FAQ: Speaker/Sub/Amp Upgrades with Factory Head Unit

If u put in aftermarket speakers they are 4 ohm, factory are 10 ohm, so u have250% more power through the A M speakers!

comanche221 wrote:

If u put in aftermarket speakers they are 4 ohm, factory are 10 ohm, so u have250% more power through the A M speakers!

yes and no. when you bring the 10 ohm native amp down to 4 ohms, you get more current out of it, but with that you get more THD and the danger of amp failure. people do it all the time not knowing and usually it doesn't break so i'd say thats probably ok. the other thing is that that type of amp is very inefficient outside of the operating range of 9-12 ohms and will put out only very slightly more power and that small increase in power is the only reason why the after market speakers being used are even as loud as the OEM speakers. otherwise the more power efficient OEM speakers would actually be louder. (thats also why the original speakers are very easy to blow using an any after market amp - the amp wants to feed way more power than those speakers can use)

Only the rear 6X9"s work at 10 ohms. The fronts are rated 4 ohms, so you won't get any more output with aftermarket speakers unless they are very sensitive (have a high SPL/1M/1W). Unfortunately, most speakers are less sensitive than our stock drivers.

If you want to get loud, get an amp(s). If your amp doesn't have high-level inputs, a high-to-low level converter can be used. They don't cost that much.

Aaron, I never bother to check this since I pulled the unit out but what is the combined resistance of the two front speakers? I saw the tweeter was 4ohm and I never had the original 5.1/4 to check.

It's still 4 ohms because the mid and tweeter play different musical bands.

When you wire two identical drivers (4 ohms ea) in parallel, you'll see 2 ohms, but since the tweeter is crossed over with a cap, it plays only the highs. The mids naturally play only the midrange sounds, so the impedance should be fairly consistent across the frequency range with both speakers wired together.

Keep in mind you can't measure DC resistance (ohms) with a meter to get true speaker impedance. Since audio signal is AC, speakers are rated in nominal impedance. The typical 4 ohm speaker actually measures about 3 ohms DC.

The 6x9"s on the other hand, are 1-way drivers rated at 10 ohms each. I believe is to reduce output from the rear channels, as most systems tend to sound better set-up that way.

OK - so I replaced my front speakers with a set of two-way coaxial units.

Am I missing any freq range on these because of any stock cross over to the old ones?

Such as the highs missing because I used the mid's wiring for my new speakers?

No, you're okay. The "crossover" is just that little cap inline with the tweeter. As long as you tap in at the midrange, you're fine.

AA wrote:

The 6x9"s on the other hand, are 1-way drivers rated at 10 ohms each. I believe is to reduce output from the rear channels, as most systems tend to sound better set-up that way.

You are right on that the reason they are is to stage the sound since the 6x9's can handle alot more power. The stocks are ohmed up to keep an equal sound.

Agreed. My system sounds best with the 6x9"s turned all the way down. I only fade to the rears when people are in the back seat. Most people won't do this, but when they hear mine they wonder how it sounds good. The secret is a combo of good quality front speakers, decent/clean power, proper EQ/crossover, tweeter angle, and a properly tuned sub. If you get it right, there's no need for rears at all.

I wouldnt say you dont need rears you still need it for stagging if you have dirrectonal 6x9 with the tweeter that moves try angleing each at the other a pilla i dont fade my 6x9s. On my aftermarket deck they still dont over power it with the great front speakers no matter front or back they clear. That was a trick my friend who owned a audio shop taught me. Oh and as for the sub i put the base controll right infront the gas release its hiden and its there at a snap . Long as you pair your speakers correctly even a cheap system can sound great.

I once heard a SQ competition system that had a guitar pedal used as a delay - not an audible echo - but a variable delay that made the interior sound larger. As a listener you couldn't detect it, it just made the cabin sound more spacious, like a hall. After that, I shut my rears off and promised myself I'd never turn them up unless employing delay. Some heads have this feature built in now, but I like my stock head, so no rears. Sound stage seems right in front of me, and the Riv's flat dash provides a psychological stage as well.

I know AA has this but I am wondering how hard is it to a hook a amp up if you have a stock head unit.

I'm not sure if there is a stock sub/amp or not but if there is you can get a special something and run your setup. I could help you further if I wenret drunk.

I am looking at getting what AA has for his. I am curious to how well it works and how excatly you hook it up.

riviera2454 wrote:

I am looking at getting what AA has for his. I am curious to how well it works and how excatly you hook it up.

you can hook up your reference wires to the rear speakers..... that how i had my subs/amp hooked up before i got a deck!

JL Audio Also carrys something called a " CLEAN SWEEP II" Which Will eliminate the preset EQ settings from your Stock HU and allow all of the potential power and sound to be divi'd up evenly, using this and crossover Components, witha na amp and subs, ill alow you to sound great without altering the Factory look in the interior of your Riv

If your sub amp has high-level inputs, you may run wires from each of your 6x9"s, in parallel, to the amp. If you don't have high-level inputs, you must purchase a hi-low level converter (about $30).

My amp has only rca inputs. I am looking at the device you AA. Is there anything else you can tell me about it.

It's a pretty simple component, a small box with speaker level inputs, and RCA outs:



The holes are adjustment controls. Using a small flat screw driver, you can adjust the input/output levels.

This goes behind the hu so you have to remove hu or can you wire it up in the trunk?

Either way is fine. I tapped in up front, mounted it below the cup holders. Remember you need to run the RCA cables to your amp if you do it that way. Easiest is to put it in the trunk.

I wanna install subwoofers, but never done it, do I have to replace the stock player? I was thinking of leaving it coz of the steering wheel controls and getting everything else changed, I want better sound system. any suggestions?

You should be able to do it from the stock head unit. Just have an amp wired up and bypass the stock head unit's volume and power limiters.


Personally though, I'd fix those electrical problems with your car before doing anything as power-intensive as a subwoofer. Not the best thing for a 13-year-old wiring setup.

RIVIERASC95 wrote:

I wanna install subwoofers, but never done it, do I have to replace the stock player? I was thinking of leaving it coz of the steering wheel controls and getting everything else changed, I want better sound system. any suggestions?

For subs, you can just get an amp with high level inputs and just tap your rear speaker wires for the signal. That makes the install pretty much a joke to do since your battery is about a whole foot away from the trunk. You shouldn't have to worry about RFI using the high level inputs since all the wiring is short and simple and its for subs (LP amp) which pretty much cancels any audible noise.

If you want to upgrade your speakers, you can do the same with another 4 channel amp but you have to worry about RFI then. When I do an install like that, I get a stand alone signal converter and put it right behind the head unit and then use high quality RCA cables to move connect it to the amp (assuming it's in the trunk). That method is a bit more work and adds some cost but it's a pretty safe bet to avoid RFI. Trust me, you won't be happy if you spend a bunch of money on nice sound equipment and then have to listen to your spark plugs firing through it while you drive - not cool

I'm getting ready to do a small simple install for my friend on his 91 Riv. He wants just a small 300w RMS amp with a small sub just to get a little better sound quality. Problem is he is wanting to use his stock headunit without RCA outputs. The amp he has does accept high level inputs and has Front Left, Front Right, Rear Left, Rear Right, with all the speaker wire color indicators. Do every single speaker output from the headunit(Front Left, Front Right, Rear Left, Rear Right) need to be connected to the amp? Or just one input (Rear Left) need to be connected.



PS any idea's on how to install the amp turn on wire so when the car ignition is turned off the amp shuts off?