I have two 10" subs that I wanna get a box for. I saw a box on net that will fit under the back seat. Now I need to install my AMP, I really don't wanna replace the head unit because I like the stock CD player. I just wanna add some bass to the truck. Can I install an amp on a factory CD player and will it deliver the sound quality that i'm looking for? Thanks.

 

Yes you can. You can get an amp with high (speaker) level inputs or you can get a LOC (level output converter) and convert the speaker outputs to line (RCA).
David Navone Engineering makes some great LOCs. Some with level controls and filters.

www.davidnavone.com

 

Will I still receive good sound quality still using the stock radio? I'm gonna bring the truck somewhere to have them install the amp and box so I don't screw anything up. Thanks .

 

You will get varied opinions on this but the fact is that todays factory head units have very good sound. They are lacking in features and flashy screen savers but the sound is just as good as most aftermarket units and better than some. The problem areas are speakers and output choices. Ford Speakers are paper crap. None of the Visteon (Ford) head units have RCA line level outputs for use with external amps. Even the vehicles with external amps do not have RCA (unbalanced line level) outputs. Visteon uses differential outputs which are more immune to noise problems. A quality LOC will allow you to convert your speaker outputs to line level inputs for external amps. The best way to wire this is to run quality speaker wire from the head unit to where the amps will be located and place your LOCs near the amps. The reason it is recommended to do it this way is because speaker level signals are less likely to pick up noise. Long runs of line level signals can create large noise problems. Todays aftermarket head amps basically accomplish the same thing by amplifying their line outs to 4 volts or more rather than the older 1 volt standard. If you want all the bells and whistles offered on todays aftermarket HUs then go for it but do not base your decision on sound quality. If all your gains are set correctly and you do not drive the internal amps to clipping levels you will not notice any sound difference (I am sure there will be disagreement here but it was proven by Richard Clark and David Navone, two of the top authorities in the Car Audio world) between todays OEM HUs and an aftermarket unit.

 

One more thing, you can spend more money on quality amps, speakers and proper installation and later on if you chose to you can change the head amp for some of the new features like Satellite radio and video systems.

 

I agree FULLY with Norm here. I've always used stock HU's over the last few years with GREAT results. Just get an amp with "Speaker Level Inputs" and you don't have to buy, install or bother with LOC's.

For example, just finished installing a Kenwood amp, utilizing speaker level out from stock Visteon head unit (Mach MP3/CD player). Sounds great.

And another thing, I think the aftermarket HU's SUCK!! Because the buttons are too small, they rarely have dimming feature (to dim with rest of dash). To many flashy colors, lights and crap so you can't actually get any usefull information from the screen like what song, track, CD is playing or simply the time. Also, they don't match the dash light colors.

The other thing I don't understand, everyone says "But the aftermarket units are higher power'd". Then, they follow that by saying "I have installed an Amp...". Ok, so then what good is the "high power" in the head unit?? You running line level out into an Amp anyway!!

But as Norm said, I'm sure a bunch of folks will disagree.

 

"The best way to wire this is to run quality speaker wire from the head unit to where the amps will be located and place your LOCs near the amps. The reason it is recommended to do it this way is because speaker level signals are less likely to pick up noise. Long runs of line level signals can create large noise problems. "

I don't follow you on this... I have run RCA's from my LLC (directly in back of the factory HU) to my amp in the rear. Are you saying that the shielded audio cables will be more prone to distortion than a long run of unshielded speaker wire?? I beleive that either way, using the LLC, there will be noise present that is going to be amplified again. But the question is, will it be noticable when running just one sub (100 to 300Hz)?? I don't think it will matter.

-Matt

 

Thank you guys, that was exactly what I was looking for. Now I just need to find a box for the back seat of the truck. Where can I get a box for a decent price? Thanks again.

 

As mhussey said, I too am interested in what norm said...

I already own an amp and speakers that I was planning on installing this weekend. I went to the audio shop and bought an LOC and asked the guy there if I should mount the converter by the amp or by the HU. He said to mount it by the HU because that way if/when I decide to swap out the stock HU for an aftermarket I won't have to rerun the RCA cables.

More input please...


Brett

 

I think what Norm means (and I'm sure he'll clear it up), is NOT that unsheilded wire is better than RCA shielded wire. He is referring to the fact that a Speaker level "signal" (NOT wire), has more voltage in it than a line level "signal" and is therefore less susceptable to noise pick up along the way. And Mhussey, in most cases you're probably right, as long as the wires are run properly (not near noise sources...) it really doesn't matter because once you crank up the Bob Marley, ya ain't gonna here nutin' but boom!!

 

hmmm. I have never used a speaker level amp....how are you guys hooking it up the HU then.... If you are adding a sub amp and didn't want to unhook any of the four corners, you would be splicing in and changing the Ohm load...right?

 

Jeremy,

Well, yes and no. Yes you would be splicing in, and no you are not adding to the ohm load. The speaker level input uses miliwatts of power, no load at all.

In my case, doesn't matter. I ran the speaker level output from head unit to 4 ch amp, ONLY. Then from the Amp to the 4 speakers. Then I took the RCA line level out of the amp, and ran it to the line level input of my powered subwoofer box.

In my last truck(GMC Jimmy), I did what you said, I added a powered Bazooka to my stock hu and speakers. I just spliced on to the rear speaker wires and ran them to the too Bazooka speaker level inputs. It boomed. Did not affect speakers at all.

 

I have to say this man stay away from letting people install your stuff unless you realy know the person. I have a friend who payed 1000 dollars for a systme that would have cost 500 max with him installing it himself. Now here comes the real kicker they did it wrong and he has to go back and fix there mistakes. Im not saying all shops are bad but its just better to bring it to the person you trust the most, Yourself

Good Luck
Syeth

 

CCarrara:

When you talk about "In my case, I ran the speaker level output from head unit to 4 ch amp", when doing this, is there a plug or clip from the HU that will attach to the Amp or is there a bunch of wires that you have to figure out which is which that will go into the Amp. I am trying to figure out if you simply unhook a plug from the back of the HU and then plug it into the AMP.

I have the premium HU. I have already replaced my brown paperbag speakers with Polk DX7's. I am going to get an AMP this weekend and would like to try and install it myself. Also, how many watts should I get. Is 75 x 2 enough? I plan on moving the Polks to the rear and get some components for the front in the future. Don't plan on getting sub.

2001 SuperCrew
Oxford White
Midland, Texas

 

CCarrara is right, the higher voltage of speaker level signals is less likely to pick up noise. It is not the cable that is the issue. It is also not distortion, that comes from having your input too high for the amp you are using or driving the amp too loud or with a speaker load that it cannot handle. Speaker level can be as high as 14 volts if you turn your **** all the way up. (It would be a horrible sound at this level, your amp would be clipping) Typical listening levels are probably around 4 to 8 volts. Standard line level is only 1 volt. Newer aftermarket heads have pushed this beyond 4 volts to help with this problem. Actually sheilded RCA wires can pick up huge amounts of noise like alternator whine. The sheild sometimes acts like an antenna. Most professional installers use unsheilded twisted pair interconnects. The twisting of the wires cancels out the noise. If you have your LOC (LLC) near your HU and have run RCA interconnects to your amps and have no noise then you are all set, do not worry about it, enjoy it!