A couple of questions on a new amp and head unit install - The amp and Head unit both support RCA as well as high level inputs. Is there any reason I should use RCA over High level? - If i use the pre amp output on the Head unit, do I essentially miss out on getting any of the wattage out of the new head unit? It is a 200+ Watt Head unit and it would seem like a waste to bypass the HU amp. The amplifier that I bought is a 4 channel, 600 watt amp (Sony xplod). - I have after market speakers already installed. Do I really need to change out the factory wire to something thicker (i.e. 8 gauge) now that I am going to run an amp? The current wire is OEM in a Jeep and it might be something like 16/18 gauge. I am not sure but I would hope to avoid having to redo all wiring to the speakers. Can I use existing wire without blowing up the amp/HU? I don't care too much about maximum quality as I am just trying to get a little more power since this is a topless jeep. - Do I have to run the amp to the battery or can I hook the amp power to an accessory switch? Can I attach it to the same accessory/power (red wire) as the Head unit? Thank you!
First, the RCA provide a cleaner signal to the amp and second, you only have the power from the last thing inline. In other words, you said you have a 600 watt amp, you only have 600 watts, whether you use high level or RCAs. I always recommend changing the speaker wire but realistically we don't need to. Your Sony amp is only 300 watts of real power at the most. So 75 watts per speaker the factory wire is OK. YES you HAVE to run a power wire to the battery.
Thanks for the reply If my amp is only really 300 watts (rated as 600), what wouuld the 200 watt head unit really be capable of? I am better off installing the amp, right? I will change out the speaker wire to 12/16 gauge.
A 200 watt hu is 50 watts x 4 at peak. Most good hu are 17-22 watts rms per channel. Ur typical oem hu output at rms is 12-14 watts per channel. So about a 5 percent increase. The main reason to upgrade are the feature capabilities. Like 4 volt preouts for a cleaner sound and better control over mid/high pass and sub controls and the addition of some eq settings.
I agree with Ranger. ALWAYS run a separate power line to your amp. Be sure to get an inline fuse to splice in your power line for extra insurance for your amp. The factory wire for speakers should be Ok for now, but if it were me, I would wire a thicker gauge since you'll already have the interior already half out of the vehicle installing your amp. Sony products are notorious for being overrated (mainly Watts, though some say quality as well). Having the wires done now will make Amp replacement much faster and easier if you decide to get a new one later. Who installed your speakers? Another reason to maybe run new wire is to be sure all your speaker connections are secure(especially for trucks and jeeps). Some DIY'ers just snip the factory plugs off and twist the bare wire through the tiny hole on the speaker terminal. Solder is best especially if you are off road alot. If you do upgrade the wire, don't waste money buying premium stuff like Monster Cable. There is plenty of quality cable out there just as good for 1/2 the price IMO. If you ever plan on getting a sub later, PLAN now! Get a thicker gauge power line and run a second set of RCA cables. (even if they aren't connected). It will save you the hassle of tearing up the interior a second time. You didn't mention a budget. If this jeep is just a beater and you don't have any extra cash, you can disregard my post although the extra cables should be in the $60-$75 range if you stay away from that MONSTER stuff.
No intention of hijacking your thread, but I've seen a lot of posts where people talk about high and low-level inputs/outputs and hi-volt line outs, so I wanted to make a few points. Hi-Level vs LOC A lot of people think they will get a cleaner signal going through an LOC on a factory HU, rather than inputing at hi-level. This is just rubbish. An LOC just drops the voltage out of the HU, making it more compatible with RCA inputs, but you're still getting the same high-distortion signal from the HU. Running hi-level into an amp's specific hi-level inputs is the same thing, the LOC is just in the amp already. RCA outputs from a deck are cleaner because they come from the pre-amp stage and bypass the inferior internal amplifier altogether. Now some amps may have a poorer LOC than one you could buy, but it's essentially the same animal. If your amp has hi-level inputs, you may want to save a bit by not purchasing an LOC. The biggest argument for using one is that if you plan to replace the head unit later, you might have the RCA cable already there (if you put the LOC behind the radio). Hi-Volt RCA I know a lot of people swear by the hi-volt line outs, but this IMO, is also a myth. The point of hi-impedance (low-level) outputs in the first place was that, being low-voltage, they sent a cleaner signal to the amplifier. Somewhere, somebody felt that by increasing the voltage greatly that this is going to decrease the noise? This is only getting closer to hi-level. A lot of these units can just about drive a speaker directly from their RCA connectors. How is this better? The only possible advantage I can see is being less susceptible to radiated engine interference, but not a cleaner signal. If you think 5,6, or even 8-volt line outs are better, then ask yourself why audiophile home audio products have not adapted this same system.
I tend to agree with you on the LOC issue, however, higher voltage line level outputs do have advantages. Being in a mobile enviorment, there is plenty of RFI and EMI issues that have to be dealt with. And using very low voltage on the interconnects tends to make things worse. This typically means that the input sensitivity or gain on an amp will have to be turned up, along with this you increase noise in many forms. I would tend to think that home auidio has not adopted this idea due to the relatively noise free enviorment in which it operates.
