4ch. Highs + Mids "Dimming" after 30-40 sec of high volume playback

[TheGDog 10+ year member]

During high-volume playback (meaning with volume at like 37, 38 or 39 out of 50) when I focused on a particular song for troubleshooting this issue (so I'd have a constant thing I could use to measure whether a new step I tried had a positive effect) the outpu of the highs+mids (aka the 4ch amp) just dims-out, fades down.

When this happens I can turn the volume back down to like maybe 34 and you can hear the highs+mids slowly start creeping back up until they return to what they should sound like.

It's not the gains. I tuned them individually (meaning 4ch amp was tuned with the SUB output set to ATTenuate so I could hear the 4ch amp playing solo). For the 4ch amp I tuned the gains to sound as high as they could before distorting with volume at like 38 with no eq settings whatsoever.

From what I understand and have figured out from reading a buttload of forums, this symptom sounds like an issue related to power delivery to the 4ch amp.

Because of this issue I decided to add a 2nd battery HC600 out back behind my rear seats near the amps.

It is also because of this issue that I did the Big 3 upgrade to 4 Gauge Monster Cable.

It is also because of this issue that I returned a JENSEN Power 760 and decided to go with a more name-brand amp instead thinking at first the JENSEN was more than likely the culprit since it's sort of a lesser brand.

It is because of this issue that I went back and also ran the 4 gauge ground wire in Parallel (as well as the power I initially did) from starter to 2nd battery per Kinetik's instructions.

This problem is annoying as all get-out!! Spent 2 hrs searching these forums. Did not find anything similar enough to my issue to give me some insight so posting my question.

DETAILS:

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2002 Ford Explorer SportTrac

Stock Alternator (130 Amp)

Big 3 done (w 4 gauge).

Starter Battery = DuraLast Gold (Autozone less then year old)

2nd Battery Kinetik HC600 (Wired in Parallel w 4 Guage with StarterBattery)

4 Gauge off 2nd battery Pos+ to Non-fused Distribution Block

2 (no name) short 4 Gauge pieces from Dist Block to both amps.

4ch amp Grounded to 2nd Battery. (previously to chassis w same problem occuring)

Mono amp Grounded to Rear Seat Bolt.

Headunit = Sony CDX GT630UI (Problem occurs CD or USB)

4ch Amp = Pioneer D9500F (same symptoms w Jensen Power760 I tried before this)

Mono Amp = HITRON HA.1000-1 (Has always played fine)

Most of the ring terminals involved are the nice Allen-wrench cinch kind (either Monster 300 series, of Stinger Gold-Plated) except for maybe 2 of the Big 3 wires (which are Monster 200 series crimps). All but one of the crimped connector (all done in table-vise) were also soldered rapidly via Propane Torch w same Flux I used for my Copper plumbing in recent bathroom remodel. I think Alternator Pos+ (not Monster 200 series) was the only one just crimped w/out solder and the connection to battery side is nice Allen-wrench kind.

NOTE: Finsihed Alternator Case to Frame chassis of Big 3 upgrade this evening. It seems my car idles a teeny bit higher/better now and I'd swear the lights look brighter. but the issue STILL happens with the 4ch amp output!!!

NOTE: Things that come to my mind to possibly try at this point are...:

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- Perhaps NOT connect 4ch Ground to 2nd Battery Ground since Mono amp is not connected to 2nd Battery but connect to Rear Seat anchor bolt and seems to do fine.

- I DO NOT have the speaker-wire to the 4 doors fully upgraded to thicker stuff. I only used aftermarket speaker-wire to connect from where I cut the wires.... to run back to amp.. then run back to the other side of where I cut the wire to then let the factory wire that was there feed the power into the speakers in the doors. The outpu of the 4ch Pioneer is CEA Compliant 75 W RMS per channel. Even with the skinny wire from factory is SHOULD be able to hang with this.. right? I mean... it does sound kick-*** for those 30-40 seconds where it's playing back the music at full-tilt volume.

- Replace Starter Battery with an AGM battery of some kind? I was thinking Kinetik 1800 but since then I have read a thread where a gentleman with a 2003 Explorer said it was too tall and he couldn't close his hood.

- Replace Mono amp with a Class D amp to draw less power perhaps?

Any insight, or thoughts on what to look at, test, or try next would be Greatly appreciated. Thanx.

Click to read more...

 

[TheGDog 10+ year member]

Anyone? Hellooo... "Is 'dis thing on....??"

 

[TheGDog 10+ year member]

Phew... ****.. ok... I found it!

The freakin' power cable to the back... the fuse holder right next to back battery (it's a cheapy cylindrical-fuse type) wasn't passing current along.... or passing it along very poorly.

Took a Voltmeter to front battery 12.2 back battery 12.4

Started car.... front battery 14.?? back batter 12.2... WTF? Ding! Ding! Ding!

Off I go to purchase a nicer ANL type fuse holder (the kind that screw-down on both ends)

 

[Stryker 10+ year member]

nice! glad you found it.

 

[TheGDog 10+ year member]

DANG IT..!!! This still did not cure this problem!!!!

Replaced fuse at front with 150A (shoudl be about right). Installed a nice ANL one out back near the 2nd Basttery. The fuse in that out-back one is too big right now (300A) will likely swap it out for a lesser one soon.

With car running Voltmeter shows 13.89 at back battery, 14.2 (I think) on front battery.

Out back.... just to be sure... I hold Voltmeter Pos+ lead on Bat Pos+... then held other end to amps Ground wire connection... 13.89 (for both of them)... Even did the reverse of this... touched amps Pos+ and the Bat Neg- (both of them) 13.89 w car running.

ARGHHH.....!!! Soo mad about this issue. //content.invisioncic.com/y282845/emoticons/rage.gif.0ad8a6e5565b5fddce406566fdd05149.gif:rage://content.invisioncic.com/y282845/emoticons/rage.gif.0ad8a6e5565b5fddce406566fdd05149.gif

Since no one is saying anythign advice-wise... gonna maybe try running thick speaker wire all the way into the doors next whenever I get enough time.

 

[TheGDog 10+ year member]

OK.. I may have just had higher expectation than what the 4ch is capable of.

After dinner... I read the manual on the amp again and noted (again) the following excerpt..

" A cut in sound output may indicate improper setting of the gain control with the head unit as a hihg volume, set amplifier gain control to a level appropriate for the preout maximum output level of the head unit, so that volume can remain unchanged and to control excess output "

So... I backed-off the gains ever-so-lightly... and I mean you'd have to REALLY be staring at that sucker to see the movement with your eye.

Seems this is the issue with the output dropping... as I was now able to play the songs I've been focusing on at 38,39 volume without perceiving that "dimming" in the output.

It's a shame really... the output sounded so great for those 1st 30-40 seconds before. Makes me think I should perhaps consider moving up to an amp with a stronger RMS rating. The 6x8's are 85 W RMS rated @ 4Ohm. This 4ch does 75 W RMS.

But at least now I'm ok with the output... FINALLY!

 

[Stryker 10+ year member]

I think 13.89V is fairly decent with your rig running. A line driver would help with the gain setting as you could certainly have them turned low enough with

8V of signal that the drop in output would prolly not happen. Phoenix gold PLD1 would be ideal. I have one if you are interested in buying it.

 

[KnightWhoSaysNI 10+ year member]

Another thing you could try just to see if it sounds better to you would be to drop th gain a bit and bridge the Pioneer to your fronts and use your head-unit's internal amp to power your rear fill. Worse case scenario your out a little time, a little speaker wire, and some heat shrink.

 

[Side Show 10+ year member]

^^ this is what i would do

 

[SpeedEuphoria 10+ year member]

So you turned the gain up on the sub amp to get the same watts to the sub as before at 38/39 right??

If not the issue may still be there

Just saw this same prob and assumed it was a power delivery issue but turned out to be the remote wire. Had to add a relay circuit for the remote wire and prob went away

 

[sexy 10+ year member]

there are threads about isues like your system has they all point to one problem in the end it is that certain HUs and certain amps have a circuit that turns down the power output when the HU or the amp gets to hot. i would try seaching again start with that head unit and power surging then the amp. 38/39 on the head unit is a bit high thats why i sugest checking that first.