ok, humour my complete inexperience here...

i have a pioneer head deck , and its something like 55w channels, now i also have still in boxes, some sony xplod gear, 2 6x9's (220w), and two 6.5" (120w),.. my question is..

what am i gonna need extra to hook these bad boys up, amp, sub, or can they go straight in replacing the factory ones in my tj?

obviously my math tells me, the headdeck 4chan 55w doesnt add up to powering 220w rears and 120w fronts, so, whats the recommened go lads - without being silly ;) ?

i did notice someone had a 500w sony amp for sale.. if thats whats required, that would be sweet.

also, i had an issue when i bought them that the orginal car they wer ebought for that i no longer have had mounts for 6inch fronts lol.. obviously the effort involved there is the reason they are still in boxes lol. so i thought id give them a good home on my mangaratti, and replace the tired factory ones im slowly destroying :)

also lads, i have very limited boot space for any mods, as its actually used for luggage aka twin pram heehe. so any uber subs would have to try real hard at fitting in the gap between the rear seats.

Those speakers will run fine off the headunit. It's when the amp is more powerful than the speakers you have to be careful.
However you CAN amp them and yes they will sound better. But you can save yourself some money if you're not too fussed.

cool, wont they drain the 55w? or do i have that understood backwards as in the headdeck can only pushout 55w to the 220/120w speakers, which obviously can handle that rating?.

i was thinking the speakers would try and draw that much wattage.

and i gather the rating on a example, 500w amp would split between all speakers 220,220,120,120 would be enuff without overpowering anything, also, what sorta load does this put on the existing car electrics/battery? i have a brand new battery anyway, but it would be a nice comfort anyway to know i wont go killing the battery.

i tihnk the factory ones are 15w rears from what i can see, so that explains why they sound rather beaten at the moment, due to the 55w over pushing them yer?

the speakers will run fine off the deck. You can use an amp to run them if you want but you will notice a big diffirence with just the new deck and speakers though.

cool, wont they drain the 55w? or do i have that understood backwards as in the headdeck can only pushout 55w to the 220/120w speakers, which obviously can handle that rating?.

i was thinking the speakers would try and draw that much wattage.

and i gather the rating on a example, 500w amp would split between all speakers 220,220,120,120 would be enuff without overpowering anything, also, what sorta load does this put on the existing car electrics/battery? i have a brand new battery anyway, but it would be a nice comfort anyway to know i wont go killing the battery.

i tihnk the factory ones are 15w rears from what i can see, so that explains why they sound rather beaten at the moment, due to the 55w over pushing them yer?

I think you've misunderstood how the power rating works. The rating for speakers is what they can handle before you damage them. The rating for an amp is how much power it can produce. The speaker will not try and pull more power from an amp, they will just use the power the amp provides. If your head unit is providing 55 watts per channel, then that's what the speakers get. Keep in mind that is 55 watts max, which is the maximum instant power the head unit can produce, not it's continuous power. It's probably producing more like 18 watts RMS, which is the continuous power. 55 watts will be the peak, ie; thumping bass at max volume.
Now, onto that 500w amp. The speakers will not draw the power they are rated to as you suggested. They won't take 220w to the rear and 120w to the front. If it is a 4 channel amp, that figure will be divided equally by the four channels. So a 500w amp will provide 125w per channel, to each speaker. The amp doesn't care what speakers are connected to it, it will just make that amount of power for each channel. If you have 50w speakers and turn it up to full, the amp will provide 125w and blow the shizer out of the speakers. This is where you have to be careful. You should either choose speakers that can handle more power than the amp can provide, or be aware that you can't turn your volume up to full with lower rated speakers.
All that being said, you can run those speakers off the head unit with no problem. The speakers are made to handle much more power, but you will have no problems running them off that unit, you just won't get ear blowing volume.
If you want it louder, put in an amp. The amp, obviously, will amplify the signal from the head unit and provide more power to the speakers. Your options are to get a 4 channel amp, to power all four speakers, two 2 channel amps (one for each pair of speakers) or one two channel amp (amp one pair of speakers and run the other pair off the head unit, probably amp the fronts).

I would recommend getting a four channel amp with around 100w per channel. Even 50w per channel would be good. Don't get this confused with the 55w per channel your head unit provides: as I said earlier, your head unit is measured in peak power, where a 4x50w amp is measured in continuous RMS power (trust me, there's a big difference).
You can pick up pretty decent 4x50w amps pretty cheap these days, and with the gear you already have it will make a big difference in sound at higher volumes.
If you have any more questions about this stuff, just ask. Hope it helps.

It's when the amp is more powerful than the speakers you have to be careful.
However you CAN amp them and yes they will sound better. But you can save yourself some money if you're not too fussed.

Actually to most peoples surprise it kinda works the other way around...

If your amp is underpowered you tend to crank it up, which leads to the amp (or amplification chip if it's the stock head unit) to clip and send out square waves instead of the nice curvy sine wave we are all used to. This means that at the peak and trough of the signal the amp is sending DC current to your speakers which will kill them.

You are less likely to blow up a speaker with a slightly over powered amp than an underpowered one.

Saying that though, if you go nuts with a huge amp then you can tear the spider or cones on the speaker instead of melting the voice coil to the magnet.

Your pick I guess :bowrofl:

N.B. My knowledge comes from Live sound (I'm an audio engineer) not from car sound, so I could be wrong...(you car sound guys do some crazy stuff... Bridging??? AHHH, scares the crap outta me)

N.B. My knowledge comes from Live sound (I'm an audio engineer) not from car sound, so I could be wrong...

Nope you are correct! :D

If you dont want heaps loud music or back thumping bass but just want a better sound than factory and an install that you can do yourself in a Saturday, just use the speakers you have and wire them up to the headunit. You will be happy.
My guess is with the dual pram you have little kids in the car and you wont be cranking the sound anyway.
Its also a much cheaper option!

Cheers
Pete

This means that at the peak and trough of the signal the amp is sending DC current to your speakers which will kill them...

THANK YOU!!!!! i got grilled for saying this ages ago in a similar thread!

get that up ya all you disbelievers!!!

THANK YOU!!!!! i got grilled for saying this ages ago in a similar thread!

get that up ya all you disbelievers!!!
Yep, i was gonna say you are correct also.

Even though you can damage speakers by underpowering them (by clipping), you'd have to be pretty stupid too as the sound will be absolutely horrid.....still doesn't stop people doing it (my mate included) :doubt: .
For someone who doesn't know anything about audio, i'd rather them install something underpowered than overpowered. Though overpowering you should here distortion, but sometimes it's not as obvious esp. if you're running a HPF.

top stuff! thx guys, much appreciated!

do have this right...if the amp is rated at as said above 100w per channel, and as the headunit is max output of 55w per channel, so if the audio peaks, it would be doing 55w+100w per channel? in that case the 120w channel speaker would be stressed yer? and the 220w channel would be still under the total yer?

or, would that be total output 100w to each channel, and obsorbed the 55w during the map process?

obviously this is a peak audio issue that would rarely be exceeded, but id like to configure it so that any track played at whatever level would stay under the peaks, thus not prematurly castrating the life of said system/s.

just wrapping me head around the various inputs, outputs :)

ill fish out the exact specs of the head unit tonight, but so far sounds like a easy job, thanks guys!

hehe, well, the audio enjoyment is more for when no one else is in the car ;)

Cheers,
Dave.

Say the amp is rated at 100w max per channel, thats the MAX it will output no matter what your input is and no matter what speaker you attach to it.
Doesn't matter if your headunits output was 1 million watt, the amp is what is producing the power (althought if it were possible to input 1 million watt into an amp, i think you'd fry the actual amp :P).

(althought if it were possible to input 1 million watt into an amp, i think you'd fry the actual amp :P).

one word:

superconductors :D

sic, thx guys!