200 Watt Amp - How to Wire at 2 ohms and Will There be Too Much Power in Front?

[RebelDan]

So I can buy a Pioneer 2 Channel 200 watt amp with 40 watts rms at 4 ohms and 50 watts rms at 2 ohms from my friend for like $20. I've got Kicker KS60's in the rear and some cheap DS525's in front. The KS60's handle 65 watts rms, and the DS525's handle 35 watts rms. I've also got my stereo that does 22 watts rms x 4. With that said, I'm trying to figure out which speakers to hook up to the amp. Correct me if I'm wrong, but if the stereo is not powering 2 of the speakers it will put out 44 watts rms, right? So what I'm thinking is I'll hook up the amp at 2 ohms to the rear speakers, and the stereo will just power the front speakers. The real question is will the front speakers be overpowered, and how do I wire the rear speakers at 2 ohms? Any help would be appreciated and sorry if I cause any confusion.

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[Side Show 10+ year member]

put in the pioneer 200w amp and run the kicker speakers off it. then decide if you want more speakers

 

[bbeljefe]

Your head unit does not produce 22 watts per channel. It and every other head unit can only do 18 watts per channel... ever. And only running two of the four channels won't change the power output.

And you can't wire the rear speakers at 2Ω. They're single 4Ω coils and that's all they can be wired to.

 

[n2audio 5,000+ posts]

Your head unit does not produce 22 watts per channel. It and every other head unit can only do 18 watts per channel... ever.

That's not true.

And why are you acting so absolute about it being right?

Not that it matters -- 15, 18, 22w -- realistically all about the same. Enough to work ok, but not enough to drive many speakers optimally.

 

[RebelDan]

Well my stereo is the common 50w x 4 which is a useless number but it's listed at 22rms x 4, but it could put out 10 watts for all I know. So I guess I'll hook the amp up to the rear speakers for now at 40rms which is still a good upgrade from the stereo, then someday I'll upgrade the front speakers and amp. Also when I have the key on run (running on battery, engine is off) my stereo will shut off when I turn it up too loud, and will turn off at lower volumes if I turn bass boost on. I've checked the wiring and that all seems okay and I can keep the radio on forever as high as the stereo will go without shutting off, and then the battery still cranks the engine right over even when it's 20 degrees in the morning the past few days. Therefore I'm assuming that the battery is fine and the stereo just can't power the speakers at high volumes. With that said will powering the rear speakers with the amp help or even solve this problem?

 

[n2audio 5,000+ posts]

Yes, moving one pair of speakers from the HU to the amp should help with the stability of the HU.

Here's an idea for a cheap but significant upgrade...

Get GOOD front speakers (maybe try to adapt some 6.5's?) and use the amp in bridged mode to run them -- that's 100x2 at 4 ohms (assuming it's bridgeable).

That should bring your front stage to life.

You can switch back to the HU to run the rear (fill) speakers.

 

[bbeljefe]

That's not true.And why are you acting so absolute about it being right?

Not that it matters -- 15, 18, 22w -- realistically all about the same. Enough to work ok, but not enough to drive many speakers optimally.

Head units are not large enough to support a power supply that can boost the rail voltage high enough to get more than 18 watts per channel. The signal they have to work with is 12 volts and reference is at 6 volts. That means that the peak voltage above and below is, and only can be, 6 volts.

You can put 50 watt FETs in a head unit and boost the input signal to 14.5 volts but you're still not going to get an average rail voltage of over 12 volts because the power supply is op amp regulated. Thus... you get 18 watts per channel.

And it's not be being absolute, its math.

 

[RebelDan]

The front simply doesn't fit anything bigger than 5 1/4's. The rear speakers were originally 5 1/4 and are now 6 1/2 and the front was originally 4x6. I plan to upgrade to components in front and get an amp to power all the speakers but at the moment money is extremely limited for the sound system as the rest of the Jeep has all sorts of problems.

 

[n2audio 5,000+ posts]

Either the power supplies being used in HU's have improved since you ironed out your math, or CEA is letting companies lie that are claiming 2006 certification b/c there are plenty of HU's 20-22w rms per channel.