lack of power

I have had issues with stereos in my 97 Acura Integra. Even 4 6.5 inch speakers ran off an amp would make the lights dim. I then added another amp and powered a sub woofer. Obviously the car really didn't like that.

After many blown speakers and subs I finally was able to upgrade the alternator. I went from 80 amps to 165 amps. I haven't tested it to see how much power it is actually putting out yet. I did the big 3 with 2 gauge wire. I have a 0 gauge power and ground wire for the sub woofer amp. I have a separate 4 gauge kit for the 4 way speaker amp.

My current system is 2 6.5 inch infinity references powered by a RF 300.2 amp. The subs are 2 kicker 10" L7 in a sealed box. They are 1200 watts RMS powered by an Audiobahn 1800DT? amp which is 1200 watts RMS at 2 ohm which is how the subs are wired.

I have a 3 farad cap that is wired in series for now and is powering the Audiobahn amp.

My current issue is the fact that I just got the big 3 done. My voltage is at 14.5 on my Cap and about 14.4 at my amp. However when I play trance/techno the songs that don't even have much bass cause the voltage to drop to about 12.5 and then the amp clips. I notice that I have some pretty good RMS power. I can play rolling and continuous bass basically as loud as the bass spikes.

Is this clipping caused by lack of voltage/current?

Why does my system clip so easily? It should get a lot louder than it does before it clips.

I noticed now that the voltage will be at 14+ then drop down to 12+ after some loud listening. If I play it loudly long enough it will drop to 12s then stay there until I turn it down.

What is causing this and what can I do about it?

I just wanted to add that I am still running the stock battery which I believe has 625 cranking amps. Also my battery never seems to run down from my stereo. Ever.

If your amp is clipping it's because the gain is too high.  But I should probably ask what do you mean by "clip"?

Also, what is your ground return resistance - and if I was you I'd not use that cap.

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The sound it self is clipping. The amp also has a peak meter? on it that shows red for clipping.

I think you have a good point about the cap. I am actually using it because I have to go from 0 gauge to 4 gauge for the amp. So basically it's a reducer at the moment. That's why it is hooked up in serial.

If you or others think it is worth while I will buy a power splitter or reducer and do away with the cap to see if it helps.

If it is the cap what exactly is the problem with it? Old and crappy? Broken? Not large enough? To much load on the electrical system?

I got the cap used and it was a deal with a bunch of other components I don't have anymore so it wouldn't surprise me if it has a problem.

I do need to check the ground resistance. I will look for the article on this form.

Thank you for your suggestions.

You say you hooked the cap "in serial."  Can you describe what you mean by this?  A cap is supposed to be connected in parallel with the amplifier power, if one is used at all.  And from your description it sounds like your amp is not clipping, it is shutting down in protection mode.  Clipping is distortion and does not shut the amp off.  Again, either your impedance is too low, your voltage is too low, you have a bad ground, or your gain is too high - or some combination of all the above.

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The amp is not shutting off. It just does not play peaks well at all in the music. A bass drum is is very weak. However rolling continuous bass is rather loud.

It seems like the amp lacks power when a peak comes and doesn't play the sound at a high volume. The voltage drops and the amp clips quickly. On rolling bass I can get a lot more volume before the amp clips. It is very disappointing because of the type of music I listen to. The speakers out shine the subs by a large margin.

Sorry I have never had to describe this in text.

The capacitor is hooked up incorrectly because I have to use it to reduce my cable size until I get the problem items. I have the power cable going to the capacitor then to the amp. However I also have the ground going to the capacitor then going to the amp as well. I have to do this because my power and ground are 0 gauge but the amp will only take 4 gauge or so.

If you believe it will help I will buy the proper items today to reduce the cable size and get rid of the cap.

I will check the ground resistance as soon as I can. I was going to do it anyway so this is a perfect opportunity.

As far as getting gain I maybe a bit confused. I have two amps so I set one up to play at the volume I want without clipping at about 75% of my head units max volume. I then adjusted the sub woofer amp without bass boost to almost match it where I thought it sounded right. I then intended to use the equalizer on my head unit or the bass boost on the amp to make it louder when needed. However it isn't loud at all and it clips quickly. My friends comment on the subs not being nearly as loud as they were in other cars.

Does lack of power to the amplifier cause this?

What exactly happens when you don't have enough power for your amplifier?

Thank you again.

To clarify a little bit the amp does get distorted when it clips.

What would cause the voltage to drop so much and what can I do about it?

This is sounding a lot like a poor ground/positive supply issue to me. Check those leads.Ohm out and reduce as much resistance in positive feed cable to blocks/cap then clean and verify proper ground to chassis from the negative lead off the amp to cap, then to the floor pan. (Obtain, familiarize yourself and test with a digital volt-ohm meter) Incorrect grounding killed a friend's install that was displaying these same symptoms. It could hit and sustain long, deep bass but a sharp hit from a drum beat would sound like mud.

He eventually set his carpet on fire like this and called me only after the smoke cleared. When tested, his ground was high through a 4 ga. 12" run to his chassis - about 2.3 Ohms. Scraping the area with a putty knife, polishing to bare metal with a steel brush and a star washer later, we were good at about as close to zero as god allows us mere mortals. ;)

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Life is too short to build slow computers or weak audio!

You may be right about the bad ground. I'm having a hard time finding a good ground in my car.

Anyone know a good place to ground in a 97 Acura Integra? I'm getting to the point where I want to drill a hole and make my own. I'm kind worried about doing that though. I don't want to drill through something.

First things first, while you are in there verifying your ground and supply leads for as little resistance s possible, do what it takes to get that cap either removed from the loop altogether, but at least wire it correctly if you are going to keep it. Drawing current through it rather than across it will act like a huge series resistance. Wire it in parallel:

Batt + -> fuse -> 0 ga to distro. block -> Capacitor + -> Amp +

Batt - -> Chassis ground strap (big 3 should take care of this) -> Bare metal chassis connection to short pigtail near capacitor to cap. - terminal -> Capacitor - -> Amp -

If you are having trouble getting heavier gauge wire stuffed under the power terminals on your amp - try this:

If you have a 0 ga. distro block with 2, 4ga. taps - run a pair of 4 ga. from two ports on your block to the one positive terminal on your amp. On the two pigtails to the amp power terminals, crimp, solder and sleeve two 4 ga. lugs that are positioned 180 degrees in rotation to one another so that the spades are parallel and back to back to provide a thin enough profile to sit under the plate and screw. The rest you should be able to do and figure out with even a cheap W*lmart "Automotive" DVOM. (About $25 and pays for itself the first time it fixes something)

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Life is too short to build slow computers or weak audio!

Thank you for your advice. I just walked to the a local car audio shop and bought two 0 to 4 gauge distribution boxes. I will hook it up without the capacitor to see if it makes a difference. I will then check my ground cable resistance either way.

If I split the 0 gauge ground cable into two 4 gauge cables and send one to the amp and the other to the capacitor it will then be in parallel correct?

Again thank you both.

I suggest you don't use a ground distribution block.  Connect the amp directly to ground as close to its mounting location as you can.  Yes, you will probably need to drill a new hole, scrape the paint and use a star washer.  And get rid of the cap.

Check the "What is a good ground?" post in the Hot Topics section.  You may also want to check the "How to set your gain" post.

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I don't disagree with you on getting rid of the cap but why do you think I should get rid of it?

Large caps like that can cause more harm than do any good as they place extra load on your alternator.  You shouldn't need it.  Plus, while you're trying to troubleshoot a problem it simply adds another element to worry about (you do have it connected incorrectly as was already pointed out.)  Just eliminate it and get your amp problem solved first, then if you decide you want to add it back in we can help you connect it correctly.

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Ok. Thank you.

To clarify on how to parallel wire:

Think Christmas lights strung together in a chain, each light with power running in straight rails that do not cross and are unbroken from light to light - same polarity from end to end.

Got that in your imagination?

Apply the same thought to your wiring:

Positive from battery + to positive on capacitor post then on to the positive on amplifier power. Negative cable from chassis grounding spot to negative post on capacitor and then from capacitor negative post to amplifier negative.

DYohn speaks with much wisdom in jut leaving the capacitor out of the picture altogether, as you honestly will NOT need it if your alt, battery and wiring is air tight. You have plenty of power with your alternator upgrade. It's also One Less Thing(tm) to go wrong as you troubleshoot your particular problem.

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Life is too short to build slow computers or weak audio!

I will be doing away with my cap when I get off of work. I will let you guys know what happens.

*blink* I think I will shut up now. DYohn apparently tapped my brain or he and I are looking in the same playbook, chapter and page here... Honest - those posts popped up while I was worsmithing and typo squashing. :D

Does it at least earn this parrot a cracker? ;> I leave the place to go deal with real life for a month and come back to this spooky place filled with echoes and moderators that are spot on *good*. Sheesh, there's nothing for me to do here but sit back and watch the flames in other threads. (Rising from poorly thought out installations and shoddy advice - who are these people anyway?)

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Life is too short to build slow computers or weak audio!

It is *likely* that the alt is performing fine. High output alternators will not flow at full current with the engine idle - peak output is at about 2~3k RPM typically. Check your ground after zeroing your meter:

Touch or clip the leads together after powering it on and setting for the 20 ohm range. If digital, press the "REF" button with the leads touching after the numbers settle. This makes the meter ignore it's own reistance. (They sorta "float" around .02~.03 ohms and this makes it read 0.) If you have an analogue meter, same thing, turn it on - clip the leads together after setting next to lowest ohm range, fiddle with the zero adjust knob until zeroed.

Disconnect the negative terminal off the battery and measure resistance from the negative terminal on the amp to the negative lead that normally is bolted to the battery. If it reads higher than 1.5 Ohms, you need to work on getting it as close to zero as possible. It will never be perfectly zero, but over 2 ohms is a clear and dangerous sign that you have a ground issue still.

With the battery still disconnected, check resistance between the alternator output post and the battery positive terminal, that too should read nearly zero, typically a few hundredths (0.0xx) Ohms or so should be the measurement in a good power setup.

Bolt it all back together once you are satisfied and power up the system. Raise your engine RPM up to 1500~2000, monitor voltages. At speed, your alternator should put out a flat 14.4~14.8 volts with lights on, defroster running, audio pumping. If it is still dipping with a heavy bass hit - check your accessory belt(s) - see below. At idle, even with a high performance alternator, voltage drops will be present with a heavy vehicle electrical load, but should not fall below 13 volts.

Shut the engine down after turning off everything, no interior lights going, etc. Plate saturation in the battery will make it drop in voltage at a decent clip, but a fully charged lead-acid cell settles at 12.5v after a few minutes. Any lower, the battery and/or alternator is suspect. Either can be tested for free for the asking at many automotive parts stores. Be warned though, to test it, it has to be taken out of the vehicle.

Also consider too that belt wear will make an alternator under load slip if it's near the end of it's wear limit. Fresh, tight belts are mandatory for audio setups, so keep that in mind. (I chew through one every 12K miles on my truck even with a sedate 190 Watt X4 amp and MRP-M500 monoblock)

If after the "cheap -n- dirty" checks here do not work, may have to consider the fact that your amp may be to blame after checking your sub on a donor amp or buddy's rig. Usually a bad subwoofer will make horrendous rattling and buzzing noises or not work at all if it's gone by the wayside. Also try swapping out your amp with another of it's kind or of similar design. (I know, a lot of work but it beats shelling out bucks for a new one or a rebuild)

You sound pretty sharp and now armed with a little knowledge, go forth and kick butt! I really hope that you just discover a high resistance in a line and get it exorcised quickly. Good luck. :D


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Life is too short to build slow computers or weak audio!

D-oh! I forgot - forgive me.

Please zero your meter as described above, and take notes on your Ohm measurements and POST THEM. I want to see amp ground to battery negative cable then a reading from battery positive terminal to alternator output if you would be so kind? Then us eggheads will be able to assist more. :)

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Life is too short to build slow computers or weak audio!

Here is my update.

I checked the resistance of the ground cable from the amp terminal to the negative battery connector. The measurement was 0.2 Ohms. I measured the resistance from the power terminal on the amp to the battery terminal and got 0.3 Ohms. I measured the resistance of the Alternator to the Battery terminal and it was 0.3 Ohms.

I'm not exactly sure but to think of these resistances though. The multimeter read 0.3 Ohms when connecting the leads. I found now way to zero it out. I then added wire to both ends to extend it so I could make my connections. I measured the resistance of the extra wire and it also came to 0.3 Ohms. I don't understand how it went from 0.3 Ohms to 0.2 Ohms or even 0.3 ohms.

I started the car and disconnect the battery at the negative terminal. I then drove and started my stereo. It worked nearly perfectly. The only issue was when the bass hit very loudly, probably only when clipped, the other amp sounded distorted and sometimes cut out. However my car never died. I know, it was a weird test but I was curious about how well the alternator would keep up. My jeep used to die a lot and not start because the battery died from the stereo. My Acura didn't even die.

I got annoyed when I couldn't find anything wrong. I poked the probes from my multimeter into the power and ground cables at the amp. I then put it where my back seat should be and turned it on to read voltages. I saw that the voltage read out on the multimeter did not jump around nearly as much as the volt meter on the amplifier.

I noticed that when the amp was reading around 12 volts that the volt meter still read 13 or higher. I could even see when the alternator starting ramping up power because you could see the voltage slowly rise.

Whether the resistance measurements are wrong or not I can tell you that the voltage was good. It barely dropped to 13 volts at high loud.

My conclusion with that is my alternator seems to be powering the amp well.

The next thing I was take the subs out and hook up just one of them at 4 Ohm. It was about half as loud as both of them are at 2 ohm. I then hooked one of them up at 1 Ohm. This seemed pretty darn loud. It was dark when I did this so I wasn't able to see its excursion. I'm curious to see if I am able to give these subs the power they are supposed to be getting. I believe my amp simply isn't giving them the amount of power it's supposed to.

Is there anyway to measure an amps output?

My Acura Integra is a hatch back. Right now it is open because my rear seats are removed. It would it sound louder when I get the seats back in and it's closed off or at least partially closed off? Kind of like a corner in a room for a home sub.

Is there something silly I could have over looked that could cause this?

I do not think you overlooked much of anything - especially when you have little to no measurable resistance in your lines. Though I am a little worried that you disconnected your negative from the battery and kept running the car - that's TORTURE on your alt. :( Needless to say; do not do *that* again. It's bad juu-juu and it angers the gods of long alternator life.

Seems like it is time to find a buddy or a shop to help you out with the next stage - that monoblock is 1 ohm stable so no harm at all running your DVC's down to 1 Ohm. Yeah, they will get pretty darn loud since the amp can now dump much more power in that configuration. But I digress...

The help you will need is to either obtain a borrowed amp and see if it does the same thing when all hooked up in your particular vehicle or drag the amp to be tested on a similar 1-ohm setup and see if it drops off in punch when loaded.

Though I would also advise that you look into the sticky-FAQ here to help eliminate as much distortion as possible before you do much more of anything else:

How To Set Your Gains

If power and ground are spot on, then I would just simply make sure that everything is tweaked just right. If after the tweaks are not sufficient theeeeeen I would start to swap parts/modules to see if I can reproduce the problem with known good gear. I really hope it is not the amp at fault - I Googled it up and it is damn sexy looking...

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Life is too short to build slow computers or weak audio!

It is normal for a multimeter to read 0.3 ohms when touching the leads together then to read 0.3 ohms through a circuit?

The disconnecting the battery thing was very hard on the alternator but I was getting annoyed and wanted to see if it does what it should. LoL

el3ments wrote:

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It is normal for a multimeter to read 0.3 ohms when touching the leads together then to read 0.3 ohms through a circuit?

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Perfectly normal, that's why you try to adjust as much out as possible or press the "ref" button with the leads touching to zero it out.

el3m3nts wrote:

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The disconnecting the battery thing was very hard on the alternator but I was getting annoyed and wanted to see if it does what it should. LoL

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That worked up until the 80's or so when GM and others started making self-exciting alternators. Modern ones took it a step further with PWM fired, self-contained and regulated devices and started calling them "Generators" again. Load testing your alt needs to have it removed and taken to a shop test stand and run on a carbon pile under full load these days. Popping a cable off the battery while it is running sets up such a horrendous, life-threatening transient spike that could smoke the regulator and/or bridge rectifiers.

You have been very naughty. ;>

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Life is too short to build slow computers or weak audio!

I am thinking about picking up this amp. It is fairly cheap and it's name brand at least. I want something cheap for now to ensure I don't spend a lot of money on buying another amp in case my amp works properly.

Clarion DPX11551

I can get it new for $200. Are Clarions a decent brand? Do they over rate their amps?

Hopefully I will either get an amp to borrow or be able to buy a cheap one soon to see if it fixes the issue.

Hi guys. This will probably be my last update on this situation.

This morning I was awakened by my grandmother ringing my door bell. She asked me why my windows were broken and the doors are open. I looked at my car with the trunk and hood in the air and doors open and said "Because I got robbed".

They took all of my stereo equipment. They took my MSD spark plug wires. They nearly pulled off my intake and it looked like they were trying to decide if they wanted to take my HIDs or not.

Flash back...

A few days ago, I believe it was Friday, I took my car for a test run to see if they amp was working properly after some troubleshooting. About 7 blocks from my house some teenagers were staring at me as I went by. They turned and drove the same direction I was traveling. I turned my stereo off because I was getting near my neighborhood. I took two turns to get on the street my house is on and I noticed they were still following me. I'm paranoid of things like this so I drove past my house. They turned off on a side street so I just pulled into a drive way and turned around. I parked walked toward my house. I looked at the street and saw that same car with those punks in it. They slowly drove by and stared at me and my car.

When this happened I knew I was getting robbed. I was literally waiting for it to happen. Today it did.

I figured I could either live in fear and remove my stereo and not enjoy it or enjoy it and risk it being taken. I chose to enjoy it. Now you make think I was very smart for not doing more to prevent this after I saw them follow me but what could I really do? If they wanted my stereo or anything on my car they would just wait for it to be put back in and take it. I have two cars so that one sometimes just sits there for days.

My next project will be an alarm with a battery back up.

Thank you guys for your help.

I am unhappy to hear that you got robbed. :( Good luck next time and yeah - security of some type should be in the plans.

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Life is too short to build slow computers or weak audio!