Microphones and Speakers
Microphones and speakers are more complicated than cameras and can introduce challenges, the principal two of which are feedback and echo. Without getting into much detail regarding sound engineering, feedback happens when a microphone sends sound to a speaker and then picks up that same sound and sends it back to speaker again, and picks it up again, over, and over in a loop. This is illustrated in the diagram below.
It creates a very high-pitched, very unpleasant sound that you will want to avoid. Echo has multiple possible causes, one of which is the same as feedback but rather than creating a high pitch whining sound the sound echoes, which is only very slightly less annoying. Since echo has multiple causes, let us look at those preventing them will also prevent feedback. Also, as there are multiple possible solutions, some of which require more technical expertise than others, and which also will have variations depending on what kind of computer and equipment is in use, we will limit our discussion to the simplest and likely most universally applicable solutions.
Since feedback and echo can both be caused by the same thing, a microphone picking up its own output, let’s take a quick look at how this is caused in a meeting, which also leads us to the simplest way to prevent it. There are variations on how, exactly, this comes about, but the root cause is essentially the same—multiple devices, computers and phones, simultaneously have active audio and are close enough to each other for the microphone(s) to pick up output from the speakers. There are multiple possible technical (including acquiring potentially expensive equipment with sound dampening properties) and software solutions (such as tweaking various audio settings on the devices), but the two absolute simplest ways to combat this are:
If multiple devices are in use, place them far enough apart to prevent the problem. However, while the exact distance required will vary, it is not unlikely that it will be more than a small meeting location can accommodate.
Ensure that only one device (computer) is in use with an active audio, all others must have audio—input and output—turned off. (NOTE: Feedback/echo can be caused from any location, even a remote one, during a meeting.)
There are two other possible causes for microphone echo that might need to be addressed.
Echo cancellation failure. Most computers have an echo cancellation feature, and some audio equipment will as well. It is a good idea to become familiar with these to understand their settings and drawbacks of using various settings (e.g., some computers and applications have very aggressive echo cancelling options but using them can lead to a microphone intermittently cutting out). Sometimes a persistent echo can be controlled by adjusting these.
Bad equipment. Sometimes the microphone, or any adapters or receivers it might be attached to, develops a malfunction. This can only be rectified by replacing the equipment; thus, it is important to regularly check equipment and make sure that it is properly stored and cared for.
Time lag. Sometimes there can be a time lag between when the microphone picks up the sound and when it is broadcast back over a speaker. This will normally not be an issue for in-person participants but can create a delay for remote participants. Different systems process signals at different rates and remote participants may have different bandwidth for the on-line connections. There probably is not much that can be done about this, but it is helpful to be aware of it.
Microphones. Laptops and many external webcams have microphones, but these are normally only effective for short distances. That is fine when you are sitting at your computer, which most of your remote participants will be, but not when you stand back away from the computer, which is the situation you’ll likely have in an in-person meeting. Unlike cameras, which by comparison are simple and straight forward, microphones can be handled in many ways but can present multiple challenges. Let us address this from the standpoint of the challenges you need to solve, then consider different configurations.
Before we do that, let us consider what are trying to accomplish and why that creates the potential feedback problem, as well as possibly requiring additional equipment.
First and foremost, everybody in the meeting needs to be able to hear everybody who has a speaking part. This includes speakers, the Toastmaster of the Meeting, evaluators, table Topics participants and other roles, in other words, pretty much everybody. The technical solution not only has to ensure they can all be heard clearly, but also has to do with minimal disruption to the flow of the meeting.
Second, for the in-person portion of the meeting to actual work to an acceptable standard, all these participants must be able to do so from a lectern or speaking area and not be tethered to a computer at their seat. It also helpful if speakers can move around in the speaking area.
It can be helpful to have a separate microphone that can be used to pick up conversations from a group at least a few feet apart from the microphone in the speaking area—such as for discussion during a business meeting.
But, as we already stated, using microphones on, or attached to, multiple computers tends to cause feedback. So how do we accomplish all the above and prevent feedback?
Solutions. Before we get into this, remember that as with cameras, more capable and sophisticated solutions will also be more expensive. Your goal is to find a solution that works for your club at an acceptable level of expense (or borrow equipment from members who may have obtained it for any number of personal or professional reasons). There is also a human element to this process. Referring back to the questions asked at the beginning of this guide, it is important to know what your normal meeting participation looks like and how much will normally be in person and how much will normally be joining remotely. There may be a point of diminishing returns relative to the monetary cost.
Use the laptops integrated microphones. This can be made to work, but frequently not very well. The range is usually limited which means that speakers must be close enough to the microphone. This limits the speaking area for the speaker to a small area close to the laptop. It also makes it difficult to engage in a group discussion, such as during a business meeting, unless the meeting space is small enough for all in-person participants to be close enough to the laptop to be heard clearly. It might be possible to remedy this by using more than one computer but remember that feedback and echoing may occur if they are too close together.
Attach one or more external microphones. There are a couple of primary options for doing this.
Option 1. Attach a wired microphone to a single laptop with a long enough cord to allow movement around a speaking area or around a meeting space (if needed). This is a simple solution and depending on the equipment used, the microphone might attach directly to the computer with either an A/V plug or USB connector. However, some microphones may require an adapter and some laptops may have limited input ports that may require the use of a hub or docking port. This will be discussed further in a moment. It might also, in some cases, be possible to attach a single microphone to multiple computers though they will need to be managed to prevent feedback. It is also possible to use a single wireless microphone which allows even more flexibility.
Option 2. Attach multiple microphones to a single computer. This is also a fairly simple option but requires a transmitter that can be attached to a computer that can receive signals from multiple microphones. These will frequently be wireless which makes them flexible to use and permit movement around a speaking area by a speaker or placed in multiple points around a meeting room to facilitate group discussions. These can range from relatively inexpensive systems that allow connection of two or more handheld and/or lavalier microphones, up through very expensive professional grade systems. A wired conference room or classroom might have this capability built-in, but it may still be necessary to provide the microphones. Again, if input ports on the host laptop are too limited then a hub or docking port might be needed. Moving away from the mechanics of conducting an effective hybrid meeting as a requirement, becoming comfortable with using microphones for speaking is a valuable benefit. An example of such a system are shown below.
This is an example of set-up that is fairly readily available at relatively low cost. It's wireless, which simplifies set-up and allows movement around the room with either handheld or lavalier mikes.
There is a variation of option 2 that may provide additional flexibility. In addition to the lavalier and handheld microphones, there is another type of microphone that can be included in your systems—an omnidirectional conference microphone. These microphones can be placed in the middle of a group, om a conference table for instance, and allow multiple participants to be heard (hopefully not all at the same time!) without trying to pass around a microphone. A illustrative configuration is shown below.
This illustrates a simple arrangement for microphones without, for the moment, considering cameras, speakers, or monitors. The size of the room will also impact on the arrangement
Speakers (the electronic kind). A speaker of some sort is necessary for in-person participants to hear remote participants. And as mentioned earlier, speakers are the other half of the feedback issue and while using them is not inherently difficult, using them in a way that enhances the meeting without interfering with microphones can be a challenge. Fortunately, it is a fairly easy challenge to overcome. As with cameras and microphones, laptop computers do have speakers built in, but their volume is usually limited, and it may be difficult for in-person participants who are not close to the computer to hear remote participants. Adding an external speaker is simple to do but must be attached to the same computer as the microphone(s) to prevent feedback. And, again as with cameras and microphones, they cover a wide price range, but an acceptable capability can be purchased on the low-end of the price range.
Some meeting locations will have a public address system with microphones and speakers. Although they will have been configured to work together, it is still possible to create feedback if a microphone gets too close to a speaker. Also, many of these locations will be designed for use within the room, as in a classroom, but not be configured for the equipment to transmit on-line. It is important to understand the capabilities available at the location and whether or not it meets your needs. It is possible that you might be able to use the room’s public address system, even using the system to amplify remote participants, but you might need to augment it to transmit the speakers in the in-person location to the on-line participants. Again, doing so may generate feedback so be prepared to mitigate this. In some cases, ensuring that microphones are not pointing at each other or that sound from speakers is bouncing off walls and interfering with the microphone will be sufficient. But sometimes the built-in public address system might have to be discarded to ensure that the on-line aspects of the meeting work. These issues should be explored and resolved well in advance of your meeting as they can take some time to work through.
Connections—plugs, jacks, and adapters. This is one especially important limitation that will frequently be encountered. It is, in fact, a key issue to your success since having the right equipment doesn’t help if it can’t be connected. A meeting location with a built-in audio-visual capability will like have microphones that use an XLR connector as shown here..
Your laptop won’t. As mentioned earlier, many laptops will have limited input/output ports and jacks and, in some cases, they may not match whatever is required by the external equipment. One type of connector end you will likely encounter is a 3.5 mm (also referred to as mini-plug or 1/8-inch connector) or a USB 2.0/3.0. These are the connections most people are probably most familiar with as they are commonly used for headphones and headsets. The commonly used 3.5mm and ¼” audio connectors are shown at the right. If your microphone and speaker have one of these types of plugs, connecting them is generally easy, assuming you have enough ports. Many laptops will have a combined audio 3.5mm audio input/output port that can accommodate a microphone, a speaker, or a headset (that has both). To use both an external microphone and an external speaker you will need a separate port for each. Some microphones and speakers have USB connections, and this may mitigate this issue depending on the number and type of USB ports available. Some laptops and tablets will have only a single audio port and a single USB-C port, which means you will need to add a docking station or hub to have access to multiple connection points to separate your microphone (input) and speaker (output). These are shown below.
A USB-C connector (left) and USB 3.0 hub (right)
1/4" RCA jack (top)
and 3.5 mm jack
The types of connections listed here are just the most common ones that you are likely to encounter. There are also 2.5mm connectors that look like 3.5mm, but aren’t and thus won’t work in the same jacks, and there are variations in design even among 3.5mm and ¼” connectors. The bottom line: make sure you know exactly what you are working with, don’t rush into buying something until you’ve researched it, know exactly what you are getting and know it will work, and test everything before your really need to use it so you can replace or adjust.
If your club is buying equipment, making sure your microphones and speakers have 3.5mm and/or USB plugs will simplify doing this. However, if you are borrowing equipment then it is possible that you may be trying to integrate higher grade equipment. This is good news from a quality standpoint but does complicate your set-up since you may encounter ¼ inch RCA plugs or XLR connectors. In this case you are going need adapters or cables with different connectors on each end that allow you to connect.
Bluetooth® and WiFi. By now the thought may have crossed your mind that many devices can connect through Bluetooth®. This is a true and it is an option you may prefer, but a word of caution is in order. Bluetooth® and WiFi enabled devices must be paired to work together. This is (normally) not difficult to do but may add an extra step during set-up if the same devices are not used each time. Also, from time to time, devices do not pair, so have a backup plan.