PAC OEM-1 LOC level....

[JohnHinerman 10]

Long story short, I'm keeping the factory Nav/HDD/BLUETOOTH/IOD/DVD/MP3 head unit in my '11 Ram. I installed a PAC OEM-1 (OEM-CHR3) for the plug and play ease plus remote turn on from the can bus system. My question is on setting the output levels of the OEM-1. I installed the OEM-1 and just turned all four outputs on the LOC all the way up. Is this correct? Is there any reason I wouldn't want them all the way up to feed the amplifiers the highest signal level?

[jonbearsmt 919]

there are some reasons that you would not want a 100 percent of the power going to the low level amp inputs,

i normally put them at half way.

you can grab a DMM and a test tone and make sure the output voltage is lower then 6~ish depending on the amps.

clipping can be an issue, but the biggest issue i see is that some amps will not play or damage the amp.

i would try to leave the LOC accessible , and try it half way and work from there.

i hope someone has a more definitive answer for you .

[JohnHinerman 10]

With the LOC at full output, my 4 channel amp gain is just barely past min. I don't have the subwoofers up and running yet, and I haven't done any setup at all. Back in day ('97ish) I worked for a Consulting, design, and testing firm. Around then you were starting to see most OEM hu's using bridged output amplifiers which would give you an 8v signal. We would simply use one side output and a radio chassis ground to run signal straight into the amplifiers. This would give a 4v signal to the amp without and sound degradation by using low cost transformers or resistors to convert high level to low level. Sometimes this would work fine but with some situations there could me an issue with turn on pop or other noise, but 9x's out of 10 it was fine. And in all honesty, I only reason why I didn't do the same thing with this is because the factory hu has no turn on lead for an external amplifier. Everything in this truck is on a can bus system, even cargo lamps and anything else you could think of. the OEM-1 was quick and easy, and I haven't really heard any complaints about any audible degradation of the signal. In a world without a budget, building an LOC with something such as Jensen Transformers and high tolerance resistors would be the way to go imho.

Sorry if I am getting off subject or deeper than my original question, as I was typing I was starting to remember things I learned while working there.

Anyway, the amplifier input is rated for .2 - 4v input. the only reason I would think you might want to lower the LOC output is if for some reason the source unit was such a high output that at the 2:1 ratio which PAC claims would produce an output of higher than 4volts, and even then I'm not sure if it would cause a problem. There are plenty of line drivers that produce more than 4volts, and if memory serves me, there are not a ton of amps which normally rate higher than 4volt input. My thinking is keeping the LOC at full output will keep the signal voltage as high as possible to prevent noise

Maybe someone can correct me if I am wrong...

Thanks in advance for the help.