Those speakers are quite cheap. I highly doubt they are 300 watts. I am guessing they are using clever wording in their description. (1 pair of 150 watts = 300 watts). Plus that wattage is probably peak.
I would assume the rms wattage would be more like 75 watts.
75 watts for mid range speakers is plenty though.
Your head unit will output 22 watts to each speaker. You could use a small 4 channel amp.
you won't "blow your deck" as long as your speakers are the correct imedance for the head unit.
your pioneer head unit is more powerful than most stock radios, so it should be a significant increase in power output. you will also get more control over the EQ. (most stock radios cut the bass out at higher volumes to make up for an underpowered amplifier and to protect the cheap stock speakers). an external amplifier can provide cleaner, more powerful sound than any head unit but if you're only looking to improve your stock sound then the head unit upgrade will probably be fine.
just because the speakers say '300 watt' doesn't mean you need to feed them anywhere near that much power. that is a peak/max power rating and is probably exaggerated quite a bit as well. I would suggest you get better speakers than those cheesy soundstorms, they probably won't sound much better than your stock speakers.
well i thought that too, but i looked at their website and they look legit, but that could just be the site. i am ordering them from onlinecarstereo.com and it is only $22 a pair so it isn't that big of a loss
you're confusing wattage handling with efficiency.
yes giving a speaker 75 watts will be louder then feeding it 22 watts. but giving a speaker that is measured at 87 db @ 1w/m, 75 watts will be quieter then giving a speaker that has an efficency of 93 db @ 1 w/m, 25 watts.
There are many s.e.t. tube amps that power home audio speakers that are rated at 5 wpc... so wattage isn't everything
New System in progress:
Phaze TD1500 ~> Dynaudio MD130
Phaze TD1500 ~> Seas g18rnx/p
Zapco Ref 500.1 ~ 12" tc-9
Behringer DCX2496 ~ Envision Electronics psu
As I said, he would do better with a small amp. In comparison 22 watts and 75 watts there is a noticeable difference. It will sound more quiet when he feeds only 22 watts in.
You also have to take into account the reliability of the manufacturer.
These are cheap brand speakers. They are advertised using their max power. (always a sign of cheapness)
In reality the RMS of those should be .707 of 300. I am very much doubting these can handle 212 watts RMS.
This brings into question the accuracy of the specs all together. The previously mentioned 1W/1M: 90DB efficiency is probably a big stretch.
All I'm saying is that it would sound much better if he had an amp. Granted..you can only get a certain amount of quality out of a $15 speaker..but it will sound better with an amp.