# Dealing with Floor-Ceiling Room Mode in Living Room



## drrick (Nov 16, 2006)

Hey guys,

I have convinced my wife to allow me to do some room treatments in our living room, which is a far from ideal space, but all that is available. I have 4 inch thick OC703 bass traps in two corners, 2 inch thick triangles in two of the ceiling tri-corners, two 2 inch thick panels behind my mains, and an additional 2 inch thick panel in a floor-wall corner near one of my bass traps. Because the room is set up toward the corner, there are a lot of issues that come into play, not the least of which is doing the standard advice of treating first reflection points (i.e. treating first reflection points hasn't been something I've been able to do). Anyway, my treatments have indeed had an effect--ringing has reduced even into the 60 Hz range. 

One remaining problem is what I think is a floor-ceiling room mode centered at about 71 Hz. In my main listening position, it presents as a dip in the response, and at the other most used listening position it presents as a peak. In both places, my waterfall charts show excessive ringing at that frequency. Near as I can tell, this might be caused by the (I think) 8' ceilings in the room.

Anyway, my question is whether there is something I can do to correct this problem? I've actually been pleased with the improvement I've seen so far, but I'm not sure what else I can convince my wife to allow  I'm interested to hear your thoughts. Thanks! You all have taught me a lot already!


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## bpape (Sep 14, 2006)

A 4" thick panel directly over the seating will address it if it's height related.

I'm not personally convinced that it is completely height related. If it were, you'd have the same peak or dip at all seating locations (or very similar). The fact that one seat has a peak and 1 has a null tells me that it's at a minimum, an interaction with something else. Could be partially height related and treating the ceiling may address it - but it's not a guarantee.

Bryan


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## drrick (Nov 16, 2006)

Bryan,

Thanks for your response. I guess it makes sense that it would present itself as either a peak or a null all the time at ear height...I didn't really think about that. I'll have to mess with it a little more and see what should be done. I highly doubt panels on the ceiling are a possibility, so maybe I can fix it another way. Thanks again for sharing your expertise!


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## bpape (Sep 14, 2006)

If it's a blending of 2 problems (which is likely), then potentially, you can find the other offending position and treat that instead. 

Bryan


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