Introduction • Purpose • To 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, includingmagnet types, cone types, and mounting configurations • Introduce typical applications • Content: 14 slides • Learning Time: 10 minutes
Usage Typical Usage Accurate reproduction of voice, music, and various other audio signals. • Industries Served • Home Appliances • Safety and Security • Automotive Electronics • Office Automation • Medical Equipment • Industrial • Consumer Electronics
Speaker Structure Cone Voice Coil Plate Magnet Frame & Yoke PCB
Speaker Structure continued Cone Cap Plate Magnet PCB Voice coil Non-woven cloth Yoke
Key Specifications Sound 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.
Frequency Response Curves • 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.
dB’s • 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
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.
Magnet Types • Ferrite • Ferrite 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. • AlNiCo • AlNiCo magnets were the first magnets used in speakers and are what helped give them a smooth tone. Speakers that incorporate AlNiComagnets 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.
Cone Types Paper Paper 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.
Mounting Configurations Solder Eyelets Solder Pads Solder Pin/Posts Wire Leads
Applications Medical GPS Automotive Security Consumer Industrial
CUI Products Low Profile 10 mm ~ 57 mm in diameter CDM-13008, CLS0381M-L152, CLS0451M, CLS0501M Miniature Monitor 20 mm square ~ 46 mm square CMS0201KLX, CMS0281KLX, CMS0361KLX, CMS0401KL, CMS0461KLX Notebook with low profile designs GC0251K, GC0301K, GC0351N, GC0401S Speaker with Case CVS-1508, CVS-1708, CVS-2308, CVS-3108 Standard Profile Alnico magnet 38 mm ~ 100 mm in diameter GA0576M, GA0661, GA0701M, GA0776M Ferrite magnet 50 mm ~ 305 mm in diameter GF1003, GF1005M, GF1603B, GF3002 Low Leakage Flux GF0668TV, GF0923TV, GF0901TV, GF1562
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