Dual Sub setup question

[Big Daddy]

jibucha,

What you are suggesting is old news. There was a time in the 1980's when people started discussing and discovering stereo subwoofers. I remember reading a few articles about the benefits of stereo subs in some audio magazines. That was one of the reasons I bought two subwoofers back then.

The problem back then was that almost all subwoofers were passive and had a fixed crossover around 120Hz to 240Hz. My old DBX subwoofer worked like that. Also the vast majority of receivers/preamps were stereo. Not too many people had heard about powered subwoofers.

Typically, you would connect the the speaker wires from the receiver to the subwoofer and then use speaker wires to connect the subwoofer to the speakers. The crossover inside the sub took care of the primitive bass management. I had a set of German speakers like that in 1978-1979 as a young audio nut.

By mid 1980's there was some discussion of stereo subs. Obviously, with a crossover above 120Hz, it made some sense. By late 1980s, a few places like Dak Industries started advertising a relatively new product called subwoofer amplifiers with their own built-in crossovers that enhanced the performance of a subwoofer. We had not heard the term powered subwoofer back then. I bought two different models of DBX sub amp in 1990-1991. Currently, I use one to power a DIY subwoofer in my two-channel room. The other one is picking dust in one of the closets.

Starting in early to mid 1990's, after the introduction of Dolby Digital, receiver manufactures slowly started introducing basic bass management and LFE. Unfortunately, many people are confused about LFE.

Modern sound engineers create a low frequency effect to make their movies more realistic. Even if you have 5 super large speakers, you should still have s subwoofer for the LFE signal. Without a subwoofer, the LFE signal is directed to the front speakers and that creates two problems:

1. The speakers may not be able to handle the low frequency sound.
2. You lose the flexibility of experimenting with the position of the sub as you cannot move the front speakers to the side or to the rear. The long wavelengths of bass sound interact wih the room boundaries and create standing waves. You need to be able to move the subwoofer around the room to find the optimal position.

The second function of a subwoofer is to assist the other speakers that do not have good low frequency extension. We call this bass management by directing bass frequencies from smaller speakers to the subwoofer.

With proper placement in a room, one subwoofer can give reasonable bass sound for one listening position. However, if you move a couple of feet in either direction, the bass sound may be terrible. The solution is a second subwoofer. Although some people erroneously assume that the purpose of a second subwoofer is to increase the level of bass sound, that is not the real reason. With two subwoofers, you will have more flexibility in placement in order to reduce the effect of room modes and get a more even and smoother bass sound across the room for all listening positions.

Extensive research by Dr. Toole and his associates at the National Research Council of Canada and at Harmon International have demonstrated that the ideal number is 4 subwoofers. In their demonstrations, they have shown that more than 4 subwoofers do not benefit you as much. Remember the law of diminishing returns.

If you want to add more subwoofers to the speakers in addition to the LFE subwoofers, you can do that.