System just about done!

[lizardking]

Update-

System installed, just waiting for the LCD 7inch monitors for the headrests then I will take pictures for you all...Info of what I have thus far is in my sig. My only disappointment is the Kenwood DDX7015 has very low volumes even with me running the Eclipse amp for the full range speakers.. My guess it's do to the very low preout voltage of 2volts.. I might buy a line driver to increase voltages to 8volts RMS.

[smoketitan]

if you get a line driver the audio control matrix that I have is a very nice unit ( they have line drivers with crossovers or EQs also if you need all that )

Im running off the stock deck and my fronts get too loud for me to listen before my ears hurt--I get a steady 3v max 5v at 26 on the deck--off a PG ti600.2 with the gains all the way down

hey where did they ground your head unit? and your amps?? did they patch into the stock harness or did they ground the amps to the chasis. the only reason is I still have some minimal alternator whine that I cant get rid of for the life of me

[lizardking]

I believe they used the stock harness for deck ground...The amps are ground underneath each seat.

[lizardking]

Oh yeah just about forgot. I raised my back seat about 1.5inches. LCD's will be installed Thursday... OH YEAH.

[smoketitan]

how did you raise the rear seats--aare they still street/crash test legal etc??

so you dont get any wine at all?? if you turn you music all the way down and turn it up one click can you hear any static (minimal hiss?/) or when you rev the engine do you get a whine at all??

did they leave the stock amp plugged in?? or did they remove the blue plug

I only ask as I think I either need a capacitor, or some how the stock ground it connected to the amp connector somehow as I pulled mine out

I have noticed that when I have no more than 600w (with gains all the way down), the whine is very minimal almost inaudible), once I add the sub amp, or turn the gains up even a little the whine comes back

so I know that most amps get noisier as you turn the gains up, but that doesn t explaint he whine

[lizardking]

Not sure about the street legal thing.. I raised them by adding a longer bolts and spacers that I picked up at true-value.

I have a very slight wine but only when I raise my gains... What you need to do is set your gains using a voltmeter and test tones. This is how I set mine.

Here's how you do it:

Set head unit volume to 3/4 of maximum. Turn off all eqs/presets in the head unit.

DISCONNECT SPEAKERS

P = Power in watts
I = Current in amperes
R = Resistance in ohms (effectively the nominal impedance)
V = Potential in volts (Voltage)

Knowns:
Resistance (nominal impedance of your speakers)
Power (desired wattage)

Unknowns:
Voltage (we'll measure this)
Current

Formulas:
P = I*V (formula for power)
V = I*R (Ohm's law)

So after a little substitution to get Voltage in terms of simply power and resistance we get

V = square_root(P*R)

So, for example, say you have a 4 ohm load presented to a 150 watt amp.

V = square_root(150*4) = 24.5 volts

This means you should increase the gain until you read 24.5 volts AC on the speaker outputs of your amplifier.

As a source, use a sine wave recorded at 0db at a frequency within the range you intend to amplify. You can generate tones in cool edit or use a program such as NCH tone generator. (credit for NCH to imtfox, IIRC)

Additionally, you could use a scope to actually check if the signal is clipping, but I'm not going to get into that here as I doubt very few people have access to that type of equipment.


No, I don't think they disconected the blue plug. Should I disconnect it?


Did you route the power wires away from any of the speaker wires including the patch cables? I have power on one side of truck and the speaker wires and patch cables on the other..You must have the speaker wires away from power..

[smoketitan]

whoa talk about intricate!! but Ill think Ill try it just to learn something new. Ill go buy a voltmeter tonight any recommendations---something under $100 as I dont need a $200 unit

so back to the whine--it seems that the whine is now constant on stereo uprades with titan--there is some weird ground issue going on somewhere--your answers are helping me to locate it as I have done many test myself, and did a bunch of research here and other car audio forums

and Re: the amp you dont have to disconnect the blue connector ( it will be one less draw on your alternator--but not a big deal) --I only asked that to try and figure out if the stock ground on the harness is a lead through to the stock amp ground, but it must not be since you have the same whine as I and others have

It seems the stock alternator does not like large current draws--you have a capacitor right?? how many farads??

last question what voltage reading are you getting off the battery, and at your capacitor when the car is running?? are you getting 14v--I had mine checked and it read out only at 12.6V

[lizardking]

I don't have a cap installed yet.. Still debating if I need one.. As for the whine I don't have a wine unless I raise my gains 3/4 which I don't need too.. I have may gains set per the instructions above which put my gains about half way.. If your gains are to high this will cause noise. I have my amps grounded underneath the seats, the shorter the ground the better. My ground wire (4gauge) is only about 8inches long. I also have zero noise patch cables from headunit to amps. Another thing is the lower the preout voltage the more noise (whine) you can get. If you run a line driver like the Phoenix gold line drivers you can put 8volts rms to the amps which means the gains can be set almost all the way down (counterclockwise) instead of clockwise. As for the multimeter a cheap wal-mart will work just fine for $15. Remember you will need test tones 1khz for the speakers and 50hz for the subs. You will need to set all EQ's to flat and all bass boost to 0db and set everything in the deck to neutral (bass,treble,mids). I can send you the test tones if you want just give me your email. You can burn a disc with them and put in your cd player and then start testing voltages..

[lizardking]

Here is a link that explains the setting of gains... I found this a few weeks ago.
http://jlaudio.com/tutorials/Input_S...nsitivity.html

[lizardking]

You can give me your amps RMS specs I can give you what the voltage should be at the speakers outputs of amps.

[smoketitan]

cool Ill pm you my email address

but in regards to my whine I noticed the same thing as you the higher the gains the more whine--so I turned my gains all the way down an maxed out my line driver--so the whine is gone for now--but that is just a band aid--there shouldnt be any whine (major draw on the amp) by jsut turning the gain up. the stock HU will only output
0.4V so the line driver cant get the full 10v output fromthe line driver ) I am getting only 5 volts max).

you would have better luck than me since you went aftermarket on the deck

thx for the info,and the jl link that is a cool site

oh yeah my power/ground wire is 4GA all around---I was thinking of going 1GA--but Ill try and fix the ground issue first

as it seems everyone is getting some alternator whine

oh I have a PG ti600.2 to the fronts

and xenon 200.4 for the rear and subs--though its not connected right now

[lizardking]

http://www.nch.com.au/tonegen/index.html#104


This is the tone generator you can use to set up your tone files...

[smoketitan]

got it !!!!

thanks

[lizardking]

You will need to make a 1000hz(1khz) tone for the speakers and a 50hz tone for the subs.. I would make each about 1minute long this will give you enough time to make the gain adjustment. Make each file in stereo with 0db.

[smoketitan]

thx for the 50hz lizard