Judging from the graph (and pictures) it’s the main speakers, with no subwoofer? Part of the problem likely is the two speakers interfering with each other.
Briefly, when the sound from a speaker hits a boundary, reflects back and “meets” the original signal out of phase, there will be a “suck out” or “null” at a specific frequency. There are formulas that can calculate the exact frequency.
If you employ two large speakers with good extension, the half-way point between them is going to behave acoustically like a boundary. Thus, two full-range speakers placed 12-feet apart will exhibit a null at about 56 Hz. If either or both of those woofers are also about 6 feet from another boundary, the null will be reinforced accordingly. Two full-range speakers placed 9-feet apart will have a bass null at about 75 Hz, the same as they would have if one or both were 4.5 feet from a wall or two walls.
This can be a major dilemma for spaced full-range speakers. The solution is surprisingly simple: a mono sub, located in a corner. A subwoofer positioned that way is so close to three major room boundaries that any notches it generates will be well above its crossover-controlled operating range.
In addition, the main speakers, now high-pass filtered at, say, 80 Hz, will not generate any significant bass signals at low enough to interfere with the subwoofer.
From that point you can smooth any anomalies in frequency response that the sub might have with parametric equalization.
Regards,
Wayne
Briefly, when the sound from a speaker hits a boundary, reflects back and “meets” the original signal out of phase, there will be a “suck out” or “null” at a specific frequency. There are formulas that can calculate the exact frequency.
If you employ two large speakers with good extension, the half-way point between them is going to behave acoustically like a boundary. Thus, two full-range speakers placed 12-feet apart will exhibit a null at about 56 Hz. If either or both of those woofers are also about 6 feet from another boundary, the null will be reinforced accordingly. Two full-range speakers placed 9-feet apart will have a bass null at about 75 Hz, the same as they would have if one or both were 4.5 feet from a wall or two walls.
This can be a major dilemma for spaced full-range speakers. The solution is surprisingly simple: a mono sub, located in a corner. A subwoofer positioned that way is so close to three major room boundaries that any notches it generates will be well above its crossover-controlled operating range.
In addition, the main speakers, now high-pass filtered at, say, 80 Hz, will not generate any significant bass signals at low enough to interfere with the subwoofer.
From that point you can smooth any anomalies in frequency response that the sub might have with parametric equalization.
Regards,
Wayne
