China Wireless Microphone - OEM Wireless Microphone Manufacturer

Wireless Microphone WebSite Link:
http://www.chinese-microphone.com/Wireless-Microphones.html

China GuangZhou TianTuo Microphone Manufacturing Co., Ltd WebSite:
http://www.chinese-microphone.com/

Microphone Products are: Wireless Microphones, Conference Microphones,
Headset Microphones, and Lapel Microphones, interview microphones,
wired microphones, musical instrument microphones, drum microphones,
teaching microphones, recording microphones, computer's USB
microphones and microphone accessories and So on.

About Wireless MicsEquipment Emporium Inc. voice: 818-838-4457 or
800-473-4554 FAX:818-838-1667 15235 Brand Blvd, Suite A-110 Mission
Hills CA 91345 We are authorities in production sound recording for
video and filmmaking. We also have lots of accessories for
videography; and are dealers for Casablanca, AVIO, and Renommee non-
linear video editors; as well as turnkey AVID & AVID Liquid (aka
Pinnacle) editing solutions. If you would like a copy of our 2005/2006
"cowboy cover" catalog (free, of course), please phone or e-
mail us. We are working on a new 2007 catalog, coming later this year.
Note that we have lowered many prices in order to compete with
"New York" discounters. Always call us to check on the
latest pricing, and remember to refresh your browser, since we have
heard reports of folks looking at olde pages from ancient searches
rather than the current ones. Using Wireless Mics by Fred Ginsburg,
C.A.S. There is a saying in Hollywood that the use of wireless
microphones is more of a mysticart than it is a science. In spi
http://www.chinese-microphone.com/Wireless-Microphones.html te of all
of the technological advances, achieving reliable performance
fromradio mics is still a best case rather than an every case
scenario. The fault lies not with the manufacturers, but with the
government. Due to restrictions on power output (a mere 50 milliwatts)
and frequency allocation(sharing the wavelength with television
channels), professional wireless mic units arereadily susceptible to
dropouts and local RF interference. What this means in plain English
is that a twelve year old kid can walk into a RadioShack and buy a
walkie-talkie or CB that puts out 5 watts (5000 milliwatts), yet Uncle
Samwon't trust professional soundpeople with more than 50 milliwatts!
As for the matter of RF interference, anything that has ever caused
your television setto hiccup (such as overhead aircraft, vacuum
cleaners, computers, passing trucks) may alsointerfere with your
wireless mic. Never-the-less, radio mics are definitely an important
tool for Production Soundrecording. They are often the only practical
way to get the dialogue. Think of them as wireless cables. There is
nothing wireless about the microphone itself. The fact is, it is the
cableconnecting the microphone to the mixer or recorder that is
wireless. The microphoneremains wired to the transmitter. You may
think that I am indulging in a silly game of semantics, but this is
animportant concept to understand. The lavalier mic is not the
wireless part of the system;the XLR mic cable is what the transmitter/
receiver is replacing. Virtually ANY mic, including fishpole mounted
shotguns, can be used with a wirelesssystem providing that you have
the appropriate adapter cable or connector. Another concept that is
important is that because wireless mics (of any brand) arealways a bit
of a gamble, you should hedge your bet by only deploying wireless when
youabsolutely have no alternate solution. Avoid reaching for your
wireless as a first resort. Using radio mics is sort of likegoing to
the dentist: it is not a fun experience but we all do it when we have
to. Exhaust all of the "hardwire" ways of miking a shot. If
you can't boom itfrom overhead, maybe you can mic it from below.
Perhaps a strategically placed "plant" or fixed mic can be
rigged outside theframe or hidden within the set. If you do need to
resort to a body worn lavalier, it might be possible to trail a
micline from talent's ankle. Some scenes can be started on a wireless
for the master shot, and then switched to boommics or hardwired
lavaliers for the closer angles. Do wireless mics save the production
company money? There is a popular myth that using wireless mics will
save time and money. Not! Wireless mics cost money to rent as well as
to operate. For instance, the average daily rental for a good wireless
system is approximately $35to $40 per unit. How many units do you need
to budget for? The answer is: a couple more than you plan on using. If
you have only one actor and you bring only one radio mic, then what
happens if thatradio mic stops working either due to an internal
electronic malfunction or on account oflocal RF interference on its
frequency? Do we all get to go home for the afternoon? Add to this the
cost of batteries. Radio mics can consume an awfully expensive pile of
batteries over the course of aproduction. Most brands operate from 9-
volt alkalines, which cost around $2.50 each. The most common cause of
poor radio mic performance is weak batteries! Always beginyour shoot
with fresh, premium batteries installed in the transmitter and
receiver. The battery in the body pack transmitter should be changed
around every four hours,more or less. Even though some manufacturers
claim eight hours of life, I don't know of any top notchsoundpeople
who feel comfortable going that long on one battery. After four hours,
batteryvoltage tends to drop off steeply, along with transmitter range
and clarity. In addition, you do not want to interrupt the flow of
activity on the set in order tochange batteries while the director is
"cooking". Professionally, it is safer to change batteries
frequently than to risk an ill-timeddelay or a bad take. Receivers
don't eat batteries quite as much. Some receivers can last eight hours
on asingle battery, or a couple

of days on two or three. And if you do need to check the voltage of a
battery, or to replace it, it is usuallyeasier to access the receiver
(sitting out in the open) than to fumble with a transmitterburied
under someone's wardrobe. Battery voltage should be checked with a
digital volt meter. Inexpensive digital meterscan be purchased at
Radio Shack and other places for under twenty dollars. A fresh 9-volt
battery puts out around 9.30 volts. Replace your batteries at around
8.5volts or slightly lower, based on your experience with the radio
mics. By the way, your "discarded" batteries still have
plenty of voltage for mostconsumer devices, so it is not necessary to
toss them in the trash. Just don't use themfor professional equipment.
There is one more budget factor to consider... time. Radio mics
require fifteen or twenty minutes per unit to properly hide and rig
underwardrobe. Longer, if you experience difficulties with clothing
noise. Deciding to use radio mics on a shoot in order to save money is
a mistake. It is lessexpensive and much more reliable to hire a good
boom operator. But bear in mind that there are many situations where
wireless is the best, if notonly, practical option! Choosing a
wireless mic system. There are several factors to consider when
selecting a wireless mic system. Handheld vs. Body pack: Most of the
wireless transmitters used for Production Sound are of the body
packformat. Body packs with lavalier mics are commonly used for
dialogue. Handheld mics are generally used for vocal performance, or
audience Q & A. It ispossible to request both styles of
transmitters on the same frequency, for use with asingle receiver.
Note that you cannot utilize two transmitters on the same frequency at
the same time.When two transmitters are operating simultaneously, the
result is not a blending of theaudio as some would expect, but rather
a jamming of each other's encoded RF transmissions.ENG vs. Rack mount:
ENG receivers are designed for fiel http://www.chinese-microphone.com/Wireless-Microphones.html
d or camcorder use and have been miniaturized anddesigned for internal
battery power. Rack mount receivers intended for theater or concert
performances may require 120v ACand tend to be physically much larger.
Rack mountable units sometimes have the advantage of more
sophisticated front endfiltering to reduce interference, and often
feature diversity antenna systems as well. Rack mount units, because
of their better front end filtering, are preferred insituations
calling for a large number of radio units to operate simultaneously.
The smaller ENG units sacrifice some of the more exotic front end
circuitry in order toachieve compactness. VHF vs. UHF: VHF
professional wireless mic frequencies (169-210 MHz) overlap the
standard televisionchannels 7 thru 12, as per FCC regulation. That
means that many radio mics will only operate interference free in some
cities,dependent on the local TV channel line-up. VHF units tend to
offer greater range, longer battery life, lower purchase price, butare
more susceptible to interference. There are a handful of legal
frequencies just under channel 7, roughly 169-174 MHz,referred to as
"A" frequencies or "travelers". This narrow range
offrequencies will work in roughly 90%% of the cities nationwide. UHF
frequencies are much higher up on the spectrum. UHF's tend towards
less working range, higher battery drain, much more
expensivemanufacturing costs, but are less prone to interference. The
majority of radio mics used in our industry are VHF, but recent
improvementsin both the pricing and performance of UHF are changing
that statistic.Single antenna vs. Diversity: Most ENG receivers
utilize a single antenna. Diversity systems deploy two antennas, and
internally switch back and forth towhichever antenna offers the better
signal. Diversity units are usually rack mount size, although there
are some ENG sized brandsavailable. For diversity antennas to be
effective, they should be separated at least a quarterwavelength
(around 19 inches). Some mixers prefer to remove the antennas from the
receiver and connect them via ashort length (5 to 25 feet) of RG-59
antenna cable in order to increase the likelihood ofone or the other
receiving antenna finding a clear signal. The advantages of diversity
include less likelihood of RF dropout due to the direct orreflected
signal paths being obstructed, as well as increased working range
(based on theantenna placement). The disadvantages of diversity can
include having to deal with two antennas; audiblyrecognizable
"switching" (a trait more common in the cheaper systems);
and thechance of one of the two antennas locking onto interference.
Diversity antenna systems are more commonly chosen for presentation,
stage and concertperformances where the electronic environment is
controlled but the talent's movementsacross the stage are not. Single
antenna systems are fine for shot by shot production, since dropouts
can bedealt with by relocating the receiver in relation to talent.
Quad-Box: A quad-box consists of four individual ENG sized receivers,
non-permanently housed in acompact case. The case includes an antenna
"splitter" (RF distribution amp) so that onesingle antenna
(or two for diversity units) provides the feed for all four receivers.
Most quad-boxes also feature a centralized battery power supply that
will"externally" power all the receivers. Quad-boxes are
convenient. Their only drawback is that sometimes better performance
canbe achieved by separating the receivers and placing them
strategically closer to theaction. Receivers may be placed in
different sites to optimize antenna line-of-site for eachactor in the
scene. Rigging the Talent Attaching the body pack transmitter: Hiding
the transmitter under the wardrobe of most male performers is usually
fairlysimple, due to the fact that men generally wear looser fitting
clothing. Bulging pockets are common: stuffed with wallets, keys,
handkerchief, comb, coins, etc.The presence of a small transmitter
case rarely upsets the visual lines of the fashion. Where the
transmitter will be hidden is dependent on a couple of factors, such
as thephysical actions or stunts, and the contours of the wardrobe.
Common sites for the transmitter include: inside the waistband of
trousers, and theinside pocket of a jacket or sport coat. Other sites
are: inside the trouser leg, under the armpit (like a shoulder
holster),across the small of the back, or inside of a hat. A safety
pin can be attached to the transmitter by means of tape or a thick
rubberband, allowing the transmitter to be easily pinned onto
wardrobe. ACE bandages are another convenient way of securing the
radio mic. Professionals usually carry a variety of custom elastic
belts and cloth pouches (suchas those made by Equipment Emporium) to
facilitate rigging. The transmitters fit inside ofthe pouches, which
can then be pinned directly to clothing or slipped over
thin,lightweight elastic belts. The Velcro closured belts can be worn
around the waist, thigh, etc. A couple of quick notes about belt and
pouch kits. The belts should be thin; porous ifpossible. Velcro and
elastic can cover a wide range of sizes. White usually conceals easier
than darker colors. Very importantly, keep the belts freshly
laundered. Hiding the transmitter on a female is often more
complicated, due to the differences infashion. Whereas men's clothing
is commonly loose-fitting and lumpy, women's fashions tend to
beclosely contoured to the body. A variety of elastic belts are much
more important, since the thinner fabrics may notsupport the weight of
a pin-on transmitter. Choice of sites are based on wardrobe style,
camera angle, and physical action. Places to rig transmitters include
the small of the back (waist belt), the back of thebra, upper back (X-
shaped rig), under the arm, on the inside thigh (intimate, but
worksfor short, tight fitting skirts), the back of the neck (under
long hair), inside a legwarmer, unde

r a hat, or even under a wig (to accommodate on-screen nudity). Be
considerate of talent's privacy when preparing to rig them. Don't
advertise all overthe set that you are about to hide a transmitter
under someone's clothing! Avoid the use of camera or gaffers tape
directly against the skin. Use some sort ofcloth liner, first aid
gauze, or even toilet paper to protect the skin from these tapes. If
you are in a situation that requires taping directly to skin, then use
a medicalsurgical tape designed for that purpose, such as 3M Micropore
Action tape. Remember to clean the surface of the skin first with an
alcohol pad, in order to removeoils and dirt. Antenna considerations:
A prime consideration when selecting the body site to hide a
transmitter is the antennapath. We want the transmitter antenna to
have optimum "line of sight" to thereceiver antenna. Body
pack transmitters either utilize an antenna separate from the mic line
(such asVega), or they integrate their antenna function with the
ground wire of the mic (such asLectroSonics and Audio Technica). If
talent will be sitting on a metal backed chair, it would be a poor
choice to havethe antenna running along the back, say from waist to
shoulder. Similarly, if talent is facing up against a metal filing
cabinet, then we would try toavoid rigging the antenna along the
front. Separate antennas offer greater control over the antenna path.
We can rig the antennasolely on the basis of best line of sight. The
antenna should be kept somewhat taut, with just a little slack, which
is best doneby attaching a rubber band and safety pin to the end. The
pin is secured to clothing, andthe rubber band acts as a strain relief
as the actor moves or bends. The antenna should not loop over itself.
If the best antenna placement is downward,then invert the transmitter
rather than bend the antenna. The antenna can be kept somewhat
vertical (either upward or downward), or can be angledhorizontally
from the transmitter up to 90 degrees. If the transmitter antenna is
angled,sometimes reception can be improved by tilting the receiver
antenna to match. The antenna should never cross over the microphone
line. It is okay for the mic line toloop over itself (as when the
transmitter is inverted). Always run the mic line andantenna away from
each other; flip the transmitter if necessary so that the li
http://www.chinese-microphone.com/Wireless-Microphones.html nes do
notcross each other. Moisture will absorb RF energy, and thus weaken
the transmission. A rubber sheath ofshrink tubing, fuel line, or
surgical tubing can help isolate the antenna from excessperspiration,
rain, etc. The drawback to separate antennas is that they are an
additional element to rig andhide. However, the disadvantage of
combination antenna/mic lines is that the mic line mustbe cut to
specific (antenna) length, and that the best mic path is not always
the optimumantenna site. Greater care must be taken to keep the mic
cable as straight as possible. Avoidbunching up the mic/antenna line
and "stuffing" it into a pocket or under awaistband, since
this will reduce the transmission signal. Receiver Antennas: Good
antenna placement is the key to eliminating drop-outs and reducing the
chances ofinterference. Keep the antenna path as short as possible,
and transmit through as few obstacles aspossible. Place your receivers
as close as you can to the actors. Receivers can be just on theedge of
the set, or even hidden within the set. It is more efficient to run a
long length of audio cable from the receiver back to themixing panel
than to run a long antenna cable. Think in terms of clean line-of-
sight. The best place for your sound cart may not bethe best place for
your receivers! The antennas might have a cleaner path coming in from
the side or rear of the set Mounting your antennas high will allow
them to see over obstacles such as bodies andgrip stands. Be very
careful when mounting receivers onto camcorders. Make sure that the
antennadoes not have to "see through" the camera body or
VTR. Be aware that a lot of RF interference can be generated by the
video recording heads,and the viewfinder. I have found that when
mounting small, inexpensive receivers (such as the AudioTechnica
Pro88) onto the shoe brackets of Hi8mm and S-VHS camcorders, it is
better torotate the receiver so that the antenna faces the forehead of
the operator rather thanbeing located directly above the electronics
of the viewfinder. There are different types of receiver antennas. The
most common antennas that come with wireless mics are the stiff
wire"whip" antenna and the short rubber sheathed helicoil
"rubber duckie".The stiff wire antennas are the most
efficient, but may not be practical in an ENGsituation. The rubber
duckies are safer and more portable, but lose a little in terms
ofrange. Early ENG style receivers sometimes came equipped with a limp
wire antenna, similar tothose found on transmitters. The limp wire
antenna is inefficient unless it is kept taut. Compared to the wire
whip or the popular rubber duckie, the limp wire is a poor
choice.Antennas as accessories: Ground plane antennas look like little
camera tripods and are designed to takeadvantage of "ground
plane" reflections, sort of the way a pressure zone orboundary
plate mic uses a hard surface to gather sound. Ground planes work very
well forstage shows and the like. However, most field production
involves a lot of electromagnetic equipment (lightingunits, ballasts,
coils of electrical cables) strewn on the ground in their path, so
groundplane antennas would not be my personal choice.
"Dipole" antennas look like two wire whip antennas mounted
back to back, in avertical configuration. They achieve "higher
gain" by polarizing incoming signals (sort of likesunglasses).
Radio signals that strike the antenna at ninety degrees (horizontal)
arepassed with greater efficiency than spurious signals bouncing all
over the place. In a sense, these two-element dipoles are
'directional' in that they see a single plane(picture Saturn's rings).
Dipole antenna systems are very popular on professional motion picture
sets. The yagi type of antenna resembles a two dimensional Christmas
tree. It is a smallerversion of household rooftop TV antennas. The
yagi works like a shotgun mic. It is very directional and needs to be
aimed towardsthe transmitter. They are also very common on
professional sets. General concerns with wireless mics: Don't expect
miracles. Even the best Hollywood sound mixers have to wrestle with
their wireless. The range isnever what you expect nor what the spec
sheets claim, because you will not be operating ina perfect
environment. If you need increased range, try utilizing a dipole or
yagi antenna system. You canrequest them when you rent or purchase
your wireless. If the salesperson doesn't know whatyou are talking
about, go to a real sound house run by mixers! Another way to increase
your range is to shorten the distance between the transmitterand
receiver. Have someone carry the receiver and walk the distance
parallel with theactor. The

more units that are working simultaneously, the increased likelihood
of theminterfering with each other. Actors passing close to each other
may generate a buzz. If you know that actors will beworking close,
assign them units on frequencies as far apart from each other as
possible.Think carefully before you just grab a radio mic and stick it
on someone. Check your batteries often. Weak batteries in the
transmitter or receiver are the maincause of problems. Periodically re-
check your transmitter rigging. Actors have a tendency of
adjustingtheir wardrobe, and upsetting your carefully positioned mic
and/or antenna placement. If talent will be perspiring a lot, or
working in rain or near water, then it is a goodidea to encase the
body pack transmitter in a protective condom and seal it
withelectrical tape. Use standard non-lubricated latex condoms. But
don't forget to warn yourpersonal mate as to their professional use,
lest they be discovered when you get home! Clothing noise: Wireless
transmitters do not suffer from clothing http://www.chinese-microphone.com/Wireless-Microphones.html
noise. However, the lavaliers pluggedinto them certainly do! Rig your
lavaliers the same as you would if they were hardwired. For the
benefit of readers who missed the article on lavalier mics, here are a
fewpointers: Make a small loop near the mic capsule. Secure the loop
loosely with a piece ofthread or a thin strip of camera tape (sticky
side out). The loop should be able to freelyopen and close if the
cable is tugged. This loop serves to cancel out most cable
noiseconducted along the rubber sheath of the mic cable. Eliminate
contact clothing noise by securing the wardrobe on both sides of the
miccapsule. If the clothing is not free to rub against the mic head,
then there won't benoise. A popular technique is to sandwich the mic
head between two sticky triangles made fromcamera tape. Start with a
two inch long strip of (one inch wide) camera tape, and fold itcorner
over corner like a flag, sticky side out. Make a second triangle the
same way. Thensandwich the mic between them, being careful not to
block the grill. In the case of a button down shirt or blouse, attach
the sticky triangle onto thefabric overlap, just above one button. Let
the tied off loop hang opposite of the button. Secure the next inch or
two of mic line with a simple strip of camera tape along theoverlap,
running vertically downward towards the next button. Any tugging on
the cablewill be strain relieved by the section taped to the clothing.
The floating loop will isolate the mic capsule, and the twin sticky
triangles willprevent clothing from rubbing across the mic itself.
Wiring a female can be simpler. If she is wearing a bra, arrange the
triangles over themic so that one point is down. Secure the mic inside
of the bra, at the "cross yourheart" juncture in the center
of the bosom. A small strip of surgical tape can be used to anchor the
mic cable along the upperabdomen. The natural swell of the bosom
protects the mic from clothing contact, as well aspositioning it out
from the chest cavity. Clothing noise can also be acoustic in nature,
and is created by clothing fibersrubbing against each other. Starched
clothing is very noise conductive, so soften the cloth with a light
mist ofwater wherever the camera won't notice it, such as under the
sports coat. Soften a patchof clothing around the site where the
microphone is to be attached. Combat noise from clothing friction with
Static Guard. Wind noise can be alleviated by salvaging the foam tip
from a (used) video cleaningswab. Pull the tip off of the stick, and
slice the base off. What remains is a foam hoodthat will slip over
most lavaliers. These free windscreens can be painted with marking
pens to be less visible. And sincethey cost nothing, there is no risk
of sandwiching them within tape that would destroy thefoam upon
removal. Additional wind protection can be achieved by wrapping some
cheesecloth over the mic.Cut off the fingertip from a pair of child's
or woman's knit gloves, and pull that hoodover the mic and
cheesecloth. Another useful trick for rigging lavaliers is to use
moleskin and safety pins. This technique is particularly effective
when you have to wire talent quickly, or iftalent is going to be very
physically active and might otherwise dislodge a taped on mic. Wrap a
layer of soft moleskin around the head of the mic. Insert an open
safety pin,and then wrap another layer to secure it. The lavalier is
now ready to be pinned in placeunder wardrobe. The moleskin tends to
insulate the mic capsule from most clothing noise. An additional strip
or two of tape or moleskin can be added to help prevent clothingfrom
rubbing against the mic, and to strain relief the mic cable. If you
would like to join our private e-bulletin list, please reply to
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others (What, are we crazy? You're our client base!) However, we will
keep you informed of new stuff, and special bargains, close-outs,
overstocks, and deals for the hell of it.Send mail to
eqe@earthlink.net with questions or comments about this web site,
posted articles, catalog requests, or for sales / rental assistance.
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that we receive, it may take a day or two to respond. If you need
immediate attention, please phone or fax. Prices and product
availability subject to change without notice, although we try as hard
as we can to keep this site up to date. To order, just phone us. Or
purchase from our sister site on-line at theGeneral Store of the
Equipment Emporium & National Association of Forensic Video. Visit
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03/26/08 Los Angeles

Wholesale Wireless Microphone