Speaker Article Series Part 1: Basics: Speaker Types and Differences

What is a Stereo Speaker? 

The Stereo Speaker is the most important piece of equipment found in a stereo system. Speakers convert electronic audio into a mechanical movement of the speaker cone. The movement of aur caused by the speaker is what you hear. The greater the movement, producing sharp clarity of sound and a wide range of frequencies, the better the speaker will be.

Speaker Types:
Speakers come in many sizes and shapes. Most average speaker enclosures have a large woofer, midrange and tweeter speakers. The lower priced shelf units might have one to three speakers, such as my old DS-826 speakers.Others might have several tweeters, up to eight midrange speakers, or a separate large woofer. The speakers used for the high-frequency range (tweeter) are usually small metal, hard-coned or horn-type speakers. Midrange speakers vary from 3 to 6 inches, and woofers vary usually from 8 to 12 inches.
The best frequency response is from 20 to 20,000 Hz; most speakers ary from 37 to 20,000Hz. Very few men can hear above 15,000Hz or below 50 Hz, but some women can hear above 22,000Hz. Besides the frequency response, how a speaker sounds is significantly influenced by its speaker enclosure.

1. Acoustic Suspension:

AS speakers are completely sealed

Speakers in an acoustic suspension (AS) enclosure are completely sealed without any extra openings. The AS enclosure offers easy listening to all types of music. A three-way acoustic suspension speaker system might have two or three speakers. Because it takes more power to move the air with AS speakers, they usually have a higher maximum power-handling capacity. The tweeter might be a 1 or 2 inch cone, dome, or ribbon-type speaker. The midrange speaker might consist of a 2 to 5 inch cone or dome-type speaker. A woofer speaker in the AS enclosure might be 6 to 10 inches in diameter. The frequency mightvary from 22 to 44 kHz, although many AS speaker frequency responces can go above 50 kHz.


2. Bass-Reflex

Bass-Reflex speakers have a visible porthole

The bass-reflex speaker produces stronger and deeper bass frequencies. They are designed with a tuned porthole to allow the enclosure to resonate and produce low-frequency notes. Some bass-relex enclosures have up to three different sizes of portholes. Bass-reflex speakers can be driven harder and are designed for people who like high-power music.
The small bass-reflex enclosure might have two speakers with a bass-reflex porthole, and a 1 or 2 inch cone speaker supported with synthetic resin for eliminating distortion caused by edge resonance. You might find a 1 to 2 inch conce or dome speaker as tweeter, with a 2 to 6 inch midrange and an 8 to 12 inch speaker as woofer. For power-handling capacity, heat resistant voice coils and adjustable thermal-relay protection circuits are found for safety under high-power driving. A carefully tuned bass-reflex enclosure for producing tight and solid bass reproduction is found along with an antiresonating baffle board in some units.
The bass-reflex enclosure provides good reproduction for classical, jazz, easy listening, rock, and country music. The average frequency response varies from 35 to 20,000Hz. The bass-reflex speaker is capable of covering the entire musical range.


3. Passive Radiator

Note the smaller radiator of this PR speaker

The passive radiator (PR) speaker enlcosure produces greater bass than any other type of speaker. The passive radiator enclosure has two separate woofer speakers, but one is a simple cone without any voice coil or signal applied to it. It has thus an active main driver and a passive radiator.
Actually, the passive-port cone acts as a variable port, increasing the bass frequency response. A two speaker PR enclosure might have a 1 inch dome and an 8 inch speaker with another 8 inch dud cone. The passive radiator is usually larger than the bass speaker. In some units, the woofer cone might be a special design with corrugations for wide-range response.

SEE VINTAGE SPEAKER REVIEWS HERE