Need upgrade on amp

[Mikka]

I'm new in this electonic and new member too.
16y, student

I have two 150wRMS and two 60wRMS sub-woofer. I found out my amp is not powerful enought to make my 4 sub push to the limit.
I bought four 70V 10000mf capacitors and install them in, the subs really work better but also not powerful enought.

My question is:
1) How big is the capacitor need to be install to push the limit?
2) Do I need a bigger transformer? Or just add more capacitors.
3) I need lower bass, what do I need to upgrade?

[nar]

Adding capacitors won't give you more output power.To achieve it you need more bias ,i.e. idle current and higher voltages for the supply rails.

You also need more heatsinking I guess

[Mikka]

Do You mean have to upgrade the transformer?

[skaara]

Bigger transformer, more output devices, more heatsinks..