# when to use a line driver?



## DonutHands (Jan 27, 2006)

i think i may be in a position where i need one.


----------



## 02bluesuperroo (Oct 31, 2006)

I think any system where you are not already inputing the max voltage for the amps can benefit from a LD.


----------



## DonutHands (Jan 27, 2006)

its beginning to look like i can not get to an adequate listening level without severe distortion


----------



## foley316 (Aug 26, 2005)

I don't think a line driver will help that situation. The gains on an amp are level matching. Therefore, if your input is extremely low and the gain is all the way up, if you're not higher on the gain than the input, theoretically you should'nt be clipping. Either the drivers you use cannot handle the power you are giving or you are clipping the amp in an effort to get more power from it than it can provide. The amp has a rated output that will never change just because you throw more input voltage at it.


----------



## 02bluesuperroo (Oct 31, 2006)

Can you describe your setup?


----------



## DonutHands (Jan 27, 2006)

stock HU (it has line out rcas) --> 
crossover/EQ (pioneer cd-1000) --> 
amps (aura 2300 and 4200) --> 
speakers (lpg25nfa - rs52 - silverflute6.5[x2] )


----------



## WLDock (Sep 27, 2005)

I seriously doubt the stock head unit has a strong signal out...A line driver here is a good start.

Line Drivers:
Navone Engineering /Autosound 2000
http://www.davidnavone.com/linedrivers.htm
On ebay:
PHOENIX GOLD SLD22 (search SLD-22 also)
PHOENIX GOLD SLD44 (SLD-44)
PHOENIX GOLD TANTRUM TLD22 (TLD-22)
PHOENIX GOLD TANTRUM TLD66 (6 ch)
PHOENIX GOLD PLD1
AUDIO CONTROL OVERDRIVE
AUDIO CONTROL MATRIX 6 CH 
PAC TURBO 1

I guess I really need to ask how much voltage can your CD-1000 crossover input and what is the max output voltage? Also, how much voltage out of the head unit? Play some pink noise and measure the AC output.


----------



## Melodic Acoustic (Oct 10, 2005)

Add the Audio Control MVC (Master Volume Control) to that list. This is one of the best product audio ever made.


----------



## DonutHands (Jan 27, 2006)

i dont have specs on the CD-1000 and i cant find specs anywhere.


----------



## WLDock (Sep 27, 2005)

internecine said:


> i dont have specs on the CD-1000 and i cant find specs anywhere.


Play some pink noise and measure the AC output at about 3/4 volume max


----------



## chad (Jun 30, 2005)

WLDock said:


> Play some pink noise and measure the AC output at about 3/4 volume max


Have you ever measured pink noise with an AC voltmeter? What was the meter weighting?

Chad


----------



## 02bluesuperroo (Oct 31, 2006)

Here-I-Come said:


> Add the Audio Control MVC (Master Volume Control) to that list. This is one of the best product audio ever made.


Hmmmmmm, shameless plug much?  

http://cgi.ebay.com/Audio-Control-M...ryZ79842QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


----------



## DonutHands (Jan 27, 2006)

so i was thinking, i could play pink noise or any tone and measure the voltage of the RCAs straight out of the HU, then go through the CD-1000 and measure again with the same tone. then adjust the input level on the CD-1000 until it matches the voltage of the RCAs before the CD-1000 was introuduced.

if this sounds good i will try it out. but i also have out put levels that go from negative infinity to zero on each output of the crossover, what should those be set at while im testing this out?

this will be my last attempt at setting gains before i know i need to change somthing out.


----------



## WLDock (Sep 27, 2005)

chad said:


> Have you ever measured pink noise with an AC voltmeter? What was the meter weighting?
> Chad


No not SPL, just talking about using Pink Noise as a souce of equal energy at all frequecies so that the output at the deck can be measured with a multi-meter. Could use a 1KHz tone or just some dynamic music.


----------



## HIS4 (Oct 6, 2005)

internecine said:


> so i was thinking, i could play pink noise or any tone and measure the voltage of the RCAs straight out of the HU, then go through the CD-1000 and measure again with the same tone. then adjust the input level on the CD-1000 until it matches the voltage of the RCAs before the CD-1000 was introuduced.
> 
> if this sounds good i will try it out. but i also have out put levels that go from negative infinity to zero on each output of the crossover, what should those be set at while im testing this out?
> 
> this will be my last attempt at setting gains before i know i need to change somthing out.


Do you really want to have no gain across the CD-1000. I would think you would want the output after the CD-1000 to be slightly higher than the output after the head unit. You should adjust the input gain of the CD-1000 such that the output is high enough to drive your amps to full output without clipping the signal. You should start with your amp gains set low and then turn up the input gain of the CD-1000 until you have reached the point where you have the highest unclipped signal. Then you can adjust the gain of your amps accordingly.


----------



## Peter_Euro (Oct 25, 2006)

internecine said:


> i dont have specs on the CD-1000 and i cant find specs anywhere.


 2 volts in and out, if line outputs on your HU are fully functional, you should not need a line driver. If your HU signal is less than 2 volts, you can bring it up using input sensitivity adjustment on CD1000.


----------



## HIS4 (Oct 6, 2005)

HIS4 said:


> Do you really want to have no gain across the CD-1000. I would think you would want the output after the CD-1000 to be slightly higher than the output after the head unit. You should adjust the input gain of the CD-1000 such that the output is high enough to drive your amps to full output without clipping the signal. You should start with your amp gains set low and then turn up the input gain of the CD-1000 until you have reached the point where you have the highest unclipped signal. Then you can adjust the gain of your amps accordingly.


Damn....nevermind, I didn't read that you had output level controls for the CD-1000 too. In any case, you can adjust the gains in a similar fashion. Start with everything set to minimum. Then start turning them up from the one closest to the head unit until you get all the way to the amps. Of course, making sure each time that the adjustment doesn't result in a clipped signal.


----------



## DonutHands (Jan 27, 2006)

blowup - do you have a cd-1000? or a manual for it?

HIS4 - I need to play with it more, but it appears that the signal begins to clip with the input setting on the cd-1000 set to minimum. at minimum input on the cd-1000 and max gain on the amps, its not loud enough to overcome roadnoise at freeway speeds.


----------



## HIS4 (Oct 6, 2005)

internecine said:


> HIS4 - I need to play with it more, but it appears that the signal begins to clip with the input setting on the cd-1000 set to minimum. at minimum input on the cd-1000 and max gain on the amps, its not loud enough to overcome roadnoise at freeway speeds.


What is the volume setting of the head unit when you take this measurement? Can you go to about 3/4 of max on the head unit and then turn up the input gain a little. Then try to compensate by turning up the output gain of the CD-1000 to get acceptable output without clipping the signal.


----------



## DonutHands (Jan 27, 2006)

3/4 to max and it dosent get very loud at all. 

ill try that out. but it starts to clip pretty quickly. theres even a clipping light on the cd-1000, which begins to light up as soon as i start increasing the input gain.


----------



## Peter_Euro (Oct 25, 2006)

internecine said:


> blowup - do you have a cd-1000? or a manual for it?
> 
> HIS4 - I need to play with it more, but it appears that the signal begins to clip with the input setting on the cd-1000 set to minimum. at minimum input on the cd-1000 and max gain on the amps, its not loud enough to overcome roadnoise at freeway speeds.


I may have one somewhere but I have used this piece before and still remember... It may be you do not have enough power if you optimize the gains on the amps...


----------



## HIS4 (Oct 6, 2005)

internecine said:


> 3/4 to max and it dosent get very loud at all.
> 
> ill try that out. but it starts to clip pretty quickly. theres even a clipping light on the cd-1000, which begins to light up as soon as i start increasing the input gain.


You have Symphony HU from a B5 right? Where did you tap the low level signal? Are you using any line output converters or did you tap the output directly in the harness?


----------



## DonutHands (Jan 27, 2006)

yea, symphony HU. Im using the blaupunkt adapter.

i think i have enough power to get this system going at a decent listening level.


----------



## HIS4 (Oct 6, 2005)

internecine said:


> yea, symphony HU. Im using the blaupunkt adapter.
> 
> i think i have enough power to get this system going at a decent listening level.


Okay, try this. Connect the output of the head unit directly to the amp. Remember to turn the gains down on the amp. Can you turn up the volume on the head unit without clipping the signal? It may not be as loud as you want but at least it's a starting point and it tells you two things:

1. The output of the head unit is okay and can reach a decent level without clipping.

2. The amp is working and not clipping the signal on it's own.

If it sounds okay without the CD-1000, then try putting the CD-1000 back in. Now you just need to play with the input and output gains on the CD-1000. If you cannot get an unclipped signal with both the input and output gains on the CD-1000 at minimum after your test without the CD-1000 was okay then something is wrong with your CD-1000.


----------



## legend94 (Mar 15, 2006)

when to use a line driver?

when you have an adcom amp


----------



## Melodic Acoustic (Oct 10, 2005)

02bluesuperroo said:


> Hmmmmmm, shameless plug much?
> 
> http://cgi.ebay.com/Audio-Control-M...ryZ79842QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


Man, you didn't have to put me out there like that.  , But did it work. It has been sold.

I just did not need 3 of them anymore, so I put one up for sale.


----------



## DonutHands (Jan 27, 2006)

gains on the amps are maxed, output levels on the cd-1000 are maxed and the input level on the cd-1000 is up as far as i can get it without clipping. gets louder, but not as loud as i had hoped it would, can still carry a conversation without raaising your voice too much. hell, my old kicker component set got much louder. 

i played pink noise and measured the rcas off the deck at max volume and it read .4 volts.

i dont know, this sucks.


----------



## DonutHands (Jan 27, 2006)

one other thing. 

so i measured .4 volts from the rcas coming out of the HU while playing pink noise. i then measured the rca after coming through the cd-1000 and got nothing on my meter. now the meter does not have the best resolution, but it will do tenths of a volt.

so whats up with that? i spun the input level all the way around and it made no difference. i still get audio out of the thing, but no measureable voltage.

the way i measured was neg probe to the chassis ground positive to the center pole of the RCA


----------



## chad (Jun 30, 2005)

internecine said:


> one other thing.
> 
> so i measured .4 volts from the rcas coming out of the HU while playing pink noise. i then measured the rca after coming through the cd-1000 and got nothing on my meter. now the meter does not have the best resolution, but it will do tenths of a volt.
> 
> ...


It's VERY difficult to measure the voltage of pink noise, AND it's not 100% duty cycle. It's noise.

Chad


----------



## DonutHands (Jan 27, 2006)

really? i will try again with a tone tonight, but when i did it off the HU rcas it measured ~.4 volts easily. i had a CD with multiple 1min tracks of pink noise. when the noise was playing i got .4, when inbetween tracks it read 0.0

soooo, i guess i will try again with a 0db tone tonight.


----------



## chad (Jun 30, 2005)

Do you have the gain of the least efficient passband cranked all the way up?


----------



## DonutHands (Jan 27, 2006)

not sure i fi know exactly what you mean.

but i had the level knob (gain?) of the band i was metering. this happend to be the mid range from 300-7k

so i think you are saying i should try again with either the midbass or sub channel? somthing like a 50-100hz tone


----------



## chad (Jun 30, 2005)

Well, we know that in order to balance the system out the gains for each passband will be set differently. For example the sub is usually the least efficient, and before the handwavers arrive, I know this can change.

So if it won't get loud enough and the sub is least efficient is the gain on that amp cranked? If so you have a possible issue, if it's not cranked then turn it up.

I've seen a lot of people complain that it won't get loud enough but they have the gains backed way down... Well... No **** sherlock 

In other words, put the meter away for now, volts ain't gonna say a thing at this pont, especially with pink noise and tones are only going to give you a 100% duty cycle reference which will never happen with music. 

Chad


----------



## DonutHands (Jan 27, 2006)

well, i do not have my sub right now as its not as important to me as getting the rest of the system going. although it is a DIYMA 12, just need to pick up a small box for it.

the whole thing with the meter was to find out if my components are at least working right. which concerned me when i would read voltage off the HU but not off the crossover.

as i have it set now i have the output on the crossover 5/6 of the way, the gains on the amp 5/6 up and the input on the crossover is as far as it will go without clipping, this clipping is most noticeable in the midbass. the midbass is only playing from ~100-800hz right now


----------



## dodgerblue (Jul 14, 2005)

not much for info in my books on the cd-1000, it was man. between 92-93 - looks disc. in 94 , unf. no ref. to input or output voltage  , crazy though that unit in 92 rtled for 1200.00


----------



## Peter_Euro (Oct 25, 2006)

internecine said:


> well, i do not have my sub right now as its not as important to me as getting the rest of the system going. although it is a DIYMA 12, just need to pick up a small box for it.
> 
> the whole thing with the meter was to find out if my components are at least working right. which concerned me when i would read voltage off the HU but not off the crossover.
> 
> as i have it set now i have the output on the crossover 5/6 of the way, the gains on the amp 5/6 up and the input on the crossover is as far as it will go without clipping, this clipping is most noticeable in the midbass. the midbass is only playing from ~100-800hz right now


are you using a true RMS meter to take the readings? You should use test tones with single freq to measure the voltage too...


----------



## chad (Jun 30, 2005)

The question arises... What is unity gain for the crossover outputs? Knobs pinned? Don't be afraid to crank the crossover outputs and amp inputs. If you have noise from improper gain structure then it can be dealt with later. Remember you are missing the most likely least efficient part of your system, the problems may compound.

Also, is the level low with the headunit pinned? Or is it say, not loud enough when you THINK it should start getting loud relative to the position of the volume control. Remember there are linear taper and audio taper arrangements, many new decks use a linear taper adn won't make full output till cranked balls out with the tone controls jacked up.

Keep the meter out of the equation now, it's only going to confuse the situation more, especially not knowing the model, make, or frequency response of the meter.

Chad


----------



## DonutHands (Jan 27, 2006)

on the meter, its just a cheap craftsman i was using to measure line out voltage. not to get concrete numbers, just to make sure things were working. but i will put that away now.

ive been doing all this with the bass mid and treble on the HU in the dead center. which i realize now that you have mentioned it, those should be all the way up. but then i will have to bring down the input level on the cd-1000 or else clipping does occur.


----------



## chad (Jun 30, 2005)

internecine said:


> on the meter, its just a cheap craftsman i was using to measure line out voltage. not to get concrete numbers, just to make sure things were working. but i will put that away now.
> 
> ive been doing all this with the bass mid and treble on the HU in the dead center. which i realize now that you have mentioned it, those should be all the way up. but then i will have to bring down the input level on the cd-1000 or else clipping does occur.


Is that crossover OK? Have you tested it outside the car? It seems that ALL of this hubbub is over clip lights coming on. And you say you aren't hitting the crossover hard and getting it to clip while it's not putting out enough output? And nobody can find cold hard specs on it?

Chad


----------



## DonutHands (Jan 27, 2006)

i base the clipping on when i hear it clip more than the light. the mid bass will pop if i turn the input level up to high on the crossover.

like didgerblue said, was made in 1992 and sold for $1200. i dont think many people bought this thing. ive searched the net and searched pioneers website. it could be quite the piece of equipment if i can get it working for me.


----------



## chad (Jun 30, 2005)

My midbasses pop when I turn the gain up too high too, if the crossover point is set too low and/or the slope is not steep enough. There is no box there to control the excursion remember.

Electrical clipping does not generally sound like a pop.

Chad


----------



## DonutHands (Jan 27, 2006)

maybe im describing it wrong. crossover is 18db @ ~100hz


----------



## chad (Jun 30, 2005)

The popping is most likely the driver bottoming out or the PS in the crossover collapsing.

OK, What do the midbasses do WITHOUT the crossover? Do they get loud enough? Can you put a HPF on them at the head unit?

Edit... ARRGGGHH what is the stock head unit? is there EQ on the headunit put on from the factory? What kind of LOC? Does the LOC ground or common ANYTHING? Do you have access to a junker headunit with line outs to test the rig with?


Chad


----------



## DonutHands (Jan 27, 2006)

first off, Chad, thank you for helping me out with this. I would be at a complete loss without this place.

Stock HU has a adapter that fits the pin out on the back of the HU. This replaces the connection that goes to the amps for the stock bose speakers. The line outs are grounded within the HU.


----------



## HIS4 (Oct 6, 2005)

internecine said:


> first off, Chad, thank you for helping me out with this. I would be at a complete loss without this place.
> 
> Stock HU has a adapter that fits the pin out on the back of the HU. This replaces the connection that goes to the amps for the stock bose speakers. The line outs are grounded within the HU.


Did you "De-bose" the system. I wasn't aware that you had Bose. If you don't know how to do it, go back to Audiworld and ask on the Audio forum. It has something to do with a wire being grounded. The guy to ask is avincar.


----------



## DonutHands (Jan 27, 2006)

well, i would check it out, but audiworld is down, argh.


----------



## chad (Jun 30, 2005)

Yeeaaahhhhhh, there's an electrical issue here..... AND... AND... AND... Bose is no stranger to the use of Uber Radical EQ to get things to sound er, um, the way they think they should. Is that EQ in the amps or the head unit? Regardless, I'll bet you a beer the end result is not flat on their system. It's just a matter of where it becomes Un-Flat 

Chad


----------

