What is better a speaker with more way like 3 or 4 or with more ohms.?

Question

What is better a speaker with more way like 3 or 4 or with more ohms.?

Answer 1

Used to be, back in the old days of audio equipment, there was one speaker driver (a woofer or a tweeter is called a driver) that was a full range speaker. This single driver had limited frequency range, because the single cone was too large to reproduce high-frequencies and too small to produce low frequencies. You also had the problem of intermodulation distortion, where the single cone trying to reproduce multiple frequency ranges would distort the sound.

Later, electrical engineers discovered that they could build a cut-off filter - called a crossover - that sent the high frequencies to a smaller speaker (a tweeter) and low frequencies to a bigger speaker (a woofer). The two-way speaker was born.

As the technology developed, they began building crossover networks that actually broke the spectrum of audio signals up into many different bands of frequencies. Speaker manufacturers began putting out loudspeakers with as many as three, four, or five separate speaker drivers, each putting out the audio signals for a different frequency range.

This turned out to be overkill. As the manufacture of the drivers got better, the individual drivers needed to deliver a flat frequency response across the entire audio spectrum ended up being 2-way or 3-way systems (woofer and tweeter; or woofer, midrange, and tweeter).

The impedance of a speaker is how much resistance to alternating current a loudspeaker exhibits across the range of frequencies it puts out. This is a function of the voice coils in the drivers (where the audio signals are applied), the crossover networks, and the number of drivers in the system.

The impedance of a speaker system is usually around 8 ohms. That is, across the range of audible frequencies, the speaker exhibits about 8 ohms of resistance to the audio alternating current signal. Some speaker systems have impedance ratings as low as 2 ohms, while others have ratings as high as 16 ohms. But, almost all stereo amplifiers are designed to operate best with an 8-ohm speaker.

Amplifiers are usually rated at a certain output across an 8-ohm impedance. This rating changes for different impedances. Also, a lower impedance means that the amplifier must be capable of producing a high amount of current. So, you usually find the lower impedance speakers to be higher-end speakers, because they require a high-current amplifier to drive them properly. High impedance speakers are usually the kind they use for PA systems, because they usually have long cables to them, which would result in significant signal loss at higher current.

The specs you want to look for in a speaker are  power handling capability (peak and continuous), frequency response, and efficiency.

Peak power handling capability means what kind of instantaneous (or very short) blasts of power can these speakers handle without being damaged. Continuous power handling capability means what amount of amplifier power can these speakers handle indefinitely without being damaged. And, you want a power handling capability of your speakers to be greater than that of your amplifier's maximum output power.

Frequency response means what are the maximum and minimum frequencies that these speakers can reproduce, and how much deviation is there (in loudness) from the minimum to the maximum frequencies, as well as everything in between? The range of human hearing is from 20 Hz up to around 20,000 Hz (20 kHz). Below 20 Hz, you feel the vibration more than you hear it. And, above 20 kHz, you might feel the sound pressure, but you can't discern the sound. The closer you can get to these ranges of human hearing with as flat a response as possible (+/- 0 dB across the range) is the best. This ensures as faithful a reproduction of the tonal qualities of the audio source without "coloring" it at certain frequencies.

Efficiency is the amount of audible sound (loudness) you can get out of a speaker for a given input (usually rated at dB per watt at 1 meter distance). The higher is not always the better. Some high-end speaker systems might put out only about 85 dB at 1 watt input, while some so-so speakers might put out closer to 90 dB at 1 watt.

But, Klipsch speakers - known as some of the finest loudspeakers on the market - have been rated as high as 98 dB at 1 watt input. This means you can get a lot more loudness for given amplifier input, which means you can also get the same amount of loudness for less amplifier power. This then means that you have less chance of clipping the amplifier (having it go to it's maximum output, possibly damaging the amplifier and/or the speakers).

A good pair of Klipsch speakers (several hundred $ apiece) would be a three-way system that will give you about 98-dB sensitivity, a frequency response of about 30 Hz - 20 KHz (+/- 3 dB), and a power handling capacity of about 200 watts continuous at 8 ohms nominal impedance.

Answer 2

If the amplifier can handle low impedances (like 2 Ohms), then it could deliver more power to the speaker with lower impedance.

Basically it is a matching problem. You want to match the speaker to the amp.