Hi guys, I'm new to this site so please bare with me! I've got a Hartke HA3500e head and an Ampeg BA410 cab. The cab is rated at 400W at 4 ohms and the head is rated 350W RMS at 4 ohms and 250W at 8 ohms. The head has 2 speaker output jacks both with a 8 ohm symbol next it and the cab also has 2 input jacks. Should I be plugging both to achieve the full 4 ohm load? Also, I'm concerned with my overall power in general. I play in a metal band, with 2 guitarist that have really nice setups that are LOUD. I don't really have a problem matching their volume but I'm concerned with how much I'm driving my set up to achieve an appropriate volume. For instance, I've got my master volume on my head set at about a 6-7. The volume is fine at that level, but I can't help but notice some thwarting sounds coming from the speakers from time to time when I'm really attacking the strings. I'm not really sure if that is due to pushing it too hard or if that is all about my playing style and presence. On top of all that, my speaker cable has been popping out of my cab due to what it seems is the vibration. Is that a power issue or is the jack just not tight enough? I would love if someone could give me some input/advice on these topics or at least point me in the right direction!