Del Namco Solo

basically, old head unit is 2v (Pioneer DEH-3200UB)

new head unit is 5v (in mail)(JVC KD-R900)

amp says "input sensitivity 200mV-6V" (Crunch P1 600.2)

now does the voltage equal quality of sound, loudness, or both? I don't mind if its just quality, but loudness would be a plus as well. I keep thinking my amp with 6v is only getting 2v so i feel like its being underpowered?

thanks in advance!

0c00l

Higher voltage on the low voltage output of a head-unit means much better signal strength at the amp's input stage. Quality of sound really is based on the head-unit it self. If the head-unit uses high end components like burr-brown crystals for the cd player instead of sand based glass and high quality transducers, caps, and so on for the radio side. You can have a radio with 5v pre-out voltage and still be pushing garbage sound to your amp. It helps to have a higher voltage so you can use less gain at your amp in order to match your head-units output.

nsxxtreme

The reason for high voltage pre-out is that a car is a noisy environment. If your the loudest thing in system then the "noise" becomes less noisy. An amps gain is made such that it can operate with different head units with different pre-outs. You should match the amplifiers gain to the stereo's output voltage. Meaning if your stereo had a 2V output the amplifier gain should ideally be set to 2V. I say ideally because with any electronic device there are tolerances that can effect the system. Just because someone prints 2V on the gain of the amplifier doesn't mean that's exactly where 2V is. It could be a little to the left or a little to the right. You should not think of the gain as a volume ****. You also want to make sure you get the most out of your system. Alot of stereo's will distort when set to max volume. You can increase the gain slightly so that you can reach max volume without having to set the volume **** at it maximum setting. The point is to maximize your system.

There are tons of online resources of how to set the gain. JL Audio has a dumbed down version that is fairly easy to follow.

Del Namco Solo

Well, so far, with the stuff i said i already have, the headunit's max volume is around 62ish (if im thinking right), and I never really pass 40 (anything more and you get distortion in the sound no matter if its amped or not). Then the amp, i turned the level all the way up (bass boost off and freq cut @ 65ish-70) and it puts perfect sound to the speakers, and as ive said before, anything past 40 and it distorts. I was hoping either the new 5v headunit will make the sound either clearer or louder.

0c00l said that the higher voltage lets you match your headunit better, does this mean that it gets louder because you don't need as much gain on a 5v vs a 2v? and thus leaving the amp up high and switch to 5v means it would be louder no? The speaker (JBL P660C) are rated 90rms per side and 270max per speaker (both box, purchased website, and jbl website all say so as well).

amp cranked to max gain, and hitting my 40 spot on the dial (as ive said it distorts after that) it sounds amazing, but it seems like the speaker can handle much more power.

The amp says it will do 150watts rms at 2ohms (which the JBL P660Cs happen to be) and 300 max at 2ohms. It (to me) doesn't feel like 150 watts (more like 70ish)

I was thinking that my amp wasn't using full power since it is rated 6v, i was thinking i was only running 1/3'd the power with a 2v headunit. then on top of that i was thinking 2v would be at the max 62 (distortion area) which means i would actually be running less then 2v which made me thing i was running even less power.....

just trying to figure this **** out, i can build a motor and work on cars but give me voltage and electronics and i have no clue (except computers).

sorry if all this is jumbled my mind runs pretty fast its hard to express myself in words.

0c00l

My mind runs the same way, plus I work a million hrs. You definitely don't want your amps gain all the up. Anything past 3/4 is distortion as well, even with good a class A/B amp. The only thing higher volt pre-out (5v) will do is allow you to run your amps gain even lower but it wont be louder. If your speakers are rated for 90rms (are they these:http://www.jbl.com/EN-US/Products/Pa...aspx?PID=P660C)? and your amp is rated for 150rms per side at 2ohm then your giving them more then there rated for and with a good dose of distortion due to your amps gain being all the way up. They may sound like they want more, but they probably won't last long. The only real way to know (other then by ears) if your amp is clipping or sending the speakers a distorted waveform is to use an O-scope so you can actually set the gain to it's max right before clipping. Other then that you'd have to get different components that can handle much more power and get a cleaner amp. A new radio won't give you the sound your looking for.

nsxxtreme

Higher voltage lets you drown out noise. Low voltage system have been used years before high voltage systems. A headunit has many things to do and analog output is just one of those things. Which would you rather have doing your analog audio amplifying? Something that was designed specifically for audio amplification really well or something that was designed to do everything pretty good?

Amp ratings don't mean much of anything these days. If your interested in sound quality you want a higher impedence. If your just interested in it being louder then drop the impedence as low as you can go.

You just need to set the gain properl and you will get the most out of your amplifier. If that isn't enough invest in a better amp not a new head unit.

Think of voltage like horsepower and current as torque. Having high HP with no TQ is worthless. Your amplifier is a voltage amplifier but also has the added benefit of also providing additional current. The volatage is what makes it loud the current is what allows you tro drive large speakers.

0c00l

How exactly does higher voltage drown out noise if the source of the higher voltage is full of noise? It will only amplify it.

Which will smoke the amp or speakers when square waves are sent out and the amp over heats. Go as low as the amp allows 2ohm stereo.

Which was stated

Del Namco Solo

So the head unit (jvc r900) was delivered today and I put it in. Man you are all so full of ****.

2v vs 5v is so much louder. Not to mention higher quality (but that's probably the TI/Burr-Brown 24-bit DAC). I pretty much figured it would be louder so I turned down my amp before I started the car and when it came on, with the amp being on ZERO GAIN, and the headunit maxed, was as loud as my old headunit and yet there was no distortion like my other headunit. Not to mention I was able to actually max the speakers rolling back the power right before you hear the speakers and sounds distort.

Its louder and clearer. Why I ever ask questions anymore is beyond me....

nsxxtreme

Says the guy that can't figure out how to set the gain.

Your amp only has so much output boosting the input source doesn't magically make the amp now more powerful.

If you had an issue you had the gain set incorrectly or you had a crap head unit. Set your gain to max and rock on dude!

Del Namco Solo

The gain don't need to be maxed anymore. Let me see if I can explain it better.....

On the pioneer, it had 2v pre outs, and it was only a mid level unit (low end of the mid end i should say). It's max volume was 62, and I noticed without an amp the music got distorted around 40, so 40 was my sweet spot per say. then with the amp hooked to it, I could crank the amp's gain to max still with the head unit at 40 and it would be perfect, but I felt it should be louder.

Then on the JVC, it has 5v pre outs, and its a high end unit. It's max volume is 50, and surprisingly I can take it all the way to 50 with no distortion unlike the Pioneer which would **** out at over 40 some songs at 40. I turned the amp's gain all the way down (basically off?) and at 50 it sounded like my pioneers 40 yet clearer and better sounding.

Now I have the JVC at 30 with the gain up slightly as to be able to turn up louder for some songs, 30 for most, and lower for the other few. Its slightly louder then before (without distorting) and much clearer, I would call it perfection...... LOL. Only thing I need now is a subwoofer (the JVC doesn't do bass like the pioneer and nothing is changed in its settings so its all stock).

nsxxtreme

I was being sarcastic......

That has nothing to do with 2V vs 5V. That has to do with having a craptastic reciever. You can't hear the difference between a 2V vs 5V system assuming both are set up properly.

89hybrid

You should really take a moment and go back and read the other posts. These guys are exactly right on their explanations.