I am looking at using Mach 5 audio IXL15.2.2 driver in sealed cab for 2600cu.ft.dedicated room. Looking for a sub that can go down to 20hz with decent output. Any recommendations on volume of the cabinet? I am looking at other 15" drivers but Mach 5 audio driver seems to be one of the best value for what I am looking for. Are there any other 15" drivers I should look at? I have looked at TC sounds but they can get quite expensive.
Haven't checked the price differences lately but you should have a look at the dayton HF drivers. Last I saw they were under $200 and have very low distortion. Nicely built driver. I'm thinking they like larger boxes.
Also check the JBL GTI MKII 15" driver. Ebay has them for under $300. It's an excellent driver even though it does not have a lot of displacement, 20mm of xmax, but your room is not that big. What this driver has is very low distortion and excellent SQ, along with good output. Around 800W to power it and a box of 3-4cf should do it.
I've not heard the titanic, but I have heard from others that have heard it that it sounds pretty one note-ish. It does do well in a smaller cab though.
To get low with authority you will need either a lot of drivers or a bigger box...or both. Unless you use some eq to boost down to 20 hz it won't be a very flat response. And if you do use eq you're going to run into distortion.
A way around this is to go a bit bigger with the box and go ported instead of sealed.