4 channel amp question

cam5860

okay lets say you run your components off the fronts channels and bridge the rear channels to a sub. My question is when you balance from the left to the right shouldn't you be able to hear sound from either channel? Because I'm getting sound from the right side but not the left side.

I switched the rca's around and now I get sound from the left side but not the right side. I'm thinking in bridged mode it's just one channel. The next problem I have is when I fade to the front my sub does not cut out. But yet when I fade to the rear my fronts cut out like they are suppose too.

The only thing I can figure out is my rca's are all out of wack. I have not had much time to trouble shoot it because I just noticed it about a hour ago. I'll see what I can figure out tomorrow. It's always some **** like this to keep you pissed off all the time.

exalted512

You probably have the front channels in bridged mode which sums the signal to make one. Take it out of that and put it back into stereo mode.

Do you have the rear channel hooked up to a sub output off your radio? If so, it is a 'non-fading' output, meaning fading to the front, back, left, or right will not affect output.
-Cody

cam5860

No cody what I had was the front channels on my amp running my components in the front and my rear channels running my sub in bridged mode. You was right about my amp being set in mono instead of stereo. I had set it up for mono because i'm only running one sub. So to get the balance right I just set it back to stereo. But the only problem i'm still having is on the fader. It will not cut my sub out when I fade to the front but yet it will cut the front out when I fade to the rear. I have checked my rca's they are right. The only thing I think it could be is maybe since I have the rear channels running off the sub rca outlets. It will not let it fade like it would normally do if you had the front and rear rca outlets running to the amp.

eloplayspolo

Your stereo doesnt know what is connected to the chans, it only knows what it is labeled for, front rear sub, so when u fade u fade rear or front, not your sub, it doesnt matter if your amp is labeled front or rear, your stereo doesnt differentiate how many amps or what kinda amps its running, its call common sense when u look at it from the labels on the stereo, if u wana turn your sub down u should use the option on the stereo or the amp itsself, fading wont do anything to it.

If i missunderstood im sorry.

cam5860

No what I am saying is generally a 4 channel amp is used for a set of midrange's in the front and a pair in the rear. People don't generally use a 4 channel amp to push subwoofers they buy a mono amp for that. so really what i'm trying to say is by running my front jacks on components and running my sub jacks on the rears channels could be **** with the fade.

MacLeod

Thats weird. 4 channel amps are made to run in all kinds of configurations and having the rear channels bridged to run a sub is quite normal and shouldnt be **** up your fade.

Try it in reverse. Run the front speakers off the rear channels and bridge the fronts and see if this changes anything.

audiobliss

What several people have tried to say, I think, and the only thing I can think of that is causing your 'problem'...

How is your RCA from your HU connected to your amp for the sub signal? If you're using the subout on the HU, that signal doesn't receive any processing from the HU's fade operation. When you fade, that's front versus rear. And yes, you're using front and rear on your AMP, but you're only using front and sub on the HU. So, when you fade to the rear, the front goes out and the sub stays the same. When you fade to the front, the front gets louder, but the sub stays the same...'cause the signal the HU is sending to through the rear preouts is fading out, but you have your sub connected to the SUB out...which isn't being processed at all from the fade operation.

So, if that makes any sense, I think that's where your 'problem' is. You should have some kind of an operation in the HU's menu to adjust the sub preout's level.

Does that make any sense? Is that the case?

cam5860

yes audiobliss thats what I was thinking something like that. I mean don't get me wrong it's not the end of the world. It's just nice to be able to cut your sub out sometimes and listen to your components. Since generally the sub over powers the sound coming from the front speakers. Audiobliss that makes prefect sense thanks man. I just wanted to make sure my headunit was not screwed up.

audiobliss

Cool deal. I figured that had to be it.

What HU do you have? I'm sure there has to be some menu command in there somewhere to adjust the sub preout's level. It may be cumbersome to get to...then again, it may not be.

cam5860

I have your favor headunit just the model below it. It's the kenwood excelon x791. Yes It's easy to adjust the sub preout's level on the kenwood. It's in the main menu. First item actually.

cam5860

You still driving that red jeep? If so what kind of system you got in it these days?

audiobliss

Oh yeah. I'm hoping to drive that red Jeep until I get a second car and modify the Jeep some. I'm just hoping it lasts long enough that I'll be in a position to afford two cars when the time comes to find a new DD.

I still have the same old stinking system in it, haha. It hasn't changed at all in the last year or so. You can see it in my sig, if you're interested in the equipment.

I was just thinking tonight on the way home from school that I really need to fix a few things about it. I had the system out for a while, and then threw it back in in a hurry, and my left tweeter doesn't work, I've yet to properly set my gains, and my HU is loose in the dash. I just need to take the time to address those issues.

And I really really really need a sub. Would help out the low end a lot, and then I'd be able to run the mids at a higher frequency and so could play them louder. I'm not happy with the volume output with the windows down going down the highway at 70+. And for having 75watts to each driver and Boston Acoustic components, that doesn't make a lot of sense to me.

But I don't wanna put any more money in it right now, so it's just been stagnant for a while.

eloplayspolo

cam, do u have a remote gain switch? that could be a quick fix to your desire to "fade" your sub

cam5860

you talking about on the amp or the headunit?

audiobliss

I think a remote gain switch is usually connected to the amp and mounted anywhere you want it in the car.

But if you can access the sub preout's level easy enough on the HU, problem solved, right? Doesn't that do what you were wanting?

cam5860

Thats what I was thinking that little box you mount by the driver seat with the gain knob. I would not need that with the sub preout level in my headunit. But I know what you all are saying. I don't need to fade the sub when I can just cut the sub level back.

exalted512

What output from you 791 do you have the RCA going to the rear channel of the amp at? Front, rear, or sub?
-Cody

cam5860

I have the sub out running to the rear channels of the amp in bridged mode.

cam5860

Hey cody far as the balance from left to right on the sub. You was right about me having it in mono mode. I switched it back to stereo and that solved the balance issue I was having man.

exalted512

Ok, the sub out is a non-fading output. This means if you fade to the rear, the subs will still play, your front speakers will not. If you fade to the front, your front speakers will play, your subs will also play.

If you want to fade the subs out, put them on the rear outputs of the deck, otherwise, use the built in control your deck has to adjust the level of the subs.
-Cody

eloplayspolo

i still think remote gain switch is about as easy as it can get

cam5860

I gotcha cody. Thanks for the input bro.