line driver?

[aimone 4]

what do ya'll think? i have a pioneer deh-p3500 and the s/w outputs only put out 2v ......my uncles jvc arsenal h/u puts out 4v ........the same system swapped from my car to his but running on his h/u packs alot more punch and sounds better...........so instead of spending money i dont have on a h/u on the same level as his ive been looking into line drivers cause they arent so pricey ......but i recall several years ago my cuzzin had one and it ended up frying his amp.......so are line drivers a good idea? if so wut brands are good but cheap...and...how many volt output one should i get?

[shizzzon 461]

if it was the reason for frying the amp then he must not have payed attention when adjusting the settings. I can see how one could cause damage to an amp but these things shouldnt be necessary.

If you keep the gain control the same from one head unit to another then yes, his would sound "better" because his preouts are stronger, that doesnt mean better though.

the gain controller is used to match that of your hu's preout, that's it.

Easy, huh?

The more you crank the gain up, the lower the voltage listing goes on the dial.

so lets say your amp is adjustable from 0.1 to 9v. that means when the gain is turned all the way counter clockwise, that's 9v and all the way over is 0.1mv. You need 2v which "should" be somewhere around 70& clockwise but don't go by that to set the gains...

IF the gain is set too high, you'll start clipping.

[deathcloud 6]

I think line drivers are just for eliminating noise from the systems electrical system. I know that I have a line driver that outputs 8 volts and my deck is 4 volt pre outs (even though u don't get nearly that).

I then used my line driver to get the 8 volts at 3/4 volume via a DMM and now my gain is almost not turned up at all. So this means that my amp is not working that hard. Producing less heat. Giving it a longer lasting life. It is not clipping at all. I used to do it by ear but I wanted to make sure that my amp was set exactly right.

[Lucky 76 5]

I think line drivers are just for eliminating noise from the systems electrical system. I know that I have a line driver that outputs 8 volts and my deck is 4 volt pre outs (even though u don't get nearly that).

I then used my line driver to get the 8 volts at 3/4 volume via a DMM and now my gain is almost not turned up at all. So this means that my amp is not working that hard. Producing less heat. Giving it a longer lasting life. It is not clipping at all. I used to do it by ear but I wanted to make sure that my amp was set exactly right.

If you wanted to set it exactly right you would have used an oscilloscope not a DMM. A DMM has no way of telling if the amp is clipping, it simply measures the output voltage you are producing (among other things).

As far as not clipping at all you have no idea whether it is or not since minor clippage is not audible to the ear.

[shizzzon 461]

moderate clipping might not be either.

Clipping is a lot harder to detect in a subwoofer. That's why many people damage subs or else they'd know to turn it down when somethin weird sounding happens.

[deathcloud 6]

If you wanted to set it exactly right you would have used an oscilloscope not a DMM. A DMM has no way of telling if the amp is clipping, it simply measures the output voltage you are producing (among other things).

As far as not clipping at all you have no idea whether it is or not since minor clippage is not audible to the ear.

Wait a minute. Everyone says using a DMM is the smartest thing to do. Clipping is when your pushing the amp more than its capable right? Well when I do

60hz test tone is used. Then you put it 3/4 volume. U then do the formula to set the right wattage to the amps capabilities. So lets say you have a 1000 watt amp. Running at 2 ohms. You would do

root (1000 x 2) and get 44.7 volts. So you would adjust the gain on the amp at 44 volts with the 60 hz tone at 3/4 volume. This would mean if you don't go past that 3/4 volume it won't go past the amps limit of 1000 watts.

You are saying that isn't the safest way?

[shizzzon 461]

hehe, u know to get ohms you must have voltage and amperage present.

So, if you set your gains with speakers connected, then you will have impedance rise to deal with.

You won't know what the rise is unless you clamp one fo the 2 wires and take a voltage reading at the same time.

Pointless route to go.. an oscope is the most accurate way of setting gains on an amp.

[Impious 1,476]

There are several assumptions involved when setting the gain with a DMM and the voltage formula. These assumptions may or may not be accurate. As a result, your gain setting with the DMM may or may not be accurate. There is no guaranty clipping will not occur with the DMM method because, as stated, the DMM doesn't measure the shape of the wave....only the voltage.

The DMM method helps get the gain setting within the general ballpark so people aren't going crazy with the gain control. But in reality it's not an exact or accurate method.

[Impious 1,476]

what do ya'll think? i have a pioneer deh-p3500 and the s/w outputs only put out 2v ......my uncles jvc arsenal h/u puts out 4v ........the same system swapped from my car to his but running on his h/u packs alot more punch and sounds better...........so instead of spending money i dont have on a h/u on the same level as his ive been looking into line drivers cause they arent so pricey ......but i recall several years ago my cuzzin had one and it ended up frying his amp.......so are line drivers a good idea? if so wut brands are good but cheap...and...how many volt output one should i get?

There could be many factors at play here, none of which are related to the headunit's output voltage.

For starters, as was mentioned, the gain control is included on amplifiers for the express purpose of allowing the amplifier to reach full power output with a wide range of input voltages. You first need to properly set the gain control. With a properly set gain control, there will be no difference in output from the amplifier between your uncle's headunit and your headunit. This is exactly what the gain control is there for. You do not need a line driver.

Second, you could be experiencing a difference in vehicle acoustics. The exact same system in two different vehicles will sound and behave completely differently. While I don't know the details of the entire system (i.e. this would have been helpful information to have included in your original post) or what the two vehicles are a discussing here, trying something such as different placement and/or positioning of the subwoofer in your vehicle may change the sound of the system for better or worse. But without fairly advanced attempts at creating "equal" results, there will be some unavoidable differences in sound simply due to the two different vehicles.

A third issue could be due to the strength of the respective electrical systems of the two vehicles and the amplifier. If the amplifier is not tightly regulated, and your electrical system is much weaker than the electrical system in your uncle's vehicle, then the amplifier will not be performing as strongly.

A fourth issue could also be due to difference in various system settings between the two installations (EQ, crossover settings, "loudness" settings, etc) as well as differences of the other speakers and their respective performance involved in the two systems, integration of the speakers and subwoofers in the system, etc.

And that's the short list based on limited information.

Long story short; Hard to blame a single factor when there is a multitude at play that need to be fully considered. And to eliminate it from your list, the headunit's preout voltage is not one of the factors with a properly set gain.

[Impious 1,476]

hehe, u know to get ohms you must have voltage and amperage present.

So, if you set your gains with speakers connected, then you will have impedance rise to deal with.

You won't know what the rise is unless you clamp one fo the 2 wires and take a voltage reading at the same time.

Pointless route to go.. an oscope is the most accurate way of setting gains on an amp.

Having a speaker connected isn't going to change the voltage an amplifier can supply before clipping occurs.

The impedance rise will affect how much power the speaker sees, but not how much voltage the amplifier can cleanly supply.

[aimone 4]

wow lots of topic replies but thanx to whom gave there comments on the question

the system is 2 of the new 1200 watt kenwood 12's in a sealed box powered by new kenwood amp 1800w rms w/ cheap walmart cap. 1 system just swapped into other car

the cars...

my uncles-- 96 nissan 240sx --stock alternator---with 8gauge power wire---jvc arsenal h/u

mine-- 76 chevy caprice---stock alt.---4ga power wire---big 3---pioneer deh-p3500---trunk not completly sealed

now ....he said his h/u is wut makes the most difference because his 4v preouts and his multiple sub settings...i am just wondering if getting a small line driver (found an audiopipe one for 30 bucks) if it will give my system that boost his h/u gives the system......

and i know that my car has alot more space then his but its not just a size or placement sound difference its a serious difference

so line driver = better/more amp sound output yes or no?

[jcarter1885 995]

wow lots of topic replies but thanx to whom gave there comments on the question

the system is 2 of the new 1200 watt kenwood 12's in a sealed box powered by new kenwood amp 1800w rms w/ cheap walmart cap. 1 system just swapped into other car

the cars...

my uncles-- 96 nissan 240sx --stock alternator---with 8gauge power wire---jvc arsenal h/u

mine-- 76 chevy caprice---stock alt.---4ga power wire---big 3---pioneer deh-p3500---trunk not completly sealed

now ....he said his h/u is wut makes the most difference because his 4v preouts and his multiple sub settings...i am just wondering if getting a small line driver (found an audiopipe one for 30 bucks) if it will give my system that boost his h/u gives the system......

and i know that my car has alot more space then his but its not just a size or placement sound difference its a serious difference

so line driver = better/more amp sound output yes or no?

First take the cap out of your car or whoever has one. Like stated above it is not his head unit that makes it louder, just set your amp's gain setting to match your pre-out voltage (which will give you the same results as stated above). The car makes the sound seem different in two different vehicles with the same equipment, plus his stock electrical is probably better then yours which will provide more power. So a line driver wont do it, read all these post above carefully and you will understand no line driver.

[Impious 1,476]

wow lots of topic replies but thanx to whom gave there comments on the question

the system is 2 of the new 1200 watt kenwood 12's in a sealed box powered by new kenwood amp 1800w rms w/ cheap walmart cap. 1 system just swapped into other car

the cars...

my uncles-- 96 nissan 240sx --stock alternator---with 8gauge power wire---jvc arsenal h/u

mine-- 76 chevy caprice---stock alt.---4ga power wire---big 3---pioneer deh-p3500---trunk not completly sealed

now ....he said his h/u is wut makes the most difference because his 4v preouts and his multiple sub settings...i am just wondering if getting a small line driver (found an audiopipe one for 30 bucks) if it will give my system that boost his h/u gives the system......

and i know that my car has alot more space then his but its not just a size or placement sound difference its a serious difference

so line driver = better/more amp sound output yes or no?

Apparently I didn't make my first post clear enough. Let's try it again;

YOU DO NOT NEED A LINE DRIVER.

Your uncle is wrong, plain and simple, that the sound difference is related to his 4v outputs (UNLESS YOU DID NOT PROPERLY RESET THE GAIN. IN WHICH CASE, CORRECTLY RESET YOUR GAIN). With a properly set gain, there will be NO DIFFERENCE AT ALL in the power output of the amplifier. Get this line driver thing out of your head. You don't need one. It won't help. Waste of money.

Go back to my previous post. It explains everything. Things you don't think make a big difference do, in fact, make a huge difference.

[jcarter1885 995]

Reading is very fundamental

[CrazyKenKid 64]

lol it sure is!!

[aimone 4]

sorry i didnt fully read ur post there was 2 much excess bullshit being posted bout dmm's but yeah he has the cap i learned already caps are a waste the big 3 is better ....

yes we adjusted the gain and it didnt come close to sounding the same.....

electrical is the problem tonite once i turned my head lights on my p.o.s tens werent hittin the same and when i hit the brakes my lights would dim and my stereo would dim and shut off so i think its time for a big boy alternator and battery