Sound System Interconnection

Rane Technical Staff
RaneNote 110 written 1985; last revised 11/15
  • Cause and prevention of ground loops
  • Interfacing balanced and unbalanced
  • Proper pin connections and wiring
  • Chassis ground vs. signal ground
  • Ground lift switches


This note, originally written in 1985, continues to be one of our most useful references. It's popularity stems from the continual and perpetual difficulty of hooking up audio equipment without suffering through all sorts of bizarre noises, hums, buzzes, whistles, etc.-- not to mention the extreme financial, physical and psychological price. As technology progresses it is inevitable that electronic equipment and its wiring should be subject to constant improvement. Many things have improved in the audio industry since 1985, but unfortunately wiring isn't one of them. However, finally the Audio Engineering Society (AES) has issued a standards document for interconnection of pro audio equipment. It is AES48, titled "AES48-2005: AES standard on interconnections -- Grounding and EMC practices -- Shields of connectors in audio equipment containing active circuitry."
Rane's policy is to accommodate rather than dictate. However, this document contains suggestions for external wiring changes that should ideally only be implemented by trained technical personnel. Safety regulations require that all original grounding means provided from the factory be left intact for safe operation. No guarantee of responsibility for incidental or consequential damages can be provided. (In other words, don't modify cables, or try your own version of grounding unless you really understand exactly what type of output and input you have to connect.)

Ground Loops

Almost all cases of noise can be traced directly to ground loops, grounding or lack thereof. It is important to understand the mechanism that causes grounding noise in order to effectively eliminate it. Each component of a sound system produces its own ground internally. This ground is usually called the audio signal ground. Connecting devices together with the interconnecting cables can tie the signal grounds of the two units together in one place through the conductors in the cable. Ground loops occur when the grounds of the two units are also tied together in another place: via the third wire in the line cord, by tying the metal chassis together through the rack rails, etc. These situations create a circuit through which current may flow in a closed "loop" from one unit's ground out to a second unit and back to the first. It is not simply the presence of this current that creates the hum -- it is when this current flows through a unit's audio signal ground that creates the hum. In fact, even without a ground loop, a little noise current always flows through every interconnecting cable (i.e., it is impossible to eliminate these currents entirely). The mere presence of this ground loop current is no cause for alarm if your system uses properly implemented and completely balanced interconnects, which are excellent at rejecting ground loop and other noise currents. Balanced interconnect was developed to be immune to these noise currents, which can never be entirely eliminated. What makes a ground loop current annoying is when the audio signal is affected. Unfortunately, many manufacturers of balanced audio equipment design the internal grounding system improperly, thus creating balanced equipment that is not immune to the cabling's noise currents. This is one reason for the bad reputation sometimes given to balanced interconnect.
A second reason for balanced interconnect's bad reputation comes from those who think connecting unbalanced equipment into "superior" balanced equipment should improve things. Sorry. Balanced interconnect is not compatible with unbalanced. The small physical nature and short cable runs of completely unbalanced systems (home audio) also contain these ground loop noise currents. However, the currents in unbalanced systems never get large enough to affect the audio to the point where it is a nuisance. Mixing balanced and unbalanced equipment, however, is an entirely different story, since balanced and unbalanced interconnect are truly not compatible. The rest of this note shows several recommended implementations for all of these interconnection schemes.
The potential or voltage which pushes these noise currents through the circuit is developed between the independent grounds of the two or more units in the system. The impedance of this circuit is low, and even though the voltage is low, the current is high, thanks to Mr. Ohm, without whose help we wouldn't have these problems. It would take a very high resolution ohm meter to measure the impedance of the steel chassis or the rack rails. We're talking thousandths of an ohm. So trying to measure this stuff won't necessarily help you. We just thought we'd warn you.

The Absolute Best Right Way To Do It

The method specified by AES48 is to use balanced lines and tie the cable shield to the metal chassis (right where it enters the chassis) at both ends of the cable.
The absolute best way to wire audio cables

Figure 1a. The right way to do it.

Recommended chassis ground

Figure 1b. Recommmended practice.

A balanced line requires three separate conductors, two of which are signal (+ and -) and one shield (see Figure 1a). The shield serves to guard the sensitive audio lines from interference. Only by using balanced line interconnects can you guarantee (yes, guarantee) hum-free results. Always use twisted pair cable. Chassis tying the shield at each end also guarantees the best possible protection from RFI [radio frequency interference] and other noises [neon signs, lighting dimmers].
Neil Muncy, an electroacoustic consultant and seasoned veteran of years of successful system design, chairs the AES Standards Committee (SC-05-05) working on this subject. He tirelessly tours the world giving seminars and dispensing information on how to successfully hook-up pro audio equipment2. He makes the simple point that it is absurd that you cannot go out and buy pro audio equipment from several different manufacturers, buy standard off-the-shelf cable assemblies, come home, hook it all up and have it work hum and noise free. Plug and play. Sadly, almost never is this the case, despite the science and rules of noise-free interconnect known and documented for over 60 years (see References for complete information).
It all boils down to using balanced lines, only balanced lines, and nothing but balanced lines. This is why they were developed. Further, that you tie the shield to the chassis, at the point it enters the chassis, and at both ends of the cable (more on `both ends' later).
Since standard XLR cables come with their shields tied to pin 1 at each end (the shells are not tied, nor need be), this means equipment using 3-pin, XLR-type connectors must tie pin 1 to the chassis (usually called chassis ground) -- not the audio signal ground as is most common.
Not using signal ground is the most radical departure from common pro-audio practice. Not that there is any argument about its validity. There isn't. This is the right way to do it. So why doesn't audio equipment come wired this way? Well, some does, and since 1993, more of it does. That's when Rane started manufacturing some of its products with balanced inputs and outputs tying pin 1 to chassis. So why doesn't everyone do it this way? Because life is messy, some things are hard to change, and there will always be equipment in use that was made before proper grounding practices were in effect.
Unbalanced equipment is another problem: it is everwhere, easily available and inexpensive. All those RCA and 1/4" TS (Tip-Sleeve) connectors found on consumer equipment; effect-loops and insert-points on consoles; signal processing boxes; semi-pro digital and analog tape recorders; computer cards; mixing consoles; et cetera.
The rest of this note gives tips on how to successfully address hooking up unbalanced equipment. Unbalanced equipment when "blindly" connected with fully balanced units starts a pattern of hum and undesirable operation, requiring extra measures to correct the situation.

The Next Best Right Way To Do It

The quickest, quietest and most foolproof method to connect balanced and unbalanced is to transformer isolate all unbalanced connections. See Figure 2.
Transformer isolation of audio signal

Figure 2. Transformer Isolation

Many manufacturers provide several tools for this task, including Rane (see the BB22, BB44 and LT22). Consult your audio dealer to explore the options available.
The goal of these adapters is to allow the use of standard cables. With these transformer isolation boxes, modification of cable assemblies is unnecessary. Virtually any two pieces of audio equipment can be successfully interfaced without risk of unwanted hum and noise.
Another way to create the necessary isolation is to use a direct box. Originally named for its use to convert the high impedance, high level output of an electric guitar to the low impedance, low level input of a recording console, it allowed the player to plug "directly" into the console. Now this term is commonly used to describe any box used to convert unbalanced lines to balanced lines.

The Last Best Right Way To Do It

If transformer isolation is not an option, special cable assemblies are a last resort. The key here is to prevent the shield currents from flowing into a unit whose grounding scheme creates ground loops (hum) in the audio path (i.e., most audio equipment).
It is true that connecting both ends of the shield is theoretically the best way to interconnect equipment -- though this assumes the interconnected equipment is internally grounded properly. Since most equipment is not internally grounded properly, connecting both ends of the shield is not often practiced, since doing so usually creates noisy interconnections.
A common solution to these noisy hum and buzz problems involves disconnecting one end of the shield, even though one can not buy off-the-shelf cables with the shield disconnected at one end. The best end to disconnect is the receiving end. If one end of the shield is disconnected, the noisy hum current stops flowing and away goes the hum -- but only at low frequencies. A ground-sending-end-only shield connection minimizes the possibility of high frequency (radio) interference since it prevents the shield from acting as an antenna to the next input. Many reduce this potential RF interference by providing an RF path through a small capacitor (0.1 or 0.01 microfarad ceramic disc) connected from the lifted end of the shield to the chassis. (This is referred to as the "hybrid shield termination" where the sending end is bonded to the chassis and the receiving end is capacitively coupled. See Neutrik's EMC-XLR for example.) The fact that many modern day installers still follow this one-end-only rule with consistent success indicates this and other acceptable solutions to RF issues exist, though the increasing use of digital and wireless technology greatly increases the possibility of future RF problems.
If you've truly isolated your hum problem to a specific unit, chances are, even though the documentation indicates proper chassis grounded shields, the suspect unit is not internally grounded properly. Here is where special test cable assemblies, shown in Figure 3, really come in handy. These assemblies allow you to connect the shield to chassis ground at the point of entry, or to pin 1, or to lift one end of the shield. The task becomes more difficult when the unit you've isolated has multiple inputs and outputs. On a suspect unit with multiple cables, try various configurations on each connection to find out if special cable assemblies are needed at more than one point.
Balanced audio test cable

Figure 3. Balanced audio test cable

See Figure 4 for suggested cable assemblies for your particular interconnection needs. Find the appropriate output configuration (down the left side) and then match this with the correct input configuration (across the top of the page.) Then refer to the following wiring diagrams.
Cable connector table
cable wiring
cable wiring

Figure 4. Interconnect chart for locating correct cable assemblies.

Note: (A) This configuration uses a standard "off-the-shelf" cable.
Note: (B) This configuration causes a 6 dB signal loss. Compensate by "turning the system up" 6 dB.

Ground Lifts

Many units come equipped with ground lift switches. In only a few cases can it be shown that a ground lift switch improves ground related noise. (Has a ground lift switch ever really worked for you?) In reality, the presence of a ground lift switch greatly reduces a unit's ability to be "properly" grounded and therefore immune to ground loop hums and buzzes. Ground lifts are simply another Band-Aid to try in case of grounding problems. It is, however, true that an entire system of properly grounded equipment, without ground lift switches, is guaranteed (yes guaranteed) to be hum free. The problem is most equipment is not (both internally and externally, AC system wise) grounded properly.
Most units with ground lifts are shipped so the unit is "grounded" -- meaning the chassis is connected to audio signal ground. (This should be the best and is the "safest" position for a ground lift switch.) If after hooking up your system it exhibits excessive hum or buzzing, there is an incompatibility somewhere in the system's grounding configuration. In addition to these special cable assemblies that may help, here are some more things to try:
  1. Try combinations of lifting grounds on units supplied with lift switches (or links). It is wise to do this with the power off!
  2. If you have an entirely balanced system, verify all chassis are tied to a good earth ground, for safety's sake and hum protection. Completely unbalanced systems never earth ground anything (except cable TV, often a ground loop source). If you have a mixed balanced and unbalanced system, do yourself a favor and use isolation transformers or, if you can't do that, try the special cable assemblies described here and expect it to take many hours to get things quiet. May The Force be with you.
  3. Balanced units with outboard power supplies (wall warts or "bumps" in the line cord) do not ground the chassis through the line cord. Make sure such units are solidly grounded by tying the chassis to an earth ground using a star washer for a reliable contact. (Rane always provides this chassis point as an external screw with a toothed washer.) Any device with a 3-prong AC plug, such as an amplifier, may serve as an earth ground point. Rack rails may or may not serve this purpose depending on screw locations and paint jobs.

Floating, Pseudo, and Quasi-Balancing

During inspection, you may run across a 1/4" output called floating unbalanced, sometimes also called psuedo-balanced or quasi-balanced. In this configuration, the sleeve of the output stage is not connected inside the unit and the ring is connected (usually through a small resistor) to the audio signal ground. This allows the tip and ring to "appear" as an equal impedance, not-quite balanced output stage, even though the output circuitry is unbalanced.
Floating unbalanced often works to drive either a balanced or unbalanced input, depending if a TS or TRS standard cable is plugged into it. When it hums, a special cable is required. See drawings #11 and #12, and do not make the cross-coupled modification of tying the ring and sleeve together.


If you are unable to do things correctly (i.e. use fully balanced wiring with shields tied to the chassis at the point of entry, or transformer isolate all unbalanced signals from balanced signals) then there is no guarantee that a hum free interconnect can be achieved, nor is there a definite scheme that will assure noise-free operation in all configurations.

Winning the Wiring Wars

  • Use balanced connections whenever possible, with the shield bonded to the metal chassis at both ends.
  • Transformer isolate all unbalanced connections from balanced connections.
  • Use special cable assemblies when unbalanced lines cannot be transformer isolated.
  • Any unbalanced cable must be kept under ten feet (three meters) in length. Lengths longer than this will amplify all the nasty side effects of unbalanced circuitry's ground loops.
  • When all else fails, digitize everything, use fiber optic cable and enter a whole new realm of problems.


  1. Neil A. Muncy, "Noise Susceptibility in Analog and Digital Signal Processing Systems," presented at the 97th AES Convention of Audio Engineering Society in San Francisco, CA, Nov. 1994.
  2. Grounding, Shielding, and Interconnections in Analog & Digital Signal Processing Systems: Understanding the Basics; Workshops designed and presented by Neil Muncy and Cal Perkins, at the 97th AES Convention of Audio Engineering Society in San Francisco, CA, Nov. 1994.
  3. The entire June 1995 AES Journal, Vol. 43, No. 6, available $6 members, $11 nonmembers from the Audio Engineering Society, 60 E. 42nd St., New York, NY, 10165-2520.
  4. Phillip Giddings, Audio System Design and Installation (SAMS, Indiana, 1990).
  5. Ralph Morrison, Noise and Other Interfering Signals (Wiley, New York, 1992).
  6. Henry W. Ott, Noise Reduction Techniques in Electronic Systems, 2nd Edition (Wiley, New York, 1988).
  7. Cal Perkins, "Measurement Techniques for Debugging Electronic Systems and Their Instrumentation," The Proceedings of the 11th International AES Conference: Audio Test & Measurement, Portland, OR, May 1992, pp. 82-92 (Audio Engineering Society, New York, 1992).
  8. Macatee, RaneNote "Grounding and Shielding Audio Devices," Rane Corporation, 1994.
  9. Philip Giddings, "Grounding and Shielding for Sound and Video," S&VC, Sept. 20th, 1995.
  10. AES48-2005: AES standard on interconnections "Grounding and EMC practices -- Shields of connectors in audio equipment containing active circuitry" (Audio Engineering Society, New York, 2005).
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From Rane Corp. Used by permission. 

User Review of the Elite Core HS09 Earset Mic

Countryman's E6i and E6o mics continue to be the "go to" earset mics for churches around the globe.  DPA's d:fine mic is making an excellent case for "the best" at the high end price point.

I've been looking to find the "right" mic for a good earset mic, that may not be up to Countryman's audio quality, but is also not up to Countryman's price. I think I may have found it.

This is a review from a church tech director who took the time to compare the Elite Core HS09 with the Countryman E6 mic. Here's what he concluded:


Hey David,

I wanted to take a second and shoot you a quick evaluation of the [Elite Core HS09] headset mic I bought from you last week.

As you may or may not remember I bought this mic to be a backup/guest mic.  I didn’t want to spend the cash for an E6 so you helped me find this solution.

When I first unpacked the mic I was worried about the lack of flexibility and mold-ability.  But when I put it on, the mic was very stable as it was shipped.  When our [guest] speaker wore it yesterday, his experience was exactly the same.  

It didn’t sound exactly like the E6.  But when we used the E6 and then something else happened, and then we used this mic it sounded like the E6.  Which is to say, it sounded pretty darn close. In fact, it was so close that I used almost the same EQ curve that I had for one of my E6's.

It also seems to be pretty hardily built.  The E6 seems fragile (which is probably a result of the ability to mold it so easily).  This mic seems as though I can slap it on a kid during a Christmas production and I don’t have to worry about them.  

I did not like where the wire connects to the head piece.  I think it’s great that it connects by screwing on, but the placement is a little awkward and is very visible on the wearer.

Overall, I was very pleased with the purchase.  I will continue to purchase E6’s for my senior pastor, but for those that speak for a few moments in the service I may switch to these.

I thought you may enjoy seeing my thoughts on this mic.

Matt Lampley
Pastor of Media and Communications
First Baptist Albany, Georgia

FCC Changes in Wireless Reallocation Plans

Last Fall, the Federal Communications Commission announced plans for an incentive auction of the 608 to 698 MHz UHF spectrum — the previous UHF TV channels 36 through 51. Many of these frequencies in this 600 MHz band are used by professional audio users, whether for wireless mics, IEM's, intercoms and IFB talent cueing systems. 

Ironically, some of these affected systems migrated to those frequencies after the FCC's previous “reallocation” of TV channels 52 to 69 (the so-called “700 MHz band” from 698 to 806 MHz) in 2008, which were made illegal for pro wireless applications after June 12, 2010. But a recent change at the FCC may spell some good news for pro wireless users.

Major telecom providers —among them ATT and Verizon — have been anxious to snag every bit of that bandwidth, and with billions of dollars at stake (possibly as high as $20B), it is unlikely that pro audio users could possibly compete in a bidding war against these corporate giants. However, leading manufacturers of pro wireless have been very active in working with the FCC to make the commission aware of the needs of our industry and there may be a ray of hope on the horizon.

The first good news came from a recent announcement by FCC commissioner Tom Wheeler that the Broadcast Television Spectrum Incentive Auction — originally scheduled to begin in 2014 — has been rescheduled to next year, which hopefully would give the FCC more time to examine the issue.

Stage Directions recently spoke to Shure VP Mark Brunner, seeking an update on the reallocation proceedings from the pro industry's standpoint.


“As you know, the FCC is planning further auctions of the UHF television spectrum,” Brunner explains. “Those auctions have now been moved back to mid-2015, with a report in order sometime in the late spring regarding the rules of the incentive auction, which will indicate how much of the UHF band will be made available for auction to licensed users and the telecom companies — ATT, Verizon, T-Mobile — and the future rules relating to wireless microphone operations. Many things are under consideration here — reserved channels for wireless microphone operation, their future and the future status of those channels; also guard-band access between the licensed swaths of spectrum and how much of that could be made available for wireless microphone use. These are open issues the FCC is considering right now.”

And the pro audio community is united in this regard. “The wireless microphone industry and many of the manufacturers are in discussions now to put forward plans and ideas forward to the FCC on the best way for our industry, indicating our needs and our use of UHF spectrum on a daily basis across a variety of industries,” Brunner continues. “The industry and Shure, Sennheiser, Audio-Technica and Lectrosonics remain committed to putting the best foot forward for our users and making sure the commission is aware of our issues. We will continue to advocate for wireless microphone operations and protections going forward as further spectrum decisions are made.” 

For more info, visit


Preliminary Report: More Wireless Channels May be Taken

This is only a preliminary report, but that’s appropriate, as the information described here is still not finalized.

The FCC is giving pretty suggestive indications that they’ll be taking more bandwidth away from our range of available wireless microphone frequencies. Nothing is firm yet, but it appears that they’re targeting part of the 600 MHz range

The clearest indications are suggesting that the change wouldn’t happen until 2017 at the earliest, though that may be an early date. Those sources are also suggesting that the frequencies being considered are the 658 MHz to 697 MHz.

You’ll remember that the FCC sold 698 MHz to 806 MHz in 2008, largely to cell phone companies, though much of one block was purchased for television broadcasts. The sale generated $19.592 billion; that’s a lot of money, and it appears that they’re motivated by the same goals again.

There are some significant differences this time around:

·         The preliminary reports are that they’re looking at fewer frequencies (658 MHz to 697 MHz), though that decision, like all the others, is still up in the air; it remains possible that they could expand the auction.

·         There has been some not insubstantial noise made, largely by Sennheiser, to require the winning bidders to compensate the existing bandwidth users (that would be you and me!) for the loss of the use of the frequencies.

·         There is apparently discussion going on about re-opening some of the frequencies that had been previously removed from availability to wireless microphone use. The rumors center around frequencies “adjacent to digital TV channels.”

·         Last, but certainly not least, the FCC appears to be working with a more transparent process this time around. This is, in reality, pretty advance information: much better than last time!

While discussing these changes in the RF spectrum, and the growing demand for the very limited amount of RF spectrum that’s available (a limitation of physics), we discussed other options for the demand for wireless audio devices. We discussed infrared technology, Bluetooth, and WiFi as potential options among those technologies currently available. Nobody admitted to be working on completely new technology.

Disclaimer: This article is a summary of “not authorized for public announcement” conversations about public information. While the individuals in the conversation are very familiar with the industry, much of this is rumor and none of it is an official announcement (as far as I know) yet. This article is merely discussing rumors in the field.

And even the most alarming rumors are certain that nothing will happen until 2017 at the earliest. This is not (this time) a rush project.

A Skeptic Looks at the Behringer X32

You want my perspective on the Behringer X32?
This is the place in the conversation where I generally hesitantly ask, “Do you want the polite answer, or do you want my honest and politically incorrect answer?” 

But I know which one you want. So here goes:

Behringer is marketing this, as some have said, as “a Midas design wrapped in a Behringer blanket.”
When I first heard it, I discussed that concept with Midas factory people, and in the process, I learned some fascinating new swear words. . . .

The first report was “The X32 has Midas preamps,” which also generated substantial “highly colorful invective” from Midas.

The second report was, “Midas helped us design the preamps” which, I’m told, is enough closer toward the truth, so that you can even see the truth from there (“ *cough!* They made a phone call.”), but still brought colorful invective into the conversation.  

At that point, it appears that Uli Behringer’s name was brought into the conversation, and the Midas guys were reminded who it was that signed their paychecks…. Now they try so very diligently to stay out of that conversation, but they do toe the party line when you push them.

From an outside-of-Behringer perspective, the X32 board is kind of confusing to me: it is actually far better built than Behringer analog boards, and it both works and sounds better than the previous Behringer digital board (which gave new scope and clarity to the term “hot mess”).

A friend whom I trust (and who drives an Avid SC48 regularly) may have said it best: “Huh. It doesn’t suck. Who’da thought?” And now he recommends the X32 to small churches.

The board sounds pretty good. I can’t comment on “better than the other guys” because I don’t have that comparison data, though I do know that Behringer has earned their reputation for over-statement (see above).
A better question for the entry-level digital board world is, “Does it sound pretty good?” And yes, it really does sound pretty good! It doesn’t suck! 

Does it sound better than the other guys? No, but it's not unusable. 

It’s not as easy to use as some others digital consoles; in fact, they actually are consistent with Midas on that issue: neither digital console is very intuitive! But it’s not ridiculous. It can be learned.

The more important question is whether it will last as long as the functionally bulletproof industry leaders (who have asked not to be named in an article about Behringer). The answer to this one is as yet unknown, but I haven't met a single person who was willing to even entertain the idea that it might.

The X32 doesn’t have the legacy of durability on its side. Behringer analog consoles have had a rough failure rate (in my experience) over the past year, and the first shipment of X32s had a 50% fail rate (my experience; I’m told it was closer to 30% nationally), but they seem to have fixed that; recent shipments have not had failures: none. I confess that I am going to be very interested to see how long they DO last.

Behringer has got a few things incredibly right:

·                     Price point. ‘Nuff said. Ain’t nobody does price point like Behringer does.
·                     Moving faders. I don’t know that most churches need moving faders, but some a lot of sound guys want to have ‘em just to have them. (One of my concerns: moving faders strike me as the best candidate for the first break point on an economy-built board.)
·                     Gadgets: It’s easy to add Behringer personal monitor mixers and (“AND!” Are you listening, Soundcraft?) their digital snake. No, I know that nobody in their right mind, buying a board in this price range needs a digital snake. But they want one.
·                     It doesn’t suck! Either in sound quality or in usability. Again: that’s worth noticing. This is a very usable board.
·                     Price point. Did I mention that? This is an awful lot of digital mixer for $3k. Wow.
·                     Durability: This is the scary part of the conversation.

The thing that scares me the most is what I call the TT24 Syndrome: There was another price-point-driven digital mixer a few years back that comes to mind. I won’t mention the brand name, because that’s not polite, but it was a great mixer, when it came out of the chute! It sold well and performed well over the first couple of years. They were wonderful!

And then the factory had some challenges: they had done quite well in developing the board and selling the board, but they didn’t do as well supporting it. And pretty soon, the firmware updates were fewer, and there was more time between them, and they didn’t solve as many of the outstanding issues… Eventually, the whole project was kind of swept under the carpet in the back of their unnamed Woodinville warehouse, and nobody ever talks about it any more.

Behringer can smile and point to features all day long, but the real-world success of the mixer won’t actually be determined in 2013, and probably not in 2014 either.

On the other hand, for a $3000 mixer with all these features? You know, it doesn’t suck. I think I'm impressed!

Pro Audio Parade Music

I’ve been researching: How do you do pro audio for a Fourth of July Parade? In this case, we’re trying to give a bunch of dancers some dancing music and share that music with the audience, but we could be playing music on a float or a trailer. I know lots of churches who are involved in parades nowadays, and their entries always involve music. How do we make parade music so that everybody can hear it, and so it doesn't sound like garbage?

We’ve all seen the little battery powered systems; they’re great for a small group in a quiet environment, but they aren’t enough for sound in a parade: the high school marching band two blocks away will overwhelm it. Let's save these for mission trips or fellowship halls (they're pretty good for that!).

I consulted with Fred Tomke an engineer at QSC Audio. Fred knows his stuff: he’s been using his own K12 speakers on top of a bus in his own local Fourth of July Parade for a few years. OK, Fred, what do I need to power them properly?

It turns out that the only thing you need is a competent inverter for the vehicle. He uses a “basic 800 watt” inverter to power his (2) K12 speakers (1000 watts each), a small mixer, and a CD player. He says he’s never run out of headroom. “The secret is in the power supplies on the speakers: they’ll handle anything from 85v to 240v.”

To connect multiple devices (like the mixer, CD player, and multiple amps), just use a power strip. And we ended up using the smaller, broader-dispersion K8 speakers on this project: The smaller size made it easier to load onto their minivan’s roof rack, and the 105ยบ dispersion pattern means more people alongside the parade route will hear it, even if you lay the speakers on their side (as any sensible minivan driver would do!). It still has the same 1000 watt amp built in, so “loud enough” is not an issue.

The little JBL EON210P system will also work nicely in this environment: a little poweredmixer and two 10” main speakers.

There is one important detail: don’t use an inverter that connects via the vehicle’s cigarette lighter. That lighter is limited, typically, to about 5 amps, and you’ll pretty much need all 6.7 amps that an 800 watt inverter can provide. Instead, use one of the inverters that connects directly to the vehicle’s battery, or extend to the battery with 10- or 12- gauge cables.

Oh, and make sure you vehicle is running. This kind of power consumption will drain your battery pretty quickly.

With this kind of setup, you can get loud enough that the parade officials will come tell you to turn the music down! Or you can use this system for your concert-in-the-park after the parade!

Happy Fourth of July.

Using the Presonus Studio Live Mixer

The Presonus StudioLive digital mixer may be the most popular small mixing board for churches this year. But as easy as it is to operate, it's not the same as an analog board.
Recently, Presonus's Rick Naqvi did a very detailed webinar on the board. It's an excellent source for learning how to use the new board.