Please weigh in on using line driver

thedeal7235 · Post by **thedeal7235** » Sat Jul 26, 2008 5:32 pm

Ive been trying to help deathcloud understand how a line driver works, and I know hes been asking some guys, but can everyone weigh in and help to let him know the benfits of having one?, and if you use them or not? Thanks guys, btw, he recently bought my ti400.2 for his highs/mids, and i saw a post he left wher he wants his highs/mids to blow his dads away, i think in sq a line driver will increase that for him, and give him more control, and less wear/tear on his new ti 400.2

Post by **kg1961** » Sat Jul 26, 2008 7:41 pm

I use mine with a hu deck or just a POS
it makes the sound louder
yes if you have a ground or nosie problem(not good) but you can use the amp before clip at about 50% less than without and the amp will not stress out before the sound/noise... very nice
I have always used one since 1999 audio contol and pg they are a must

deathcloud · Post by **deathcloud** » Sat Jul 26, 2008 8:01 pm

hmmm... Anyone else? So far it seems like it is a necessity. I'm really trying to cross the line into audiophile systems and it seems like line drivers are a must!

soth · Post by **soth** » Sat Jul 26, 2008 8:45 pm

Line drives pros.
- Mount near HU as close as possible.
- Test with a dynamic track until it starts clipping then back off a bit.
- Amplifier doesn't need the input sensitivity (gain) turned up as much
when you are using one thus preserving the life of the amp. Amp doesn't have to work as hard.

Here is a good article.
http://stason.org/TULARC/entertainment/ ... C-IDB.html

brenzbmr@sb · Post by **brenzbmr@sb** » Sun Jul 27, 2008 2:24 pm

actually the major benifit of using a line driver is that it will increase the output voltage of your signal

lower floor noise
also keeps signal from degrading from length of cable and resistance

only thing is like soth said is line driver must be installed infront after signal sourse

flogger11 · Post by **flogger11** » Sun Jul 27, 2008 3:45 pm

It also depends on your head unit, if you already have 4 volts of output or more, you really wouldnt need anything more than that on a ti, I believe the max they can even handle is 6 volts of input...

Post by **fuzzysnuggleduck** » Sun Jul 27, 2008 4:01 pm

It's also not a bad idea to use a line driver in combination with another device at the back of the vehicle that will take a high level voltage and step it down before the amp if your amps don't take a very high input voltage. That way you maintain your high noise floor for the path from the HU/LD to the back but still provide a sensible input voltage for your amps.

flogger11 · Post by **flogger11** » Sun Jul 27, 2008 4:04 pm

fuzzysnuggleduck wrote:It's also not a bad idea to use a line driver in combination with another device at the back of the vehicle that will take a high level voltage and step it down before the amp if your amps don't take a very high input voltage. That way you maintain your high noise floor for the path from the HU/LD to the back but still provide a sensible input voltage for your amps.

That doesnt make much sense to me... You set your line driver to provide the correct voltage at the amp, also make sure your gain on the amp is set to 0.

Post by **fuzzysnuggleduck** » Sun Jul 27, 2008 4:57 pm

Edit:

I just realized the configuration I was envisioning isn't possible because my EQ only does -12db input gain at minimum and -20db max output level control, which can't bring an 8V signal down to 2V (unless I've got the math wrong YET again).

flogger11 · Post by **flogger11** » Sun Jul 27, 2008 5:00 pm

Ya, with that much equipment, no biggy, LOL!

KHPower · Post by **KHPower** » Sun Jul 27, 2008 6:49 pm

I use my SLD44 for a few reasons:
1. MyPioneer HU only delivers 2.4 volts
2. I have 3, 20 and a mono y adapter rca's of signal to feed to the bass cube. After the Basscube my RCA volts were around 1.2 volts , now with the sld44 cranked I have a steady 7.88 volts going into my amp.
3. No more messign with my gain on my amp its set at 0 and the perfect amount of voltage is perfect.

The only cons about a line driver in my case is the placement , but that depends on the vehicle used. The sld 44 isnt the smallest thing but I finally found a place under the passagers side floor mat that it fits under quite nicely(up far enough that no ones feet will harm them.

Also , If you head unit makes noise then the line driver will just amplifiy it

brenzbmr@sb · Post by **brenzbmr@sb** » Sun Jul 27, 2008 10:42 pm

actually just because your headunit puts out four volts doenst mean when
gets to your amp it will be four volts... to many variables

second having a line driver in front and a reciever in rear is a good idea and is not a new concept..pg did it back in 1988..it make alot of sence
also just because the line drivers "set" at a voltage doesnt mean your amp is recieving that voltage, to many variables involved.

KHPower · Post by **KHPower** » Mon Jul 28, 2008 5:48 am

brenzbmr@sb wrote:actually just because your headunit puts out four volts doenst mean when
gets to your amp it will be four volts... to many variables

second having a line driver in front and a reciever in rear is a good idea and is not a new concept..pg did it back in 1988..it make alot of sence
also just because the line drivers "set" at a voltage doesnt mean your amp is recieving that voltage, to many variables involved.

Thas what a good DMM is for

flogger11 · Post by **flogger11** » Mon Jul 28, 2008 5:51 am

KHPower wrote:
brenzbmr@sb wrote:actually just because your headunit puts out four volts doenst mean when
gets to your amp it will be four volts... to many variables

second having a line driver in front and a reciever in rear is a good idea and is not a new concept..pg did it back in 1988..it make alot of sence
also just because the line drivers "set" at a voltage doesnt mean your amp is recieving that voltage, to many variables involved.
Thas what a good DMM is for

my thoughts exactly...

deathcloud · Post by **deathcloud** » Mon Jul 28, 2008 6:25 am

DMM? Come on dont use abriviations!

KHPower · Post by **KHPower** » Mon Jul 28, 2008 6:32 am

deathcloud wrote:DMM? Come on dont use abriviations!

Digital Multi Meter (DMM)

it is one of the most handy tools in car audio other thsn wire strippers . I have one that can measure frequency as well and is alot of help when tuning

Post by **stipud** » Mon Jul 28, 2008 6:55 am

If you install a linedriver to make your stereo louder -- you're doing it wrong. With your amp gains set correctly at 1 volt or at 8 volts, the stereo should be no louder than it was before. A 100 watt amp will make 100 watts with a 1 volt or 8 volt signal, as long as you set the gains correctly.

The point of a linedriver is noise rejection... Assume you have a 0.25 volt radiated static noise hitting your RCAs. At 1 volt, that 0.25 volt signal accounts for 25% of it's voltage, so you would have lots of noise. At 8 volts, that 0.25 volt signal accounts for 3%. 3% noise is much lower than 25%!

Also, Fuzzy and Brenz are correct... if you have an amp like an original MS series, they were only built for 2 volt input. However, that does not mean you have to limit your linedriver to 2 volts... otherwise, you're not getting as much noise rejection as possible. You can use a driver to increase the voltage up front, and then right before your amp you can drop it back down to 2 volts. This way any noise that hits your RCAs between the transmitter and receiver has very little effect.

PG's TBA (the balancing act) is a great example of this. Not only does it boost the signal voltage to well beyond the MS amp's input capabilities, but it also runs a balanced signal (which the MS can't support either). Balanced means you run the inverse of the positive signal along with it. So, any noise will radiate to both the positive and inverse signal. However, at the receiver end, it flips the inverse signal back around, thereby creating a negative image of the noise added to the line. Finally, the two signals are added together, and the inverse and positive noise cancels itself out. This way, you don't just get the added noise rejection from the higher voltage, but you also get noise rejection from the balanced line as well... even though you only end up with a single-ended 2 volt input into your MS amps.

dwnrodeo · Post by **dwnrodeo** » Mon Jul 28, 2008 7:23 am

I noticed that my Phoenix Gold equipment is listed that it can only handle 2 volts of input signal, so will it be okay to use my PLD1 to drive 8 volts of signal to my amp or processor?

Since music is dynamic with peaks and valleys that allows a lot more leeway with input signal voltage. Music is not like a test tone (which is normally used to test equipment), so in reality any Phoenix Gold equipment will accept 8 volts of signal. So if it says Phoenix Gold it will handle 8 volts of signal, no problem.

I copied this from the PG webFAQ found in the Manuals and Info sticky.
It states that sending 8 volts to MS or any PG amp is O.K.

denim · Post by **denim** » Mon Jul 28, 2008 7:53 am

I prefer to use them due to long runs of RCA's or backing the gains down on the amplifiers.

Post by **stipud** » Mon Jul 28, 2008 7:55 am

You know, I've always been skeptical about that. If you built a voltage divider circuit to drop your 8 volt to a 2 volt signal, then sure... but playing 8 volt dynamic music with a long bass hit could clip and fry an amp set at 2 volt gains. I know they are stating that the headroom on dynamic music (recorded with higher dynamic range, unlike today's music) would easily be absorbed even with 8 volt gains, but if you listen to rap or anything like that, it would definitely do some damage.

Please weigh in on using line driver

Please weigh in on using line driver

item very good yes!!!lol