Everybody wants a great, high quality sound from their audio system. Usually people want a sound to fill the room and have a deep bass, a clear treble and a rich middle range. The sound quality should not deteriorate when you crank up the volume and you certainly don’t want insane vibrations, static hiss or smoke coming out of the speakers at any point!

Speaker watts are only one figure to think about in your quest for quality. Other important values are the sensitivity of the speakers and total harmonic distortion (THD) etc. If you read through this page you will get a good idea of how to work out what a sound system will deliver just from the manufacturer's specifications.

Loudness in Decibels (dB)

This is a measure of loudness and is important for choosing speakers, especially if you like to listen at high volume. Something to remember about decibels, is that for every 10 decibel rise the noise is twice as loud- so small increases in decibel levels= a big impact on the ear.

Power in Watts (W)

A watt is a measure of electrical power. The output of an amplifier is measured in watts. All loudspeakers have a maximum number of watts that they can cope with and the manufacturer will tell you what this is.

It is important to make sure that your amp does not put out more power than your speakers can handle or they can be damaged.

Usually, the manufacturers give 2 figures for power for both amplifiers and loudspeakers

1. For Amplifiers 

RMS = the power an amplifier can put out over a long period
Peak = the power an amplifier can put out in short bursts.

2. For Loudspeakers

Nominal power= what a speaker can handle long term without being damaged

Peak power= what a speaker can handle in short bursts without being damaged

Speaker Sensitivity

Very good speakers are more sensitive than mid-quality speakers and can deliver a lot of sound with only a little power coming from the amplifier. Mid price range speakers need more power to give you the same volume.

Speaker sensitivity is expressed in terms of the number of decibels (dB) of sound pressure level (SPL) per 1 Watt of amplifier power measured at 1 meter from the speaker. Usually manufacturers drop the 'SPL/W/M' and just say ‘db’.

Most loudspeakers have sensitivities in the range of 85 to 91 dB. So a sensitivity of less than 85dB is not so hot.

Total Harmonic Distortion (THD)

This is a measure of how faithfully speakers translate what is on a disc or hard drive into sound. The lower the figure, the less distortion there is. Usually the values are between 0.05% and 0.08% THD for a quality "clean" system but any figure below 0.1% THD is pretty good.

Speaker Impedance

This tells you how much current a speaker will draw. 8 ohms is standard. 4 ohms is very good and usually a lot more expensive. If you are buying 4 ohms speakers you need a very good amplifier to get the most out of them.

Headroom

This is a measure of what a system can deliver in short bursts. A large headroom figure is important if you have a home cinema system and want to get a jolt from the explosions in action movies.

I think you can select your audio equipments with good quality after you know very well of these. Let Naphon be with you through your journey.