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car stereo help, PLEASE HELP!!

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magick_man

Forum Magician
Joined
Mar 5, 2004
Location
Bedford, Texas
ok we just installed a full stereo in my mom's 96 impala SS and now we are having a couple of problems
the system:
headunit- stock radio from that car, delco electronics cd/stereo that works fine and she wants to keep it "stock looking"
front speakers- infinity INI 6000CS 6 1/2" component http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8868&qp=0&oid=67912&m=0
rear speakers- infinity INI 9603I 6 x 9" 3 way http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8868&qp=0&oid=67917&m=0
sub- infinity INI 1030W 10" http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8871&qp=0&oid=71444&m=0
front and rear amps- a pair of MTX RT202 http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8865&qp=0&oid=62869&m=0
and the sub amp- sony XM2100GTX http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8865&qp=0&oid=86766&m=0
and we put in a optima yellowtop battery

for now only the 2 mtx amps are plugged in and not the sony/sub

ok now onto the problems

1. when you turn they key to accessory the amps turn on and everything works fine but if you start it from accessory mode something pops and the amps wont play until you restart the car.

2. there is a whine from the alternator, we got a tsunami 2 farad cap and put it on there and it didnt help. would we need to use a "noise filter" also?

those are the main problems so far, whenever we get those worked out we're gonna hook up the sony amp and the sub and hopefully it doesnt cause any more problems.

thank you in advance for any help, it will be very appreciated-
~Magick_Man~
 
First, sounds like your alternator is going bad. Usually whining is a tell-tell sign of such. I would recommend replacing it with a high output model that will better support the amount of power you want to run. Second, double check your grounds and your power cable coming into the amps. I had a similar problem and it was because of a bad ground. Hope this helps.
 
magick_man said:
ok we just installed a full stereo in my mom's 96 impala SS and now we are having a couple of problems
the system:
headunit- stock radio from that car, delco electronics cd/stereo that works fine and she wants to keep it "stock looking"
front speakers- infinity INI 6000CS 6 1/2" component http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8868&qp=0&oid=67912&m=0
rear speakers- infinity INI 9603I 6 x 9" 3 way http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8868&qp=0&oid=67917&m=0
sub- infinity INI 1030W 10" http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8871&qp=0&oid=71444&m=0
front and rear amps- a pair of MTX RT202 http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8865&qp=0&oid=62869&m=0
and the sub amp- sony XM2100GTX http://www.circuitcity.com/detail.jsp?c=1&b=g&u=c&catoid=-8865&qp=0&oid=86766&m=0
and we put in a optima yellowtop battery

for now only the 2 mtx amps are plugged in and not the sony/sub

ok now onto the problems

1. when you turn they key to accessory the amps turn on and everything works fine but if you start it from accessory mode something pops and the amps wont play until you restart the car.

2. there is a whine from the alternator, we got a tsunami 2 farad cap and put it on there and it didnt help. would we need to use a "noise filter" also?

those are the main problems so far, whenever we get those worked out we're gonna hook up the sony amp and the sub and hopefully it doesnt cause any more problems.

thank you in advance for any help, it will be very appreciated-
~Magick_Man~

The capacitor won't fix any noise problems like that. I suggest taking it back if you still can. Try disconnecting the signal cables from the amplifiers, and see if the noise goes away.

As for starting it with the accessory mode, can you check and see if the amplifiers are going into protection mode when you switch it that way?
 
MechaWyvern said:
First, sounds like your alternator is going bad. Usually whining is a tell-tell sign of such. I would recommend replacing it with a high output model that will better support the amount of power you want to run. Second, double check your grounds and your power cable coming into the amps. I had a similar problem and it was because of a bad ground. Hope this helps.

I think he was talking about alternator whine coming through the speakers.
 
alternator whine from the speakers is a sign of a bad ground somewhere.

Unless you're using well shielded RCA's, i'm hoping you didn't run the RCA's alongside the Power wire for your amps.
 
Know Nuttin said:
Unless you're using well shielded RCA's, i'm hoping you didn't run the RCA's alongside the Power wire for your amps.

Running your power wires along with signal cables is almost never a problem. The current induced by the power wire is negligible.

The entire chassis of the car conducts current as well (although not as much as the power wire), but we don't have to isolate our signal cables from the chassis.
 
update

as of right now my dad is switching out the signal wires going from the amp to the stereo.
we were using the speaker "high level" inputs but he is switching them out for double shielded rca cables and hopefully that helps.
also we installed a new alternator but it didnt really change anything.
it is 140 amps so it should be powerful enough, we hope :eh?:
hopefully this fixes it because we are spending crazy amounts of money on this thing and my parents are tapping into their vacation savings to pay for it :bang head *so now me and my brother might not have the house to our selves for the week of the 4th :bang head *

thanks for the help so far, will update when he is done installing the rca cables

~Magick_Man~
 
Definately a ground issue. And why didn't you have Circuit City install all that stuff for you? Generally if you spend more than $100 or $200 in components its a free install?

In any case, replacing the alternator wont make a difference -- although you'll have to worry about a drained battery a lot less often and supply a stronger current to your amps.

Nicer cables always helps (monster cable kit fixes everything, not to much mention a better signal-to-noise ratio).

That Infinity 1030w amp more than likely does have an auto-cut-off. Have you tried turning the player completely off, and then back on? See if that kicks the amps back on (so you don't have to turn the car off and back on)?

-Frank
 
Last edited:
a c i d.f l y said:
Nicer cables always helps (monster cable kit fixes everything, not to much mention a better noise-sound ratio).

If it's almost certainly a grounding issue, then how would buying new expensive cables fix the problem?
 
Azzkiller said:
Running your power wires along with signal cables is almost never a problem. The current induced by the power wire is negligible.

The entire chassis of the car conducts current as well (although not as much as the power wire), but we don't have to isolate our signal cables from the chassis.

I don't know what kind of amps you use, but 100Amps of current (very common in this day and age) flowing through a 4Ga wire WILL induce LOADS of noise into an unbalanced line if ran parallel. If you are talking about supplying 7.5Amps to a Pyramid amplifier, you are probably OK paralleling the power and signal feeds.

The chassis is carrying some current, but look how widely it is spread out. With a 4Ga wire, it is concentrated enough to induce noise and actually create a magnetic feild!

a c i d.f l y said:
Definately a ground issue. And why didn't you have Circuit City install all that stuff for you? Generally if you spend more than $100 or $200 in components its a free install?

Nicer cables always helps (monster cable kit fixes everything, not to much mention a better signal-to-noise ratio).
-Frank

Monster cables might be "OK", but they are a RIPOFF! Not to mention, good cables will not help a poor install (if the power and ground ARE ran together, Monster can not "Magically" fix that with a $50 RCA that I could make myself for $10).

Alternator whine is almost never a sign of alternator failure. 95% of the time it is a sign of poor installation/poor wire routing/poor components - or a combination of the 3 if you shop at CC/BB.

If you have CC or BB install your stereo, why not have Toy's R Us build your PC? Same analogy IMO. You get what you pay for - Point in case with CC's "Free" installs. If you take Audio as seriously as your PC, STAY AWAY from CC and BB. I am an "Audiophile", so I hope I don't come across as "Stuck Up". I tend to have higher audio standards than most, just like the "Hardcore PC Users" here would NOT use AOL, right?

Fo the record, I have done my own installs for the past 15 years. No one else will do it right, or at a price that is right ;). I do it FREE, and spend the thousands I saved on installs on better equipment!

Sounds like one of your components is freaking out on the very short interruption of power on the switched +12. Most of the Switched +12v taps will turn "OFF" when the starter is cranked to allow maximum curerent to the starter. This is making ALL of your components turn OFF and ON very quickly (via the Radio's Amp Remote wire, I hope?).

If you can find a switched +12V source that does NOT cut out when the starter is engaged, this might help. Hook the Radio's "RED" wire to this new +12V source (you can tap it at the Fuse Box, or hardwire if you are comfortable). The Ignition/EFI circuit will obviously be one possible source, but may have induced noise (The injectors and EFI computer are fairly noisy).

Later :cool:
 
ok so he switched the signal wires from straight speaker cable ran to the back for each speaker to now he used a rca converter and rca cables for the signal feed for the amps.
we figured out what the problem was with the mtx amps cutting out,
when you use the speaker "high level" inputs they turn the amp on and off instead of the signal wire so when you turn the car on from accessory mode it trips something in the amp and puts them in "protection mode" or something like that.
and the rca cables for the signal feed's fixed 95% of the whine, the rest was removed by adjusting the gain on the amps, they were on the highest setting.

ok so all the major problems are solved and tomorrow we should be sealing the box my dad made for that sub and tidying the wiring.
ill get pics if i can

thanks for the help, ~Magick_Man~
 
Randyman... said:
I don't know what kind of amps you use, but 100Amps of current (very common in this day and age) flowing through a 4Ga wire WILL induce LOADS of noise into an unbalanced line if ran parallel. If you are talking about supplying 7.5Amps to a Pyramid amplifier, you are probably OK paralleling the power and signal feeds.

Sure but how loud is the music when the amplifier is drawing 100 amperes of current? Can you really hear 50-60dB of induced noise when your stereo is playing over 120dB???? My point is, induced noise most likely isnt going to happen to the point you can hear it.

The chassis is carrying some current, but look how widely it is spread out. With a 4Ga wire, it is concentrated enough to induce noise and actually create a magnetic feild!

True, but it still is creating a magnetic field. ;)

Monster cables might be "OK", but they are a RIPOFF! Not to mention, good cables will not help a poor install (if the power and ground ARE ran together, Monster can not "Magically" fix that with a $50 RCA that I could make myself for $10).

I agree 100 percent.

Alternator whine is almost never a sign of alternator failure. 95% of the time it is a sign of poor installation/poor wire routing/poor components - or a combination of the 3 if you shop at CC/BB.
Agreed :)

If you have CC or BB install your stereo, why not have Toy's R Us build your PC? Same analogy IMO. You get what you pay for - Point in case with CC's "Free" installs. If you take Audio as seriously as your PC, STAY AWAY from CC and BB. I am an "Audiophile", so I hope I don't come across as "Stuck Up". I tend to have higher audio standards than most, just like the "Hardcore PC Users" here would NOT use AOL, right?

Also agreed.
 
magick_man said:
ok so he switched the signal wires from straight speaker cable ran to the back for each speaker to now he used a rca converter and rca cables for the signal feed for the amps.
we figured out what the problem was with the mtx amps cutting out,
when you use the speaker "high level" inputs they turn the amp on and off instead of the signal wire so when you turn the car on from accessory mode it trips something in the amp and puts them in "protection mode" or something like that.
and the rca cables for the signal feed's fixed 95% of the whine, the rest was removed by adjusting the gain on the amps, they were on the highest setting.

ok so all the major problems are solved and tomorrow we should be sealing the box my dad made for that sub and tidying the wiring.
ill get pics if i can

thanks for the help, ~Magick_Man~

My guess is that the high to low converter stage in the amplifier wasnt very good quality, and that was what caused the problem. Anyways, I'm glad that fixed the problem. :thup:

So you are still using the accessory wire as the turn-on lead on the amp?
 
You were likely getting a serious ground loop from the radio's crappy output stage (the built in amp) to the amp's "Speaker Level" input (probably floating ground output stage). Could be the poor transformer in the amp's input as well. If RCA's are avalible, ALWAYS use them over a Speaker level interface...

I get your points on the S/N azzkiller. I think I can't agree. What if the passage of a song has a solo bass note - the mids and highs WILL obviously be audible with a LOUD buzzzzzzzz. We BOTH know IASCA would KILL you for doing that! (I no longer compete - just for my divine pleasure). I prefer to rip my vehicle to shreds, and start from a bare passenger compartment for clean, neat, secure wire routing. I have had my fair share of "Half As$" installs, and I learned from my 15 yeras of "mistakes" and noisy installs (I did work at a specialty car stereo shop about 15 years ago).

My system is cabaple of dynamic range only dreamed about by most, so noise IS VERY VERY important to me. My system averages 95dB S/N to the amps (only 3' of analog RCA's to the 7 amp channels, the rest is Optical TOSLINK from HU, the 2 changers, and the X-Over/EQ/Time Alignment processor - the Sony C90 & XDP-4000x - familiar with it? $2400 retail.) Definately NOT your grandpa's stereo!

On another point, I use a Rockford BD1500.1 on subs, and it has the remote bass control. I had this "Phone Wire" for the bass control knob ran with the power cables. I figured it was not carruing signal, just control voltages/resistance. WRONG! I got a horrible low frequency hum at any volume! Problem was solved by bundeling the bass knob's wire with the RCA's down the center console. So power wires CAN induce noise - even with no sound playing (no extreme current draw with the sound down).

Just some points to consider - Iasca has rules for a reason.

Later :cool:
 
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