Understanding Speakers and Speaker Guidelines

By: Jeff Hyndman
Submitted: 2007-01-17 16:23:19
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When most people shop for home audio speakers they often find a lot of information, but don't know what much of it means. The purpose of this article is to provide a basic understanding of some of the key elements in speakers and to offer some guidelines for the average audio consumer.

Most home audio speakers bought today are 2-way speakers. This means the speaker has a woofer for low or bass sounds and a tweeter for high sounds. There are also 3-way speakers which add a mid-range and these can sound clearer, all things being equal. For most people, however, a good 2-way speaker is fine.

Home audio speakers typically come in either rectangular or round designs. Round ceiling speakers are ideal for background music and rectangular wall speakers are ideal for surround sound systems. With this said, in-wall speakers are often just not practical to install in a given room due to room lay-out and furniture. There are certain designs of round speakers which can help offset the inherent benefits of rectangular speakers for surround sound.

One of the problems with round ceiling speakers is that they basically send the sound straight down beneath them instead of out into the room or area most desired. However, some speakers offer angled woofers so that you can install them in the corners, for example, and still have the sound directed outward into the room.

Typical sizes for speakers are 5.5, 6.5 and 8 inch. The 8 inch will generally have stronger bass with the larger woofer. 8 inch speakers are recommended for surround sound systems and 6.5 inch for background music. I would not recommend 5.25 inch speakers except for very small rooms.

A dual voice coil home audio speaker helps handle small rooms where there isn't really enough room to place two speakers. The dual voice coil speaker provides for both channels from the amplifier and these can be quite handy in bathrooms, for example.

Power ratings of speakers always get a lot of attention, but often too much attention because power is but one factor among several others. The fact is most people will rarely if ever use the full power of most speakers today because they would soon become deaf if they listened to music at peak power. Power is rated two ways; RMS and Peak. RMS essentially means the volume level the speaker can handle all day long without distorting. Peak is the top power level the speaker can handle before blowing. For most people in most homes, 40-50 watts RMS is plenty. Some speakers only specify their Peak power rating and as a rule-of-thumb, divide the Peak rating by 2 to estimate the RMS rating.

The sensitivity rating should be 89db or more is the usual recommendation. This specification has to do with how clear the speaker sounds, and below 89db the sound clarity may be poor.

Range, or frequency response, represents the low and high end range of the speaker. Here the low end range is the more important of the two, and typically, 45-50Hz is the low end of what most of us can hear. On the high end, most speakers today exceed what we can hear and usually they are 20KHz or more, which is well above what we can hear.

A speaker has to divide the signal coming into it between the tweeter and the woofer. The crossover is in effect a filter that performs this function, but whenever sound is divided there will be some signal loss. A crossover of 12db is the most common today, and again, is fine for most people. Most speakers use passive crossovers, but some high-end speakers use active crossovers which are more sophisticated and allow for adjustments. Few homeowners need speakers with active crossovers or want to make these kinds of adjustments.

The materials that woofers are made of are often cited in speaker specifications. Polypropylene is the most common material used and is okay, but bass sounds will not be as full as with other materials. Kevlar, fiberglass or aluminum woofers will cost more but do offer stronger bass end sounds. For true audiophiles with lots of money there are other highly specialized materials available, but again, just not needed for average listeners.

You will also find that some speakers today feature bridge mount tweeters and this can be a plus. Bridge mount tweeters do not penetrate the woofer cone and will not, therefore, interfere with the woofer low-end sound. This is not to say that there aren't good speakers who do not bridge mount their tweeters because there are such speakers where very few people could tell the difference. However, the difference is there and if you want a superior speaker then a bridge mount tweeter is one consideration.

The range of speaker prices today is quite remarkable. The truth is you can buy a decent pair of ceiling speakers for as little as $40 and you can buy a great pair for $200. Some people want the best and you can find those for as much as $1,500 a pair. As always, to some degree, you get what you pay for. However, it is also the case that the vast majority of us would have trouble telling the difference in sound from a good quality $100 speaker from a better quality $200 speaker.

Article source: Expert Articles