Sub In The Fireplace

I couldn't disagree more. I have a reasonably large masonry fireplace in between 2 main speakers, and the fireplace plus chimney gives a hollow boomy signature to the sound. The only solution was to wall the whole affair off with tube traps, thanks to which the speakers now have normal staging and a reasonably linear frequency balance. And that is with the speakers well out (55") from the front wall and fireplace.

Flex, difference is, his fireplace has a large sub in it and yours was trapping rear wave inside of a square hole. I'm not sure that the center of the rear wall is the best place for a sub but could be fine in some rooms, like Rives said, take a measurement.

Thanks for the responses... Rives, I guess I should have been more specific. But, yes, the fireplace is actual brick, and sits on the same foundation as the rest of the house which is a concrete slab. As far as the leveling jacks... are you suggesting this as a method to couple the sub to the concrete (in a sense)? Or simply as a way to cover the flue?

Sogood51, I wasn't sure if you were referring to me or not...
"I'm not sure that the center of the rear wall is the best place for a sub".

The sub is in a fireplace that is in the middle of a wall which one would face when listening to music.

And Flex, I see what you're saying... but I can't say that I've run into that same problem.

Sorry, should have read, center of the front wall. I need to start reading my posts over more often.

Sogood,
I measured my room response before, during and after treating the fireplace. Placing absorbers or diffusors inside the fireplace cavity, or covering the front with glass doors and partially treating the exterior did not work either. 8' tube traps do work.

Vectorman, if you haven't found the problem so far, then you probably don't need to worry about it.