and the echo is gone.

My Wishlist

Somehow, this whole experience reminds me of wiring the TV to the stereo in my first apartment. With today's technology, this setup represents to me a "budget" or "value" setup. Some upgrades I would see might be:

• A premium workstation with massive processor, massive RAM, premium video card with multiple monitor support, a premium sound card with multi channel digital input and output.
• A wireless keyboard and mouse with extended range.
• Better yet, a universal remote that would run all functions desirable for a presentation.
• For microphone support, a multi point microphone system with premium microphones.
• Lavaliere mics would be good for special presentations.
• For sound reinforcement, premium amplifiers and speakers including an earthquake-like subwoofer.
• For video support, a premium video display system.
• Perhaps multiple plasmas in a grid setup, or a couple projectors working in concert with automatic dropdown screens . . .
• Audio treatment for the room would be an upgrade as well.
• Custom lighting to enhance the video experience would be an upgrade as well.
• For the video cameras, multiple remote control cameras with smooth controls for transitions would be an upgrade as well.

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