With regards to the original post and the original question, I’ve asked the same question before and was informed bracing, and cross bracing, the inside of the cabinet will yield the best results to combat the problem which you describe!
Douglas makes a good point in that your time, money and effort might be better spent moving up in speakers. If you like the Kef q1’s, look for some kef xq1’s or anything in the kef xq series. I’ve had 2 pairs of xq(‘s and they are lovely speakers. Coincentric design with a super tweeter pulled straight from their reference series , curved boxes to reduce internal standing waves, and extremely well braced inside.
I sold my last pair of xq5’s for $600...
Douglas makes a good point in that your time, money and effort might be better spent moving up in speakers. If you like the Kef q1’s, look for some kef xq1’s or anything in the kef xq series. I’ve had 2 pairs of xq(‘s and they are lovely speakers. Coincentric design with a super tweeter pulled straight from their reference series , curved boxes to reduce internal standing waves, and extremely well braced inside.
I sold my last pair of xq5’s for $600...