Okay guys I need some help. I have four 8in dvc 4ohm powered by 1 rp-4500.1d 2 channel wired the subs in parallel and the bass is weaker than the 2 8’s I had before this setup what am I missing or doing wrong?
If you wired four 4 ohm DVC subs into parallel that would be a 1 ohm load per channel. If you didn't bridge the amp and ran 2 subs to one channel each that would be a 1 ohm load per channel. That being said, that amp is a mono amp, it just has 2 sets of speakers terminals, not channels, so if all the subs are wired parallel then your at a .5 ohm load. That amp is not rated for a .5 ohm load. You need to run those subs in series. Then adjust your gain etc..
Wire it like the top one. A dual VC 4 ohm speaker wired parallel makes it 2 ohms. Now if you wire it parallel to the same speaker done the same you will have a 1 ohm load with both of those speakers in parallel. Now if you run the other 2 the same way you will have another set of 1 ohm speakers in parallel. Now if you run them all to the same channel you will have a .5 ohm load. That diagram at the bottom is for a 2 channel amp, your amp is not 2 channel, its a bridged mono amp. You need to use the top diagram.The bottom picture is how it’s wired
You may also be off phase? Like Grimmjoww said, wire 2 subs in parallel then wire them in series with the other two. You will run the positive of 1 set to the amp and the negative of the other set. You will then run a negative from one set to the positive of the other set.The bottom picture is how it’s wired