Frequency range
The total audio frequency range reproduced by all speaker speakers.
Obviously, this range should not be too narrow, so that the acoustics do not cut off the lower and/or upper frequency limits of the reproduced sound. At the same time, the human ear perceives sound within 16 Hz - 22 kHz, and it simply does not make sense to provide speakers with a wider frequency range. We also recall that in
mid-frequency acoustics and tweeters, reproducible frequencies are limited due to specialization (for more details, see "Type"). And the overall sound quality will depend not only on this indicator, but also on a number of other features.
Sensitivity
This parameter determines the volume of the sound of a particular speaker when a certain standard signal is fed to it. Typically, this is considered a 1 W signal with a frequency of 1000 Hz. The higher the sensitivity, the less the speaker is demanding on the power of the amplifier. So, it is believed that for acoustics connected directly to the car radio, the sensitivity should be 80 dB or more; for less sensitive systems it is recommended to use a separate amplifier.
External crossover
Crossover is part of acoustic system that divides the overall signal into separate frequency bands fed to the corresponding speakers (for more details, see "Bands"). All multi-band speakers (component and coaxial, see "Type") have their own crossover; it is usually located directly in the speaker body. However, in some models, usually the most advanced ones, the crossover can be made as a separate device, in its own body.
External crossovers are considered to provide better sound quality and introduce less distortion into it; in addition, they often provide the ability to fine-tune the sound.
Tweeter size
Size of the high-frequency speaker(s) included in the speaker design.
Size affects the amount of space required to install the speaker. However, high frequencies do not require large diffusers, so this dimensions is usually small and does not significantly affect the overall dimensions of the speaker system. The only exception is individual high-frequency tweeters (see "Type"), where the overall dimensions of the housing are directly related to the dimensions of the diffuser.