"The best way to evaluate a speaker is to listen to it but there are those of us who insist on thoroughly examining the specs and if you're going to read the specifications, make sure you know what they mean."
"Surrounds and spiders are kind of like shoes, they're not very flexible at first but with use, they become much more flexible and as the surrounds and spiders in your speakers become more flexible, your speakers will sound better."
"Before you rush out to begin frantic listening tests with a dozen of speaker systems, you might want to spend time preparing a few questions you might discuss with the audio consultant. What kind of amplifier or receiver will power the speakers? What is the maximum budget, and what budget is comfortable for me? Where are the speakers to be located, and what if anything, limits their placement? What kind of furniture, walls, and overall size describe the room?"
General construction - The drivers in a speaker create powerful vibrations, yet if they cause even minor deformation of the enclosure, performance will be degraded. When the enclosure volume changes in response to vibrations of the drivers, this is a form of resonance that colors the sound, and can detract from low frequency response. To avoid unwanted resonances, enclosures must be constructed solidly utilizing internal crossbracing and corner bracing. You can examine the speaker enclosure yourself to determine the quality of its construction and one quick way to examine is to rap your knuckles on the speaker enclosure. If it sounds like you are rapping against a piece of granite, this means the enclosure is well damped from vibrating on its own, and will suffer less from coloration due to enclosure resonance. If rapping your knuckles against the enclosure results in a drum-like sound, the enclosure may not be well damped, and could very well obscure sonic detail in the midrange and mid-bass areas. A good enclosure isn't a guarantee of good performance, but it's a start.
Enclosure materials - Plywood is a common enclosure material, and it makes an excellent choice so long as good grades are used. Better grades of plywood may have an exterior veneer of hardwood for beauty, and many alternate layers of other wood, their "grain" running perpendicular to each other, which helps damp any resonances. Many manufacturers use "particle board" for enclosure construction and this very dense, anti-resonant material is formed of compressed wood chips and glue-like resin. MDF (medium density fibreboard) is also very popular and preferred over particle board because it is easier to work with and is made of higher density wood fibers. These boards can be finished with plastic, laminate or wood veneer, as well as paint, while some enclosures are made of plastic or metal and some even use concrete or other highly rigid materials. As a rule of thumb, the speaker enclosure should be at least 1/2" thick with emphasis on the thickness of the front baffle when possible.
Cone materials - Speaker cones can be manufactured from various materials depending on driver implementation, desired frequency response and budgetary considerations. High frequency drivers (dome tweeters) are usually made from metallic or fabric materials. Usually metallic drivers (Aluminum, Titanium) tend to be very revealing and detailed but may tend to be bright sounding with certain program materials or electronics, especially if mated with a poorly designed crossover that doesn't fully account for high frequency resonant modes inherent in many metal dome designs. Fabric domes (Silk, Mylar's) tend to have a more reserved sound with less emphasis on brightness and more on smoothness. No material is not better than the other, just different, usually requiring different design trade offs and considerations. Paper drivers for tweeters should usually be avoided as paper is not the proper material for accurate high frequency reproduction. Most paper tweeters are 2" or more in diameter and a driver this size is usually not suited to produce high frequencies with the accuracy and detail, and can also suffer from larger break up modes leading to higher distortion. Quality midrange and bass drivers are usually constructed from paper composites, kevlar, aerogel, aluminum, or polypropylene materials, which have very high strength/weight ratios and tend to be immune from flexing during large excursions. This allows the driver to react quickly during transitions in music and minimizes driver distortion. Many high end woofers achieve excellent sonic performance when constructed from high quality paper laminates. If done right, paper woofers can outperform many exotic drivers made from fancier materials.
Fasteners and joints - Many enclosures use a glued, mitered butt-joint because it allows the corners to have a smooth seam. It is especially important that this type of joint be reinforced by glue blocks, which add strength. Ideally, screws should also be used, in addition to the glue blocks. When screws hold down the back of a cabinet, there must be enough of them, perhaps one every two or three inches, to keep the back from vibrating and to prevent air leaks which would degrade performance. Nails are generally not used because they can loosen due too the constant vibration of the enclosure.
Bracing - Even particle board enclosures can resonate, especially when there are large panels. Better designs will include internal braces, placing them between panels or across them, as required, to dampen resonances. You may be able to see the braces and glue blocks through a port, or by removing the enclosure and looking inside.
Damping material - Fiberglass “wool” will often be found inside enclosures. Placing this material where there are parallel faces helps to reduce internal reflections and standing waves which cause resonances but excessive use of fiberglass will not only lower the resonant frequency, it will reduce efficiency. The fiberglass vibrates in response to driver motion, and its internal friction becomes heat, dissipating energy that might otherwise have left the enclosure as sound. To get around the problems of excessive bulk, over-absorption, and standing waves, the most desirable construction is a combination of damping materials, such as fiberglass and thick felt.
Finishes and grilles - Finish of the cabinet plays no role in the overall contribution of sound quality of a speaker system; it is merely a statement of fashion and prestige. While it is desirable to have a speaker system with a nice wood veneer finish, it should not be a primary concern as these types of finishes add cost to the system without an increase of performance. Most speakers have a vinyl finish with a wood grained appearance and some of these look like real wood, and it is difficult to tell that it is vinyl. There are many examples in the audio industry of speakers with black vinyl finishes that sonically outperform costlier speakers with fancy wood finishes. Don't be fooled by a speakers appearance; it is what's inside that matters when sound quality is the primary concern.
Choosing a speaker system merely on appearance or name brand recognition may be the worst mistake a consumer can make when they are evaluating new speakers.The grilles protect the drivers from dust and physical injury and should be "acoustically transparent". Most speakers have removable grilles which can safely be vacuumed clean. On many speakers, the baffle behind the grille is finished attractively to enhance the speaker appearance and this finished baffle board is a very nice feature when a grille is not wanted. Most conventional cloth grilles have excellent acoustic properties, are visually pleasing and very durable. However, for critical music listening, it is recommended that grilles be removed.
Speaker connection - Five-way binding post is a high-quality terminal connection able to accept multiple types of speaker wire with a variety of terminations or ends. The connections are used on speakers and amplifiers. These bindings screw down onto bare wire or wire terminations (spade lugs and pins) for a strong connection. They also provide easy push-in connection through banana terminations.
Five-way binding posts allow the maximum surface contact area between the post itself and the speaker wire allowing the most complete connection and best possible signal transfer. Gold-plated binding posts are found on many high-end amplifiers and speakers. Speakers and amplifiers with five-way binding posts are much preferred over speakers and amplifiers or receivers with other connections, the most notable of which is the cheap spring-clip connector found on many inexpensive speakers and receivers.
Spring-clip connection is an inexpensive method of connecting speaker wires to amplifiers (particularly amplifiers integrated into receivers) and speakers using a thin sheet of metal that is pushed against bare speaker wire or a pin-type connector by a small spring. Spring connections are inferior to five-way binding posts because they do not accept other forms of speaker wire terminations or connectors such as banana connectors and spade lugs. They also do not transfer power well because they have a very small contact area with the wire or connector, and they do not hold wire firmly. Whenever possible, five-way binding posts should be sought out instead of spring connections.
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