© 2013 CUI Inc

Speakers

© 2013 CUI Inc

PurposeTo provide an overview of CUI Inc speakers

Objectives Introduce speaker structure Introduce speaker working principles Define common specifications Introduce various options among CUI’s speaker line, including

magnet types, cone types, and mounting configurations Introduce typical applications

Content: 14 slidesLearning Time: 10 minutes

Introduction

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Usage

Industries Served Home Appliances Safety and Security Automotive Electronics Office Automation Medical Equipment Industrial Consumer Electronics

Typical UsageAccurate reproduction of voice, music, and various other audio signals.

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Speaker Structure

Cone

Voice Coil

Plate

Magnet

Frame & Yoke

PCB

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Speaker Structure continued

Cap Cone Plate Magnet

Voice coil YokePCB Non-woven cloth

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Working Principle

0

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Key SpecificationsSound Pressure Level (dB)- Sound pressure level, SPL, is the deviation from atmospheric pressure caused by the sound wave expressed in decibels.

Max Input (W)- Maximum power that can be used for a very short period of time without permanently damaging the speaker.

Nominal Input (W)- The nominal input wattage is the amount of power the speaker can safely handle during long-term use.

Impedance (Ohm)- Electrical impedance is the ratio of applied voltage to current. It is important to match the speaker impedance to the system impedance.

Resonant Frequency (Hz)- It is the frequency at which the cone begins to vibrate.

Size (mm)- Frequency range is determined but the size of the speaker. Smaller speakers will operate in higher frequencies, while larger speakers operate in lower frequency ranges. Low frequencies are used to deep bass sounds while mid-range frequencies are used for voice reproductions.

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A perfect speaker would recreate every frequency without attenuation or gain. There is no perfect speaker.

The frequency response curve is a series of data points that represents how a speaker responds to a range of input frequencies.

Frequency Response Curves

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dB stands for decibel

It is not a unit, but rather a numeric scale

Values increase exponentially, instead of linearly as in counting numbers

Expressed in “normal” numbers, 2 dB is ten times 1 dB

Allows for a huge range of values to be expressed in relatively little space

dB’s

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The Human Ear and A-Weighting

Generally, most humans can perceive frequencies from 20 Hz ~ 20,000 Hz.

However, the human ear is more sensitive to some frequencies than others.

A-weighting places more value on frequencies which the human ear is more sensitive to.

Some CUI speakers specify SPL using the A-weight system. I.E. dB A.

Comparison of Different SPL’s

Jet engine at 30 m 632 Pa 150 dB

Threshold of pain 63.2 130 dB

Hearing damage (possible)

20 Pa Approx. 120 dB

Jet at 100 m 6.32–200 Pa 110–140 dB

Jack hammer at 1 m 2 Pa Approx. 100 dB

Traffic on a busy roadway at 10 m

2x10-1–6.32x10-1 Pa 80–90 dB

Passenger car at 10 m

2x10-2–210-1 Pa 60–80 dB

Normal conversation at 1 m

2x10-3–2x10-2 Pa 40–60 dB

Very calm room 2x10-4–6.32x10-4 Pa 20–30 dB

Auditory threshold at 1 kHz

2x10-5 Pa (RMS) 0 dB

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Magnet Types

FerriteFerrite magnets, also called ceramic magnets, are low cost magnets that maintain their magnetic strength well. They are heavy and are not generally used for applications that require portability. Speakers that incorporate ferrite magnets will tend to sound better when driven near the maximum handling capacity.

AlNiCoAlNiCo magnets were the first magnets used in speakers and are what helped give them a smooth tone. Speakers that incorporate AlNiCo magnets are a more expensive option than ferrite-based speakers, but they are less prone to cracking.

Neodymium (NdFeB)Neodymium magnets, also known as rare earth magnets, offer the highest field strength of any permanent magnet known. Speakers made with NdFeB magnets offer a good frequency response, are light in weight and are much smaller than speakers that incorporate ferrite or alnico magnets. This makes them an ideal magnet for small speakers that are required to output a high SPL.

© 2013 CUI Inc

Cone Types

PaperPaper cones offer excellent sound quality and are good at self-damping. However, they can be susceptible to environmental factors such as humidity that could degrade sound quality.

Mylar (plastic)The ease in maintaining tight tolerances during the manufacturing process makes speakers with Mylar cones attractive from a price point perspective. Mylar is also commonly used for speakers requiring an IP rating for different levels of immunity to water.

Cloth Cloth cones are a lower cost option for speaker applications such as lap top computers speakers that are asked to deliver economical performance in relatively small packages.

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Mounting Configurations

Solder Eyelets Wire LeadsSolder Pin/PostsSolder Pads

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GPS Automotive

Applications

Medical

Security Industrial Consumer

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Standard ProfileAlnico magnet 38 mm ~ 100 mm in diameter

GA0576M, GA0661, GA0701M, GA0776M

Ferrite magnet 50 mm ~ 305 mm in diameter GF1003, GF1005M, GF1603B, GF3002

CUI Products

Low Profile10 mm ~ 57 mm in diameterCDM-13008, CLS0381M-L152,

CLS0451M, CLS0501M

Miniature Monitor20 mm square ~ 46 mm square

CMS0201KLX, CMS0281KLX, CMS0361KLX, CMS0401KL, CMS0461KLX

Notebookwith low profile designs

GC0251K, GC0301K, GC0351N, GC0401S

Speaker with CaseCVS-1508, CVS-1708, CVS-2308,

CVS-3108

Low Leakage FluxGF0668TV, GF0923TV,

GF0901TV, GF1562

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Summary

CUI Inc’s speakers are used across a range of applications

The three main magnet types are: Ferrite, AlNiCo, and Neodymium (NdFeB).  

The three main cone types are: Paper, Mylar (plastic) and Cloth

180+ models are available now through Digi-Key

© 2013 CUI Inc

www.cui.com