Originally Posted by Peterc613
A friend of mine was looking to buy two Reaction Audio Gama 218 subs at $3,249/pair or two Captivator 1400's at JTR's pre-sale price of $3,198/pair.
I suspect the RA's dual opposed sealed 18" drivers have the same 1400w ICE amplifier that JTR is using, but they're calling it 1850w. I believe it may be the ICEpower amp that consists of two (2) 700 ASC/ASX amp modules; each module is rated 1% THD at 700w @ 8 ohms and 350w @ 4 ohms 800w (10% THD at 800w @ 4 ohms). Unless the RA 18" drivers are rated at 8 ohms, they're each probably going to get half the power of the single JTR 18" driver drawing from the same amp. The JTR drivers have a 30mm Xmax (60mm total) and the RA drivers have a 3" (76mm) voice coil. The JTR motor may be more powerful at 256 (bl^2/re) whereas the RE motor is unspecified. The JTR's response is 16-190 Hz +/- 1 db while the RA's response is 20-200 Hz.
From what I've seen in the DIY section the greater efficiency in output of a ported sub outweighs the output of a sealed sub when using the same driver. However, I don't know what the comparison is between dual opposed sealed versus single ported using the same driver. I know that you replaced your PSA XS30 sealed dual opposed 15" subs with DIY ported UXL-18" subs and were very pleased with the improvement. Attached is your graph showing three SI 18's, ported vs sealed. You commented it wasn't until about 12-13hz that the sealed design had the advantage, however, the output advantage of a ported sub from 15-40hz was not even close. Others have also gone ported over sealed for the same reasons.
Why did you decide to go with the sealed dual opposed RE 218'?
How would a pair of RE 218's compare to a pair of JTR Cap-1400's at the same price?
I suspect that Joe or Jeremy will have a much better answer than I would but I think a better comparison would be between the Echo 18 and the Cap 1400.
I think it all comes down to what your priorities are. The Cap 1400 should be pretty flat down to its port tune in the 16 HZ range. Below that, the 218 would have a clear advantage in the ULF as the Cap and Echo will fall off dramatically below their port tune.
Without measurements, it would be difficult to say which sub would have the advantage above 16 HZ. I think Jeremy is planning on sending a few subs to data-bass for measuring and I also think that Jeff is going to send a Cap 1400 so that will clear this up. My OPINION is that the 218 would be able to keep (if not slightly exceed) up with the Cap 1400 in terms of output but in terms of FEEL, the ported design of the Echo 18 and the Cap 2400 will provide a more tactile sensation. Again, it may come down to what design you prefer and what your room is like. If you are on a concrete floor, then ported may be the way to go unless you go with multiple sealed subs. If you are after <20 HZ ULF then a sealed design may be the way to go.
Another idea would be to read through some of the GTG results comparing the Cap 2400 to some sealed designs like the Submersive HP. People have widely ranging opinions based upon what they hear (and feel) - not necessarily measurements. Just based upon what others wrote, it was easy for me to go with multiple sealed subs as I don't want to give up the ULF.
I personally am going with multiple sealed subs to get the best of both worlds. Again, the above is mostly opinion and speculation based upon what we know. I have not had the pleasure of hearing any of the above and without measurements, it is all speculation.