[ShoTme]

I know there are many seasoned audio experts on this forum and I'm hoping to get some input here, no pun intended.

Basically, I have an audio control LC6i and a 300/4v2 and 5001/v2 JL Slash series amp. The issue(s) are that over the last 10 months I've had 3 AMPS GO BAD. There was an odd issue about 4 months ago where the volume would just randomly fluctuate on both my sub and 4 channel amps and anytime I had a screw driver near my gains or anything medal near the gains on my amps, there would be a power increase. It was an odd issue but had something to do with the boards in my amps. Both were replaced under warranty. But now I am having an impedance issue on my 300/4v2 amp, where the low impedance light stays on all the time even with all rca's and speaker wires disconnected from the amp. I had the amp tested today and it is definitely defective. All lines were tested with a voltmeter and are perfectly fine.

In talking with the guy that did the install initially, he thinks it may of been that my audio control "gains" were set too high. Audio Control actually states the way to set the gains is by disconnecting the rca's and turn the gains to the point where the maximize light gets solid..and then go back a notch. When I followed that, my gains on my LC6i got to about 80% of the way before the maximize light became solid so I set the gains at 75%.

The guy that did the install counters what audio control says in terms of setting the LC6i gains, because my Slash series amps draw a lot of power, much more then a typical amp and as a result, the gains on the LC6i should be set LOWER, and if more juice is needed, then the amp gains should be set higher.

So with this being said, i'm confused and have two questions. 1) Could the LC6i gains of been set too high, (even though I followed audio control's method of setting their LC6i) causing 3 JL amps to go bad in less then a year? 2) I guess this depends on the answer to question 1, but as of right now, my gains on my LC6i are all set to about a quarter of the way, while my amp gains are set to about half way. Am I losing anything but having the LC6i gains set as low as they are when they could be set all the way to 3/4 of the way before any clipping occurs?

Thanks VERY MUCH in advance for any advice or suggestions on this.

 

[minbari]

when you say they are going bad. do they come back from repair with blown out inputs?(RCAs) if not, then that is not the issue. most inputs on amplifiers use op-amps (if not all of them) and they are pretty well protected against too high voltage. if will sound like ass, but still not hurt the amplifier.

do you know how much voltage the LC6i is putting out when you have your HU turned up 3/4 way?

 

[ShoTme]

@minbari,

thanks for the reply. No, it was deemed something wrong with the circuit board by JL, the circuit board got replaced by JL. There was nothing wrong with the outputs. My JL amps have a switch for low and high voltage. I believe the low voltage setting is for up to 4 volts and the high setting
I believe was for 4-9volts or something similiar.

The L6ci can output up to 9 volts, but that's assuming the gains on the LC6i are at or near the maximum setting. My gains right now on the LC6i are at 40%, so with my h/u at 3/4 of the way, the voltage output is probably right around 4-5 volts. I should also mention I never turn my head unit further then 3/4 of the way but do have it near or at 3/4 of the way probably half of the time.

So based on what you said with the amps protection, that likely wasn't the issue....i'd really like to know whether or not it would be recommended to have the gains on the LC6i set higher, and the amp gains set lower, or vice-versa?

 

[minbari]

that is a delicate balancing act, lol. you need to know how far you can set the LC6i without clipping it. then dont set it higher than that. for the most part, it you have the LC6i set to 40% and then match the gains on the amplifier for max power, or set the LC6i for 20%, then set the amp gains higher, it will sound nearly the same. (gains set too high on an amplifier will start picking up "hiss") if you have a DMM or o-scope then I would measure your LC6i output and then match your amplifier output.

as for the amplifiers being damaged. how big is the power wire you are using? are you loading them to max? (IE: low ohm loads on all channels) good grounds? do your headlights dim on bass hits? can you measure the voltage under heavy load? (both at the battery AND the amplifier) how much voltage do you lose?

 

[ShoTme]

minbari, thanks again for the reply. You are essentially saying the same thing audio control says in order to set the gains on the LC6i. I did exactly that when I got the LC6i. I took the RCA's out of both amps, put my head unit to 3/4 of the way, and slowly turned up each of the 3 channel gains on the LC6i. The result was that it had to get to around 75-80% before it clipped and the maximize light became solid. So I took it back a notch and had it set right at 70% before adjusting my amp gains. The shop I had the install done at said because my JL amps draw a lot of power as it is, I should have the LC6i gains set even lower, around 40-50%. When the gains were set lower, around 20-30%, you're absolutely correct, I had to turn my amp gains up even more to compensate and as a result, there was static present.

So just so I can have these set and not have to worry about it again...knowing that at 20-30% I have to set my amp gains to the point where the static has an effect...and 75% is where the LC6i shows clipping,... but 50% is where the LC6i gains can be set and the amp gains can be set to where I don't hear static and the volume output is fine for me. In my situation, is there any reason I should set the LC6i gains closer to the 70% and amp gains even lower, or leave my LC6i gains at 50%, amp gains set where they are (around 50%), and leave it as is?

I guess what i'm saying is that I can set the LC6i gains another 20% and reduce my amp gains to compensate and get the same volume output I have now. Is there any benefit either way?


Now as far as the amps....I had a suspicion it may be a result of something from the beginning but when you are able to respond to the settings issue...I'll mention what I think it may be and see what you think. As far as the wiring..I believe it is 100Amp, far more then I needed which I got just to be safe...and my lights did flicker initially..at least my dome lights did...I don't think my head lights ever did, but my dome lights did and I got a capacitor installed and there's been no flickering ever since.

 

[uvoo114]

I've own the 300/4 and 500/1 in my bimmer before and my 300/4 keeps on going into protect mode. I got it fixed a couple of times and the same thing kept on happening and I finally decide to check out the speakers then found out the my rear speaker connector hit the vehicle's chassis when driving. So even with everything disconnected the protect light was still on. I don't think the high voltage that your AC is feeding your amps is the cause because I've been using a LOC that gives out 4v and my Mac is only accepting 2v but I no problems what so ever. I am not an expert or anything and hope you can find out the problem. Goodluck

 

[minbari]

minbari, thanks again for the reply. You are essentially saying the same thing audio control says in order to set the gains on the LC6i. I did exactly that when I got the LC6i. I took the RCA's out of both amps, put my head unit to 3/4 of the way, and slowly turned up each of the 3 channel gains on the LC6i. The result was that it had to get to around 75-80% before it clipped and the maximize light became solid. So I took it back a notch and had it set right at 70% before adjusting my amp gains. The shop I had the install done at said because my JL amps draw a lot of power as it is, I should have the LC6i gains set even lower, around 40-50%. When the gains were set lower, around 20-30%, you're absolutely correct, I had to turn my amp gains up even more to compensate and as a result, there was static present.

So just so I can have these set and not have to worry about it again...knowing that at 20-30% I have to set my amp gains to the point where the static has an effect...and 75% is where the LC6i shows clipping,... but 50% is where the LC6i gains can be set and the amp gains can be set to where I don't hear static and the volume output is fine for me. In my situation, is there any reason I should set the LC6i gains closer to the 70% and amp gains even lower, or leave my LC6i gains at 50%, amp gains set where they are (around 50%), and leave it as is?

I guess what i'm saying is that I can set the LC6i gains another 20% and reduce my amp gains to compensate and get the same volume output I have now. Is there any benefit either way?


Now as far as the amps....I had a suspicion it may be a result of something from the beginning but when you are able to respond to the settings issue...I'll mention what I think it may be and see what you think. As far as the wiring..I believe it is 100Amp, far more then I needed which I got just to be safe...and my lights did flicker initially..at least my dome lights did...I don't think my head lights ever did, but my dome lights did and I got a capacitor installed and there's been no flickering ever since.

either way will work and there is no benefit one way or the other. if the LC6i can be set for 60% or so and then turn the amp gains down, do it. you will get a little less noise from the amplifiers.

I guess what I meant is, what gauge of wire are you using for power? a cap will fix the headlight flicker problem, but it is only a bandaid. if the power wire or the alternator is not up to the task, you are still going to starve the amplifier and this will result in a lower voltage at the input durring heavy bass sections. Low voltage input to an amplifier will result in higher current draw. (simple ohms law) this is hard on an amplifier. it is certainly worth checking.


checking your speakers for shorts is worth a look too.

 

[BlackFx4InTn]

Sorry to bring up an old thread but I am curious about this as well. I have the Audio control LC2i which I believe is pretty much similar to the 6. I have a set of front stage RCA outputs coming out the LC2i that then go into Y splitters to run 4 channels, 2 channels for my tweets, and 2 channels for my mids biamped. I'm running some Clarus C61-2's. It sounds really good except for the fact that when I turn it up close to 3/4 HU volume, my mids start to distort due to over excursion.
I have set the gains to 100W on my mid amp, with different output positions on the LC2i. Should I raise my HPF on my mids? The lowest SSF setting is 55 on my amp, and right now it sits between 55 and 110. Did you find a good seetting on your Audio Control unit?