dunpealhunter

iTrader: (1)

I am considering keeping stock 6 disk changer bose head unit. When I use a line converter to go from head unit to amp, what voltage will my amp be getting 1v, 1.5v, 2v, ? This is the setup I am going with

Kenwood KAC-x811D 514w x 1 @ 4 ohms
1 - Pioneer Premier TS-W2501D2 in a sealed MDF enclosure behind the drivers seat, not sure which way to fire it yet. (by the way the car is a drop top)

Kenwood KAC-x541 60w x 4 @ 4ohms
4- Alpine 6 1/2 SPS 170A

seekndestroy19

iTrader: (16)

well i dont think your LOC pushes voltage to your amp. its just to convert the frequency from the line level speakers to your RCA's

Paul350Z

iTrader: (1)

Line level is about .3 volt RMS (root mean square) at -10 dBV. At 0 dBV you should get 1 volt RMS. In other words you use an RMS AC volt meter you're going to read one volt across a 1000 ohm load at peak volumes. Most amplifiers will take 1-4 volts and some up to 6 volts of input.

dunpealhunter

iTrader: (1)

Do amps work twice as hard at a 1 volt input as they do with a 2 volt, or is the sound quality just half as good?

Paul350Z

iTrader: (1)

Not right. How about a very little basic electricity?

Line level converts do lower the speaker level voltages to match the lower input requirements of the amplifier. If it's tampering with the audio frequencies that's a bad thing, a really bad thing called distortion! They also match the resistance to each portion of the circuit showing a low resistance to the speaker level output of your head end while driving the high Resistance input to your amplifier.

(yeah I know impedance not resistance but this is basic electricity!)

Voltage is electron pressure - the higher the voltage the higher the pressure. If you put too much pressure in a garden hose it pops. If you put too much voltage into an amplifier it pops (smokes). Stronger hoses with thicker walls can hold more pressure, stronger wires with thicker/better insulation hold the voltage better. Look at a spark-plug wire verses a speaker wire.

Current in amps is the flow of electrons past a point. If you put too much current into a garden hose it's going to wear away the sides and burst. If you put too much current though a wire it's going over heat and melt. Getting a bigger hose (a bigger wire) allows more current to flow. Look at the fire truck hoses verses a garden hose - and the large wires needed for amplifiers and the battery compared to thin ones for a CD-changer.

Wattage is a measure of power - or work. Volts times Amps (the current) is wattage. A bigger hose with more pressure is going to fill up a barrel with water faster. A bigger high current wire with lots of voltage is going to have more power handling ability in watts.

The last part of Ohm's law is the load resistance measured in ohms. Resistance is the opposition to current flow. In water think of it as a gate valve or an obstruction in the water's flow. Given enough pressure we could blow out the gate valve. Given too much voltage we can blow up our electrical load too. If we pass massive amounts of current pass an obstruction in our hose we will eat it away - if we pass massive amounts of current (in amps) though a load we will overheat it and smoke it (or send it into thermal protection at least).

Advanced lesson: Resistance is the opposition to DC current and impedance is the opposition to AC current. The difference is that impedance varies with vector that can put the phase of the opposition of the current out from the voltage - ole ELI the ICE man. In DC the two are always in phase with each other.

In an inductive circuit (L) like a speaker coil the voltage (E) leads the current (I) where in a capacitive (C) circuit the opposite is true with current (I) leading the voltage (E). A wee bit of trig is needed to do the actual calculations and we'll save that for another day.

Paul350Z

iTrader: (1)

The amplifers are limited normally by there output transistor's wattage. The manufacture designs the input stages to grab the small line level voltage and boost it up to drive the output stage(s). This is where you're limited to 20, 40, 120 watts or whatever.

The sound quality is equal given a properly designed system. Car stereo manufactures have developed a line-level amplitude race where the even the +$25,000 home stereo amplifier manufactures haven't. The one MINOR advantage that a higher level pre-amplfier out put has - the bigger line level - is that if noise is introducted into the wire that the S/N (signal to noise) ratio is lower.

If you're using normal 1V line level on one amplfier and 6V on another and both wires get the exact same equal amount of noise the 6V amplifier will have a S/N ratio of about 7 dB better. I would just remove the noise from the wire all together and not have to worry about it at all! Spend another five minutes and move the wire or pay another $30 and get a quality signal wire rather than $350 on a line driver.

dunpealhunter

iTrader: (1)

Wow Paul that is a lot to chew on.... So ahhh what is it exactly that you do for a living. I'm thinking not something with the phrase "You want Fries with that?"

Thank you for all the information Paul. I have decide to go with Stock Stereo. All the equipment from above is from previous car. I just got this car 2 months ago and I will be (after original purchase ) another 7 Grand into it after the custom paint next month..... Got to scrimp a little on the stereo and I like keeping the inside electronics looking stock. It keeps the honest people out

Thanks again

RedBullRR

iTrader: (7)

Hey Man, sorry to bring this back up again. But you seem like you know a **** load of good information regarding this subject. I am having a problem out of no were. I lost bass in my car and cant figure out what happened. My amp has power and is not in protection mode. However I no longer have anything going to the Zenclosure Box. I unplugged and re-plugged everything back in and still no bass. If I hit a bump in the road it will come on for a quick second then go back out. Last night I checked all the wires including the solbaric speaker wire and the PAC-OEM Wiring but nothing was out of place. Completely lost. Do you know if I put a meter tester to the out put of the PAC-OEM adapter what Volts if any I should be reading?

Paul350Z

iTrader: (1)

You're welcome.

I'm a project engineer for a television and radio broadcast facility and have worked previously as as both a television and radio studio engineer. Acoustics and music has been a passion of mine for a long long time.

Paul350Z

iTrader: (1)

Well if the power and signal are making the amplifier - and it's not in the self-protect mode ... have you looked at the signal wire which supplies +12 VDC to turn the amplifier on and off remotely?

The main power for the amplifier likely comes straight off the battery via a fuse and a marine fuse box. The amp would drain your battery over night if it wasn't for the second power wire which is the on/off signal wire. Most of the time it's pulled off the head end's power antenna wire but it can come from any switched source.

Failing that you could try connecting into the amplifier directly with an iPod. Radio Shack sells 1/8" mini-jack (headphone) to RCA adapters for about $5. This would let you plug your iPod directly into the amplifier. Drive around and see if it cuts in and out - this will tell you that your bass amp and wires are fine and the trouble is in the PAC or the head end signal wires.