REL customer service recently told me they won't repair either of my subs should they ever need it. Hmmm...also, "speed" is a silly term and I don't think it's applicable to subs or really anything else in audio. I think some bass overhang in reverberant environs might be what makes people think there's a velocity issue, and many think it comes from cone material...it doesn't.
Subwoofer matching
I was all set to pull the trigger on a pair of REL subwoofers. These would be used with my Avangard Duo’s and Pass Labs XA 60.8 monoblocks. My main music is Rock, Jazz and Blues. I have been given advice by a few people now saying the 107 efficiency of the Duo’s will make it very difficult to find a matching paint odd subwoofers. Feed back I have been given is “... it will take a powerful subwoofer to be able to match the output levels of your speakers“ and “The only REL model that may work for this application will be the 212/SE, which has a very powerful amplifier that will allow it to blend well with your speakers.” A pair of REL 212/SE is a budget breaker for me. I am in not position to judge if the advice is correct or not. Does anyone have experience negating a pair of subwoofers to a highly efficient speaker?