This is very correct info! I've got a system in my Dodge Ram that is very loud but sounds good both at the same time. Subwoofers etc..etc.. Without going into a long winded post do the above and you'll have a nice sounding system.
you are also correct on this sr as i also have a massive sound system in my ram with multipul amps pre amps and high end deck. on a good day i can hit 142 spl.
take the advice every has given you. and you should be happy with what you end up with when its done.