(SPOT.ph) Filipinos love music and sometimes, we tend to be loud about it—literally. Even if earphones, earbuds, and headphones are more affordable and handy these days, it is still pretty common to see Filipinos carrying portable loudspeakers on the streets, not necessarily boombox style, but we don't think even that's impossible. So if you're on the lookout for your next great music companion, let our handy guide help you out.
In this article, let’s talk about the history of speakers, their different types and variants, and what to look for when buying a brand-new or secondhand unit.
History of Speakers
A speaker is a device that converts audio signals into sound and vice-versa with the use of an electroacoustic transducer. Using magnets, electrical charges repel and attract when an audio signal passes through the voice coil of a speaker. This produces musical waveforms that move up and down while the voice coil attracts and repels them through the magnet attached to the speaker. The air pressure created by this process produces a sound that the human ear can appreciate.
Originally conceived as a communication device add-on for the telephone, the speaker saw many developments over a short period of time since the day it was first introduced.
In 1861, Johann Philipp Reis installed a speaker device on his telephone which produced clear tones but the sound came out muffled. It was Alexander Graham Bell who got a patent for the first loudspeaker in 1876. His device was capable of reproducing intelligible speech and was part of his telephone invention. The following year, in 1877, Werner Von Siemens created an electromagnetic coil-driven speaker that was based on Bell’s design. In that same year, Thomas Edison patented a system that uses compressed air to amplify the sound produced by cylinder phonographs but used horns for amplification.
Horace Short patented a loudspeaker driven by compressed air in 1898. The device made by Short produces better sound than previous speakers, but he, later on, sold the rights to his invention to Sir Charles Algernon Parsons, a British engineer who invented the multi-stage steam turbine that revolutionized marine propulsion.
Types and Variants of Speakers
When we talk about loudspeakers, we can classify them according to type:
Perhaps the most common type of speaker in Filipino communities is the horns—locally known as “trompa”. We see them in places of worship, barangay halls, gymnasiums, and even on the streets for public announcements. Earlier versions of horns do not use electricity and could not amplify sound very much. With the use of electrical amplification, horns were able to generate loud sounds that can fill large public spaces.
Modern-day speakers are actually electrodynamic loudspeakers that use an electromagnetic coil and diaphragm to create sound. Electromagnets turn electric signals of varying strength into movement with the coil of copper wire moving as the magnet energizes via induction. This coil is connected to a cardboard, paper, or vinyl cone that serves as a diaphragm that vibrates along with it. Sound is then created and amplified by the diaphragm. Sub-types of this speaker are tweeters, mid-range electrodynamic speakers, woofers, and subwoofers. This is the most common type of speaker in the world today.
Flat Panel Speakers
For decades, inventors and engineers had been working on flat speakers to decrease the size of speaker boxes. The main difference between flat panel speakers compared to electrodynamic loudspeakers is the presence of an “exciter” attached to a square panel. In this type of loudspeaker, the flat panel acts as the diaphragm, which can be made of vinyl or Styrofoam.
Flat Panel Speakers are further sub-categorized into five: the Standard Flat Panel Speakers; Planar Magnetic Speakers; Electrostatic Flat Panel Speakers (ESL); Ribbon-Driven Speakers; and Multi-Cell Flat Diaphragm Speakers.
- Standard Flat Panel Speakers
This type of flat panel speaker has paper bonded on both sides of the polystyrene (synthetic polymer) to help sound production. Aside from polystyrene, it can also be made of PET foam, polypropylene foam, polypropylene, ABS, glass fiber, and carbon fiber. The corner points of the diaphragm are then attached to a cushion with the exciter pushing the center forward to cause bending in the surface to generate sound waves.
- Planar Magnetic Speakers
This type of flat panel speaker has a conductor attached, or at times embedded, in the diaphragm of Styrofoam. The diaphragm makes sounds by moving forward and backward. It is regarded that this type of speaker has traditionally worked better than a standard flat electrodynamic loudspeaker because the entire Styrofoam flat surface moves easily without requiring a large electromagnet to drive it.
- Electrostatic Flat Panel Speakers (ESL)
Often called ESL (ElectroStatic Loudspeakers), they use two (02) metal grids with a diaphragm made of a plastic sheet coated with graphite, which is electrically conductive. The diaphragm of an ESL has a constant charge with a high-voltage audio signal created by the electrode grids. Speakers of this type have a poor bass response but look interesting as a rectangular flat screen. If combined with a regular electrodynamic woofer, ESLs can be made into a full sound system.
- Ribbon-Driven Speakers
Using super light aluminum foil film as a diaphragm, Ribbon-Driven Speakers do not need a transformer between the amplifier and the speaker. This type of loudspeaker uses a thin strip of aluminum on mylar, that is durable and suspended between two bar magnets.
- Multi-Cell Flat Diaphragm Speakers
Though categorized as flat panel speakers, Multi-Cell Flat Diaphragm Speakers are related to the Electrodynamic Loudspeaker since both use magnetic fields to move an element with their shapes being the main difference. This speaker has the coil directly mounted on the diaphragm, with the copper coils wrapped around the base of plastic bulges. The long permanent magnets create separate “cells” and the whole diaphragm ends up moving uniformly. Compared to flat panel speakers, this type is a heavier speaker and requires a transformer because each small cell has a lower impedance than a standard speaker with a single exciter.
Plasma Arc Speakers
In Science, we learned that plasma is an ionized gas or current sent through a gas. It is responsive to electrical fields, hence one can turn the electric signal of sound into an electric field to manipulate the plasma.
The plasma does have mass and will vibrate creating a sound similar to how a diaphragm moves air to make a sound. This kind of speaker is an eye-catcher but produces limited sound quality. It also has the tendency to have reliability problems which is why it is often considered just a novelty.
This type of speaker uses an expanding and contracting crystal to vibrate the air and produce sound. Piezoelectric speakers can only produce limited frequency response, and for this reason, they are only used as tweeters or in small electrical devices like watches (clocks) to make simple sounds. Since Piezoelectronics are a solid-state technology, it makes them durable and good for use as a microphone underwater. These speakers are used as microphones in submarine warfare as it can detect other microphones and hear the sounds of other vessels.
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Things to Look Out For (Specs of Speakers)
If you are out to purchase your next loudspeaker, here are the specifications that you need to check to get your money’s worth:
One of the most important speaker specifications that are often ignored is sensitivity. Measured in decibels (dB), a speaker's sensitivity indicates its loudness in both a non-echoing environment or a room environment. Most manufacturers specify the sensitivity measured in an average room environment. The higher the sensitivity rating, the louder your speaker is. An average speaker comes with a sensitivity of around 87 dB to 88 dB, while a speaker with a sensitivity rating over 90 dB is considered excellent (a normal speaking voice is between 65-70 dB, while a car horn has 110 dB).
Measured in ohms, impedance refers to the speaker’s resistance. Think of a speaker as a hose and water that flows through it as electric current—audio signals. If a hose has a narrow opening (high resistance), less water will flow through it and vice-versa. If a speaker has low resistance (impedance), more current will pass through the speaker. The lower the impedance, the more current flows through the speaker. Generally speaking, a good speaker should neither have high impedance nor low, but rather should have an optimum impedance (somewhere between six to eight ohms.
Frequency Response or Frequency Range
Measured in Hertz (Hz), this speaker specification tells us how low and high the unit can play. The human ear can hear between 20Hz and 20KHz, with bass frequencies below 30Hz are less heard and more felt. Any speaker that reaches 50Hz or lower is considered good and is not required to be teamed with a subwoofer (unless you want to hear the deepest bass).
Specified in Watts (W), the power handling of a speaker tells us how much power it can bear without causing any damage. A speaker may get damaged if it gets the amount of power more than what it is rated for.
Signal-to-Noise Ratio (SNR)
SNR refers to the sound that a speaker produces to include some level of noise. When audio signals are sent to a speaker, they are converted into a sound that we hear. But the sound that we hear is not purely audio signals that the speakers get – they also include some level of noise. This noise is added by internal components of the speaker. The higher the number of SNR (measured in dB), the better.
It is believed that the bigger and heavier a speaker is, the better the sound it produces compared to small and lightweight ones.
Also one of the most neglected specifications of a good loudspeaker is the cabinet. A good speaker housed inside a bad cabinet may produce a not-so-good listening experience. When buying a speaker, ensure that its cabinet is made of a dense material like wood, as light materials vibrate the sound produced by the speaker, affecting primarily the bass.
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Popular Brands, Usual Prices & Where to Buy Speakers
When we talk about popular speaker brands in the Philippines today, popular names like JBL, Bang & Olufsen, Harman Kardon, Logitech, Marshall, Bose, and Pioneer are the usual suspects. One can easily buy any of these brands off-the-shelf in their concept stores in shopping malls or right at the convenience of your home via online shopping at the brands’ websites, or through eCommerce platforms Lazada and Shopee.
Depending on the size, feature, and brand, be ready to set aside a budget of somewhere between P2,000 to as high as P100,000 for a brand-new loudspeaker unit. Of course, you can still find units below P1,000 from lesser-known brands via different online shopping platforms, but be ready to accept the fact that their quality and durability may not be comparable with the branded ones.
Tips When Buying Secondhand Speakers
If your budget can only afford secondhand speakers, be sure to do the following first before jumping on and completing the transaction:
A quick visit to the brand’s physical store can give you more details not present on websites and reading materials related to a particular speaker model. By doing so, you may also physically compare the different speaker models to help you decide if that is the one for you.
Check with the brand if that particular speaker model has spare parts still available. If a particular model that you are eyeing does not have spare drive units available in the market, it is suggested that you stay away from them.
Inspect the speaker’s physical appearance: minor scratches in the cabinet are okay. If the speakers have heavier damage that could compromise the integrity of the enclosure structure, it’s probably best to pass. Damage to the speaker’s cabinet is usually not easy or cheap to fix.