I have an extended cab Nissan Frontier, and the space behind my front seats is not only tiny but constantly crammed full of stuff which I use for work.
1. As I understand it, whereas you can put things on top of your subs and still be OK, amps need to have enough breathing room or else they can overheat, is that right? Is this only true at near-maximum volume levels, or even at moderate everyday use?
2. And how much of a difference does a built-in cooling fan make? That's one of the attractions of the PPI PCX-480.
3. I was thinking of a wall-mount, just wanted to make sure that it wouldn't have any bad effects on the amp since they are probably designed to dissipate heat upwards?
4. Is it possible to mount an amp on top of the sub enclosure box, or would that cause interference? Especially if I use a truck box, which is only about 5" deep on top, whereas most amps are at least 10" deep...would I have to go to a 10" deep hatchback box?
5. Do i need any space between the back of the sub and the wall, or can the sub be mounted flush against the wall?
1: amps always have to get good air flow. they get hot. if they get too hot, they shut down.
2. the fans are useful IF you have good airflow already, on class-AB amps due to their lower efficiency. My class-AB amps run around 160degF at normal listening volumes once they warm up. They'll give good second degree burns if you're unwise enough to stick your hands on one of them when they're warmed up.
3. don't mount them upside down. on their side is fine. In fact I was going to suggest just that. Place a sheet of MDF or plywood against the rear wall of the cab, and mount the amp(s) there.
4. you can mount an amp on top of the speaker box, but it usually looks lousy.
5. the subs need at least 4-6" between the magnet and the rear of the enclosure to work properly. The subs also need boxes built to the proper volume to work well.