Long overdue update, been away on vacations and just finished the backtraps yesterday. The below was done :
2 corner traps behind the speakers, close to 3 feet wide at the mouth, and 2 feet deep at the apex of the triangle.
1 trap behind listening position, 8 feet wide x 8.5 feet high x 1 feet deep.
Couldn't stop my excitement to have a listen. But please bear in mind that iam listening after almost 25 days. First impression on female vocals from Annette askvik and Adele was WOW, the clarity definitely improved. But the bass still sucked at times to be honest. I was sure that iam still having my old suckout at 60hz and reverb in the bass. But didn't bother to measure yesterday.
Come today, added 4 nos of thin panels at side wall 1st reflection points, with supposedly 50% diffraction and 50% absorption, all in the upper midrange to treble region. And the improvement in vocal clarity is stunning. Iam actually over the moon right now, except for the bass which still sucks
So finally I started measuring today with REW, and my RT60 time above 200hz is already close to 300 ms. Though some bass frequencies are still close to 500ms. I think I need more bass absorption to be added. I have 2 nos of 3 feet wide alcoves next to the back bass trap at either sides. I could this time use lower density rock wool at 60kg / cu.M to fill those upto 4 inches deep, but not sure if adding anymore absorption will be detrimental. Iam happy that the room is still very live sounding.
By the way, the way I built the panels, I've kept a consistent 2 inches gap between the geowool and the edge of the wooden frame, so that I could cover them with rocksul 370 or acoustic foam as required. So I still have this option to reduce RTA60 further in the higher frequencies. But the adamant RTA 60 in the below 200 hz region, is really proving beyond my ability to address.
So here are the pics of the room ( sorry for the mess, I live in a flat, so I've been chopping wood as well as 520 kgs of rockwool in the same room for sometime now
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I can post graphs tomorrow if anyone is interested. Though I should have ideally taken measurements of the empty room which I stupidly couldn't. So my measurements only start after the addition of the 3 bass traps.