My friend has a dodge intrepid with two Memphis 15" subs facing up, and it is painful to sit in his car. It kind of makes me sick, lol. And they are just some entry level Memphis subs, and that is LOUD. He sold them and put some Audiobahn 15's in there place and same result, it was VERY loud. Now, we never compared it to facing them straight back bcuz of the dimensions of the box, but it was PLENTY loud facing up.
He sold those Audiobahn subs eventually, and I borrowed his box. I only had one fifteen to put in the box, but it sounded niiiice. I wish i had a matching fifteen at the time, it probably would've BANGED like his did. I gave it back to him and went with another setup bcuz that 15" I had needed too much power for just one speaker, and i wanted a pair of speakers. He bought some cheap DHD subs and put in the up facing box, and it BANGED again, lol. Some cheap DHDs banged, lol.
Facing UP in some cars simply BANGZ. I liked the way it sounded in MY car with ONE fifteen. Btw, the box was sealed.
If I decide to get 2 15" ED 16oV.2 subs instead of my IDMAX 10's, I will face them up too. I talked to an ED tech and asked him about facing them UP, and he said in my car it should sound awesome. He also said he has several friends that face theirs up too. I am really considering doing that.
I think it would look neat too, to pop my trunk and see two 15's looking right up at me and watch them dance, lol //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
I've read people that give advice on it that say you shouldnt bcuz it will cause "cancellation" facing up, but I sure didnt hear it in the UP facing setups i've listened to. It must depend on the vehicle.