Bass Response on Dunlavy SC-IVa

The problem is the variation in the reaction of the woofers to the floor and the ceiling. You have a large differential in boundary effects. The woofer on top is much further from the ceiling than the woofer on the bottom is from the floor. So you probably have a bass suckout of about 6db at 60 to 70 hz at ear height at your listening position. This is where much of the hit bass is on most recordings. Some geometric panels {and not soft} to act as a lens to refocus lost energy back at your chair would greatly enhance phase and frequency. Tom

Try this: Move your listening chair,place a ladder where your chair use to be. Play a constant test tone at about 60hz. Climb the ladder up to ceiling height, make reference of the 60hz tone with either an spl meter or your audio memory. As you come down the ladder at each step make another measurement and record the output, do this until you reach about 2 feet from the floor. Now after you have done this move the ladder, re-install your chair at the original position and take the same measurement at ear level {38to40in.}..At ear level you will have a 6 to 8 db suckout..in contrast to the floor and ceiling measurements.The frequency of the suckout maybe 50 to 80 hz so your reference tone may vary slightly.While doing any of these tests do not touch the volume control. ..You can mitigate some of the phase cancelation by moving your ceiling or by building an acoustic lens attached to the ceiling ..Tom

John, Peter Snell had a speaker [Type 1} that had its drivers near the floor level on an angled baffle tilted back with a ramp in front to reduce the floor bounce effect..He also had a U.S.patent on baffle designs to reduce room boundary effects. Truly a designer who thought outside of the box. Had a in home demo of that Type 1 speaker and a sales meeting with Peter Snell...that was probably in 1980 or 81..to bad he is no longer with us.He was truly a innovator. Tom