Hey guys! I'm running a two sub setup in a fairly large room about 20' x 40'. I'm going to be building some HTM-10s this winter which I'm excited to share with everyone in a build thread. I was thinking about the possibility of doing a DIY subwoofer and have been reading around a bit about people recommending subs with X or Y wattage based on room size. My question is this. When it comes to sub power, is there something unseen about benefits other than headroom and volume? I use the principle of dialing back subwoofer volume until no longer audible and then raising slightly from there. Using this method I don't think I have ever come close to overdriving a subwoofer in my life. They usually are louder than necessary even at like 25% of their volume. Based on that, is there a point to upgrading other than possibly increasing my frequency range? I'm running JBL 550s right now.
When it comes to powering subwoofers headroom and volume are the only two benefits to more power assuming the subwoofer driver in question can handle more wattage. So say you had a subwoofer that could handle 1000w and a 1000w amplifier but only turned it up so that during peak output it used at most 200w then there should be no audible or measurable difference between that 1000w amplifier and a 250-300w amplifier. You don't want to use an amplifier riding right on the edge of its limits as distortion often jumps at that point. Now beyond just amplifiers there is a benefit to using multiple subwoofers, not only do you get increased output, headroom and lower distortion but if the subwoofers are properly positioned around the room you can greatly improve bass response and more importantly seat to seat consistency by reducing the impact of boundary interactions and modal issues.