designing commercial systems for maximum performance and profit

Designing Commercial Systems for

Maximum Performance & Profit

2/17/2015

Introductions

Rodney Rupp

Sales Application Engineer– Harman Professional

© 2013 HARMAN. All rights reserved. 1



2/17/2015

The Gear – What’s The Difference?

Quality / Dependability Issues • 24/7 Usage

Warranty Concerns • Is Commercial Use Covered?

Performance Depth • Volume requirements / Paging Headroom

• System Functionality / Use of Microphones

Efficiency in Design • Low Z (8 ohm) vs. Hi Z (70 volt)


Lets Look at the Low Impedance Way

Low Impedance means WHAT? • This refers to 8/4/2 Ohm Means of Connecting Speakers

– Conventional Home Stereo

• Requires Load Balancing if several speakers are needed

– Either additional Hardware required or Complex Series Parallel Connections

• Requires Large Gauge Conductors; copper is expensive!!

– Copper Costs UP 4X in just last 10 years

• Requires More of this High-cost Wire for Load Balancing

– More Home Runs

4 © 2013 HARMAN. All rights reserved.

Power Drawing

70/100V

(Amplifier)

Speaker Wire

Speaker

Transformer

Speaker


There Must Be A Better Way…

Constant Voltage Speaker Systems • 25V Systems

– Used primarily in schools K-12

– Class 2 Wiring in the USA and no conduit required in most cases (Open cable is acceptable in most localities; check local standards adopted)

– Less loss and easier applications over 8 Ohm Series Parallel

• 70V Systems

– Used in many applications from Life Safety, Industrial, Medical, Stadiums, Education, Clubs, Themed Entertainment

– Class 2 Wiring in the USA and no conduit required in most cases (Open cable is acceptable in most localities; check local standards adopted)

– Less loss than 25V, as it is higher voltage

• 100V Systems

– Used in similar applications as 70V; more prevalent outside the USA

– Less loss than 70V, as it is higher voltage

– Must be in conduit in USA; voltage exceeds Class 2 Standards


Constant Voltage Speaker Systems

Advantages

High Z Systems - 70V Systems; 100V Systems

• Multiple loudspeakers: Many loudspeakers can be driven by a single

amplifier without complex series/parallel connection schemes.

• Multiple power levels: Different sound-pressure-level targets can be

achieved at different listening areas while still using a single amplifier.

• Less expensive: Since the voltage of the signal has been stepped up

and the current is relatively low, lighter, less-expensive cable can be used

without incurring additional loss. Where a typical 8 ohm speaker system

might require 12 gauge cable, a 70 volt system could use 18 gauge or

smaller cable.

• System expansion: A 70 volt system can be expanded easily.

• Easy volume adjustment: A passive volume control may be installed to

give the user easy, level control over a single loudspeaker or a multiple-

speaker zone.


Constant Voltage Speaker Systems

Disadvantages

25V Systems; 70V Systems; 100V Systems

• Distortion: Overdriven transformers can add distortion. Additionally, low-

cost transformers are prone to distortion at higher power levels. However,

distortion can be present in all types of systems. Proper engineering will

avoid these complications.

• Insertion loss: The transformers themselves commonly reduce total

power applied to the loudspeakers by 10-20%. At 1 watt tap, this

represents 1.1 to 1.2 watts.

• More expensive: Some local building and electrical codes may require

70 and 100 volt cabling to be carried within conduit, increasing the overall

project cost.

• Difficult troubleshooting: Since constant voltage systems tend to have

many speakers, locating the defect is sometimes difficult. If there is a

short circuit half way to the end of the circuit, sound can still be present in

the first half and it may not be obvious where the issue is.


Which makes more sense? • Residential you can control or anticipate where the listener

will sit.

– We can expect that the stereo or surround image will benefit

the listener

• Commercial there is no control or anticipated location of

the listener.

– We would not want the user sitting under a speaker to only

hear one channel of content?

Therefore Home theatre = Stereo or Surround

Commercial Systems = Mono



In the Home this is what we

are trying to recreate.


In Commercial this would

represent the missed

content.

Restaurant & Bar

Floor Plan 6 Speakers Bar

4 Speakers Host

14 Speakers Seating

3 Zones


s s s

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Restaurant & Bar

Low Z Method (Series Parallel) Series Parallel Network at Equipment Location

½ hr per speaker

8 hrs per 1000’ wire

¼ hr per termination@Rack

Approx 950’ cable required

Complexity = HIGH


s s s

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Restaurant & Bar

High Z 70Volt Method All Speakers in each Zone in Parallel

½ hr per speaker

8 hrs per 1000’ wire

¼ hr per termination @ Rack

Approx 450’ cable required

Complexity = LOW


s s s

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s s s s

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Restaurant & Bar

Which one looks easier?

Which one Saves you Install Time?

Which One saves you Cable?

Which one allows you to use smaller cable?

Which one puts more money in your pocket?

Do you Like More Money?


Residential Home


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Floor Plan 9 Speakers

1 Zone

Residential Home


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Low Z Method

Look at all this Cable!!

Residential Home


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High Z Method

Small Doctors Office


s

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v

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Floor Plan

1 Speaker and Volume Control per

Room

9 Speakers in Hallways for Sound

Control



s

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v

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v Would a Doctor of sound do this?

Low Z Method



s

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High Z 70 Volt Method

Residential Home

Which one looks easier?

Which one Saves you Install Time?

Which One saves you Cable?

Which one allows you to use smaller cable?

Which one puts more money in your pocket?

Do you Like More Money?


Audio Essentials –

Ceiling Speaker Coverage

Sound Pressure Level decreases with Distance

Speaker Efficiency


Typical 70 Volt System Calculations

Control 29AV-1 Nominal Sensitivity 90db 1w1m

90db@ 3.3’

90 – 6db at 6.6’ = 84db

84 – 6db at 13.2’ = 78db So we have 78db @ 1 watt

Sports Bar and Grill Application = 90db SPL Goal

Ceilings at open to deck at 16’

Patrons are seated

16’ minus 3’ on average for seated patrons = 13’

13’ minus 2’ for speakers mounted at bottom of Ceiling structure = 11’ . Therefore we need our 90db Goal at 11’


So now we need to calculate TAP for the speaker to hit our 90db Goal

Typical 70 Volt System Calculations

78db @ 1watt

78 + 3 = 81db @ 2watts

16 watts

81 + 3 = 84db @ 4 watts

84 + 3 = 87db @ 8 watts

87 + 3 = 90db @ 16 watts

So what is our tap to be set at?????

Typical 70 Volt System

You have a 500 watt per channel, 70volt amplifier • Crown CDI-1000

You have 44 speakers adjusted to 14 watts each • JBL Control 29AV Speaker (Sensitivity :90 dB (35Hz – 20kHz),1W, 1M)

• 44 Speakers X 14 watts each Divided into 2 zones = 308 watt load per

circuit

192 watts of reserve power (Future growth and

Headroom)

At 14 watts you could potentially use 64 speakers!

IT’S AUDIO BY THE ACRE!

Designing a System - Density Options - Square

Edge to Edge Minimum Overlap Full Overlap




Square or Symmetrical Used to keep the ceiling

Looking Symmetrical.

Hexagonal or Alternating Can Save Some Money 14 vs 16 Speakers



Key Takeaways…

Specify commercial gear in appropriate applications…

Know when a 70 volt solution makes the most sense…

Understand and communicate the cost efficiencies and

profit opportunities that come into play…

Know the basics of calculating a Tap…

Understand speaker coverage density and turn it into an

opportunity…

Use the resources available to you from Harman…


Troubleshooting

Why can’t I use my Ohm Meter? • Ohm Meter uses DC Voltage and on a coil will only

indicate the resistance of the actual wire, but not the

Impedance of the coil.

• Looks more like a short, as a “length of wire” and Not

As a COIL.

How do we check coils? • Impedance Bridge checks coils for Impedance at a

given frequency. (1Khz Typical)

If we are going to do the job, we need to

have the right tools!!


Troubleshooting

Use the Bridge to check your entire load and use the

equation we learned earlier. E = Voltage Squared Divided

by Impedance • Lets say the Bridge reading states 125 Ohms

• 70.7 X 70.7 = 4998.49 (5000)

• 4998.49 divided by 125 = 40 watts on this speaker line

• Benefit is this checks both the wire/transformers/speakers and is the

actual wattage the amp will be loaded to.

• This takes the guesswork out of it!!

Note: Document your Bridge readings on your job documents so later, when

you get called back, you can look for the same reading. If it is not, then you

have an issue on speaker load.


Troubleshooting

Shorts – How do I find the needle in the haystack? • Listen to the system and walk the system.

• IF it works but is much lower than expected, walk the speakers and listen

for a drop. Walk back a few speakers and split your circuit here.

• Take Bridge reading at this point on the open (not connected to amp) part

of the circuit. Does it represent what the load should be? Adding up Taps,

then using the Bridge reading. Are they approximately correct?

• Keep halving your speaker circuit, checking both ways without connection

to amp to find the short.


Troubleshooting

Other cool tools for 70V and audio systems

in general • Music Supply Company TS-1A Audio Test Set

• Use it as a speaker, mic, check output line level, etc.…

• Best tool on the planet for checking audio systems


Thank you

Insert Audience

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