How Microphones Affect Web Conference Sound Quality

Source: http://feedproxy.google.com/~r/TheWebinarBlog/~3/tg0KSNQypo8/thewebinarblog~How-Microphones-Affect-Web-Conference-Sound-Quality.html

Come, let’s get nerdy together. In today’s post, I’m going to give you a demonstration that shows how critical your input device can be on a web conference.

I started a web meeting in LogMeIn’s GoToMeeting web conferencing product. I could have used any such product for this demonstration and the choice was somewhat arbitrary. I happened to have the software handy. One convenient feature of GoToMeeting (also found in many of its competitors) is that attendees can choose to provide audio input by computer or telephone. I decided to run through a wide selection of input devices I had lying around my office so you can compare and contrast how they affect the sound your participants hear.

I used the built-in recording capability in GoToMeeting to save the audio to my computer. I then loaded the file into my GoldWave audio editing software. I cut out pauses when I switched devices and balanced volumes between different devices, but that is the only processing I performed.

You can listen to your choice of playback format. All files have identical content… I merely saved them in different formats (compressed and uncompressed) to see if I could hear any appreciable difference between them. I don’t think I can, which is not surprising. GoToMeeting records audio in MP4 format using a 16KHz, 64kbps mono rate. Audio specialists will recognize that this is not particularly high fidelity, but it saves file space and is acceptable for spoken voice. It certainly would not satisfy a professional recording engineer.

I saved the files in higher resolution formats to make sure I was not introducing additional degradation, but that doesn’t make them better than the source. You can’t improve audio resolution.

You will hear me identifying each of 15 different input devices on the recording. I’ll take you through details, impressions, and important considerations after the file listings:

CAVEAT 1: I kept saying that USB devices were connected to my motherboard. This will annoy computer geeks, as it is not literally accurate. I just meant that I was using my PC’s built-in USB ports and not a third-party sound card. I also kept referencing the currently available version of my Behringer microphone preamp instead of the older model I actually own. The notes below show the model name used in these tests.

CAVEAT 2: Microphones have different responses to different frequencies. You are hearing how they work with my male voice. Higher voices may produce different results.

CAVEAT 3: GoToMeeting uses an audio bridge to convert analog phone inputs to digital for streaming and recording. Computer audio doesn’t have to go through that conversion step. So computer-connected sources almost always sound better ON THIS SOFTWARE than phone sources. You’ll hear that. It does not necessarily mean the phone devices are objectively worse in and of themselves. But this is a fairly common consideration in web conferencing products.

CAVEAT 4: This is NOT a product review that tells you “Product A is definitively better than Product B.” A million things influence the sound you will get using your connections on your computer equipment through your web conferencing software in your room. I’m concentrating on the fact that they are different, not on building a ranking of best to worst.

CAVEAT 5: As I started adding links to products, I found that many of them are currently sold out. The sudden growth in work from home conferencing and disruptions in electronics supply chains are having a significant effect. If you are shopping, you may have to search for alternate sources or wait for supply to catch up with demand.

DEMONSTRATION SOURCES

1) Apple iPhone SE held in the classic manner against the side of the head with the speaker pressed against my ear. Using telephone dial-in.

2) Apple iPhone SE lying flat on my work desk. Using telephone dial-in in speakerphone mode.

3) Apple iPhone SE held flat in my hand several inches in front of my mouth, with the microphone facing me. Using telephone dial-in in speakerphone mode.

4) Apple iPhone SE with the included Apple earbuds headset plugged into the audio jack. There is a thin microphone built into the cord. Using telephone dial-in.

THOUGHTS: No matter how you choose to use a smartphone for calling into a web conference, it’s always a bad idea. In addition to generally lower quality sound, it’s hard to maintain a constant distance between your mouth and the mike. And you will eventually run up against interference, dropouts, signal degradation, or battery drain. Just say no!

5) Aastra desk telephone hard-wired to a cable company phone service. Handset held against the side of the head with the speaker pressed against my ear. Using telephone dial-in.

6) Aastra desk telephone hard-wired to a cable company phone service. Sennheiser HME280i headset plugged into the phone’s headset jack using a hard-wired cable.

7) Sennheiser HME280i headset plugged into an ASUS Xonar Essence STX sound card installed in my desktop computer.

THOUGHTS: Note the difference between 6 and 7. Same microphone, same device. But one of them ran through the phone network and audio bridge. The other didn’t. Quite a change, eh?

8) Logitech H390 wired headset connected to my computer’s USB port.

THOUGHTS: Not the world’s greatest sound, but much better than you will get from a built-in laptop microphone. This is my default recommendation for something cheap and easy to get for guest speakers who need to get up to a level of minimum acceptable quality quickly.

9) Audio Technica ATR20 handheld microphone (dynamic cardioid design) plugged into a TechRise USB audio adapter.

THOUGHTS: This microphone has since been replaced by the similar ATR-1200. Ridiculously cheap for good vocal quality! You will see the TechRise adapter mentioned several times. It’s inexpensive and acts as a convenient USB interface for mikes that have a 3.5mm jack.

10) Audio Technica AT2020 desk microphone plugged into my computer’s USB port.

THOUGHTS: My workhorse for narrative work. The world is split into those who use this and those who use the Blue Yeti. You can’t go wrong with either one. The next step up in quality is much more expensive.

11) No-name, no-brand Chinese earhook “whip” microphone plugged into a TechRise USB audio adapter.

THOUGHTS: Unbelievable! I ordered this from China for $7 shipped. How do they do it?

12) Sound Professionals SP-LAV-1 lavaliere clip-on microphone plugged into a TechRise USB audio adapter.

THOUGHTS: I have never had good luck with inexpensive lavaliere mikes. Sound is variable at best and volume changes as the speaker moves their head. This sits unused in a drawer.

13) Logitech C920S webcam mounted on top of my computer monitor. Connected to my computer’s USB port.

THOUGHTS: My office space is just not set up to get good sound out of a webcam. You can hear it. I am envious of people who have the luxury of open space behind their webcam (especially if they put an acoustic anti-reflective baffle there). No matter what webcam I try, it sounds muddy with a slight tin can echo. So I don’t use my webcam for audio.

14) Audio Technica AT875R shotgun microphone pointed toward my mouth. Phantom power supplied through an XLR connection to a Behringer MiniMIC MIC800 preamp, feeding into an ASUS Xonar Essence STX sound card installed in my desktop computer.

THOUGHTS: As with lav mikes, I have bad experiences getting good, consistent sound out of shotgun mikes. I have stopped trying. The Behringer preamp I use has since been replaced by their Tube Ultragain MIC100, which is what I keep referencing in my narration.

15) JK MIC-J 071S earhook “whip” microphone. Bias power provided by step-down Rode VXLR+ transforming adapter that reduces phantom power voltage and changes XLR connection to 3.5mm stereo plug. Signal processed through a Behringer MiniMIC MIC800 preamp to an ASUS Xonar Essence STX sound card installed in my desktop computer.

THOUGHTS: This was quite the Frankenstein’s monster of an input chain to assemble, but I love those little lightweight whip mikes. They are designed to be used with wireless belt packs, but I don’t believe in wireless. Almost invisible on camera (if it happens to match your skin tone). Great for webcam presentations. But for the price differential and ease of use, it’s hard to recommend this over the slightly thicker and more obvious microphone in #11.



tomas

Online enterprenuer. Lean leadership consultant.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.