Sandpat- great intro to the forums. You ask great questions and have a good attitude. Well done. We’ve had a lot of know-it-alls who have signed up lately and proceeded to school us all and save us from our ignorance. Not a great first impression.
I can’t help with advice for your issue, but it sounds like you’ve plenty of that. I just wanted to second the recommendations for room measurement. I recently purchased a calibrated USB mic that I use with REW, a free program. It’s the mic they recommend and was $90 shipped. Each mic also has a specific calibration file to use, making the whole process more accurate. I’ve found some bass modes that I thought were there, but I didn’t know at what frequencies or if they truly were problems. Now that I’ve the info, I need to decide what to do. But that is a way better situation than buying room treatments and placing them based on my thoughts instead of data.
I can’t help with advice for your issue, but it sounds like you’ve plenty of that. I just wanted to second the recommendations for room measurement. I recently purchased a calibrated USB mic that I use with REW, a free program. It’s the mic they recommend and was $90 shipped. Each mic also has a specific calibration file to use, making the whole process more accurate. I’ve found some bass modes that I thought were there, but I didn’t know at what frequencies or if they truly were problems. Now that I’ve the info, I need to decide what to do. But that is a way better situation than buying room treatments and placing them based on my thoughts instead of data.