Even .5 dB is probably too big a difference, tho might be more easily done at home with that kind of "matching".
Yes, but at least it would make it harder to tell a difference that is based on the level difference alone. I am insensitive to people reporting hearing a subtle difference anyway but I do find it unfortunate that people often would do a sighted comparison, most likely just level match by ears, and without being able to switch back and forth quickly. It is even worse when they post their claims of hearing huge differences, such as much more details, wider soundstage, more bass etc., as though their subjective impression/experience = facts that brand A "sounds" much better than brand B, whatever that "sounds better" might mean.
I find that unfortunate because while I don't blame them, such posts would likely encourage, inadvertently more dishonesty in the industry. Over the years, the end results of hearsay created by such claims/posts might have indirectly encouraged manufacturers to focus on and spend more on marketing, even resulted in the misguided use of unnecessary hardware/design time etc, e.g. HDAMs, exotic Opamp ICs, copper plates for shielding, pseudo balanced/XLRs, so called "fully balanced" just to name a few, feel free to add
that don't actually improve on anything real, sometimes may even hurt. It would have been better if manufacturers would invest on new/innovative design and implementation that could actually benefit the consumers in terms of reliability, lighter weight, smaller size, efficiency, and/or even theoretical transparency (whether audible or not), and appearances.
