stereo help please, need more volume out of speakers

This is in my 67 chevelle. I am throwing this system together with a new HU and 6x9s and everything else was laying around my garage so it has been a budget DIY system.

I hooked up a pair of 3 way 100W rated (400peak) 6x9s (GTX6931 Sony) to 1 front channel each of my 4 channel amp. (RockFosgate 160.4) (front channel set to full range)
I hooked up my 12" Alpine sub to one channel on the rear side, with one channel left untouched for the rear. ( set to low pass)

The sub sounds great like it used to when the amp was dedicated just to the sub.

The 6x9s though are not very loud. They distort at higher input volume but they aren't producing much sound. I will have the HU cranked to max with the gain at about max and it is still quieter than one worn out 6" in my boat that runs just off the HU. The amp states that it is 20w x4 at 4 ohm and 40x4 at 2 ohm.

My head unit is not connected to any speakers, just 2 pair of RCAs to the amp.

I am fine with the subs performance. How can I get more volume from the 3 way 6x9s?


My uneducated ideas are as follows:

1) Run the 6x9s in parallel off one front channel and switch my amp from 4 channel to 2 channel on the back

Question: Then do I need to bridge my sub so the amp is essentially bridged on both sides??? The amp is labeled for bridging on both front and rear channels, and printed on the back 40wx4 @2 ohm so I will assume it is 2 ohm stable. Do I wire it in the ports marked for bridged or just wire the parallel 6x9s into left or right in the front?? If safer I could run in series as well, but I think I will just get the same power as I am now (20per 6x9)

2) Other idea is to run the 6x9s off the HU (50x4) and leave the amp dedicated to the sub. So eventually I will have 2 5 1/4s and 2 6x9s all off the 50x4 HU. (not what I really want but it will work cuz it does in my boat)


I am guessing I am only getting about 20w to each 6x9 and that is causing low volume, tinny sound when isolated and distortion??

Thanks for the help sorry if I butchered the terminology and math, sorry for the repost out of nonwakeboarding but I wasn't getting any love.....

THANKS!!