Home

dB SPL

Crossover and Drivers

Basket

Enclosure Type

Construction and Materials

Specifications

Speaker Tweak

Set-up Basics

Before the Listening Tests

The Actual Listening Test -
How to Audition Loudspeakers

About

Site Map

"If you are tempted to leave the decision to a friend or a trusted salesperson, remember this; nobody knows better than you what sounds good to you! Speaker preferences are personal, and you should make the selection. If you do leave it to a friend, you may end up owning what your friend likes and not what you like!"

 

"A solid bass output, at first, may be boomy later; too much bass, lacking in definition and poor overall balance."

 

"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?"

 

"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 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."

 

"An enclosure with three or four drivers is not necessarily a 3 or 4-way speaker, since many manufacturers use several drivers to cover the same portion of the audio spectrum."

 

"Floor-standing, or tower speakers have been around for years and in many ways remain the standard against which all other speaker types are judged."

Break-in period - All audio electronics need some break-in period to sound properly. Break-in period is the playing time required for a new component to reach its full sonic potential. Dynamic speaker drivers (the cone woofers and dome tweeters) have moving parts that are generally rather stiff when they come out of the factory. One of these parts is called the surround; it's the rounded piece of rubber or foam that connects the outer edge of the cone or dome to the speaker basket. The other is called the spider; it's the part that connects the center of a woofer cone to the back part of the speaker basket, and that keeps the woofer's voice coil centered in the voice-coil gap. 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 Some speakers sound just a little better after break-in while others go from sounding horrible out of the box to sounding glorious after 24 hours of break-in.

Bi-wiring - Conventional hook-up between an amplifier and a pair of speakers uses a two-core cable per speaker. One conductor is designated positive, marked with a '+' symbol (red plugs and terminals). The signal goes into a crossover in the speaker and is split between the drive units; in a 2-way speaker, the bass and midrange signals go to the woofer, while signals above a certain frequency go to the smaller tweeter. In a 3-way speaker, the signal is split into bass, midband and treble. Standard crossover works by using one pair of cables to carry signal to and from the amp. The problems with this method is that bass signals can tend to swamp the more delicate treble stuff, especially in the return (or negative) connection back to the amplifier. By separating the signal all the way back to amplifier's output stage, using two runs of cable or a purpose-made four conductor bi-wire cable, the swamping effects can be avoided. To do this, you need speakers designed for bi-wiring; meaning the crossover needs to be completely split, without the common negative found in standard design. Picture below illustrates a bi-wiring connection.

A bi-wirable crossover has two separate circuits, one to filter the treble out of the signal for the bass driver, the other to prevent the bass from reaching the treble driver. The speaker should have four terminals (two positive, two negative) on the back of a bi-wirable speaker. If the are no multiple terminals, bi-wiring is not possible. To to allow them to be used with a single two-core cable, the terminals on bi-wirable speakers are usually connected by some kind of jumper bar or link (the speakers manual should have instructions how to remove these to prepare the speaker for bi-wiring). That done, you need two positive and two negative connections between the speaker and the amplifier. At the speaker end, the four conductors (two positive, two negative) are connected to the terminals, but what happens at the other end depends on the outlets the amplifier provides.

Any amplifier, minus amplifier with spring-clip terminals, can be used for bi-wiring. Some provide twin sets of speaker terminals specifically designed for bi-wiring, while others have A and B speaker outlets. For A and B speaker outlets case, you need both sets of terminals turned on all the time. An amplifier with a single set of terminals (left +/- and right +/-) can also be used; the two positive conductors from the left speaker are connected into the left '+/red' terminal, and the two negatives into the '-/black'. Repeat this for the right speaker, and that's it. If you have an amplifier with banana socket terminals, most cable manufacturers and dealers will supply bi-wire cables 'commoned' into a single set of plugs to make this even easier. If you have to use bare wire connections, check the polarity of each amplifier-to-speaker connection, it's very easy to get the left tweeter out of phase with both the left bass and the right speaker. All that done right, what you should hear is better focus and clarity in the treble and particulary the bass, plus better soundstaging.

Bi-amping - This involves using one amplifier channel for each drive unit to give further improvements. A stereo pair of 2-way speakers will therefore need four channels of amplification. The popular way is the use of an integrated amplifier along with a power amplifier. Two conditions must be fulfilled, the first is that the integrated amp must be fitted with a pair of preout sockets for this purpose. Amplifier in which the pre and power sections are linked with jumper bars, are generally not suitable for bi-amping; check with your amplifier's manufacturer. The second is that the power amplifier you use should have the same gain (though not necessarily the same power output) as the integrated amplifier you have. That means that for a given input voltage, both the integrated's onboard power section and the external power amplifier you use will give the same output. Otherwise, you would have a sound with much louder bass than treble, or vice versa.

The requirement for this gain-matching means it's best to use combinations from the same manufacturer, designed to be used together. To bi-amp, your four-conductor runs to the speaker will need four connectors at the amplifier end, be these plugs or bare wires. The integrated amplifier and the power amplifier are connected together with a stereo pair of interconnect cables, pre-out on the integrated to pre-in on the power amplifier. You then use one amplifier to drive the left and right high frequencies, and the other to power the left and right low frequencies. In other words, the integrated drives the treble, and the power amplifier the bass.

Speaker cable- Speaker cable or wire is a metal wire used to connect the speaker-level outputs of an amplifier to the bindings on a speaker with the job of transferring power from the amplifier to the speaker. It comes in a variety of styles with a variety of particular features varying from manufacturer to manufacturer. Speaker cable is often made of copper, a good quality conductor for the price. The actual metal wire is encased in some form of plastic-like coating that insulates the wire while still allowing the wire to be easily bent and turned. Most high-quality speaker cable is fairly thick with a gauge around 12, with some wire even thicker. Quality cables are usually terminated in some sort of metal connector. The most commonly used of these connectors are spade lugs, banana connectors, and pin connectors with spade lugs and banana being the best quality connectors. Bare wire without a connector may also be used without the benefit of a wire termination.

Speaker cables should be heavy gauged with gold-plated spade lug or banana connectors for good signal transfer between amplifiers and speakers. Lengths of speaker cable should be kept to a minimum and the lengths used should be the same for left and right speakers. Long runs of speaker cable should be heavy gauged to ensure enough power is transfered and the amplifier is not presented with too great an impedance or resistance. Speaker cable also has its own impedance or resistance to the flow of electric current with heavier gauge cables having lower resistance ratings allowing the efficient flow of power from the amplifier to the speakers

Troubleshooting - If the system isn't working on one channel, check the speaker cabling, especially at the connection end. Even the tightest connection can shake loose by the constant vibration of speaker. Turn off the amplifier, check all the connections at both amplifier and speaker ends, listen to each of the speaker drive units in turn, getting your ear up close to check each one. If the connections seem good, internal component failure may be the cause. Swap the speakers over and see if the fault moves to the other channel. If so, the problem is in the speaker.

If for some reason, you have problem identifying the polarity of the speaker follow this standard test method. Put a battery across the speaker terminals. When the "+" of a battery is put on the "+" marked terminal of the speaker, the speaker cone should move out. 1.5 Volt battery is safe to use. Note: Not to be used to test a compression driver.

Optimize your listening - One way to improve your listening experience is to close your eyes and concentrate on the music and imagine someone is singing in front of you. Try listening to your system with the lights out, you will probably discover that it sounds better. You'd be amazed how much more you will get out of your system if your experiment. Ambient noise, for example, can mask much of the detail on a recording. There is no advantage of having a dynamic range of 90dB or so on your CD player, if traffic, the washing machine or just general household noise creates a background level of 60dB or so, most of the quality will be lost. Have you ever wondered why systems tend to sound better late at night?

Soundproofing - Most of us do not have a dedicated listening room in a family home and the idea of soundproofing a room is just impractical. However, there are some steps you can take; shutting the doors and windows will help exclude the noise, using heavy window curtains, soft furnishings, well-stocked bookcases, rugs on bare floorboards between speakers and listening seat (particularly) will help control the sound. A bare room will echo, muddling imaging. Clap your hands and determine if the echo is distinct, if so, extra damping is definitely needed but avoid over-damping the room as it will make it sound lifeless.

To further help make the system sound better; switch off computers or any other potential radio frequency radiation sources. Avoid running washing machines or dishwashers which will introduce electrical noise on you ring-main. Warm-up the system by keeping it powered up. This will help you enjoy the music immediately and that gets you off to the right start and you'll concentrate on the music immediately, not the system. Be in the right frame of mind for listening because music sounds best when you're receptive to it.

Speaker stands position and support the speaker, but they also isolate the speakers and keep them absolutely still and shelves will never do a good job at that. If you have small speakers, (not cube speakers), they will sound best on stands. The right stand for your speakers will raise them to a height where the tweeter is at ear-height when you sit in your usual listening position but check your speaker manual as some manufacturers tune their speakers to be positioned higher or lower than this.

The best stand is usually a hefty stand, though some speakers are designed to be used on lightweight open-frame supports. Stand helps keep the speaker still, so that some of the energy of the drive units isn't wasted in moving the whole speaker back and forth by minute distances. The use of spikes on the stand helps locate it solidly to the floor, by piercing carpets without damaging them and they also let you level the stand by adjustment of the spikes. On hardwood floors, put a coin under each spike, and on very resonant boarded floors, a paving slab under each stand will help avoid damaging the floors. Top-spikes on stands help by locating the speakers rigidly, while minimizing the contact between speaker and stand. Filling stands with sand, lead shot adds mass, and also reducing resonances, stopping the stands ringing. If you're going to use sand, use kiln-dried silver sand. Floorstanding speakers also benefit from spikes and mass-loading but be careful when fitting spikes to floorstanders; the threaded inserts that take the spikes can twist out of the cabinet material if you over tighten them.

Avoid sitting on a high-backed sofa as it will soak up bass or sitting with your back to thick curtains as it will make treble focus a little vague. Avoid sitting hard against a bare wall as it will muddle the sound; have your seat a few feet out. Avoid reflective surfaces between your listening seat and the speakers and keep speakers clear of corners. Corners work like horns, boosting the bass and messing up the sound. If you are passionate about making your listening room sound good, you might want to invest in some acoustic wall panels. These acoustic wall panels will help to difuse, deflect as well as soaking up sound waves in the room with its absorbent foam.

Damage control - How can you damage your speakers?
A really easy one is to play the system too loud especially with a weedy amp. A 10 o'clock position on the amp's volume control will more or less deliver full power. At this level, distortion sets in. Voice-coils on your drivers get too hot and eventually melt together. Turning up the bass and treble controls to full to make the system sound louder will also damage your speakers.

Do not change connections with the amplifier power on and the volume up. The "baaarp" buzz you get when plugging in phono connections with the sockets in circuit will damage your speakers in the long run. Accidentally getting the connections wrong to create a nice feedback loop is also no good. One way to destroy the output stage on some amplifiers is by accidentally shorting the speaker leads together, just a touch of the banana plugs while hooking up will do it.

Most amps have some degree of protection built in, better safe than sorry, it's not worth taking the risk. Making or breaking connections with the volume right down or use the mute switch. To be absolutely safe, turn off the amplifier completely. If you turn your amp on and off when not in use, it's a good idea to turn the volume down before killing the power, rather than letting the capacitors discharge with lots of distortion while still passing signal. You should also always check that the volume is down and that no sources are playing before turning the amplifer on, avoiding nasty surprises and that lovely full-power blast.

One way to quickly burn out a driver is a change in the resonance of the enclosure while music is playing; this happens if you remove the back or open an enclosure in any way, or hold the cone or dome to the driver so it cannot move freely. Under these conditions, an 8-ohm speaker’s impedance can drop below 4 ohms, draw more than twice the power from the amplifier and overheat to destruction. Plain common sense can protect your speakers better than most protection devices. Never ever drop a speaker; the physical shock can cause deformation and subsequent distortion and burn out.

Back To Top

Home  . dB SPL  . Crossover and Drivers  . Basket
Enclosure Type  . Construction and Materials
Specifications  . Speaker Tweak  . Set-up Basics
Before the Listening Tests  
The Actual Listening Test - How to Audition Loudspeakers
About  . Site Map

© 2005-2007 BuyingLoudspeakers.com