Live Performance Sound


While cost is going to be an ultimate factor in the selection of your live sound gear, also consider:

Flexibility. Can your unit be expanded or connected to a larger system for those occasional uses? Can it be used for recording? Can it be used for monitor mixes on a large scale concert tour? Multiple voltages for foreign tours?

Weight. You have to lug this stuff to gigs. Can one person carry each separate item of the collective package or will two people be need to move speakers and mixing board?

Size. How well does it fit in your van or trunk? Do you have to tie the hood down, leaving part of a speaker exposed?

Sound. Does it sound good? Will it handle the kick drum or keyboards for larger venues without cracking the speaker cones or distorting? Does it have a 9 band or better graphic EQ to “ring out” a room and lessen feedback in specific frequencies?

Rule of thumb says 1 ½ watts of power for each person. Sound diminishes logarithmically to the distance from the source to the person (in other words as you walk away from the speakers the sound drops considerably) and tones shift (bass tends to become muddy at a greater distance).

Let’s talk about specifications, the biggest thing you need to know is that output power (in audio wattage) depends on the resistance (impedance) of the circuit as measured in ohms. A lot of specifications promise 50 Million Watts and in small print you see “at 2 ohms” – you won’t find 2 ohm speakers. Mostly you’ll find 8 ohm speakers and some 4 ohm speakers. If you wire speakers together improperly the ohmage could rise. Running a big power amp at a resistance that is improper for it will damage the amp and probably blow the power transistors or the main output transformer (and that gismo will cost $100 - $200 to replace). Most amps are designed to run at 8 ohms, a few at 4 or 8 ohms. Rarely do you find 2 or 16 ohm units.

An amp rated at 200 watts into 2 ohms will deliver 125 watts of sound power at 8 ohms or enough for 75 people in a small room.

Wattage is rated at “peak” for most units. This means full output from the mixing board into the amp, with a spike caused by the singer screaming. The maximum signal that amp can crank out, which is usually twice the average (RMS – Root Mean Squared) power output. So that 125 watts of audio power, rated peak, delivers 60 to 70 watts average sound. Enough for 35 to 50 people in a small room.

Speakers should be rated for 25% or more power above the peak output of the amplifier. So for your 200 Watt peak amp rated at 2 Ohms which delivers about 130 watts of peak power into an 8 ohm speaker you need a speaker that can handle 165 to 175 watts of peak power, otherwise you’ll be re-coning woofers and buying $125 voice coils for tweeters and horns on a regular basis!

Putting a compressor limiter between your mixer and power amp is a good idea to help lessen the transient peaks that can damage horns and tweeters.




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Speakers are rated in “ways” and there are one way (single type of speakers), two way (two types – low sounds and high sounds) and three way (low, mids and highs). High frequencies can damage big, bass type speakers. Low frequencies can damage small, high end speakers. To block these frequencies they use what is called a “cross-over” system which is nothing more than a capacitor set to a given value (that’s how tone controls in your guitar and amp work). These capacitors block certain frequencies (technically a process called a notch filter). Some people buy one way speakers in all tonal ranges and hook those up to separate amps with crossovers or in combination with the other speakers on the same amp, again with crossovers. You must always remember to use to correct crossovers, make sure all the speakers are rated above the power output at peak and wire them together so the ohmage always remains within the limits of your amps (generally 4 or 8 ohms for most systems).

For small clubs, churches, solo performers doing small shows and rehearsal with a single instrument or playback tape, a 100 watt system with a 10” woofer and a small horn or tweeter may work out just fine. Get a 12” woofer when possible, it will deliver a richer sound and handle more power.

Larger venues will need 15 or 18” woofers, a large horn midrange and maybe a tweeter. Make sure each of these speakers is rated for the work load (all of them must have the same power rating which is distributed or added together for all of the speakers). For a 100 Watt peak rated 8 ohm system the ideal speakers should be rated at 150 Watts or better.

Find out how much it will cost to replace voice coils on any horns in your system and don’t be shocked to find out these run anywhere from $50 to $150 each. If you burn out the horns too frequently, you should install a better crossover with a volume control or use a limiter on the mixing board.

There are two sub-groups of speakers. Self-powered and passive. Most people work with passive speakers so they can change or replace the power amps. If a self powered speaker goes out the whole thing goes in for repair.

Square speaker boxes are used for side fills and pointed towards the audience. Floor wedges are used for the performers. These can sometimes be self-powered, which can be an advantage. You normally don’t run the volume on these as high as the “mains” pointed out to face the audience! Your mixing board needs to provide a separate “feed” of sound level to these monitors. Separate tone or EQ would be nice, but rarely used by most players. If you get passive wedges you will need to have another power amp to feed the floor monitors.

In a situation where you must put the whole band through the PA for outdoor concerts you will need a robust speaker, such as the massive Voice of the Theaters or the very popular Cerwin Vega V-35s with the 18” woofer. Two to four of these work well for a small audience.

I’ve seen smaller Bose speakers that sit on stands used commercially. These do a very good job for vocals both inside and outdoors, but they will not work well for keyboards or drum kits, so these smaller, lighter speakers are only for intimate outdoor or small size indoor uses.


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Powered Mixers and Systems




Nady SPM 835 without speakers
List: $370.00

35W per channel, and is a perfect system for small venue live sound for DJs or performers. Its eight inputs include four mono balanced XLR mic along with 1/4" unbalanced line ins, and four stereo unbalanced RCA inputs. The stereo channels can be switched for line or phono levels. It provides stereo master mix output for balanced or unbalanced connection, post-fader aux send with aux level control, stereo aux return with master control, 3-band EQ on mono channels, stereo headphone output with dedicated volume, tape-in and record-out RCAs, switchable global +48V phantom power on all mono inputs, input trim controls on all channels, pan pots on mono channels and balance knobs on stereo channels, and more. Internal AC supply. All-steel construction for more road worthiness.





Fender LX-1504 INCLUDES SPEAKERS
List: $400.00

Nice entry level system for a singer to rehearse with and do small showcases or mall grand openings. It has internal reverb, offers some ability to patch in to other effects and systems, uses a 10” woofer which is a little small, but light weight, making this more for pop music not loud rock. The “brain” accepts ¼” and XLR inputs. Minimal tone adjustments. Takes up to four separate inputs of mics or instruments.








Crate PA6FX (without speakers)
List: $400.00

A mixer, equalizer, effects unit, and power amp – all in a single unit that's rugged, easy to transport, and simple to operate. The amp section delivers 160W into 4 ohms. The mixer section gives you 6 mono channels with 2 bands of rotary EQ, a 3-band rotary master EQ, Hi-Z and XLR inputs. Effects include digital reverb, chorus, and delay. Other features include 2 effects loops, a tape/aux in, and a tape out. 10" x 18" x 9.5". 29 lbs.







Rogue PRM806 (without speakers)
List: $400.00

80W powered mixer is equipped with 1/4" and XLR inputs, high and low EQ, and master reverb. Includes a mono effects loop, tape in and out jacks, send and return jacks, eight-ohm speaker outs, carrying strap, rugged vinyl covering, and corner protectors.





Rogue Roller PA INCLUDES SPEAKER
List: $400.00

Four-channel mixer includes XLR and 1/4" inputs on every channel, with gain, reverb, and 2-band EQ. The master section has volume, reverb, 3-band EQ, effects send and return, plus tape in and out. 10" speaker with dome tweeter. 50W of power. Built-in wheels and a collapsible handle. Perfect for gigs in smaller rooms. Easy on your back, easy on your budget.












Kustom KPA 4 PA INCLUDES SPEAKERS
List: $500

Four-channel powered mixer, cabs – and a rock-bottom price! Big-time value on a compact PA package that's just right for clubs, coffee houses, or other smaller venues. Includes Kustom's KPM4060 compact, four-channel, 60W PA powered mixer with built-in reverb; and two KSC10 cabs loaded with high-quality 10" speakers and piezo tweeters. A great deal on a solid PA system. 91 lbs.








Yamaha EMX640 (without speakers)
List: $650.00

6-channel mixer, a digital reverb, 2 graphic EQs, and a 2-channel amp for driving monitors and mains. RCA jacks are provided for taping on a standard deck. It's designed to allow use of additional amps and mixers when you want to expand.




Mackie 406M (without speakers)
List: $700.00

Delivers 500 real watts into 2 ohms from twin 250W FR Series High Current power amps, switchable as mains or mains plus monitor. Mixer provides six mic/line channels with inserts, input gain controls with level set LED on each channel, active 3-band EQ on each channel, and two separate 9-band graphic EQs for mains and monitors.




Components





Amps


Crown XLS 202
List: $300.00

For bands and mobile DJs. Features a rugged three-space chassis, front-panel controls and indicators, XLR input connectors, binding post output connectors, built-in high-pass filter, and built-in limiter. 145 watts per side at 8 ohms; 200W per side at 4 ohms. 30 lbs. Good for rehersals, weddings and small clubs.




Crown CE1000
List: $740.00

560W per channel into 2 ohms, 450W into 4 ohms, and 275W into 8 ohms, and 1100W into 4 ohms bridged. It works with any line voltage and its Switch Mode Power Supply allows enormous power with less weight. Other features include sophisticated protection circuitry (from shorted, open, or mismatched loads, input and high frequency overloads), a five-way fault indicator, a red LED on each channel that turns on when distortion becomes audible, a green signal-present LED, detented level controls, a mode select switch for stereo or bridged, three-speed fan, and global power supply.



Speakers



B-52 MI-15
List: $310.00 each

U.S.-made 15" woofer and one-inch titanium compression driver. 16-gauge perforated steel grill, rubber feet, and protective metal corners. Rugged carpet cover. Handles 200W.









EV Blem SX80
List: $310.00 each

Small, light for singers. 8” woofer. Handles 175 watts. Weights 18 pounds.






EV Force 15
List: $470.00 each

High-output, two-way system with a 15" woofer and constant-directivity 60x40 degree horn with driver. The speakers incorporate elements of Ring-Mode Decoupling for improved vocal intelligibility and minimized coloring. Power handling is 200W continuous and 800W short-term. The cabinets have a unique design resulting in small fronts but substantial internal volume. They are relatively light but rugged, and feature recessed side handles, corner protectors, and built-in 1-3/8" stand mounts. Each cabinet is 30.25" x 16.9" x 15" deep. 60 lbs.










Mixers (Not Powered)

Nady SRM14
List: $340.00

14-channel stereo mixer with 6 balanced mono mic/line inputs and 4 stereo channels. Includes 6 mono channel inserts. Can be rackmounted or used as a compact desk console. Each channel includes 2 aux level controls, 3-band EQ, L/R pan, and channel gain. Master section includes master and headphone levels, 12-LED meter selectable for L/R stereo master levels or as trim gain/stereo line inputs level, and dual level controls selectable for tape in or aux. Balanced stereo outs are 1/4" TRS. An input trim control is provided for each mono channel, and all mic inputs have 48V phantom power. 2 aux sends (one post and one selectable pre- or post) are provided, as are 2 stereo aux returns. Measures 19" (with rack ears) x 14.6" x 7.1".



Mackie DFX6
List: $380.00

6 input channels (2 mono mic/line and 2 mono mic/stereo line); low noise, high headroom mic pre-amps with +50dB gain range and switchable phantom power on channels 1 & 2; 32-bit EMAC™ digital EFX processor with 16 effects; 5-band stereo graphic equalizer with 12dB boost/cut; 2-band channel strip shelving EQ; 75Hz low-cut filters and inserts on channels 1 & 2; tape and CD inputs and tape output; vocal eliminator; break switch for playing music between sets; and lots more.





Mackie DFX 12
List: $480.00

12 input channels (4 mono mic/line, 2 mono mic/stereo line, and 2 stereo/mono line); low noise, high headroom mic pre-amps with +50dB gain range and switchable phantom power on channels 1 & 2; 32-bit EMAC™ digital EFX processor with 16 effects; 5-band stereo graphic equalizer with 12DB boost/cut; 2-band channel strip shelving EQ; 75Hz low-cut filters and inserts on channelss 1 & 2; tape and CD inputs and Tape output; vocal eliminator; break switch for playing music between sets; and lots more.





Studiomaster C2000
List: $550.00

Big enough for a gig, quiet enough for a studio. 10 mono channels with XLR and line inputs, plus 2 stereo channels and a 2-track tape/cd input. 3-band EQ on each mono channel, 2-band EQ on each stereo channel. 2 aux sends, one pre-fade, one post-fade. Internal power supply.





Spirit M8
List: $850.00

Full 100mm faders for smooth precision control, pro-grade connectors, special grounding features to eliminate crosstalk, and high-end mic pre-amps combine to rival the signal integrity of very expensive mixers. Radically sharp-looking metal rack-rail covers provide extra support. Eight mono input channels plus four stereo inputs and four stereo returns with level control and peak LED. Master gain on AUX inputs. Switchable direct outs, balanced XLRs and 1/4" jacks plus signal detect and peak LEDs on all inputs, with 12-segment LEDs on the main stereo mix. Logical, intuitive, roomy layout and monitoring flexibility. A/D converter and digital out. All this and much, much more ensure pro performance for stage or studio.




Yamaha GF16
List: $1,250.00

4 group outputs and 6 auxiliary outputs in addition to its stereo outputs for great system flexibility in accommodating a widest range of configurations and sources. They feature extremely low noise and distortion and a clean, straightforward channel layout for easy operation. Their full complement of essential features that maximize control. All you need to select is the model with the inputs you require. Has 12 mono inputs plus 2 stereo inputs.

Our Music Special continues with these other articles:
Learning Music | Promo Pictures | Booking Agents| Managers | Producers | Pressing CDs
Record Companies | Copyrights | Recording Software | Sound Cards | Guitar and Bass
Multi-Track Recorders | Live Sound Gear | Microphones | Recording Engineer | Bands in Texas
Teen Band: Y@nK | Gigs and Clubs | Music Theory | Radio Airplay

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