How can you tell if you have Noise Cancellation?

[Hotdog]

I have 2 12's in a ported box with 2.1 cubes after displacement tuned at 33hz

I also have 2 10's in a ported box with 1.5 cubes after displacement tuned at 36hz

the 10's I think I am going to put in one of my other vehicles but until I get all my parts in I put them in with the 12's in my vehicle just to see if I got cancellation or what would happen.

Well it sounds great to me and plays through all the different frequencies fine... I dont hear anything noticeably off anywhere.

the 12's are Subs up Port up in its own enclosure tuned at 33hz

the 10's are Subs up port back in its own enclosure tuned at 36hz

what are some things I could try to find out if I am getting cancellation?

I plan on getting 2 more 12's later on so I can have 4 12's.. but I got the 10's figured I would put them to use until I get the parts in to put them in the other vehicle.

[Hotdog]

Any idea of how to test for cancellation ?

I tried doing a search for it and all i keep getting is noise cancel head phone

[SQMonte]

Any idea of how to test for cancellation ?

I tried doing a search for it and all i keep getting is noise cancel head phone

http://www.google.com/search?q=subwoofer+c...lient=firefox-a