I have just joined recently but I have been viewing this forum for three years or so. The amount knowledge and experience here is truly impressive. I hate to ask a stupid question of such an elite group but as I was once told there are no stupid questions just stupid people who ask questions.
Is it noise or is it music? Maybe I just have the volume too high, but at one or maybe two lower frequencies I hear what sounds like resonance from my Fortes - not bad but the speaker cabinets also vibrate and the grill cloth frame buzzes (my horn diaphrams are fine). The cabinets are solid as are the bass and radiator cones. As best as I can describe it, the sound goes from "bum-boom-bom" to a "bwa" sound that you can feel as well as hear things rattling around the house. It doen't sound like a normal progression - it's sort of like a certain low note gets a little goosing. It's especially noticeable when playing certain Enya music with long sustained deep electronic bass. The effect is not specific to any location relative to the speakers, it's pretty much all over. It's very rare, but I don't know if it should happen at all.
I'm wondering if the bass and midrange might be producing the same frequency at the crossover point or is the effect caused by my amps or pre amp (old NAD 2100s and 1600)? I'm curious to learn anything. Thanks.