# 2v vs 4v preout



## King Nothing (Oct 10, 2005)

Im looking to get a pioneer F90 or F900 nav unit. the only real du=ifference between the 2 is the 90 has 4v preouts while the 900 has 2v. My processor only accepts up to 2.5v anyway, so would the extra 2 volts be worth the extra 100 dollars?


----------



## 89grand (Nov 23, 2006)

I don't think so.


----------



## trunks9_us (Oct 25, 2007)

King Nothing said:


> Im looking to get a pioneer F90 or F900 nav unit. the only real du=ifference between the 2 is the 90 has 4v preouts while the 900 has 2v. My processor only accepts up to 2.5v anyway, so would the extra 2 volts be worth the extra 100 dollars?


I think it would be better to get the hu with 4 volts

From the way I have read/learned is that the pre amp volts are only as high as they say on the hu when they reach towards max volume which then causes clipping/distortion. If you go with something that has true 4 volts then it would be better so you dont have to worry about turning it up all the way.

Maybe some one else will chime in.


----------



## SQplease (Jul 23, 2008)

4v by far


----------



## DT053 (Mar 23, 2007)

Higher your preamp voltage is, the higher your signal to noise s/n ratio is. 

dT


----------



## 89grand (Nov 23, 2006)

There seems to be some misconceptions going on in this thread.

There's no benefit to using a 4V over a 2V in most cases. If 2V will drive the amp, that's all you need.

That's why amps have gain controls, to match the headunits output. If the amp is not a POS and doesn't get noisy when the gain is turned up for 2 volts, then 4 volts will do nothing else for you.


----------



## King Nothing (Oct 10, 2005)

The equipment, while not top of the line, is definitely not POS. Memphis amps and a harrison labs SEMOD. the SEMOD says its max input and output is 2v


----------



## 89grand (Nov 23, 2006)

King Nothing said:


> The equipment, while not top of the line, is definitely not POS. Memphis amps and a harrison labs SEMOD. the SEMOD says its max input and output is 2v



I wasn't suggesting your amp was a POS, I was just saying unless an amp is one, you won't need 4 volts.


----------



## Oliver (Jun 25, 2007)

http://www.diymobileaudio.com/forum...04-rca-output-voltage-test-alpine-9887-a.html

From some old thread...

Default RCA output voltage test on Alpine 9887
I expect a lot of people to tell me how untechnical this test is. So if you think it's wrong, do you own test. I would love some more professional testing from people that know what they're doing.

My biggest question.. why with my deck maxed at 35 volume, could my RCA's only manage about 1.5V RCA output voltage? Where does that 4V rated signal magically come in? This explains a lot to me about my weak sub output, and why I had to put my sub amp gains up to 1.5V for it to sound halfway decent.

Watch the video, make the call.

http://74.220.202.31/~bellbott/rcaouts.wmv


----------



## cainst (Jan 15, 2009)

89grand said:


> There seems to be some misconceptions going on in this thread.
> 
> There's no benefit to using a 4V over a 2V in most cases. If 2V will drive the amp, that's all you need.
> 
> That's why amps have gain controls, to match the headunits output. If the amp is not a POS and doesn't get noisy when the gain is turned up for 2 volts, then 4 volts will do nothing else for you.



So, if my HU has 4V and my amp accepts from 0.8V to 2.2V, should I turn my gains all the way over to 2.2V? I currently have them at about the half way mark.


----------



## 89grand (Nov 23, 2006)

cainst said:


> So, if my HU has 4V and my amp accepts from 0.8V to 2.2V, should I turn my gains all the way over to 2.2V? I currently have them at about the half way mark.


The way I set my gains is I use a low recorded CD, then with my volume control near maximum on the head unit, I adjust the gain just until I start to get audible distortion then I leave it there. That assures that I'll always be able to get maximum undistorted output regardless of what CD I listen to.

Now with multiple amps, I do that with the midrange amp, then simply adjust the tweeter amp and sub amp gains to level match them to the midrange.

I don't bother looking at the voltage markings on the amps gain control or consider the headunits rated output preamp voltage because I think they are mostly meaningless.


----------



## Fiercetimbo17 (May 17, 2007)

You will also get a year longer warranty with the f90, and i dont think you will notice the difference in the 2v-4v
However on another note, have you used the f900 or f90 personally?
I think they are the worst thing pioneer has ever made.


----------



## King Nothing (Oct 10, 2005)

Fiercetimbo17 said:


> You will also get a year longer warranty with the f90, and i dont think you will notice the difference in the 2v-4v
> However on another note, have you used the f900 or f90 personally?
> I think they are the worst thing pioneer has ever made.


Im buying off the interweb, so I dont think Ill have a warranty to speak of. Also, Word is that pioneer has fixed the issues with the Fseries via updates and most are satisfied. If you can think of another unit that does what the F90 does for about the same money Im all ears. Needs to not use a DVD for nav because I need to be able to use the DVD player at the same time as nav. Ipod control and bluetooth


----------



## Fiercetimbo17 (May 17, 2007)

How much can you get one for?
They do have the update but they are still slow, about 20 seconds to boot up and at least 2 seconds or so between everything you do.
Bluetooth is hit or miss, wont work with iphones at all. 
Nav sucks too, multiple things wrong with it but the biggest for me is it will only do north up top. Meaning if your traveling east instead of the nav showing you going up it shows you driving sideways across your screen, doesnt sound like a big deal but when driving and trying to use it, it sucks.


----------



## King Nothing (Oct 10, 2005)

going rate on the F90 is 650ish shipped. I found an eclipse avn6620 that has dual DVD slots so the nav can be used at the same time as DVD. By the time the ipod adapter and bluetooth are added Id be within 50 bucks or so of the pio


----------

