Review on Comply Cancelling Audio Technical QuietComfort Replacement by Amy Davidson

After reading many reviews I decided to give it a try. I don't regret what I did. They are designed for the Sennheiser IEM CX400bt and do not quite match these headphones. I found them to be too long for these headphones. I'm experimenting with shaving a bit on my back until I get it right. For others, it may just be a good thing. The insulation has doubled compared to the original silicone tips. You need some patience to get the earbuds in your ear properly. Push too hard and there is no support while the memory foam expands into the ear canal. Don't squeeze enough and the liners won't go in and there will be no clutch. So far I haven't had any issues with the tips falling out of the headphones and staying in my ears as some have reported. The sound quality has improved in some respects and stayed the same in others. The bass is tighter and tighter than before to seal tighter. The top end is slightly recessed due to the longer tips and guards that I will be removing. Once I cut them to the right length, removed the strips of wax and listened a bit I'll get a better idea and will update the review. So far I haven't seen any signs of foam deterioration or collapse. They are used 8-10 hours a day and are therefore heavily used. Update 1: Before hitting submit I cut the tips to the same length as the original silicone tips and what an instant difference. They sounded almost as good as Hifiman in-ear headphones connected directly to the DAC. These buds have never sounded so good to me. I've tried out some of my test tracks, which I know almost as well as the artist, and I can't believe that advice can have such a big impact on the sound of IEM. That bass is tighter than I've ever heard. The highs opened up immediately and I'm still trying to figure out what a tremendous increase in visual and sound stage it is. It's like the buds aren't there because the soundstage is a few feet from my head. This is by far the biggest improvement I've heard in all my years of tweaking and upgrading audio hardware. All for $20 for 3 simple little pieces of memory foam. Hard to believe it streams via bluetooth aptx and can sound so good. It's worth the price, and if you enjoy tweaking and spending a little time experimenting, the results will be worth it. I think I did them as best as I could, but I have two more sets to play with, so maybe there's still room for improvement. Out of curiosity I put the silicone tips back on and all the above comments completely collapsed on good sound, but I didn't get anything like this with the modified tips. It's like the difference between a great pair of dynamic speakers and a matched set of electrostatic Acustat amplifiers. Get a set and play with them. I'm sure similar results can be achieved with other brands of headphones. Update 2: I believe the difference in sound quality is because the soft silicone tips can slightly compress and distort the shape of the canal between the headphones and the ear canal exit. Also, these tips have a direct impact (except for the wax caps, which I removed) into the ear canal. When I trimmed the tips to their original length, I noticed that the tips no longer fit the ear canal and there is some clearance between the tips and the eardrum. An improvement in comfort was also immediately noticeable. The original tips had a cross brace on the end which prevented the silicone tips from breaking but also reduced the clean cross-sectional area which I believe decreased by 40% without compression of the silicone tips. If the tips were to shrink as they were inserted, this would reduce the cross-section even further. This can be the reason why all kinds of reflected sound waves are created inside the barrel, which distort the time and phase relationships before the exit. Just a theory, but the results speak for themselves. There really is such a big difference. I'm sure the same results are obtained with other brands and some experiments.