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Discussion Starter #1
Hi guys,

Sorry if this is kind of a noob question. I am using a LOC with my stock HU to send the signal to my amplifier. The LOC (Steren brand down here in Mexico) can be adjusted I believe to output 10V. My amp (Infinity 7541A http://www.infinitysystems.com/caraudio/product.aspx?ProdId='REF7541A'&Ser=REF&Cat=AMP) has a "maximum input signal" of 5.5V.

My question is, should I try to match the LOC output to the amp input or is it better to set the maximum output on the LOC and play with the AMP´s gain to avoid distortion.

Currently I have the LOC at around half and the gain on the amp (for the fronts) around half as well. I am powering these speakers: REF 6812CF http://www.infinitysystems.com/caraudio/product.aspx?ProdId='REF6812CF'&Ser=REF&Cat=MEL

I´m happy, but not thrilled with the sound. I expected more clarity. Do you think I should try to get some nice components?

Thanks
 

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If you are using the OEM speakers, then you really should get something better. It would be pretty hard to find something that sounds worse.
 

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Discussion Starter #3
Okay, agree quality wise, but the question still stands. What is best, try to match the output signal of the LOC with the input signal of the AMP? Or set the maximum output on the LOC and adjust the gain on the AMP?

On Navone´s website, there is a recommnedation, at least for the NE-7V, to keep the "gains" on the LOC at the maximum.

What is the benefit of having "gains" on a LOC?

Thanks
 

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"Gain" in an audio context is simply another term for "volume." If your Infinity amp recommends a maximum input voltage of 5.5V, then I'd try to get your LOC close to that...if you feed the amp too much voltage, you could end up with clipping on the input path. Remember that the maximum voltage that a LOC puts out is going to be at its maximum input; a LOC's output is directly proportional to the strength of the input signal it's fed. So unless you have the volume on your headunit cranked all the time, you could probably set your LOC to 75% of maximum gain and be in good shape.
 

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[quote author=skunk2 link=topic=68251.msg1178557#msg1178557 date=1170252755]
why not measure the output on the LOC and see if it's actually 10 volts.
[/quote]

B/C it doe snot work that way. The output voltage on a LOC or and line level output is dependent on the input. If volume is at 25% and you are listening to a quiet passage, the voltage would be very low. If you increase the volume to 75% and listen to something loud like rock, the voltage will be much higher.

The best way would be to run pink noise through the front end and measure the voltage on the line level with a DVM. Set your front end volume to 75% of max, and adjust the LOC gains to achieve 75% of the line level output the amplifier can handle.

You use pink noise as that should be equal volume for all frequencies. Using the 75% at the front end and LOC allow you to have some head room to protect your amplifier.
 

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Discussion Starter #7
Thanks for your answers guys.

So trying to match my LOC and AMP (voltage wise), turning the volume on the HU at 75% percent (if I remmember correclty around 25) and then turning up the gains on the AMP slightly less from the point of distortion would be the way to go?

And a final question, exchanging my Steren LOC for one from Navone would improve the quality of sound? Is it worth it if I´m using Infinity Coaxials (RMS 60)?

Best
 

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I use a SVEN4 from Peripheral and it sounds great. As long as you are spending $20+ per 2ch with a decent brand, it will be fine.
 
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