I have a 15" RE Audio SXX, that I acquired in a trade for a single type r 12". Currently its in a super bass pro box, and it sounds so so. I have been proposed a trade for 2 12" alpine type r's. A buddy of mine who is an installer said to me that if I put the SXX in a box built to spec, it would sound just as good if not better than the 2 type r's. Should I make the trade or just get a more appropriate box?
Well do you have the specs of the box you are using? or the port and external dims measured, also what vehicle? EX if you have the 15" facing up inside a trunk, that's a bad configuration. Also what do you mean by good?
my current box is W: 32" D: 17" H: 17 and 3.85 cu ft. and is tuned to 45 hz.. my car is a 2005 camry. The box for my sxx should be 3.0 cu ft @ 35hz. by good, I mean play loud and clean. I want a sql setup. right now, its only loud on certain notes, but plays clean.
Ok so this is a plot just to have an idea (cabin gain effects excluded):
The optimal recommendation is 4@34Hz for the SXX 1000W power (green curve). and for the couple of Alpines I used 4@33Hz 1200W power (yellow curve).
At lower frequencies you could get up to 3 extra dB of acoustic power due to increased sensitivity of nearby drivers working together.
So I guess I would choose the couple of Alpines since they will peak a bit lower and may get somewhat louder but it's a *close call* when using the boxes specified above. Also assumes that your electrical is optimal and your amps are properly set.
What is definitely correct is that the tuning of that enclosure is too high peaking at 52Hz. It must sound like loud junk.
personally I prefer a single, quality 15 to a pair of 12s, but that's personal preference. I like the fifteen because it retains high output, takes less space, and typically has a lower Fs. Just pick a 15 with a good BL curve and feed it a proper amount of power to let it work. Both the RE and the Alpines are great subs. It really boils down to which you prefer.