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-   -   Car audio losing sound at low rpms! EDIT : Solved by "The Steg" (https://www.team-bhp.com/forum/car-entertainment/91222-car-audio-losing-sound-low-rpms-edit-solved-steg.html)

The Civic's ICE (link to install thread) has run into a peculiar problem of late.

When driving in bumper to bumper traffic, and any other conditions involving low rpm, the sound momentarily dips. Volume loss is anywhere between 60 - 90% and happens in EVERY drive involving dense traffic conditions. The stereo typically loses sound when coming to a halt, or at the time of idling, or when just starting off from standstill. When the stereo loses its volume, it does so for a little less than a second. However, the frequency is very high....say 10 times in a 30 minute drive. You will understand how annoying this can get.

Important points to consider:

• This problem NEVER surfaces when I'm driving on the open road. Thus, on the highway, or the early morning drive to work (empty roads), the stereo works PERFECT. Not a single dip.
• Whether other electrical components are on or off (headlamps, wipers, air-con) does NOT make any difference. The issue surfaces only when driving in bumper to bumper traffic (whether day or night). Further, on the late night drives (higher rpms), with all electrical components active (air-con, headlamps) no problem at all.
• This sound dipping seems to be getting worse with time. First two months after the install, it was running fine. Stereo started dipping occasionally somewhere around the June - July period, but has really worsened in the last 4 weeks.
• My Civic is running the factory OEM battery which is 3.5 years old. Is this the weak link?

Other points:

• I don't believe Indian Civics are equipped with the ELD (apparently only US-spec Civics are. Even Canadian & JDM cars do NOT have the ELD). Some info on the ELD : Link 1, Link 2, Link 3, Link 4

What's the way ahead?

• Get an Amaron yellow top battery (D55 / D34). Link. Is a high aH rating battery the solution?
• Upgrade the "Big 3 cables"? Some already done to my car at the time of install, others not required.
• Lower the amp gain level? Still not the real solution though, I love the sound the way it is.
• Install capacitors?

Thanks for the help!

Its the problem related to ELD and i think m4ugr8 also had same problem with his Civic ICE!

Battery should not be in picture since power to ICE would be fed by alternator in a moving car. But since other components are working fine, this should not be alternator issue.

For systems that draw a high amount of current, they typically install capacitors to smoothen out load that is put on alternator by sound system.

For reference, let us list out your system right here (only the relevant components)

• Pioneer AVH-P4250DVD
• DLS Ultimate Performance UP6
• DLS Performance 428
• Peerless Resolution Series 12" : 2pcs
• DLS CA 23 high power 2 channel amplifier - 2 pcs
• VSL 2500 W rms monoblock 1pc
• Soundquest 1/0 ga amp wiring kit

Knowing that your kit was installed by a professional, I doubt that it is an install issue - also the quality of the cables used seem to be high quality.

I have faced similar troubles in CR-V and Civics before, and sadly every time I thought I had solved it, the trouble reared its ugly head again.

Firstly, those Yellow-Top batteries were never made by Amaron, they were Optima batteries imported by Amaron, a project that flopped very badly. Whoever has bought those batteries has neither recd his money's worth nor any service. Stay FAR away from these.

If you have a 1/0 gauge wiring kit installed, there is little you can do to upgrade it.

However my question: You have 3 amplifiers in the car. ARe they all running off this 1/0 amplifier wiring kit? If yes then you must have some electrical distribution system. I would begin by looking there.

Also when you say that the volume dips - does it dip across the board? I mean does it dip from the front, rear and subwoofer? Or is it just the fronts or rears? Or since you say that you have one 2 channel amplifier for the left and another for the right speakers (an unusual arrangement) - then does the sound dip only from the left or right?

If it is just one amplifier acting up, this problem will be easy to solve.

If it is in fact across the board and has nothing to do with the electrical distribution or supply to the amplifiers, then there is trouble.

I would start by replacing the battery. I strongly recommend Amaron Green or Bosch Silver batteries. Getting a battery that has a slightly higher aH rating is better, but don't go crazy.

Capacitors will solve nothing. IMO.

Thank you for the replies.

Have PM'ed m4ugr8 requesting his inputs on this thread. And I hope he found a solution too!

She's only 3.5 years old anyways. I also doubt its an alternator problem.

Thanks for the tip.

Umm, I don't know. Will let Bass & Trouble answer these questions.

To the best of my observation, I think it's front as well as rear. Have taken Ajay for a drive and IIRC, he also commented that the front & rear, both, are losing sound. Sub-woofer is definitely dipping too.

I had mistakenly reported this in the install thread. B&T later clarified that its one amp for the rear and front speakers, each.

Will do, thanks.

1. If you switch of the engine, and try running on battery power do you face this problem
2. With car at idle, can you check the voltage at battery terminals with ICE on?
If it dips below 12.5, either your alternator has a problem, or your ICE is too heavy for this alternator.

Any evidence of sparking/corrosion at your fuse/distribution block ? Did you try connecting a voltmeter?

Have you tried getting the checking the battery voltage at idle with the stereo on low, moderate and high volume level?
Also check voltage with and without the stereo on.
Plus check for the voltage without the stereo on at idle and at with some high rev.
The amplifiers most commonly work between 11 to 14.4v and most cars can put out best around 13.6V at idle. A voltage drop at idle is what makes the amp lose the wattage. If there is significant drop in voltage at idle with stereo on I suspect it could be the battery. Other electrical like light, horns and AC needs much less current than what your 3 amp would require.

Have you noticed at night while driving or at idle if there is a slight dip in headlight output with the stereo on at idle.

I believe the amps is not getting the desired current at idle and the culprit could be the battery or weak alternator.

Hi GTO, you can try checking the contact between the Power cable and ring connector which is bolted to the battery terminal, if power cable is not soldered to the ring connector. Overtime there can be contact breaks due to the heating up of a loose joint which happened in my case. Since this is the primary contact point where all the amplifiers draws power before going to the distribution block, a loose contact affects all of the amplifier's output.

Thanks for the help, guys.

Don't know. Will check & update.

What is a distribution block?

No voltmeter connected yet. I'll get all these numbers over the weekend.

The headlamps used to dim in my Vtec (as you turn the volume knob higher), but I haven't noticed the same in my Civic.

Will check this tomorrow morning.

I am sure you don't have any problem starting the car, right? If so, there shouldn't be a problem with the battery or connections to it. But, do check the battery terminal voltage when cranking (disconnect the plugs). If it is dipping below 10, battery is going going ... If simultaneously there is a problem of oxidation of contacts in the alternator circuit, or if ELD is present and the alternator field control is not getting boosted, at lower RPMs the current drawn brings the voltage down of the whole circuit. The battery still charges enough during good times, so you wouldn't see it in starting / cranking behaviour.

Is there any speed dependent volume control feature in the HU? Haven't seen that in Japanese design HUs though.

What you are feeling as 60-90% reduction in volume could be a psycho-acoustic thing. If we are hearing at a moderately large volume, a 10% reduction also shows up as an appreciably large reduction.

Sir my two cents: try an empty basement one might not note a considerable dip in lights while driving but a dark empty basement would give a clear idea or some dark back alley. Preferable from cold start. With the help of another person if possible to judge if the light levels drop. Or it could be something as silly as a loose contact going over some large potholes does that. As silly as it sounds a start stop motion is like a see saw. So a slight movement of a wire however unlikely could cause it. Though it sounds perfectly silly.

Speed dependence of hu's come out clearly at higher speeds with lower volumes to keep the ambient sound level. So imo it won't show here. Rest I'm no electrical guy so can't say.

. O yes I can vouch for that my civic has speed dependent volume feature higher the rpm the volume goes higher too !! I am sure many civic owners must have experienced it too .by the way my battery went kaput exactly when the car was 3 and a half years old !! It died a peaceful death in the garage saving me from any jumpstart but it was exactly the day after my dad askEd me BETA A/T KI BATTERY CHALTEY CHALTEY GYAEE TO DHAKKA START BHI NAhiI HOGI NAA

No. Tried for an extended duration this morning and no issues at all.

Car starts & works fine.

This is suspect no.1. But what is causing it and, more important, where is the solution?

I can confirm that the sound goes nearly completely off at times.

Also, more information for Sam : Yes, the sub-woofer also cuts out. Therefore, its the front + rear speakers + subwoofer losing sound.

Don't think so. Why would the sound never cut off at high rpms or on the open road then?

1. I did talk to both B&T and GTO about this before this thread was started. However from what B&T told me the subwoofer was not cutting off hence based on those observations I did not suspect the distribution block. If however all 3 amps are cutting out together I would check what they share in common - the distribution block.

2. Like Invinsible as said above, at lower rpms the alternator often puts out a little less. Hence if cold be that your alternator's output at engine-idle condition is inadequate for the stereo system. I had a similar problem with my Contessa 1.8 in the late 80s and I found a alternator guy called Pai electricals in Santacruz who built me a bigger alternator that could delvier the amps I needed when when the engine was idling.

3. GTO, the way a car's electricals work is that at start up the battery provides the cranking power. Once the car is running it is the alternator that provides much of the power (while also re-charging the abttery that is still in-circuit). For certain demands where the amps provided by the alternator are inadequate the circuit can call on the power stored in the battery (think of the battery as a capacitor in this case) up to a certain point (determined by the capability of the battery to dump current). If your amps are dipping for < 1 sec. it could be an inadequate battery. If the power is being lost for less than 100ms then a 1-2F capacitor can supplement the battery but I suspect with your kind of music the capacitor will not be very effective. The only reason I would even suggest trying out a capacitor is that it takes less than 10 minutes to add or remove one from the circuit and a loner capacitor can be used for this purpose. Some capacitors have a little battery voltmeter which can also infrom you of the health of the battery.

in short I would
a.
add and remove a capacitor just to determine / oberve power loss in ms. when ading a capacitor get one with a voltmeter and you can see the voltmeter when the engine is at idle and at high rpms and observe

b.
hange battery if adding the above capacitor did help

c.
if change in battery did not help let consider using smaller amps for front and rear just to check if it is indeed the current draw of the amps that is the culprit. If it is determined that the amps are the culprit and the change in battery did not help and it is observed that the battery health at idle is not adequate to power the amp you will need to upgrade the alternator. Your current alternator would still be usable by another civic.

Best of luck.