A coaxial speaker will generally be one speaker that has 2 or more drivers built on to it. These generally come in 2-way and 3-way systems. The amount of different size drivers on a speaker determines how many “way’s” it is. A 3-way coaxial speaker is made of 3 drivers like a 6x9″ woofer, a 2″ mid range and 1″ tweeter. Coaxial speakers are generally made to reproduce the entire audible frequency range except for the lows in one self contained unit. Some coaxial speakers will dip into the low frequency range but are too small to give the thump of a larger driver like a subwoofer.
Subs and speakers are the ultimate end game of your car stereo. Speakers and subs transfer the electrical energy from your amplifier and then reproduce that energy into high and low pressure waves by a moving diaphragm called the cone. The high and low pressure waves are then intercepted by your ear drum and are ultimately perceived by the human ear to be sound. Speakers can make or break the final quality of the sound of your car stereo as well as the acoustics of your vehicle and the location of the speaker to the listening position. Real Time Analyzation, or RTA tuning, and time correction can make a dramatic difference in the final sound quality of your speaker system and should be taken into consideration when updating the speakers in your car stereo.
Subs and speakers come in different sizes, power ratings and shapes to accommodate different installation applications and sometimes specific octave ranges. The speaker cone is also know as a driver. Speaker sizes are usually referred to as driver sizes. As an example, a 6.5″ driver is a round speaker versus a 6×9″ driver is an oval speaker.
RMS vs. MAX power: The RMS rating of any speaker driver is the continuous power rating that the speaker is designed to withstand at a maximum continued volume rating. The RMS rating is the only number to go by when pairing your speakers with an amplifier. As an example a speaker with a 100Watt, or 100W for short, RMS rating and a 300-Watt Max rating is ultimately a 100 Watt speaker. The Max rating is the temporary spikes in voltage that the speaker can handle. A 100-Watt RMS / 300-Watt Max speaker is going to outperform a 100W RMS / 250W Max speaker at higher volumes, but may not be the more detailed reference speaker.
Ohms: The Ohm rating, or resistance rating, of a speaker is an essential part of a well balanced car stereo system. Many JBL factory speaker systems have 2ohm drivers. Most aftermarket speakers are 4ohm drivers. Replacing these types of factory speakers may require a wiring bypass of the factory amplifier.
Driver resistance ratings are essential when pairing subwoofer and speaker drivers with amplifiers. An amplifier that is 750W @ 2ohms might only generally be 500W or less @ 4ohms. When purchasing a subwoofer driver the correct pairing of a subwoofer’s RMS wattage and Ohm ratings with an amplifier’s output power rating is absolutely essential.
Frequency Response: Frequencies are measured in Hertz or Hz for short. The frequency response of speaker drivers will generally fall between 20Hz and 22kHz. At 20Hz the sound spectrum begins. Every time you double your frequency you move up one octave in scale. 20-Hertz to 40-Hertz covers the first Octave, 40Hz to 80Hz covers the next octave and so on. Subwoofer drivers are generally tuned to crossover at 80 Hertz. This can depend on the subwoofer type and the type of music you listen to.