RCA voltage knobs (potentiometers).

I wanted to make sure I was clear on something. I tried something, and I think this was a MUCH better way to do it. Just wanted to make sure I had the numbers and theory right.

SETUP: I recently finished my amp rack, and new setup. I think I am going to downgrade from this, but this was me wanting to go all out. This is in a regular cab, with the seats as far back as they can go.
Here it is: This is all I got.
head unit.jpg


My stereo 2.0.jpg


.
and
Here it is:
MOUNTED FINALLY PS.jpg

MOUNTED FINALLY.jpg


The wires have since been cleaned up, and the third 12" is in there. I had to work my tail off to finish it before a long drive, and I'm still recovering, (and too lazy to get the last pictures).

I have the
DS18 amp set at 82w each on some 4" JL mids in the rear,
Alpine PDX f6 - pushing 2 sets, (currently one set) of JL ZR components.
Orion amp pushing 3 12" solobaric kicker subs. (When I first started using these FRYS sold the round loaded enclosures for $59 or $79, and it was cheaper than the sub alone. I added a square, then two more. They are currently dropped down to just over 400w each, and will be 600w now that I have a fuse big enough, and have been breaking em in.

The one set of JL ZRs and mids are ear damaging loud, and I think I'm going to pull a set out, change the amp, probably do a new rack, and then the door panels can be stock, and it will be completely hidden, (which was a main goal).


I pulled this out of a durango and modified it to fit, (really liking this cupholder vs nothing).
durango cupholder installed..jpg

OKAY ON TO THE QUESTION PART:
What you will notice is the two knobs right there, (that are hidden when I sit down). The back one is for the orion sub amp, and instead of having the rear speakers on the rear channel off the head unit, I used splitters coming off the front knob and then have it going to both amps.


So when I checked my head unit with my DMM I get 4.0V at 34 (which is max rating) and 4.4V at 35 (max volume). THIS WAY, I leave my head unit on 34, and it is always sending out max voltage, instead of my amp always working at it's max. I adjust volume with the knobs, (no problem). When volume is maxed out, this changes nothing. When it's not maxed, I'm only maxing out the signal from the head unit, (AND WOULD THIS BE RIGHT), the amp's aren't working as hard. Instead of the amp maxing out the signal it's given, the signal is maxed out, and the amp is only working as hard as it needs to.
(My 3 amps are being controlled by two potentiometers. Head unit stays at or close to max, and I'm controlling the volume from those two knobs. One on the subs, and one for the mids and tweeters. It also lets me adjust them independently so that I can have maxed out bass, with as much to no volume at all. Even at low volumes I get full bass this way, (which is enough of a reason for me to do this)).


I recently was out with my windows down, listening all day, in 118 degree heat at or near max volume, and my amps were barely warm (compared to my fosgate amp). Amp heat was no problem. I'M THINKING adding this $10 potentiometer, should dramatically increase the lifespan on the amp, THE WAY I'M QUESTIONING IT, I THINK it doesn't work as hard. Therefore it also doesn't get as hot.


Am I missing something? Does anyone else do it this way?
 
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Am I missing something? Does anyone else do it this way?
Seeing as technique is called gain matching, the amp will work the same when the gain is set to the source's output voltage of 6v to 0.2v.
When setting gain, you start at the least sensitive setting of 6v (a full blocking of the radio's 6v output). You then raise the sensitivity by sweeping towards 0.2v, letting the radio's voltage flow by the potentiometer (gate) because it can now block less voltage that the radio is putting out.
So the amplifier stage will work the same from different signal input voltages. As long as the output power rating set by the manufacturer is not surpassed, the amp will work fine without overheating.
BTW, nice setup. It looks imposing.
 
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Thank you. It's been a long process learning how to go from functionally acceptable to something I really enjoy having. The first time I tried to use acrylic and that was a failure, but it looked fantastic (like a black mirror). The clear is plexiglass and gives that floating look. So far it's working well. I hope it holds up when I finally give it full bass.

Seeing as technique is called gain matching, the amp will work the same when the gain is set to the source's output voltage of 6v to 0.2v.
When setting gain, you start at the least sensitive setting of 6v (a full blocking of the radio's 6v output). You then raise the sensitivity by sweeping towards 0.2v, letting the radio's voltage flow by the potentiometer (gate) because it can now block less voltage that the radio is putting out.
So the amplifier stage will work the same from different signal input voltages. As long as the output power rating set by the manufacturer is not surpassed, the amp will work fine without overheating.
BTW, nice setup. It looks imposing.
So the amp is doing the exact same whether or not I took that potentiometer out of the signal's path. All I'm doing is essentially sending it out from the head unit at full voltage, then blocking some of that voltage on the way to the amp?

So I'm not helping the amp in any way, and now I'm pushing the head unit harder? (which isn't a benefit, but it's not a concern either), and the only benefit of doing this is having independent control of subs vs mids and highs (which is still good enough for me, it just knocks me off that horse I was looking down at all of you little ants from)?
 
Thank you. It's been a long process learning how to go from functionally acceptable to something I really enjoy having. The first time I tried to use acrylic and that was a failure, but it looked fantastic (like a black mirror). The clear is plexiglass and gives that floating look. So far it's working well. I hope it holds up when I finally give it full bass.


So the amp is doing the exact same whether or not I took that potentiometer out of the signal's path. All I'm doing is essentially sending it out from the head unit at full voltage, then blocking some of that voltage on the way to the amp?

So I'm not helping the amp in any way, and now I'm pushing the head unit harder? (which isn't a benefit, but it's not a concern either), and the only benefit of doing this is having independent control of subs vs mids and highs (which is still good enough for me, it just knocks me off that horse I was looking down at all of you little ants from)?
Your HU is designed to be used in such a manner, however it may be harder on the outputs. Id rather my HU or pre amp/processor work harder than my amps. Like you are doing. Add in a hi voltage preamp between your HU and amps, a quality one, and youll notice even more of amps being happier, more output with lower gain setting, to an extent.
 
I have a ridiculous looking box of potentiometers to do the same thing. It is helpful to know the input impedance on the amplifier so you can get get the correct pot. I think it’s best to use a pot that is close to 1/2 the input impedance of the amp, so you don’t get that situation where the potentiometer only audibly works on half the sweep and rapidly changes volume on the other half.
 
I'm using these, and "the sweep" seems to be smooth and accurate whether or not I change it slow or fast. (Other than that not sure how to describe it).
Amazon product ASIN B003FPD3IS
My mind has trouble some times now. I was thinking It was effecting voltage at/after the amp. I know that's not possible. Not sure how I got there, but thanks for helping me figure that one out.

I have a ridiculous looking box of potentiometers to do the same thing. It is helpful to know the input impedance on the amplifier so you can get get the correct pot. I think it’s best to use a pot that is close to 1/2 the input impedance of the amp, so you don’t get that situation where the potentiometer only audibly works on half the sweep and rapidly changes volume on the other half.
How would impedance (which is on the output), effect the signal input?
 
I'm using these, and "the sweep" seems to be smooth and accurate whether or not I change it slow or fast. (Other than that not sure how to describe it).
Amazon product ASIN B003FPD3IS
My mind has trouble some times now. I was thinking It was effecting voltage at/after the amp. I know that's not possible. Not sure how I got there, but thanks for helping me figure that one out.


How would impedance (which is on the output), effect the signal input?
ahh. I see. I thought you were buying raw potentiometers like these.
 
ahh. I see. I thought you were buying raw potentiometers like these.
I had forgotten about parts-express. Been a while since I bought from there. No, I went lazy with it, and just broke the casing off em.
 
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