Rep Power: 350

Man, I just finished re-wiring my stereo system and now that I'm using the HU for the pre-outs instead of a high to low converter my subs don't hit as hard. The interior speakers sound good, maybe even better than before. I don't know why that is. Does anyone have an answer?

I checked all my cables and connections, my subs are working fine, they just don't make the whole car vibrate as they used to. I also looked at the HU and it has an adjustment for the sub-out. I turned it to the max. I'm actually stumped! PLS HELP!!!!!

 
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best guess would be hi-low converter has a higher voltage out than the radio preamp.

 
Rep Power: 350

My HU has 4 volts out. But it used to make my mirrors shake, now I hear the bass but it's nowhere as hard as it used to. My trunk doesn't even rattle any more. It sounds clear and I checked everything.

 
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I had a problem similiar to yours, and it turned out that my Subs were out of phase. You may want to try switching the connections on ONE woofer (or box) input and see if there is any change.

 
Rep Power: 339

what radio, amplifier, subwoofers, and what did you change out with teh loc, or was it just the loc?

 
Rep Power: 350

I have a JVC kd-sh909 HU and two crunch amps. I know the amps aren't the greatest but they should still hit like they used to. I'm sure I plugged them into the right ports so they aren't out of phase. I used gold wire for + and white for - and that's how I plugged them in, just like b4.

My converter was a pos from K-mart, so I don't know how it would make it hit harder.

The sound is clearer now, from my interior speakers that is. I installed tweeters as well, with the stock pods. They aren't that loud, tho. I used stock tweeters and plugged them straight into the speaker harness from the HU instead of running them off the amp. Maybe one day when I have time again I'll amp them as well.

It's really annoying not to have them hit as hard as they used to. I'm going to go over everything again tomorrow when it's light out. Any input would be appreciated.

 
Rep Power: 339

other than my first guess, i have no clue why they wouldnt be as loud. well, tahst hat the gain is for, just compensate, i guess.

 
Rep Power: 350

Ok, I just went out there, as soon as I unplugged one sub it hit hard as hell but, with both plugged into the amp they're weak. It doesn't matter which I unplug, so It's not the left or right channel.

I didn't mess with the power, I have an 8 gauge power from the battery to the distro box and 10 gauge from there to the amps. I didn't change the power or ground configurations so the only thing I can think of is the HU doesn't push enough power to support both amps. Would I be correct in assuming that? I can't think of anything else it could be. Only the source for the RCA cables changed from the converter to the HU now. I'm stumped.

Edit: the gain is at max on both the sub amp and on the HU.

 
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sounds like a classic phase problem.

 
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Can you explain, pls? How do I fix a classic phase problem? It's really annoying.

 
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fontos advice: one sub is outta phase

reverse the + and - wires on one woofer, see if that helps

 
Rep Power: 350

Ok, I'll try that. I also noticed that when I unplugged one the other hit really hard but as soon as I plugged the second one in they both sound like they are drwoning out. The one that was plugged in only hits at about 1/3d of what it was and the second sub matches it. I'll check the phase thing but it sounds like they need more juice.

 
Rep Power: 0

Wait a minute. It worked before so it should work now same as before. The amps must have the juice.

Think of it like this.

Subs move in and out.

In phase means both move together.
Out of phase means they don't.

You want both subs moving out at the same time so that the sound ADDS together and they work with one another.
Otherwise while one moves out, the other is moving in. Each one is creating the exact opposite sound as the other. This way they tend to work AGAINST one another.

The same is true of your components and it can also make a huge difference in imaging.

And then the kicker is when your subs are both in phase, and your components are in phase, but they are not in phase w/ one another.

See what I am getting at ? ??????

A neat trick is to take a AA battery and hold it to speaker wires. If the + speaker wire is on the + of the battery the speaker shoud push OUT. If it sucks in you got it backwards.

Hope this helps.

 
Rep Power: 350

Well regularjoe, the connections from my amp to my sub never changed. The only thing that changed was where the amp gets it's input. It went from the converter to the HU. Now they sound all jacked up. Is there any way of making the amp get more input? Or does that even matter? Shouldn't the amp distribute whatever input it gets the same to one or two? That's why its an amp, right?

 
Rep Power: 339

easy. if you accidentally flipped one of the left/right inputs on the LOC, so that the speaker level input was reversed, then the outpt would reflect that on the amp (are you running in stereo?) hook an RCA, one of yoru inputs polarity has been reversed, and now yoru woofers are out of phase.

regardless of whether it seems reasonable or not, d try flipping the phase on one woofer. its not like its that hard to do, and if that wasnt the problem, then at laest youll know for sure.

 
Rep Power: 350

Ok, this is weird. I tried unplugging one of the inputs and that sub hit hard, then I tried unplugging the other and that one hit hard. So, I reversed the wires going to one of the subs so it was backwards and they both hit hard. So, I guess I had a phase problem. I even checked the wires from the plug on the box to each sub and they are wired right.

Could my amp be bad?

 
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Ok, what is an LOC? Is that the high to low converter? If it is then it doesn't matter because that isn't in there anymore. The RCAs come from the HU to the amp. There are no switches I'm aware of to reverse polarity. See what I mean?

 
Rep Power: 339

line out converter has 4 inputs left right + and - each. so on one channel, you messed up and put the + output to teh - input on the LOC (line out converter, hi-low converter) not a bad thing, just one is outta phase, which you corrected on the amp outputs, so teh subs are now in phaze again

hook up RCAS now, and you dont have teh LOC, which means there is no + - guess work, its correct. but one woofer was out of phase to correct before with the LOC outta phase.

flip it back right, your in buisness. classic phase problem. fonto nailed it dead on.