Headunit/Amplifier installation

[Checkers]

Hey everyone

I'm trying to put a new headunit in, along with an amp and subs. Nothing special, but currently there is no head unit, and I figured I might as well install an amp while I'm at it. First off; my headunit

The stock harness was not in good shape, in fact it didn't even work. Not really knowing what to do, I ran a positive wire from my battery, to a toggle switch, and then to my head unit's harness. I then ran a ground wire all the way back to the battery, as I couldn't find a better ground point. It works fine, but I have to remember to turn it off when I leave the car. Will this work fine? Also, since the stock harness was not usable, I have been running the speakers straight to the head unit's harness. It works decently (I haven't had any prolonged use - past a minute or two of testing) but I feel bad about it being so jury-rigged. Is there anything wrong with this? I haven't turned them up, but I like my music decently loud. Will the head unit be able to power the speakers? The head unit is a Kenwood KDC MP145 and the speakers are Eclipse speakers (Not stock for an Eclipse, but it actually says Eclipse on them).

The subs and amp I were going to install were a set from Visonik. The amp is a 500w amp, and both subs (12 inches) are 600w each. Will the amp be able to power these, even though it has less wattage than the subs? I'm new to car audio (Cars in general actually) and don't know. I have been told to run my amp power cable on one side, and my speaker wires on the other so as not to cause interference. Is this true? Also, where is the best place on a 2G Eclipse to run the amp power cable? Is it possible/somewhat simple to remove the backseats? I also can't seem to find a good place in the firewall.

And one last question. The Best Buy/Geek Squad has prices for head unit/amp/speaker installation, but I'm worried that since this is so complicated, they will charge me more. Has anyone used Geek Squad for audio installation?

I'm sorry about such a long post, I'm just worried I'll mess something up, but would still like to do it myself. Thank you for any help

 

[wings9191]

First off when you say the harness is messed up how do you mean?
It's been cut and the fuses are blown?
Do you need a color code chart?
What happened to the factory speaker wires?

And not hooking up your stereo that way is not gonna do it.
Let's start witht he head unit first.

 

[Extacee]

Well have you checked under your passenger seat to see if the factory amp is in tact?

The best way to run the power cable to the amp IS through the firewall, if you run it through the fenders you can run into shorts and it will also look tacky.


If you can try t use the factory wiring, it will make everything easier, but if you have to as a last resort to run the wires directly from the speakers to the head unit make sure you run it through the protective hose thing (I dont know what its called but hey.) so it wont cause any shorts.

 

[Checkers]

To Wings9191

The stock harness has been spliced, soldered, frayed, etc etc to all hell, and the speakers were run to an amp so they were no longer connected to the harness. Also, there are no factory speaker wires because there are no factory speakers anymore, they were replaced with these http://static.howstuffworks.com/gif...00109604-EclipseSE8355autospeakers-large.jpeg by the previous owner.

To Extacee
I had a girl from my local audio place take a look and she said there isn't a factory amp under there. I'd go and check but it's currently 3:30 with about 10inches of snow on the ground, and it's still coming. I'll check tomorrow, but I don't think there is one there. As I told Wing9191, the speakers are not factory, and there is no factory wiring either. All the speaker wiring was in the hatch, taped together with electrical tape from where the previous owner cut them from his amp, so I just rerouted it to my dash, and into the HU harness. The protective hose you mentioned, is it like a tunnel inside the car, or do you mean something to buy to surround the wiring to keep it safe?

 

[MJBean420]

The cheapest I have found for car audio is Ebay. PM if you want the names of a few reputable sellers that I have been using. Great customer service.

 

[Checkers]

The cheapest I have found for car audio is Ebay. PM if you want the names of a few reputable sellers that I have been using. Great customer service.

Hey MJBean, I really appreciate the offer, but I already have a head unit, amp, and subs, I just need help getting them installed :-\ Thank you though

 

[wings9191]

Ok sorry i forgot you put the amp in for the speakers.
I'll run over here in a few to the stero shop i used to work at and grab the color scheme and get you an ignition wire and a hot under the dash.
As far as the ground i hooked mine up to one of the bolts holding the dash tot he body of the car.
I'll get back with you here in a bit.
Oh ya......you DO have a fuse between your radio and battery right?

 

[Checkers]

Ok sorry i forgot you put the amp in for the speakers.
I'll run over here in a few to the stero shop i used to work at and grab the color scheme and get you an ignition wire and a hot under the dash.
As far as the ground i hooked mine up to one of the bolts holding the dash tot he body of the car.
I'll get back with you here in a bit.
Oh ya......you DO have a fuse between your radio and battery right?

Haha, yes, I do have a fuse. I appreciate all the work, but my main question is will this setup (Running the speakers directly to the head unit) work well, or is there a better way to do it?

 

[born2tune]

hopefully im not categorized as a car audio nerd but the ground wire should NOT go back to the battery,for starters it must ground to the frame, then you must ensure its not longer than 18 inches, because you will overstress the unit and cause a "ground loop fail" which is basically equaling a poor ground connection because the wire is too long, if you do leave it in the battery ground then you must understand that any negative frequency sent to the battery is looping back into your radio "the neg.frequencies are= headlights, turn signals, ecu, everything. so when these higher frequencies creep up into your radio you will experience "NOISE" or "STATIC" and because you will install AMPS and SUBS i can tell you it will only get worse if you hook up all of these together in the battery. you need to "ISOLATE" these grounds as much as possible.

in a nutshell:
-there should be nothing audio related hooked back up to the battery.
-you should isolate grounding points in the chassis for reduced "noise".
-im sure if you read about car audio for a day, you should understand a hell of alot more.

as far as speakers to the headunit, well if you dont have an AMP for them then theres really no other way other than directly to the unit . and personally everytime i work on a persons car i throw in my own 14GAUGE speaker wire replacing the factory, 1; i wont tamper/splicing factory wires incase he wants to go back, 2; by using my wire i ensure there are no chaffed wires that can cause a ground. 3; factory wires are ok for simple speakers but if you upgrade and use an AMP "being 400 AMP for 4 speakers(100ea. x 4) then you might want a thicker wire, not the flimsy factory ones.

 

[Checkers]

hopefully im not categorized as a car audio nerd but the ground wire should NOT go back to the battery,for starters it must ground to the frame, then you must ensure its not longer than 18 inches, because you will overstress the unit and cause a "ground loop fail" which is basically equaling a poor ground connection because the wire is too long, if you do leave it in the battery ground then you must understand that any negative frequency sent to the battery is looping back into your radio "the neg.frequencies are= headlights, turn signals, ecu, everything. so when these higher frequencies creep up into your radio you will experience "NOISE" or "STATIC" and because you will install AMPS and SUBS i can tell you it will only get worse if you hook up all of these together in the battery. you need to "ISOLATE" these grounds as much as possible.

in a nutshell:
-there should be nothing audio related hooked back up to the battery.
-you should isolate grounding points in the chassis for reduced "noise".
-im sure if you read about car audio for a day, you should understand a hell of alot more.

as far as speakers to the headunit, well if you dont have an AMP for them then theres really no other way other than directly to the unit . and personally everytime i work on a persons car i throw in my own 14GAUGE speaker wire replacing the factory, 1; i wont tamper/splicing factory wires incase he wants to go back, 2; by using my wire i ensure there are no chaffed wires that can cause a ground. 3; factory wires are ok for simple speakers but if you upgrade and use an AMP "being 400 AMP for 4 speakers(100ea. x 4) then you might want a thicker wire, not the flimsy factory ones.

Wow, I really appreciate all that, thank you. I'll be sure to find a better ground, but it's been hard. With aftermarket speakers like these, would it be worth it to invest in a 4-channel amp to power the speakers? Also, in your opinion would it better to go to a custom audio shop, or Geek Squad? One good point someone at Best Buy made is that since the chain has so much insurance, if they screw up my car, it will be all taken care of, but I have a feeling that the custom audio place would be more knowledgeable.

 

[BLINKY619]

ok first off i would find a way to use the ignition key as a power source.... i mean directly to your battery may cause problems specially if not installed right.... now for the speakers... i currently have 3 amps in my car... 2 to power the subs and the other one to power my speakers.... now if you decide to run with only one amp for the subs and the headunit to power the speakers then i would run fresh new 12gauge wire from your doors to your headunit.. the same with the rear... from the rear speakeers to the head unit... now that will ensure proper power to the speakers....


NOW for the second amp...

if you decide to do this i would look into a capacitor... trust me man systems kill battery's also depending on what amps and wattage they put out... in this case i would do the same but the thing is that it wont be as hard to connect your rear speakers since they are fairly close... now run wire from the front speakers towards the trunk... followed by your remote wire and rca's


REMEMBER, WHEN YOU HOOK UP YOUR SPEAKERS MAKE SURE THEY ARE HOOKED UP RIGHT, MEANING POSITIVE WITH POSITIVE AND NEGATIVE WITH NEGATIVE....

in the end it will make you smile.... i find that systems with only one amp to power the subs and the heaunit to power the speakers sound really clean after its bee hooked up right... most/alot of people just wire the speakers randomly and it does sound decent but when you want to go high amounts of volume it will sound all sh!tty and static...

i have alot of $ invested in my system.... 2 crossovers, epicenter, 3 amps, 2,12's, pioneer speakers all around, pioneer tweeters, pioneer head unit built in equalizer, 3 capacitors, a equalizer and more........ makes my music sound crystal clear when full blast..

 

[dj-t]

Check all fuses and replace if needed. Use a multimeter or test light to find your 12v constant wire it should show 12v on meter or light up on test light. Ignition wire should show 12v or light on (on test light) when you have the key turned to ACC. This should be in the factory radio harness no need to run extra wiring. As for ground in the harness you have to run you own ground wire. Grounds wire should be as short as possible and best if attach to bare metal. Your kenwood should be fine with those speakers. As for amp and wiring I would run the power wire through the grommet on the passenger side by the battery along the rail to where you are going to mount the amp. RCA and remote wire I would just run them together straight threw the center since you may already have the center console off already to where the amp is mounted. Ground for amp should be as short as possible (not to short that you can't work with it) securely mounted on a clean metal surface.

Is the amp a 2ch or a mono block?

If it is a 2ch bridge it, it should have a diagram of how to go about it in the manual (if it has one) or right on the amp itself. If it's a mono block just put the negative to the negative terminal and positive to the positive terminal. Also, check amp to see if it is stable at what ohm it should be on the label on amp and in the manual. It should be 2ohm stable.

Is the subwoofer 4ohm or 2ohm?

Most likely 4ohm (should say on the magnet of the subwoofer). Positive on sub to positive on amp negative on sub to negative on amp in bridged mode if its a 2ch amp. Mono block doesn't matter as long as positive goes to positive negative goes to negative. This is in parallel decreasing resistance of 4ohm to 2ohm

If it is a 2ohm subwoofer and assuming amp is stable at 2ohm you need to wire the subwoofer differently. On both subwoofers wire the negative of one sub to the positive of the other sub. Then the remaining positive connection of sub to positive of amp and the remaining negative of sub to negative of amp. This is in series and bumping up resistance of 2ohm to 4ohm.

Is the subwoofer single or dual voice coil?

Most likely single coil. Fallow said above if single coil. Single coil have only one positive and negative terminal on the sub. A dual voice coil has two terminal on the sub usually 180 degrees from one another.

12ga wire in the door is a pain in the butt to get through. Factory size wire or 16ga is way good enough for what he has and to the human ears you will not be able to tell a difference. But, if you going to upgrade your system in the future to SQ quality or other competition then yeah. 14ga is the max that I would go for mids and highs.
As for capacitors I find that running a second battery is more beneficial since a capacitor runs as much as a new battery. I think the set-up that the OP has should be fine as it is with the factory voltage system.

 

[born2tune]

Wow, I really appreciate all that, thank you. I'll be sure to find a better ground, but it's been hard. With aftermarket speakers like these, would it be worth it to invest in a 4-channel amp to power the speakers? Also, in your opinion would it better to go to a custom audio shop, or Geek Squad? One good point someone at Best Buy made is that since the chain has so much insurance, if they screw up my car, it will be all taken care of, but I have a feeling that the custom audio place would be more knowledgeable.

If you dont feel comfortable enough to where your work is 100% professional, then yes i would recommend going to best buy or geek squad, because like you mentioned their work is guaranteed and insured, but with those small custom audio shops,.... i cant tell you how much i hate them. they have special needs people in the back hooking up your wires and pulling your panels hard and cracking them, also they tend to do ghetto work, forget about screws and clips.. but thats enough bashing for them.

i dont want to overflow you with information but one more thing about an amp for your speakers is: your receiver might say 50w x4. which means 50 divided in 4 (common misconception as it wants to confuse people with the "X" sign.)

so that gives you a MAX (at one time)of 12.5watts per speaker. in turn your RMS wattage which is maybe at 6 watts (continuous power feed). to technically a head unit only provides about "24 watts RMS"

so again in a nutshell:

if you want an AMP for your speakers verify the max output of your speakers and also verify the RMS or continuous power it can handle. then decide how much power you want your speakers to handle without it reaching a damage point, or to some refered as PMPO.

 

[ramsack]

It's best to match the RMS watts, not maximum. An amp is going to hit horrible THD near its maximum, and the source has to be full line voltage (which wouldn't surprise me with today's music mastering.) Your hearing may get damaged and will probably hurt before maximums are hit. Head units that are 50w x 4 are 50 watts maximum per channel. If they were 50 watts total from all 4 channels they would be labeled 50w/4. It's not necessary to but it makes it easier to match components up by manufacturer. Like a head unit to speakers, or amps to speakers, amps to subs, etc. for matching wattages. Find speakers and amps that are efficient at turning a signal into an actual sound wave and you won't need huge amounts of wattage, and the quality of sound will be better that a system with just all-out bumping watts.

 

[born2tune]

It's best to match the RMS watts, not maximum. An amp is going to hit horrible THD near its maximum, and the source has to be full line voltage (which wouldn't surprise me with today's music mastering.) Your hearing may get damaged and will probably hurt before maximums are hit. Head units that are 50w x 4 are 50 watts maximum per channel. If they were 50 watts total from all 4 channels they would be labeled 50w/4. It's not necessary to but it makes it easier to match components up by manufacturer. Like a head unit to speakers, or amps to speakers, amps to subs, etc. for matching wattages. Find speakers and amps that are efficient at turning a signal into an actual sound wave and you won't need huge amounts of wattage, and the quality of sound will be better that a system with just all-out bumping watts.

Im sorry but im going to have to disagree with you about a head unit being labeled as 50w /4 against 50w x 4, you are wrong. It is 50 watts total divided by four, if the user choses to use only 2 front speakers you bridge, then create a"50w x 2." application.

before you try to argue my point i suggest you look into it further because im sure any company would prefer to advertise a "200w unit" instead of a "50w x 4", my friend thats how they got you to buy it.

i will not battle this out with you because there is not point. i briefed it accurately and any misunderstandings will be explained further, but again i wont discuss the point of your misconception.

 

[ramsack]

I bought a Kenwood head unit back in 2002 and it was marketed as 220 watts total (55w x 4). They dropped the total watt rating a while ago. Maybe it came when they started making multi-core CPUs. At only 50 watts total, and you have a 10 amp draw, where are the other ~90 watts going? 88 watts as an RMS total makes more sense to me to where the 10 amps current draw are going.

 

[Checkers]

Ok guys, thank you again for everything. I thought it would be a lot more simple than this. I think I'll just take it to Geek Squad, and do little things after wards instead of trying to redo everything in the car. I'm a little bothered though because I've e-mailed Geek Squad twice to ask about it, but I haven't gotten a response. Maybe someone here will know. The website says it "starts at $___" so it seems like it will go up depending on the difficulty, and my car is still having some problem after getting it so I'm trying to spend as little money as possible :-\ However, I work as a delivery boy so having some quality music to listen to is pretty important. Thankfully Christmas has helped out. Anyways, again I really appreciate all the help, and (If the roads are clear) I'll go check with Geek Squad in person tomorrow. Thanks everyone!