Originally Posted by scary1
I guess I don't fully understand the ins and outs of tuning. For instance, Nick at SI recommends tuning to 30 to 32Hz! He claims the room will get me into the 20's. Granted, that's a different driver than my RSS 390. I don't need to shake the nails out of the sheetrock, just some thud and rumble with HT and good base for music. If I tune for, say 19Hz, what are the trade offs with music?
Everything is a compromise, and port tuning is no exception. If your driver, cabinet size, and amplifier power are fixed, and the port tune is the only variable, then a lower port tune will produce more SPL in the vicinity of the port tune, than a higher tune will. But, it will have to trade-away a little more >30Hz or 35Hz SPL in the process. As long as you don't listen to music at very high SPL's, there shouldn't be any reason not to have a port tune of around 20Hz, or even a little lower. But, there really isn't any free lunch.
In my personal opinion, you are better off starting with the port tune you want, and then adding a second sub if necessary, to get more mid-bass SPL. If instead, you start with a higher port tune, that doesn't really give you the thud and rumble you want, adding a second identical sub won't really give you appreciably lower extension. (The extension is mainly defined by the port tune--acting in conjunction with whatever room gain you are getting. But, the room gain wasn't sufficient with your sealed subs, and it may not be with a higher port tune, either.)
For music, good SPL down to about 25 or 30Hz is plenty for most people--even for EDM, or other forms of bass-enhanced music. For movies, though, you don't just want to get into the twenties, you want to get into the teens. I would not start with a port tune much higher than about 20Hz, if I were you.