Amplifier / HU Settings


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I had posted this in an older thread, reposting it here with few edits. I have a 4-channel JBL GT-X646 amp installed in my Honda Brio with JBL component speakers on front door and a subwoofer in the boot. I have the amp already set in the same way as mentioned in the below quoted thread

In a typical speaker/sub set-up, we HPF (high pass filter) the components to divert freequencies above the filter we have set and LPF the sub so it receives freequencies lower the LPF settings. A typical example is HPF and LPF at 80Hz.
I have set subwoofer on LPF and front component on HPF, Crossover frequencies set in some 45 deg angle in a 32-320 dial and Input levels adjusted as required with the help of the JBL amp manual. I am using a Sony XAV-22 HU receiver which is having another 'Crossover filter' setting, there is no option to disable this filtering in the receiver. My music system is giving decent output but I believe making proper settings on the receiver side can make it even better.

There is a whining sound from my speakers when I play songs in low volume. It increases with acceleration of the car. It is pretty annoying at times. Service centre guys told it may a grounding issue, but they couldn't resolve it (tried in 2 different service centres). :help: Using good quality wiring kits by audison/ Monster can resolve this? Hope they won't cost more than my amplifier and HU itself.

I am a newbie here and I believe I have placed my questions in right place in right way! If not please correct me. [roll]




 
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Hi,

Regarding the whining sound, an ICE technician told me that I can get rid of it with RCA filters. Anyone experienced similar issues and installed RCA filter/ ground loop isolators/ capacitors ? Is there a chance the RCA filters will reduce the audio quality in anyways? Also please suggest some known brands of RCA filter which can ensure the good quality output.
 
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For tuning the Amplifier, you shall first set all your filters on your HU to 0 or simply disable all the filters. Then put the volume at 3/4th level on the HU and play any song which you are familiar with (and know the timings of the beats and effects).
In the amplifier, set the Bass Boost to 0, it is known to destroy subwoofers. Set the knob to HPF on the channels powering the front comps and set it to LPF on the channels powering the sub. Set the LPF to the minimum and increase the LPF to the point where you can hear the MUSIC (Sound of the instruments or singer) from the subwoofer along with the bass. Back off a little. Ideally, LPF should be around 60-80Hz. You can do the same way for the HPF for the front comps but make sure you have someone to adjust the settings for you, while you hear the music at the front. Ideally HPF should be in the 120Hz range where you can clearly identify the instruments without too much sharp noise from your tweeters. While adjusting the gain, decide a volume which would be kept at most times in the car, say 22. Then increase the gain on the subwoofer channels until there is jerking from the subwoofer, back off a little where the sub plays loud yet under control. Now get back on the front seat and adjust the gain on the front channels until the system sounds balanced with the subwoofer. With the amp settings done, you can continue to change the settings on the HU, as and when you want, for different songs individually. Hope it helps.

Can anyone confirm that an RCA Filter and Capacitor is the same?
AFAIK Alternator whine can be corrected with proper grounding or by changing the RCA Cables.
Do let us know the cost involved in solving your problem?
 
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Can anyone confirm that an RCA Filter and Capacitor is the same?
AFAIK Alternator whine can be corrected with proper grounding or by changing the RCA Cables.
Do let us know the cost involved in solving your problem?
Nope Both are different things,

RCA filters are only there to make money and practically of no use.

Capacitors are used in Power cables with amp,

It has nothing to do with signals or RCA.

Alternator whine is result of bad installation or faulty equipment always.
 
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RCA filters are only there to make money and practically of no use
People tell the same about fuel additives and homeo medicines [lol]. They are practically of no use if not used in the right place in the right way.
Can anyone confirm that an RCA Filter and Capacitor is the same?
No. They are not. Capacitors are used in the amp power circuit and RCA filters are connected between RCA audio out of the HU and the RCA audio IN of the amp.
When and Why Capacitors are used?: The amplifier will have occasional higher power demand when they play high bass notes etc. It may cause dimming the lights and will affect other electrical components. Using a higher rated battery is not really needed as this power demand is just occasional and not constant. As you know capacitors can store some current and use it to cater to this high demand of the amp when needed. It also ensures the amp is functioning as how it is intended to be by providing adequate power always. But it have nothing to do with the noises. The sizing of the capacitors can be done by calculating the Farads equivalent to the Watt rating of the amp.

AFAIK Alternator whine can be corrected with proper grounding or by changing the RCA Cables.
Yes. You are right!. It is always better to get it resolved this way. But often it is very tedious to locate the real culprit by fiddling with the cables and grounding. Sometimes different areas/sections of the vehicle may have different ground potentials which causes ground loops (A constant ground current flow from high potential metal part to low potential areas). In such cases things will become much more difficult to diagnose and resolve and you can make life easy by using noise filters. RCA filters have small isolation transformers and DC blocking capacitors inside them which does the job of ground loop isolation.
 
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People tell the same about fuel additives and homeo medicines [lol].
Its a car not a human body,

fuel additives usually clog the injectors so they are more harmful than beneficial(fuel additives).

Yes. You are right!. It is always better to get it resolved this way. But often it is very tedious to locate the real culprit by fiddling with the cables and grounding. Sometimes different areas/sections of the vehicle may have different ground potentials which causes ground loops (A constant ground current flow from high potential metal part to low potential areas). In such cases things will become much more difficult to diagnose and resolve and you can make life easy by using noise filters.
Bad installation should not be covered with all these things,

BTW in how many high end installations have you seen these noise filters.

I have not seen noise filters itself in my life,

Seeing it installed in any good ICEed car is a distant thing.

Though some time back heard that a member in this forum got it installed,

But Alternator Whine was still there, he told me about this upon which,

I suggested him to through it in garbage and do the wiring as I said.

Next day he called me and thanked for the advise.

And that person in Shankar Narayanan
 
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@VivekRj.Dieselhead
Exactly, I also haven't seen RCA Filter in any install, be it high end or low. I also had in mind that alternator whine can be corrected only via proper grounding. But, in this case, I am surprised that the alternator whine has gone.

Anyway, I have a question, do I need to install a capacitor in my car? I am facing dimming problem of the foglamps and the cabin light, during high volumes and bass kicks. Wondering if installing a capacitor would help, actually I don't want to waste money on items if the problem is not solved. The local car assessor guy had no idea about this and instead adviced me to change the wires, saying that adequate current is not provided to the amp! [lol]
 
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RCA filters are like steel implants for broken bones, not everyone have it, so uncommon but they serve some important purpose. But audio transformer isolation technique is used in other professional audio installations also, not just ICE. I completely agree with you guys on the fact it is not the ultimate solution, its a band-aid on the wound [:)]. At the same time I didn't get the logic of if you have't seen something, that become useless stuff.

@Niku Regarding the capacitors its a standard product widely used in installations, especially in SPL setups. You can find capacitors from renowned brands like Rockford and Scosche. You may try with higher gauge power cables if you want, if that doesn't help you can go for capacitors.
 
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@VivekRj.Dieselhead
Exactly, I also haven't seen RCA Filter in any install, be it high end or low. I also had in mind that alternator whine can be corrected only via proper grounding. But, in this case, I am surprised that the alternator whine has gone.

Anyway, I have a question, do I need to install a capacitor in my car? I am facing dimming problem of the foglamps and the cabin light, during high volumes and bass kicks. Wondering if installing a capacitor would help, actually I don't want to waste money on items if the problem is not solved. The local car assessor guy had no idea about this and instead adviced me to change the wires, saying that adequate current is not provided to the amp! [lol]
Caps are needed only in setups having too much power requirement.

A little amount of dimming is fine.

Don't worry its normal, I still advise you to do the installation properly.

RCA filters are like steel implants for broken bones, not everyone have it, so uncommon but they serve some important purpose. But audio transformer isolation technique is used in other professional audio installations also, not just ICE. I completely agree with you guys on the fact it is not the ultimate solution, its a band-aid on the wound [:)]. At the same time I didn't get the logic of if you have't seen something, that become useless stuff.

@Niku Regarding the capacitors its a standard product widely used in installations, especially in SPL setups. You can find capacitors from renowned brands like Rockford and Scosche. You may try with higher gauge power cables if you want, if that doesn't help you can go for capacitors.
Buddy its CAR Audio not human body or engine, what is this band-aid, medicines, fuel additive and all stick to the issues and resolution.

I have not seen filters because I know good installers only,

Who don't do lousy installations which in turn don't require filters.

I would advise you to meet some good installers.

Then you'll see that I am correct,

And people who install these so called filter,

Do nothing except looting you by showing these devices.
 
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Caps are needed only in setups having too much power requirement. A little amount of dimming is fine. Don't worry its normal, I still advise you to do the installation properly.
If the price is not much. I may install one, but otherwise not willing to go for capacitors, as mine is a basic setup, with only comps, basstube and amp (no rear coax.) and the current draw will not be much. I am slowly getting used to the dimming anyway.

Regarding the installation, there are not many good installers here in my area. After getting something installed, under strict supervision, I try to reinstall it myself to achieve perfection. Eg- The wiring was done without any cables, ties, etc. and I had opened up everything later and done the work to perfection.

RCA filters are like steel implants for broken bones, not everyone have it, so uncommon but they serve some important purpose. But audio transformer isolation technique is used in other professional audio installations also, not just ICE. I completely agree with you guys on the fact it is not the ultimate solution, its a band-aid on the wound. At the same time I didn't get the logic of if you have't seen something, that become useless stuff.
Brother did I say that the stuff is useless? I was just surprised at the fact that your alternator whine is gone by installing the RCA filter. Now that you have got it, you have to use it, I can understand. [:)]

Every product would have a purpose. The purpose might be useful or not so useful. But, there isn't anything that is useless altogether.

EDIT - Sorry, I thought the above message was addressed to me. My bad.

@Niku Regarding the capacitors its a standard product widely used in installations, especially in SPL setups. You can find capacitors from renowned brands like Rockford and Scosche. You may try with higher gauge power cables if you want, if that doesn't help you can go for capacitors.
Can you tell more about the price. If it is not much, then I can think of getting one installed. Otherwise, I will learn to live with the dimming. Actually, I don't use the cabin light and foglamps much but at times, it gets irritating. I am using 8 Guage power cable (from Fusion, my budget was low [embarass]).
 
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