As you likely know, these are among the best rated yet affordable subs.
https://www.rythmikaudio.com/reviews.html https://www.rythmikaudio.com/technology.htmlBut some claim to hear coloration which presumably even designer Brian Ding suspects could be due to use of less than ideal op-amps in the plate amps.
https://www.rythmikaudio.com/faq.html Assuming the plate amp's op-amps are pluggable and not soldered (???), which swappable discrete op-amps might even be better alternatives than this?
https://www.youtube.com/watch?v=zyhxKmQy-pw&t=17sOr this?
https://www.youtube.com/results?search_query=discrete+op+ampOr which of these?
https://www.youtube.com/watch?v=zDA90yMoT18OTOH, Zockopa commented here
https://www.youtube.com/watch?v=cdYFH9ms9EE&t=28s ,
that upgrading the passive components functioning directly with the op-amp (film caps with dielectrics yielding lower DA and distortion) will likely deliver more cost-effective performance.
Therefore, are at least the modest, if not brisk sales of this "snake oil" by at least the above three brands driven by placebo satisfaction-rather than vastly less measurable noise?
Otherwise, what else could account for any user claims for perceived larger soundstage, better imaging, more definable midrange and wider flatter frequency response?
And even Brian Ding says here that except for bass heavy dance music, flat response down to 14 Hz (certainly 28Hz) is quite noticeable, as it pertains to recorded event ambiance and the size and proportions of soundstage.
https://www.rythmikaudio.com/faq.html#14hz But then the task at hand is how best to upgrade the circuitry of the chosen plate amp?
https://www.rythmikaudio.com/amplifiers.html