Originally Posted by Memo
Thanks for the advice will M400/4 drive 4 in cabin JL 7.7s ok?
Yes it will....but just okay. Give it a C+.
The JL Audio M400/4 power is under-rated and will actually meet its 14.4V supply rating with a 12.6V supply. That's rare. So you can count on 4 X 75 watts into a 4-ohm load under most any conditions.
However, the M series 7.7s will handle twice that much power and really come alive with more power. The midbass attack and dynamics with 150W per speaker is a jaw dropper.
I think the M400/4 on four 7.7s is perfectly balanced with 200 to 300 watts going to a single 10-inch sub. But when you start building in bigger and more powerful subs you need to fortify the in-boat satellites in order to have balance. Besides more power, the most productive thing you can do is to add a third pair of 7.7s so that you have two pair in the cockpit. That extra surface area and extra 2 X 75 watts makes a huge difference, especially in how the coaxials mesh with the sub. The moment the sub bass overdrives the mid bass you have muddy, boomy bass.