Finally a thread I have experienced for myself.Almost one year ago,I had to make this same decision for myself,what's it going to be,the new JL 12- W3-3-4(2 subs of course)run parallel to 2 ohms needing 600 rms for the both of them???Even at that,the danger zone(black zone)by JL's specs. the subs max rating is 600 rms.1000 rms will more than get the job done for the JL's...The Alpine type 'R' 12" sub---500 rms with a top end max of a massive 1500 max!!!!!!!!!They are two completely different animals.I was fortunetly able to test these subs like this:I had purchased the new JL 12w3-3-4's ,I had the 10's,but the 12's do go a bit lower.I was using the V-PowerAlpine 650-M-mono,Got a good deal on a mrd-1005-1000 rms at 2 ohms so I put that in the car with my new 12-w3-3's in the correct size vented enclosure.The new mrd-1005 made a considerable difference with the w3's.My friend that manages the shop I do busness with and he had just put some type'R' 12" subs in a vented box,the 2 +2 ohm kind so the mrd would be at 2 ohms,proper vented enclosure.The JL's had a much better SQ.but....................the 'R's have the ability to have a mrd-1005 for each sub and still not blow,and have a great SPL and good SQ.Not as good as the JL,but,the Alpine is a economical sub.A pair of 12" type 'r's can be had for $220.00 shipped,the JL,about 200 each.I stayed with the JL.I run all Alpine--Source 9847,type'R' components,4 type 'r' co/ax,and the new pdx-4-150.I've heard all Alpine,and with the JL.The type 'r' can take twice the power,and go louder for less money.They are both great!!!!!!!!!!!!!!!!!!!!!!!!!!!02 SENTRA out..................