I just finished my setup and I was wondering if this is ok for my bass setting. I have it so that at +3 bass out of 6 it sounds perfect. Do most people have it set at +0 bass on the HU? What are signs I should watch for that I might be pushing the sub too far?
Its a JL 12w3v3 on a alpine mrp m650 amp.
It depends on how you set your gains. With your bass at +3 it is electronically the same as having it at zero with your amp gains set 3 db higher. Your adding +3 db of bass, if you do it here or there doens't really matter much. Although you are reducing the headroom of your HU by the same amount before distortion. The ideal is to send a clean signal, free of distortion, from you HU and let your amplifier do the amplification.
I suggest you set your gains with a meter and refrence disc with all controls at zero. If your listening to a song that has very little bass, then you can turn up the bass, or turn it down if it has too much.
Also at low listening levels you will want to add in some lows and highs, but when you turn up the volume, you will need to return those settings back to zero to sound good. Also be aware the bass control sends more bass to your main speakers as well as the subs. This is why it's nice to have seperate sub level control rather than just "bass" control. Use the bass control to adjust for listening levels and individual songs, and sub out to tune your system.
You should be listening for distortion and mechanical sounds from the speakers, those are bad. You want clear, clean tight bass sounds. Setting your gains with a meter and matching your amp power levels correctly with your speakers should put you near your max power levels of you HU, amp and speakers, equally and all at the same time, without too much fear of damaging your speakers.