Trying to keep the money down so wanting to get the most bang for the buck. In 18" I am going to be limited due to budget. But there is at least mach5 audio. May be others I don't know about. Power will be from a sundown saz1500d. Budget is about $250. Wanting a little sq but am willing to trade off some for loudness. Plenty of volume for either size. It needs to have a good size magnet to keep the transient response high. Which size would be better and why? And please point me in the right direction for a model. Music is rock/metal. It is for a daily driver. Needs to run for an hour at a time without thermal issues 5 days a week twice a day. Will build a competent box as well. Go ahead and suggest that if you have time. IE, ported tuned to 35 hz 4.5 ft3. That is if you have or have heard a good combo for a specific sub. Just throw any subs you can think of that will fit the criteria. I will try to find reviews on them, and ask for more details if I can't locate any info. I guess what I am looking for is for it to pound. Looking into a single to keep the $ down so hoping there is one that will be louder than a traditional dual 12 setup.