Frequently Asked Questions

General Information about Classroom Audio

  • add_circleremove_circle_outlineWhat is a Classroom Sound Field System?

    A Classroom Soundfield System is essentially a small public address sound system, designed for the confines of a typical classroom of 25 – 35 students.

    From a hardware standpoint, the system usually consists of two wireless microphones. One is primarily for the teacher, and the second microphone is generally used by students. Most sound-field systems are currently using infrared wireless microphone technology. Since infrared is based on pulsating light, the transmission of the wireless microphones will not penetrate the walls of a classroom into another room. This allows us to set up dozens or even hundreds of classrooms very close to each other with no interference.

    The system also features a built in mixer and amplifier that will also be able to amplify audio from such sources as a computer, a DVD, TV tuner, or even an Ipod.

    The next critical part of a Sound-field System consists of several (four or more) overhead ceiling speakers. The key to really making a Sound-field system work effectively is a smooth “wash” of sound throughout the entire classroom. Ideally, every student should be listening at a distance of about six feet from the nearest loudspeaker so that we maintain the illusion of having the teacher standing six feet in front of you.

    Ceiling loudspeakers are kind of like ceiling light bulbs. For even coverage, you wouldn’t use just one or two to cover the entire classroom. The same goes for ceiling loudspeakers.

    The main problem that students encounter while trying to listen to instruction is that they are simply too far from the teacher’s voice and the classroom can be a noisy environment with computers and air conditioning.

    In a world of Ipods, loud car stereos, very loud movie theatres, noisy video games and home television, most students simply do not pay attention to low sound levels (or teacher’s instructions) that are less than 63-65 decibels.

    If a teacher tries to produce 75 decibels of sound at arm’s length (about 18”) they will find that this is no easy feat. Plus, that 75 decibel sound wave is going to be reduced to 63 decibels at six feet from the teacher’s voice. (that old inverse square law rule from physics class). The front row in most schools is about six feet from the teacher.

    Back to that 63 decibel level at the first row……….Once you move back a couple of rows to twelve feet from the teacher, the teacher’s voice drops another 6 decibels to about 57 decibels. The very last row tends to be about 20 – 24 feet from the teacher’s voice and although inverse square law tends to stop being a factor after about 18 ft, that distance produces another 2-3 decibels in loss of sound. That final sound level from the teacher at 54 – 55 decibels in the back rows is simply not enough to get good student attention. Thus, the need for amplification.

    Plus, if the teacher turns his/her back to the students while at the chalkboard/interactive board, the teacher’s voice is “splattered” and reflected off the front wall or screen and is much more difficult for any students to understand.

    In summary, wearing a wireless microphone allows the teacher’s voice to always appear as if he/she is facing the student and the amplified overhead ceiling speakers give the illusion of the teacher only being six feet away. The magic of modern technology.

  • add_circleremove_circle_outlineWho will benefit from a Classroom Sound Field System?


    • Effects of high ambient noise levels are overcome
    • 30% of children will hear their teacher significantly better
    • Teacher absenteeism is reduced
    • English Language Learners experience improved word recognition
    • Academic test scores improve
    • Children with learning disabilities benefit
    • Attention and on-task times improve
    • Classroom stress is lowered
    • Behavior problems are reduced
    • Fewer special education referrals
    • Class interaction and participation increases
    • Improvement in literacy achievement
  • add_circleremove_circle_outlineI have a loud teaching voice. Why would I need Classroom Sound Field System?

    A classroom sound field system will evenly disperse the teacher’s voice throughout the classroom so that every student can hear all the components of speech as accurately as possible. A loud voice does not mean that consonants are louder. It is impossible for a person to make consonants louder and consonants are key to speech intelligibility. An audio system amplifies the parts of speech that give intelligibility and make it easier for students to understand and concentrate on what the teacher is saying.

  • add_circleremove_circle_outlineWhere would I get some more information on studies about Classroom Audio?

    Many studies can be downloaded from our website under Research Studies.

General TeachLogic Information

  • add_circleremove_circle_outlineWhat is the TeachLogic difference?

    TeachLogic is a professional audio manufacture specializing in infrared products, classroom sound-field systems. Today, TeachLogic has established a leadership position in the wireless infrared sound-field industry. Our products are designed to deliver optimum speech intelligibility-providing crystal-clear sound to students regardless of the listening environment.

  • add_circleremove_circle_outlineHow long has TeachLogic been in business?

    TeachLogic has provided high-quality Sound Field systems since 1994.

  • add_circleremove_circle_outlineWhat sets TeachLogic apart from its competitors?

    Not all classroom audio companies are the same. TeachLogic’s reputation is to listen to our customers and respond to their needs to the best of our abilities. To design and manufacture innovation, quality, products at fair and reasonable prices. To operate our business with integrity towards our customers and our employees. TeachLogic has established a nationwide network of top integrators to provide immediate customer product knowledge, sales, service and support. In addition, with TeachLogic’s dedicated commitment to customer satisfaction, TeachLogic is the ideal choice for your audio needs.

Infrared Technology

  • add_circleremove_circle_outlineWhat is the difference between RF and IR wireless technologies?

    RF (radio frequency) technology uses radio waves to transit the audio signal. These are susceptible to RF interference. IR (infrared) technology used infrared light to carry the audio signal thus keeping the signal in the room and eliminating RF interference.

  • add_circleremove_circle_outlineIs there a limit to the number of systems I can have in my school?

    With RF technology, there is a limit depending on local interference and the number of systems desired. With IR technology, as long as the classrooms are enclosed, there is no limit to the number of systems you can have on one campus.

  • add_circleremove_circle_outlineDoes IR work outside?

    No. Large open-air spaces overwhelm the IR signal. The reflective nature of this technology is ideal for standard classroom audio.

Installation Questions

  • add_circleremove_circle_outlineDoes my Classroom Sound Field System need to be installed?

    In most cases, yes. Each system is complete with everything needed to install and operate the system. The type of speaker choice will determine the difficulty in installation. TeachLogic has established a nationwide network of top integrators to provide immediate customer product knowledge, sales, service and installation of systems. TeachLogic’s service department is available to answer any questions regarding the installation.

  • add_circleremove_circle_outlineMy system needs to be moved. What should I do?

    TeachLogic’s service department is available to answer any questions regarding the re-installation. Depending on your location, we have a list of certified installers that maybe available to move your system to a different room.

Product Questions

  • add_circleremove_circle_outlineWhat are my Infrared transmitter choices?

    TeachLogic offers two different IR transmitter choices; Sapphire Pendant and handheld.

  • add_circleremove_circle_outlineWhy should I get a handheld microphone?

    A handheld microphone can also be a powerful tool to help students gain confidence when presenting or reading aloud. Also, it is very helpful for students to hear their fellow classmates as they make their presentations.

  • add_circleremove_circle_outlineHow often should I charge my microphone?

    A microphone that is being used regularly needs to be charged every night.

  • add_circleremove_circle_outlineHow do I connect an assistive listening device to my classroom system?

    The assisted listening device is patched with a cord from the mic jack or aux input on the transmitter to the mixer auxiliary output on the front of the TeachLogic classroom amplifier. All TeachLogic amplifiers have a gain control on the front panel next to the output to adjust the volume. This will then transmit the signal to the assistive listening device that the student is wearing or has on the desktop.

  • add_circleremove_circle_outlineHow many IR microphones can I operate simultaneously?

    Each classroom audio system has two frequencies so that two microphones can be used simultaneously. TeachLogic also offers VoiceLink IV with a four channel receiver for operation of up to four wireless microphones.

  • add_circleremove_circle_outlineWhy are there different speaker options?

    Not all classrooms are the same. We offer two ceiling speaker packages made for suspended acoustic ceiling and wall mounted speakers for hard ceilings.

  • add_circleremove_circle_outlineWhat type of speaker should I choose?

    TeachLogic offers several types of speakers to meet many different room sizes and acoustic needs. The room dimensions and ceiling height will determine which speaker will provide optimum performance.

  • add_circleremove_circle_outlineWhat is the effective coverage of a Classroom Sound Field System?

    The coverage for a TeachLogic Classroom Sound-Field System will depend upon speaker choice. Typically, a system covers 1500 to 250 square feet.

  • add_circleremove_circle_outlineI need Portable Audio. What is my best option?

    For regular classroom use, many teachers prefer to use the Quantum II for infrared wireless transmission. This system uses the same Sapphire Pendant transmitter that is used with the infrared classroom sound-field systems. This unit will cover up to 1800 square feet and must be used indoors. This amplifier can be wall mounted, installed on a tripod stand or free standing on a shelf or cabinet.

  • add_circleremove_circle_outlineDoes TeachLogic sell rechargeable batteries?

    Yes, we use Duracell 2450 mAh nickel metal hydride with a two-year warranty. TeachLogic has tested several battery manufactures for the best performing rechargeable battery for operation time and life span and Duracell rechargeable batteries we have found to be the best.

  • add_circleremove_circle_outlineWhat is the life span of the rechargeable NIMH batteries?

    These batteries with proper care can last up to three years.

  • add_circleremove_circle_outlineCan I use alkaline batteries in my microphone?

    Yes, but these batteries CAN NOT be charged as charging them will cause damage that is not covered under warranty. TeachLogic battery chargers have built-in circuit protection that will not charge alkaline batteries.

  • add_circleremove_circle_outlineWhat is the expected life span of a Classroom Sound Field System?

    With proper maintenance, a classroom sound-field system should last approximately 10+ years.

  • add_circleremove_circle_outlineI have radio Frequency (RF) based classroom systems. Can I upgrade to an infrared (IR) system?

    Yes. You can add an infrared microphone system to your RF system. This allows you to keep your existing amplifier and speakers and add only the IR wireless microphone component. VoiceLink I is a single channel IR system and VoiceLink III is a two channel system.

  • add_circleremove_circle_outlineDoes TeachLogic have a product catalog?

    We have a Full Line Catalog available for download. The link can be found at the bottom of the home page. Individual product brochures available in the download section of the individual product.

  • add_circleremove_circle_outlineWho will train me on the use of my system?

    The system comes with a user manual, but the local TeachLogic integrator in your area may be available for in-service training.

Sales/Ordering Questions

  • add_circleremove_circle_outlineHow do I order a TeachLogic system?

    TeachLogic has established a nationwide network of top integrators to provide immediate customer knowledge, sales, service and support. Go to our find a dealer page on the website to find a local dealer in your area.

  • add_circleremove_circle_outlineI’m planning on purchasing many systems. Is there a discount?

    Multi-system discounts are available. The discount will depend upon the number of systems being purchased.

Technical/Service Questions

  • add_circleremove_circle_outlineI’m getting feedback (squealing) – how can I minimize this?

    • Make sure that speakers are mounted as close as possible to both the ceiling and the listeners
    • Avoid mounting speakers in the teacher’s primary lecture area
    • Position the microphone closer to mouth
    • Lower the Mic. Volume control(s) on the receiver
  • add_circleremove_circle_outlineThere’s no sound coming out of the speakers (or it’s weak).

    • Make sure that speakers are mounted as close as possible to both the ceiling and the listeners
    • Verify that the receiver is on (red power light above power switch)
    • Verify that the receiver is picking up a signal (green channel indication light next to volume control knob)
    • Increase the Mic. Volume or Aux volume control(s) on the receiver
    • Position the microphone closer to mouth
    • Verify that the speakers cables are connected properly
    • Verify that the transmitter is not muted
  • add_circleremove_circle_outlineMy receiver won’t turn on – the power light is off. What should I do?

    • Verify that the power supply is plugged into both the receiver and a working wall outlet.
    • Test with another power supply.
  • add_circleremove_circle_outlineHow can I eliminate “dead spots” or microphone crackling / noise?

    • Verify that you are not blocking either the emitters on the transmitter or the sensors or mounted ceiling sensor.
    • If reception is interrupted when facing a certain direction, install an additional sensor  (ICS-55) in that area of the room
    • If team-teaching, verify that transmitters are not on the same channel
    • Recharge or replace the transmitter’s batteries
    • Verify that the emitter/mic is working (Test with another working emitter/mic)
  • add_circleremove_circle_outlineMy equipment is still not functioning properly. What should I do?

    If the problem persists, call the TeachLogic service department to further trouble shoot the problem. If the technician determines that the product needs to be returned for service, the technician will issue a return authorization number (RA#) to track the repair. Repair by other than TeachLogic or its authorized service agencies will void the warranty.

  • add_circleremove_circle_outlineWhat is an `RA` number?

    RA stands for Return Authorization. This number is used to track items that have been returned for repair.

  • add_circleremove_circle_outlineMy equipment is damaged. Can it be repaired?

    Yes in many instances. Please contact the TeachLogic service department to determine the most cost effective course of action.

  • add_circleremove_circle_outlineI am unhappy with my equipment. Can I return it?

    You may return the equipment within 30 days of the invoice and receive a full refund of the purchase price. After 30 days, there is a minimum 20% restocking fee.

  • add_circleremove_circle_outlineI want a different microphone. Can I exchange mine?

    You may exchange a microphone of equal price within the first 30 days at no extra charge.

  • add_circleremove_circle_outlineThe teacher next door is complaining that he/she hears my lesson. What should I do?

    Often, the volume of the classroom sound-field system is turned up too high. The volume should be at a level that is heard will by the students and not necessarily the teacher.

  • add_circleremove_circle_outlineShould I take any precautions when storing my system over the summer?

    The only precautions that are necessary are to fully charge the batteries, and then make sure the battery charger and amplifier are unplugged from the power source.

  • add_circleremove_circle_outlineAre there on-site service contracts available?

    Contact the TeachLogic installation company in your area, on-site service may be purchased from that provider.

Warranty Questions

  • add_circleremove_circle_outlineIs physical damage covered under the TeachLogic warranties?

    No. The warranty does not damages that are not defects from manufacturing.

  • add_circleremove_circle_outlineWhere can I find the warranty statement?

    The product warranty is on this website under Warranty (click here).