Listen to this, this one has me stumped...

I have a basic 600 watt rms 4 channel amp, and I am running two basic 4-ohm 15" subwoofers off of the amp by bridging each side...

I had a previous amplifier installed by bestbuy when I was lookin at around 300watts rms, with an 8gauge wire setup. When I changed amps, and upgraded the wiring to 4 guage, I kept bestbuy's battery terminal (very cheap)...

anyways, basically I was in a hurry while doing this, and the connector I crimped on the end of the 4gauge wire was MUCH too small for the 4guage wire, so about 1/4 of the wire was actually making contact to the connector, and to the battery... definitely a very crappy connection...

The strangest part was that my stereo ran great! Hit hard all that, so I wasn't in a hurry to change it (even though I should have)... so the other day I decided to upgrade the connections to the battery to maybe... make my subs pound harder, (I wasn't really sure what would happen, only that I knew that a better power connection could never cause a problem)...

Well I made the connectors out of stuff laying around. I had some copper tubing that I basically "crimped"(smashed) the tubing onto the 4gauge wire, then I drilled the appropriate-sized hole through the tubing for the battery post (with a brand new bolt I found laying around)

after torqing down the bolt to the battery with the starter wire, and the stereo wire firmly connected with no play, and good surface contact with each other and the battery, I figured I was done....

The car starts fine, but for some unknown reason, the subs play at a LOWER volume now! I used to have the nonfading volume at about 1/4... and now I have to put it to about 3/4 for the same volume output! very strange...

I have always had the gain on the amp set as low as it could go, because it was loud enough, and could really hit hard when I turned up the NF at the deck...

I wonder if by somehow giving the wire more amperage capability, that the amp has done something strange, and now I need to go back and increase the gain? I really just can't see how this can be true, it's just boggling my mind.

10guage -> 4guage = 1/2 power output I hope not

Anyone got any input on this? Maybe it's happened to you?

 

Did you disconnect the ground at the amp at ANY point with the RCA cables attached?

 

I didn't touch the amp at all... I only worked with the 4 guage power connection up front in the engine bay.... didn't even look at the amp, just in case.

 

That was fast!
Going to a better connection would not have caused the problem in it self, there must be other install problems. Did you check the ground at the amp and chassis? If BBY did a bad job on the ground that could have caused the problems. Do you have the ability (VOM/DMM) to check the resistance from the RCA ground to the HU's ground? What's the make/model of the amp and HU?

 

well I redid all my grounds and stuff when I upgraded to 4guage about 2 years ago...

this connector upgrade I did a few days ago...

1. I cleaned up the wire by trimming the edges (they were dirty/corroded from high current flow through small amounts of wire)

2. crimped on new copper pipe as battery terminal connector

3. put in new steel bolt with a nut on it so it would tighten nicely with the battery terminal and stereo wire....

I did not adjust anything anywhere else in the car... at all...

I wonder if there is something going on since there is a higher current flow capability?

I remember on my old-school sony amps, there were leds for high-current/high-voltage... what all did that mean?

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I would still check the RCA outputs ground.
With a bad connection there is higher resistance so when current goes up voltage drop goes up to. Lower voltage to the should cause lower volume, not more.
That old Sony, was it an explode, with the over current, offset, and thermal lights? You remember the model number?

 

it was an XM-1002hx I believe or wait.. let me see that was the 300 watt version, I had two... a 300 and 600...

XM-1002hx - 300+ watts rms
XM-754hx - 600+ watts rms

http://www.teamrocs.com/reviews/amplifiers/XM2252HX.htm
this is what they looked like

it makes me angry to think that these were stolen BOTH, along with my $100 dual 12 box... and my 2 orion xtr pros... *** damn they sounded good, even though they were paper I loved them more than my 15s... sigh

somehow they got into my car in a LOCKED yard at a local garage, with a PITBULL guarding it... then they had to climb over an actual fence, with my over 200lb sub box... plus somehow they had time to remove all the wiring without cutting anything to the amps and stuff.... amazing

I found out later that they keep the cars unlocked so the windows don't get broken... neat!

I bet you anything an employee of that garage was involved in the incident... considering the owner even agreed to give me $400 for my loss... after threatening to sue him, because they claim they have insurance and security company monitoring (which they have none of any kind)... they also forgot to tell me that they had been getting hit by "theives" on a regular basis... nice of them to tell me!

anyways, I got almost jack for $400... just an autotek sx-4160... that SOMEHOW puts out 640 watts rms, with only a 40 amp fuse. go figure! even at 14 volts thats amazing that the fuse would not be overrated... I want to kill someone...

I love my old sony stuff

 

The HV/HC light are just bells and whistles. The HV light will be on most of the time. if your diving a low impedance, less then two ohms, the HC light would light. With a low impedance the more the current demand on the amp, this amp just has a light to tell you there is a 1-2 ohm load.

 

I see... interesting


one other thing I would like to point out about this strange wiring problem... is that even though the amp seems to have a lower maximum output now with the new wires, the sound is much cleaner, and it hits harder at these lower volumes... like right now, if I put the h/u at about 3/4 NF output, its about the same volume as 1/4 NF output before (for whatever reason).... but it seems to hit much harder than before, and the bass is deeper... a very strange phenomenon, is it not?

I am going to get out my buds voltmeter and check the resistance between everything I can think of, but I may just up the gain on the amp, and call it quits! it does sound much better I must admit.

steve