Begin with one subwoofer you can always add more providing your first has an output provision. Its not critical that they be identical. If you decide on a subwoofer with equalization that equalized signal should feed extension subs that are not equipped with equalization saving you that expense. Multiple subwoofers can reduce or eliminate the rooms nulls and modes but do not provide equalization.
To find your rooms optimum subwoofer locations the link below will explain the crawl test. Make a note of every location in the room where the bass sounds best in case you add more subs.
You'll need an extension cord to power the sub from the same circuit powering your system. You'll also need a long interconnect cable (RCA or XLR). MonoPrice or Blue Jeans Cable offer very reasonably priced custom length interconnect.
High pass filtering was designed for the situation were the main systems amplifier has difficulty driving the main speakers.
Your main speakers in room response will most likely begin to fall off well below 80 Hz. Unless you're using a receiver with an LF (subwoofer output), a subwoofer with a variable crossover and phase should do a better job of matching your main speakers crossover region.
https://www.youtube.com/watch?v=AV3oLLMgS-M
Have fun.
To find your rooms optimum subwoofer locations the link below will explain the crawl test. Make a note of every location in the room where the bass sounds best in case you add more subs.
You'll need an extension cord to power the sub from the same circuit powering your system. You'll also need a long interconnect cable (RCA or XLR). MonoPrice or Blue Jeans Cable offer very reasonably priced custom length interconnect.
High pass filtering was designed for the situation were the main systems amplifier has difficulty driving the main speakers.
Your main speakers in room response will most likely begin to fall off well below 80 Hz. Unless you're using a receiver with an LF (subwoofer output), a subwoofer with a variable crossover and phase should do a better job of matching your main speakers crossover region.
https://www.youtube.com/watch?v=AV3oLLMgS-M
Have fun.