Newbie Gain Question: Please don't be mad, I searched

[eharri3 10+ year member]

Im new to the forums. The vehicle is an 04 Dodge Dakota Crew Cab. The system is a mishmosh of brand names as I've changed and added things when the impulse has hit me and when cash has been available.

At this time it consists of:

Eclipse SC 8632 components in front.

Infinity Reference Coaxials in the rear.

Alpine CDA 9883 with 2 volt pre outs.

Eclipse EA4200 to run the door speakers.

Pioneer Premier 10 inch shallow mount in too small of a box (It was the best the shop could do for the space I wanted it in.)

The most recent change was replacing an MTX 704X 4 channel (too big and only OK sound quality) with the new Eclipse 4 channel. The install was perfect and I thought the tuning was perfect too until I realized they tuned the amp with the loudness on, which I don't want because I'm trying to get into the habit of getting the sound I want out of a quality recording with everything flat. I had it on when I took it in and they must not have known when they tuned it.

As it was, the the volume with everything flat could go up to maybe 2-3 clicks short of max, maybe 32-33 out of 35, with zero audible distortion, giving me the impression that I'm not getting everything out of the amp that I could be now. Without loudness on, everything sounded WAY too quiet. I have played with it and it now sounds better with all settings at zero and the loudness off but I had a question about my gain dial.

The last three amps I have had have been set up the same way: The sensitivity is lowest and the volume of the stereo is lowest with the dial all the way to the left, on 7 or 8 volts. Sensitivity increases and volume of the music at a given head unit volume increases as I turn the gain dial to the right. So for instance right now my front and rear gains are adjusted to right about 6 volts on the dial and this is where everything seems to sound OK. Any higher and distortion comes to low. Any lower and I loose some output. I just don't get the logic of how the numbers are set up and I haven't found this dumbed down sufficiently enough for me to understand anywhere because it conflicts with what you hear about 2 volts being about right for a 2 volt HU, 4 volts for a 4 volt HU, etc...

If I take the markings literally it means that all of the last three amps have had to be tuned to between 6 and 7 volts to sound OK with a 2 volt head unit. I don't get it.

Am I corret in assuming that if I adjust the input sensitivity upward by turning the dial cockwise, when the dial goes from the 8 to the 6, the amplifier gains have actually been adjusted to about 2? Again, I think I understand the basic principals of adjusting gain and why it's important, I'm just confused about how the actual level relates to the markings on that dial.

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[dman4486 5,000+ posts]

Im new to the forums. The vehicle is an 04 Dodge Dakota Crew Cab. The system is a mishmosh of brand names as I've changed and added things when the impulse has hit me and when cash has been available.
At this time it consists of:

Eclipse SC 8632 components in front.

Infinity Reference Coaxials in the rear.

Alpine CDA 9883 with 2 volt pre outs.

Eclipse EA4200 to run the door speakers.

Pioneer Premier 10 inch shallow mount in too small of a box (It was the best the shop could do for the space I wanted it in.)

The most recent change was replacing an MTX 704X 4 channel (too big and only OK sound quality) with the new Eclipse 4 channel. The install was perfect and I thought the tuning was perfect too until I realized they tuned the amp with the loudness on, which I don't want because I'm trying to get into the habit of getting the sound I want out of a quality recording with everything flat. I had it on when I took it in and they must not have known when they tuned it.

As it was, the the volume with everything flat could go up to maybe 2-3 clicks short of max, maybe 32-33 out of 35, with zero audible distortion, giving me the impression that I'm not getting everything out of the amp that I could be now. Without loudness on, everything sounded WAY too quiet. I have played with it and it now sounds better with all settings at zero and the loudness off but I had a question about my gain dial.

The last three amps I have had have been set up the same way: The sensitivity is lowest and the volume of the stereo is lowest with the dial all the way to the left, on 7 or 8 volts. Sensitivity increases and volume of the music at a given head unit volume increases as I turn the gain dial to the right. So for instance right now my front and rear gains are adjusted to right about 6 volts on the dial and this is where everything seems to sound OK. Any higher and distortion comes to low. Any lower and I loose some output. I just don't get the logic of how the numbers are set up and I haven't found this dumbed down sufficiently enough for me to understand anywhere because it conflicts with what you hear about 2 volts being about right for a 2 volt HU, 4 volts for a 4 volt HU, etc...

If I take the markings literally it means that all of the last three amps have had to be tuned to between 6 and 7 volts to sound OK with a 2 volt head unit. I don't get it.

Am I corret in assuming that if I adjust the input sensitivity upward by turning the dial cockwise, when the dial goes from the 8 to the 6, the amplifier gains have actually been adjusted to about 2? Again, I think I understand the basic principals of adjusting gain and why it's important, I'm just confused about how the actual level relates to the markings on that dial.

the markings on the dial are voltage markings....they should go from high to low clockwise around the knob

gains are used to match the hu's output voltage, and the numbers on the dial theoretically should match hu's voltage ie. 2v hu then gains should be set at 2v

the problem with this is that when a hu is labeled as 2v, it may not ever actually put out 2v! set gain with a Dmm to get a desired wattage. This removes all doubt

 

[GabeC 10+ year member]

use search button noob

 

[Macklessdaddy 10+ year member]

use search button noob

Didn't you read the title of the thread AssJack

 

[eharri3 10+ year member]

No biggie, I now how people are here. Not alot of patience. That's OK, just remember, I think this place wouldn't be so fun if there weren't a such a broad range of levels of car audio experience here so you guys should keep that in mind when you reply.

As embarassing as this is, I re-read the manual and messed with the dial again and I feel very stupid to say, I was looking at the wrong edge of the dial and it is as someone else explained. Now last stupid question, I swear: I started back where they had it set then budged the gain just a tiny notch counterclockwise to compensate for the loudness being off, logic being, before with it on I had a lower distortion point at the head unit because the emphasized frequencies started to distort before the unboosted ones. Now that everything goes to distortion at the same time, I have a slightly higher volume limit at the head unit which means if I should decrease the unput sensitivity on the amp to match it.

Also: They set the gain lower on the rears than on the fronts. I'm not sure if it's because the rears are lower quality speakers or because they wanted to emphasize the front stage. Do people here normally set the rear and front channels the same or is it common for there to be such a big difference? I made it as equal as I could and then controlled the emphasis with the fader instead. The way it's installed, whole front bench seat would have to be removed if I wanted to get at it with a voltmeter or anything to look for that precise 15.5 volts at the speaker output so that's not happening, I'm just looking for opinions on whether I generally did the right thing to compensate for the adjustment I made at the head unit.

 

[dman4486 5,000+ posts]

No biggie, I now how people are here. Not alot of patience. That's OK, just remember, I think this place wouldn't be so fun if there weren't a such a broad range of levels of car audio experience here so you guys should keep that in mind when you reply.
As embarassing as this is, I re-read the manual and messed with the dial again and I feel very stupid to say, I was looking at the wrong edge of the dial and it is as someone else explained. Now last stupid question, I swear: I started back where they had it set then budged the gain just a tiny notch counterclockwise to compensate for the loudness being off, logic being, before with it on I had a lower distortion point at the head unit because the emphasized frequencies started to distort before the unboosted ones. Now that everything goes to distortion at the same time, I have a slightly higher volume limit at the head unit which means if I should decrease the unput sensitivity on the amp to match it.

Also: They set the gain lower on the rears than on the fronts. I'm not sure if it's because the rears are lower quality speakers or because they wanted to emphasize the front stage. Do people here normally set the rear and front channels the same or is it common for there to be such a big difference? I made it as equal as I could and then controlled the emphasis with the fader instead.

setting the gain lower on the rear is the same as mine having an amp for the front but not the rear....rear fill does not sound good to me, so I only turn the rear speakers on when I have passengers

 

[eharri3 10+ year member]

That's what everybody says, and mine is usually faded almost all the way to the front. But every shop I've been to, from BB, CC, to higher-end places that are supposed to be a notch above, they look at me like a wierdo because I'm making almost no use of the rear speakers.

 

[dman4486 5,000+ posts]

That's what everybody says, and mine is usually faded almost all the way to the front. But every shop I've been to they look at me like a wierdo because I'm making almost no use of the rear speakers.

don't worry about what they say, do what sounds good to you!!

 

[eharri3 10+ year member]

In case anyone cares: I read up a bit. I was familiar with the concept of using test tunes but never realized how audibly the done changes when you start to distort. I downloaded a 1K hz one from the net, popped it in the CD player.

With the gains all the way down, treble and bass flat, balance and fade flat, loudness off, and sub turned off, I popped the CD then turned the head unit up until the tone changed, which happened at 30, so I backed off one click to 29. Then keepign that on I adjusted the front gains until the tone changed, backed off until it stopped. Then did the same with the rear. Music now sounds good to 29 instead of 24 or 25, which definitely helps with some of the lower volume, poor quality blues recordings I have. The background hiss is nonexistent on the CDs and very low on the IPOD music, though I dont' think I'll ever get rid of that. (A whole nother story: Some CDs I download onto the IPOD have hiss, anything I download directly from I tunes sounds perfect.)

I wont' be ripping the seats up to get to the outputs and doing anything with a voltmeter and I don't have the time or motivation to try to track down and then learn to properly use an oscilli-whatever it is but this seems to have gotten everything to sounding as good just about as good I could hope. And MUCH easier listening for an audible change in the beeping sound than trying to hear it in music, where you're more likely pass that point before you know you're there.

The head unit's rated at two volts and... funny coincidence... both gain dials ended up centered almost exactly at the two volt notch after I did this. Not too far from where I put them before, but the front was quite a bit lower and the rear quite a bit higher than where the stereo shop put them. After seeing a Best Buy and a Circuit City tune amps for me by blasting music, then getting it back and finding this independent shop really didn't seem to be right on the money, it seems like the shops that break out all the fancy gizmos and doodads and measure things are few and far between. It doesn't even seem like the ones I've been to so far even use test tunes. I think I'll have to check their work more often from here on in. I know I'm still not an expert but it seems easy now to tell the difference between close and way off.

 

[drpeeb 10+ year member]

That's what everybody says, and mine is usually faded almost all the way to the front. But every shop I've been to, from BB, CC, to higher-end places that are supposed to be a notch above, they look at me like a wierdo because I'm making almost no use of the rear speakers.

You would absolutely puke in my Titan then ... speakers only in the back!!!

(right now anyway)

 

[cj407]

wow...way to bring up an old thread noob......only to put a retarded comment in it.