Researching A/V Equipment for SVPB - Microphones

18 minute read

This article is part of multipart series: Researching A/V Equipment for the Silicon Valley Prayer Breakfast (SVPB).

Summary

Proposal #2

1x snake

#	Item	Price	Qty	Total	Description
1	Whirlwind 4 XLR Male to 4 XLR Female Fan	$439.99	1	$439.99	1x long XLR snake for the 4 wireless lavs
2	Kopul Premium Performance 3000 Series 100’ XLR	$29.99	8	$239.92	2x dedicated long XLR for handheld mic-receivers-to-mixer; 2x dedicated mixer-to-speakers (L/R); 2x speaker-to-speaker (side-to-front); 2x backup
3	Kopul Premium Performance 3000 Series XLR 50’	$19.99
4	JBL Dual EON615 15” 2-Way Powered Speakers with dbx DriveRack 260 Control System & RTA-M Measurement Microphone	$1,529.95	1	$1,529.95	JBL EON615 Speakers with speaker alignment and feedback elimination controller (cheaper as bundle)

Proposal #1

We could choose to use all handhelds so nobody has to be mic’d up beforehand, avoiding the needed coordination to ensure it’s clipped on to the vocal and then turned on.

#	Item	Price	Qty	Total	Description
1	GLX-D	$499.00	2	$998	Two wireless handheld mics
2	Shure SB902 Rechargeable Lithium-Ion Battery	$29.99	2	$59.98	Backup batteries
3	Shure A58WS-BK - Black Windscreen	$5.49	2	$10.98	Windscreen noise and protection covers
	Subtotal			$1,059.96
	Tax	8.75%		$92.75
	Total			$1,152.66

If you’re looking for enterprise multimedia services, please contact us at reservations@wemassmedia.com. If you’re looking for personal, family, and wedding multimedia services, please contact us at reservations@justintoocreations.com

Lavalier Mics

#	Item	Price	Polar Pattern	Frequency Response	Dynamic Range	Signal-to-noise Ratio	Maximum Input Sound Level	Power Requirements	Output Connectors	Reviews
1	Shure MX185 (lav only)	$207.00	Cardioid	50Hz - 17kHz	94dB, (@ 1kHz, A-Weighted)	65dB	123dB, (@ 1kHz, 1% THD)	11 - 52VDC (with Belt Clip Preamp, Included)	TA4-F (4-pin mini connection); XLR-3M Type (with included RK183T2 preamplifier)	Too big, too sensitive (handling noise), but good output
2	RodeLink Wireless Filmmaker Kit	$399.00	Omnidirectional	60 Hz to 18 kHz	112 dB

MX150: Subminiature Lavalier Microphone

Lavalier microphone for TV broadcasting, lectures, teleconferencing, houses of worship, and live sound.

The XLR version has an in-line preamp - an electronic amplifier that converts a weak electrical signal into an output signal strong enough to be noise tolerant and strong enough for further processing.

RodeLink Wireless Filmmaker Kit

See nofilmschool.com: Experience With The Rode Rodelink Filmmaker Kit :

I’ve been using one since they came out The negatives is that the lav itself is definitely not as robust as the sennheiser ones, and the camera and belt packs are much bulkier. But they are the easiest things in the world to use as they don’t run on radio frequencies, they are digital so they will link themselves up. Also despite the hefty price I’ve always had interference in some form or another with the sennheisers just because of their UHF nature, there are radio signals bouncing around everywhere. So for general all round use you could do a lot worse than the Rode. They may not last a lifetime in build quality, but are much easier to use and sound pretty close.

They are the best value right now, if you go cheaper you can tell, if you go more expensive most people won’t hear a difference.

They also provide great service. The first Lav would cut in and out if the wire was bent the wrong way. I contacted Rode and two days latter I had a brand new Lav in my mail box, no charge, no need to exchange.

Handheld Mics

See sweetwater.com’s Shure Wireless Systems Buying Guide (with SM58):

#	Item	Analog/Digital	Frequencies	Systems/band	Range	Battery	Rack-mountable	Dual-Channel Option	Price
1	BLX	Analog	96	12	300 ft.	2xAA - 14 hrs	Yes	Yes	$399.00
2	SLX	Analog	960	25	300 ft.	2xAA - 8 hrs	Yes	No	$599.00
3	UHF-R	Analog	2,400	40	500 ft.	2xAA - 8 hrs	Yes	Yes	$4,747.00
4	ULX-D	Digital	2,500	60	300 ft.	2xAA - 11 hrs (recharge. option)	Yes	Yes	$3,425.00
5	GLX-D	Digital	n/a	8	200 ft.	1xSB902 - 16 hrs	No	No	$499.00
6	PGX-D	Digital	26	5	200 ft.	2x AA - 10 hrs	No	No	$379.00
7	QLX-D	Digital	2,500	60	300 ft.	2x AA - 9 hrs (recharge. option)	Yes	No	$999.00

See shure.custhelp.com: BLX vs PGX vs PG.

See thegearpage.net: What’s the difference between Shure’s Digital Wireless and BLX Wireless?:

Only, the PGX-D, GLX-D, and ULX-D series are digital. What differentiates the GLX-D from the other two is it uses the 2.4Ghz spectrum (Wifi) for transmitting, rather than traditional RF bands. So all three systems have digital audio, the GLX-D is the only one that transmits digitally.

I would consider any series under the SLX entry-level, as you would not see them used in professional applications. In fact, the GLX-D is still not fully reliable, as it has a much higher latency than other digital systems.

The BLX is analog and is Shure’s newest “entry-level” system that utilizes some of their technology usually reserved for higher systems. Here’s a quick run-down of Shure wireless:

BLX: entry-level analog, but newer technology. Good investment for newbies to wireless.

GLX-D: entry-level. Pure digital, 2.4Ghz Wifi spectrum. Not proven technology yet, and has received mixed reviews thus far (largely area dependent.)

FP: analog. portable receiver technology. Not recommended for music, but for broadcast/theater.

PGX-D - entry-level. The digital version of Shure’s older PGX series. Still transmits on analog RF bands.

SLX - mid level. analog. Rack-mountable with more available frequencies and simultaneous system options. Recommended if your band does any traveling.

ULX-S(Standard) - mid-high level. Analog. Basically the ULX-Pro but minus some bells and whistles.

ULX-P(Pro) - high-end. Analog. Old Standard for tech-riders. Still used in many places but is quickly being replaced with ULX-D.

ULX-D - high-end digital (still analog RF band). The newly-adopted standard for tech riders. low latency, high-end build quality. Works with Shure’s Axient system.

UHF-R: Shure’s ultra-high-end analog system. Still used as standard for top-level tours and events. As the ULX-D becomes more widespread, this system may start to decline in use.

Shure SM58

Tuned to accentuate the warmth and clarity of lead and back-up vocals.

For capturing audio, the QLXD24/SM58 Handheld Wireless Microphone System by Shure is a good choice to get the job done. It can be used for mid-size events and installations in businesses, hotels, government offices, schools, houses of worship, live performance spaces, and more. It features 24-bit digital audio, network control, and AES-256 encryption.

Shure QLXD24/SM58 Handheld Wireless Microphone System

Wireless Systems

See the Shure: Wireless Systems Comparison PDF.

Shure GLX-D

GLX-D

See B&H reviews:

We needed a system to give presentations during all hands meetings to both local office (about 100 people) and to remote employees via laptop and online meeting software. We tried some cheap system and got nothing but trouble out of it. Then I ordered Shure equipment and mixer/usb interface. All problems solved. Quality of sound, useful range, noise levels are outstanding. I was worried a little bit about potential interference because our office is tech gadgets heavy but everything works just fine. I especially like built-in battery charger and easy to understand display on base. So far I had zero issues with this system.

I bought this because our campus has 60 wireless in the UHF band and I had no room for more. So I went with the 2.4GHZ band and even with all our wifi floating around this was able to find an open channel. Very Clean, No dropouts. Best sounding transmission over non digital wireless mics. I will be buying several more. The battery life lasts forever and you can recharge it easily with the receiver. And set up was so easy I pressed one button and both transmitter and receiver were synced. I have no Cons for this mic.

I use this Shure microphone for a number of uses; vocal microphone, presentations, concerts. The range is amazing! The quality is outstanding. The best part is the rechargeable battery, slides into the receiver for quick, easy charging. Typically last 10-14 hours. The battery has never died on me! The pick up range of the microphone is awesome. People can hold the microphone where it’s comfortable and it will still pick up their voices.

See shure.custhelp.com: The Emergence of 2.4 GHz Wireless:

GLX-D Digital Wireless Systems offer an operating range of up to 100 feet indoors and up to 65 feet outdoors

The challenge of 2.4GHz is that Wi-Fi traffic can be unpredictable. GLX-D meets these challenges as follows:

a) Prioritizes and transmits on the best three frequencies per channel - choosing from a pool of six frequencies across the 2.4GHz band.

b) Repeats the most important information such that one frequency can be taken out entirely without audio interruption.

c) Continuously scans during usage to rank all frequencies - both current and backup frequencies.

d) Quickly moves away from interference to use backup frequencies without audio interruption

Coexisting with Wi-Fi

If Wi-Fi will be active during a performance, turn on Wi-Fi devices prior to turning on GLX-D and scanning for the best channel. GLX-D detects and avoids other Wi-Fi traffic by scanning the entire 2.4GHz environment and selecting the three best frequencies to transmit on. “Bursting” Wi-Fi is harder to detect as it is periodic; however, because GLX-D repeats the most important information, even bursts at very high-levels often will not have an effect on audio performance. If there is a Wi-Fi transmitting device in use, the GLX-D receiver must be placed at least 10 feet away from the device.

Challenging Wireless Environments

Challenging Wireless Environments

Some environments are more difficult than others for 2.4 GHz wireless system performance. Additionally, RF signal absorption by the human body has a greater impact in the 2.4 GHz spectrum, compared to the UHF spectrum. The simplest solution often is to reduce the transmitter to receiver distance such as placing the receiver on the stage with a clear line of sight. Challenging environments include:

a) Areas with few reflective surfaces such as: Outdoors; Buildings with very high ceilings.

b) A venue where three or more GLX-D receivers are in use.

c) Strong Wi-Fi presence. A typical Wi-fi transmitter/receiver will emit a signal ten times stronger (or more) than the GLX-D signal.

d) Non-Shure 2.4 GHz systems in use - unlike analog TV band wireless system (which typically use the same type of RF transmission no matter the manufacturer) every 2.4GHz wireless currently on the market uses a different type of wireless transmission. These differences make it difficult to successfully mix and match 2.4 GHz from multiple manufacturers.

Predicted Operating Distance

Indoors: Up to 100 feet (30 meters) is typical, with a maximum of 200 feet (60 m) under ideal conditions. Outdoors: Up to 65 feet (20 meters) typical, with a maximum of 165 feet (50 m) under ideal conditions.

However, adverse local RF conditions can limit GLX-D operating distance to as little as 10 to 20 feet. In the worst case, the GLX-D may not operate at all.

See GLX-D Pro / Con of the 2.4 GHz Frequency Band and User Hints:

There is no perfect frequency band for a wireless mic system. Every frequency band has pros and cons. GLX-D operates within the 2.4GHz ISM band which is utilized by Wi-Fi, Bluetooth, and other wireless devices.

Frequency band

See thegearpage.net: What’s the difference between Shure’s Digital Wireless and BLX Wireless?:

If you do go with a Shure system, try to stay as low in the alphabet as possible when selecting frequency bands. The G band is best. H and J are ok. L is iffy.

The reason for this is that the FCC is again looking at restricting frequency spectrums. They took away the 700Mhz spectrum back in 2010. They are in talks to take away the 600Mhz band in the next 2-5 years. The G band is best because it operates in the low 500Mhz band. So if the FCC does come after it, it will be the furthest down the road.

The reason Shure is trying out the GLX-D system (2.4Ghz band) is to circumvent the issue altogether. The FCC hasn’t licensed the 2.4Ghz band so that’s why it’s used for everybody’s Wifi. The problem with that is that IT’S BEING USED FOR EVERYBODY’S WIFI. It’s very crowded and dropouts are not just likely but virtually guaranteed. To combat that, Shure’s GLX-D system has 3 frequencies on that band simultaneously and jumps back and forth constantly. It does a good enough job, but in areas where Wifi is super heavy, audio professionals are hesitant to rely their jobs and reputations on it yet. Plus the whole latency thing.

2.4 GHz

See GLX-D Pro / Con of the 2.4 GHz Frequency Band and User Hints:

Pros

No license required in any country.

No interference from local TV stations.

Cons

Used for many other wireless services, such as Wi-Fi. Note there are audio mixing boards that use Wi-Fi for remote control.

Heavy RF traffic in this band can adversely affect the GLX-D performance. Symptoms can be short transmission range, frequent loss of signal, inability to operate multiple GLX-D systems at the same time. In theory, it is feasible to simultaneously operate up to eight GLX-D systems in one venue under optimal conditions. However, local interference in the 2.4 GHz band will often reduce this number to four or less.

The human body efficiently absorbs and blocks this frequency. The short 2.4 GHz wavelengths (4.9 inches) make it essential to maintain line-of-sight between the transmitter and the receiver for the most reliable operation.

Microwave ovens can produce local interference in this frequency band.

At 2.4 GHz, transmission distance outdoors is typically far less than indoors. Outdoors there is a lack of surfaces to reflect the transmitted signal. Such reflections improve transmission distance indoors. As a general rule, 2.4 GHz waves do not effectively penetrate many types of walls.

Digital or Analog

See thegearpage.net: What’s the difference between Shure’s Digital Wireless and BLX Wireless?:

Advantages to digital systems (systems that use digital audio) is that you get exactly that. Digital audio. The quality is MUCH closer to a wired microphone. However, With digital systems, you now have latency. Most systems have ~0.4ms - 4.0ms latency. This isn’t noticeable until you introduce more digital elements into your sound system. Once you get to around 8-10ms latency, there is an audible delay. So if you are using a digital console, digital snake, etc, each element adds to the latency. Your goal is to keep it under 5ms total. The GLX-D system specs it at 4-7ms by itself (because of the 2.4Ghz band it uses), so there is a MUCH higher chance of encountering latency with other digital gear in the mix. Digital systems also don’t have quite the range (100’)that analog does (~300’). So you’re trading audio quality for a bit of portability.

See shure.custhelp.com: :

An important point, though, is that no matter if the system is analog or digital, RF interference is something that can happen. In the case of UHF systems (again, this applies to digital or analog wireless in this range), you still need to coordinate the frequencies to avoid direct interference from active TV broadcast and other UHF wireless sources while, at the same time, using a set of frequencies that don’t interfere with each other. This can be done with software programs such as our Wireless Workbench (version 6), available for free on our web site. This can be used to help you or the customer find frequencies that avoid interference from other UHF wireless in the building. If however, the system is not UHF…many digital wireless systems in these other bands (2.4 GHz, 1.9 GHz, etc.) cannot be coordinated and instead rely on scanning and automatic frequency coordination and interference avoidance to deal with interference from other devices in those spectrum ranges. That sounds much easier (and it is) but, of course, these systems also are usually not able to do quite as many compatible systems. In this case, seven mics is not that many, though.

If security such as encryption of the wireless link is a must, the choice is already made for you between analog and digital. If you want encryption, you will need a digital wireless system. Most of our digital wireless systems employ AES-256 bit encryption, generally thought to be the most secure encryption standard.

It is difficult to say whether analog wireless or digital wireless systems are better or worse than one another as a rule. In general, digital wireless systems tend to have “better” audio as far as dynamic response and frequency response as well as usually being less noisy at end of range situations since, like with most things digital, they are either on or off. This difference is much more noticeable though at lower to mid tier wireless. Some high-tier analog wireless systems have been designed in such a way that the audio section is actually quite good and comparable, especially if the application is only speech which requires far less dynamic range and range of frequencies for good fidelity and intelligibility.

One key thing that people latch onto with the digital versus analog discussion is latency and whether it will be an issue. Analog, of course, has zero to negligible latency while digital wireless has differing amounts of latency depending on the processing and RF mechanisms employed in the particular digital wireless system. This amount can be as little as a few milliseconds. The amount of latency that can be tolerated depends on the application as well as the people involved. For teleconferencing applications with limited to no local sound reinforcement, latencies of 15 ms or more are typical and completely acceptable. However, for performance applications, especially those involving situations where the talker/singer will be able to monitor themselves through an in-ear monitor, headphone, or close loudspeaker, latency generally needs to be much lower than that to work well.

Mixer

Mackie 802 VLZ4 8 Channel Mixer - $199.99

Shopping Criteria

gearank.com: The Best Wireless Microphone System Guide - Handheld:

Number of Channels. This determines the maximum number of compatible systems you can use at the same time. For example if you need to use 20 wireless mics then you’d need 20 channels so you can run 20 systems simultaneously.

Range. The ranges presented below are for line of sight where you can see the receiver from where you are using the mic. If you are going to have obstacles, such as walking around a crowd of people as you might in a theater restaurant or house of worship, then it’s best to get one with at least twice the range as the actual distance to the receiver. For the kinds of gigs most bands play you won’t really need to go beyond 150 feet.

Receiver Frequency. If you, or someone else nearby, are using other wireless systems for mics or instruments, then be sure to check which frequencies they use and get a new wireless mic system that runs on a different frequency range. You can find the frequency in your manual or printed on the back of your receiver.

Analog vs Digital. Theoretically digital systems should provide slightly less noise at long range and slightly better dynamic and frequency response. The reality is that for most music and worship applications the analog systems are rated higher than their more expensive digital cousins

Common Mistakes

blog.shure.com: Avoid These Five Mistakes in Wireless:

Understanding the basics of how wireless systems and radio waves function will help you consistently triumph over dropouts, interference and distortion:

Signal blockage - Maintain line-of-sight between the transmitter and receiver antennas as much as possible; don’t coil or fold the flexible antenna connecting.

Incorrect antenna type or placement - To ensure good diversity performance, space antennas apart by at least one-quarter of a wavelength (about 5 inches at 600 MHz). The receiver antennas should be angled apart in a wide “V” configuration, which provides better pickup when the transmitter is moving around and being held at different angles.

Poorly coordinated frequency set - Frequencies must avoid local active TV channels (up to one million watts compared to typical microphone sound systems 50 mW (fifty one thousandths of one watt!)) and frequencies must be mutually compatible; “Local” is generally considered to be up to 50 or 60 miles, depending on the coverage area of the particular TV transmitter; use Channels that are all in the same Group

Poor battery management - Despite the fact that transmitter battery life is a top concern with wireless mics, users continue to try and cut operating costs by using inexpensive batteries. Most wireless manufacturers specify alkaline or lithium single-use batteries because their output voltage is very stable over the life of the battery. This is important because most transmitters will exhibit audible distortion or signal dropouts when supplied with low voltage. Rechargeable batteries often seem like the ideal solution, but many rechargeables provide about 20 percent less voltage than a single-use battery — even when they are fully charged. To combat battery problems, carefully compare the transmitter’s voltage requirements with the battery’s output voltage over time to make sure that the battery will last through a full performance.

Improper gain set-up - Setting the proper input gain is one of the most important adjustments on a wireless microphone system. Distortion may occur if the gain is set too high, while poor signal-to-noise may result if the gain is set too low; Its purpose is to set the input sensitivity low enough to prevent input overload or “clipping” but high enough so that the signal level is well above the system noise floor.

External resources

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Summary

Proposal #2

Proposal #1

Lavalier Mics

MX150: Subminiature Lavalier Microphone

RodeLink Wireless Filmmaker Kit

Handheld Mics

Shure SM58

Wireless Systems

Shure GLX-D

Frequency band

2.4 GHz

Pros

Cons

Digital or Analog

Mixer

Shopping Criteria

Common Mistakes

External resources

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