how does graph relate to room ?

[ausvette]

This is my first graph I've produced and posted. Its for a full range speaker and was taken approximately 2.5m in front of the speaker in a room 5.5m wide, 8.5m long and 2.6m high.

I've been improving all the electronics of my audio and am probably long overdue in looking at treating the room acoustically. Been very interesting reading this forum and learning a bit about the amazing REW software. I was about to order some treatment, but really wasn't happy starting that until some scientific testing had been done to see where the room was at and what effect the treatments had. So this is my start !

Room currently has no acoustic treatment. Has 8 large leather recliners in it, is carpeted and has some curtains. I guess looking at the graph my immediate concern is what is causing the big dips at 80Hz and 160 Hz - though the whole region is low from 63Hz to 295Hz ?

I'm presuming bass traps would help that 20 to 60Hz region which appears to be accompanied by ringing in the waterfall graph ?

Speakers are 100kgs each and I haven't tried repositioning them yet to see what effect that has.

Any comments gratefully appreciated

[JohnM]

Try measuring with the mic in a few different positions to see how the position affects the reading. A quick way to do that is to use REW's RTA together with the Pink PN signal to get a live update as you move about the room, that will let you see whether you measuring position is in a modal null - alternatively the speaker may be in a null, but at 100kg I understand your reluctance to start dragging them about

Looks like you have REW running just fine, for general advice on acoustic treatments the Acoustics forum is a great resource. To affect the 20 - 60Hz region would require very large volumes of bass trapping, placement (of speakers and listeners) is probably your easiest first step.