Hi guys (and gals) Newbie here with a few questions. I'm 43 and haven't installed an aftermarket stereo in over 22 years, so please excuse some of my ignorance. I recently purchased a 79 Pontiac Trans Am to fix up (mid life crisis). I knew I wasn't going for a totally stock restoration, so I decided to do what I haven't in years and add a decent audio system. I have the interior out of the car so seemed like the best time to install. I've got a Kenwood kdc-mp 142 receiver, a Kenwood kac 6404 amp, a pair of kfc-x693 300 watt 6x9's in the rear, and a pair of Kenwood kfc-1662s 180 watt 6.5" door speakers. I've mounting the amp to a carpet covered board in the trunk to the rear of the back seat. The receiver only has RCA's for a subwoofer so all my speaker out hookups from the head is using the line in? wires. One question, when a pair of speakers are rated 300 watts max, is this 300 each speaker or 150 each? I'm trying to determine how to set the channels power outage to not blow speakers. I bought an amplifier install kit, so I'm using the supplied powerwire, groundwire, ect. I've got the amps main power supply (with fuse) ran to positive terminal of battery and the ground running to the chassis, area is bare metal and tight. I also have a ground wire going fromn battery's - terminal to chassis. I haven't got to the receiver yet, but I do have all the wiring in place, have wire going from head's power control (Blue/white) to amps power control terminal, and a wire from there going to the dash area waiting to be hooked up. Ok, the heads yellow (battery) wire I have run to the battery's positive terminal (not hooked up to battey yet), I have installed an inline 25a fuse in this wire. So can I take the power control wire (blue) from the amp, and the receiver's ignition (red) wire, and run BOTH wires to the same power supply from the car's fusebox ? I have located the harness for the factory radio's power(ignition), and thought if I could run both wires on the same circuit, at least I'd know what to look for in the fuse box if I did blow a fuse. I know I've written a novel guys (sorry). Just trying to give as much info as possible. I want to do this right, but I'm guilty of overkill sometimes Any advice / help would be greatly appreciated.
does your head unit have a remote out for the amp? wire the blue wire from the amp to the head unit. that kenwood amp is never going to make 300 watts per channel. so you'll be fine on powering them. now to set the gain is a diff story. since your using the speaker wires as the signal your gains can be set fairly low. you may want to google how to set your gains. youtube it also. should be easier that way. the speaker power rating is per the pair.. so 150 each.
The blue/white from the radio goes to the amp Power control terminal, so far so good. NO, you have the radios blue/white going to the amp, we don't need any other connections there. Now the HU yellow does not need to go to the battery. Just some constant source. The ignition source should be easy to locate. That wire should already be there behind the dash. The factory radio was hooked to it. Now that amp has an output of 40-watts RMS per speaker, so you should not have a power problem. The Kenwood kfc-1662s can handle 35 watts RMS so we are in good shape. The kenwood kfc-x693 has a power handling of 130-Watts RMS. Again No Problem I hope I answered at least one question right
Pedro: The only thing the head has is a rear preout/sub preout. Ranger Svo: Thanks to both for the replies. I was reading the diagrams from both manuals, and some how go it in my head I needed the hu remote power going to the amp, and the another wire going to a power source. Thanks for clarifying. So I guess that wire Blue/White from hu is simply telling the amp "Hey I'm on so you need to turn on as well". I guess my main concern with the power was I was thinking without cutting anything, I'd be putting 125watts from the amp and 50watts from the head (175 total) to each of the 6.5's which are rated at 90 each. Anyway, thanks again, think I get it. Hopefully will get to finish install in the next couple of days, I'll report back how she goes. Thanks again and Happy New Year!
I also just realized I'm running at 2ohms, so the amp is actually only doing 60 watts per channel, so I guess I'll just set the power to "full". Again, thanks.
WHOAAAAAA!!!!!!! Did I read you right rycher? Are you going to run the same speakers off the amp AND the radio at the same time? Meaning tieing the amps speaker outputs and the radios speaker outputs togetherr???? if so DONT DO THAT!
Maybe I stated that wrong or I'm just not getting it. My speaker "outs", from head unit are running to the amps "speaker ins", or the way the manual has it listed "speaker input level". Then the speaker outputs from the amp are going straight to the speakers. That's the only way I see to hook it up. When I run the head to the amp does that "kill" the head's power output, so that I'm using just the power from the amp?
OK! Your good to go then! Basically you are correct in what you said about the head units power. The amps speaker level input will "reduce" the power from the radio to an acceptable level it can use as a source signal.
