so i have 4 kenwood KFC-C6882ie speakers in my truck that are just being powered by my headunit. i kinda would like to power them with an external amp. the box for that speakers says they are rated for 60w but it says they have a peak power of 240w. my question is how big of an amp should i get?

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01 xlt 3.0 extended cab
Kenwood speakers
JVC head unit
Fusion 12" sub and Fusion amp
Monroe coilover shocks in the rear
Tow Package
Mustang Dome

I have the same speakers. Mine are powered with an Alpine MRP-F300 4 channel amp. It is 50 watts RMS x 4. You should be alright with up to a 75 watts RMS x 4 amp. RMS is the only wattage figure that means anything real. Forget peak or max. Those are good speakers. If you get an amp that outputs more than 60 watts RMS per channel, just set the gains with a DMM using 60 watts. Since my amp is only 50 per channel, I used 50 x 4 ohms = 200. Square root of 200 is 14.14 volts AC. If you get a 60 watt per channel or more, you would use 60 x 4 = 240. Square root of 240 is 15.49 volts AC.

Any of these would work - http://www.crutchfield.com/App/Produ...R3004&g=347050

Sound Ordnance is a good product. I wouldn't hesitate to get the S/O 75x4 for those Kenwoods.

alright thanks for the info. helped a ton

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01 xlt 3.0 extended cab
Kenwood speakers
JVC head unit
Fusion 12" sub and Fusion amp
Monroe coilover shocks in the rear
Tow Package
Mustang Dome

okay so i ended up getting the kenwood kac-8405 4 channel and got it installed yesterday. how do i get it tuned right?

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01 xlt 3.0 extended cab
Kenwood speakers
JVC head unit
Fusion 12" sub and Fusion amp
Monroe coilover shocks in the rear
Tow Package
Mustang Dome

Be very sure you get it wired correctly. If you got it from Crutchfield, you get a good wiring kit half off. Connect the Fusion sub/amp with the RCA preamp outputs from the head with a quality RCA patch cable. No speaker wires will connect to it at all.

In the JVC head menu, set the preamp outputs to subwoofer. Set the lowpass filter in the same menu to 111 hz. Subwoofer level to 0. Set the loudness off. Set the amplifier gain control to high, still in the head menu, not on the amp. Set the I-EQ on User and as follows: Bass 80hz-Q1.5 level 1, midrange 1khz-Q1.0 level 3, treble 15khz level 5. Set source volume on CD or USB or aux or whichever you play the most to 0. Set balance and fader to centers.

On the Fusion sub/amp - set the lowpass filter as close to 120hz as you think it is on the dial or around half dial or a tad less. Turn the gain or input sensitivity or level knob (whatever it has, all the same thing) all the way down or fully counterclockwise. If it has bass boost, turn it all the way down.

On the Kenwood amp, you will connect it with the speaker level inputs with the speaker wires from the JVC head (high level), all 4. Make sure you get the polarity absolutely correct and accurate.Turn the input sensitivity all the way counterclockwise to min (Ach and Bch). Set filter on HPF (Ach and Bch). Set bass boost off (Bch), mono/stereo to stereo(Ach and Bch). LPF/HPF frequency 150(hz) or just a tad less (important to get these as close as possible on both channels).

This is the way to set the gains without test tone CDs or a DMM -

Remember to disconnect the ground cable from vehicle battery before disconnecting and/or connecting power to any component.

Disconnect power cable from Fusion. With your favorite or loudest CD or USB or aux song or whichever you play the most, turn up the head volume until you start to hear the sound distorting, then back it off until it stops (1 or 2 numbers) it should be about 3/4's of the way up (36 out of 50 ?). It is important to keep the same song playing. Now disconnect the rear speaker (Bch) output from the Kenwood amp. Turn the Ach input sensitivity knob clockwise until you start to hear the sound distorting, then back it off until it stops. Do this very very slowly, it is very sensitive. Leave the setting there. Disconnect the front speaker (Ach) output and reconnect the rear speaker (Bch) output and adjust the input sensitivity the same way. The input sensitivity knobs may or may not be about the same on the dial, that's OK. Disconnect the rear speaker (Bch) output and leave both front and rear (A and B) disconnected for now.

Reconnect power to the Fusion sub/amp.

Play a really really bass filled song with alot of lowbass in it, from any source. Leave the head volume on the same number as before. Turn the gain or input sensitivity or level knob (whatever it has, all the same thing) clockwise very slowly until you start to hear distortion, then back it off until it stops distorting.

Reconnect the speaker wire outputs on the Kenwood amp. That's it. Play with the EQ settings in the head all you want until you get it where you want, but don't move the gain settings on either amp, unless you want to play test tones for each one and reset with a DMM. I can walk you thru that also, if you want. If you turn up the bass boost on the Fusion and it distorts, just turn it back down, that's a good sign the gain is set well. It is preferable to turn up the bass at the source (head), for much better sound.

I hope I covered it all. Just ask if you have any other questions, and let us know how it goes and how you like the sound.

my head is a jvc kd-r600. also i have a 12" powered sub so can i go higher with the hz?

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01 xlt 3.0 extended cab
Kenwood speakers
JVC head unit
Fusion 12" sub and Fusion amp
Monroe coilover shocks in the rear
Tow Package
Mustang Dome

What powered sub do you have ? If you will list all your mods and whatnot in a signature line, we won't keep having to ask you what you have.

fusion active wedge 12"

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01 xlt 3.0 extended cab
Kenwood speakers
JVC head unit
Fusion 12" sub and Fusion amp
Monroe coilover shocks in the rear
Tow Package
Mustang Dome

edited a post above with explicit instructions for setting gains

thanks for the instructions! ill post back here when im finished

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01 xlt 3.0 extended cab
Kenwood speakers
JVC head unit
Fusion 12" sub and Fusion amp
Monroe coilover shocks in the rear
Tow Package
Mustang Dome

got the amp tuned and all set up. it was a good match with the speakers, they are super clear and very powerful. instructions above were spot on!

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01 xlt 3.0 extended cab
Kenwood speakers
JVC head unit
Fusion 12" sub and Fusion amp
Monroe coilover shocks in the rear
Tow Package
Mustang Dome

Very good ! Did you get the fusion setup tuned as well ?

yup

__________________
01 xlt 3.0 extended cab
Kenwood speakers
JVC head unit
Fusion 12" sub and Fusion amp
Monroe coilover shocks in the rear
Tow Package
Mustang Dome