Zhu962

Hey I need some help with my amplifier because like in the title, it's receiving power but my sub woofers won't activate. I checked the fused on the amp and it's all clear and good. It's a Directed 600d Amplifier and as far as I can see all the wires and connections seem good. It used to work just fine but one day it just decided to give me a problem. I'm befuddled. Any help is greatly appreciated. Thanks for looking, and please help?

fcm

I would check the sub, disconnect the subs speaker leads at the amp, use a batt., AA, AAA, C or 9V, [9V works the best] touch the speaker leads to the batt. terminals, speaker should "pop", if it does not pull the sub and check connections in the box, but before you do that try this simple test, using both hands press on the subs cone, does it move in and out freely, no noise, [scratching, scraping]? 94

02 accord

The sub can also be tested by connecting it to the car battery. Makes it much simpler because you already have one, and the 9v you most likely don't and would have to go out and buy.

fcm

LOL, DO NOT connect the sub to the car batt., there are enough CCA in a car batt. to burn the VC so fast the cone will catch fire. 94

02 accord

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fcm &raquo;</TD></TR><TR><TD CLASS="quote">LOL, DO NOT connect the sub to the car batt., there are enough CCA in a car batt. to burn the VC so fast the cone will catch fire. 94</TD></TR></TABLE>

There is no way you will get enough power to the sub to do that. Ohm's law says it all:

12v / 4 ohms = 3 amps.
3 amps * 12v = 36 watts.

I don't see how that would burn the coil. Subs have 100+ watt power ratings, right? Even a 2 ohm coil should hold up. It will only dissipate 72 watts. Shouldn't be a big deal for a sub.


It's the same principle when you have an amp that puts out 2kw at 1 ohm, 1kw at 2 ohms, .5kw at 4 ohms, and 250w at 8 ohms. Let's say you connect an 8 ohm speaker to that amp. Yes, the amp can put out enough current to supply 2kw of power, but according to ohm's law, no more than 250 watts will be sent into the 8 ohm speaker due to the fixed max output voltage.


Modified by 02 accord at 4:10 PM 4/22/2007

Zhu962

subs pop so there's nothing wrong with the subs. I confused...

*edit* I did a ghetto mod to my AA batteries, I combined them to get that 9v you told me

Zhu962

is there something wrong with the amp itself? I really have no clue as to what to do now

fcm

The problem is in the amp or the signal to the amp, try this, reconnect the sub, unplug the RCAs at the HU or at the amp and plug in another set, hold one of the RCA leads in your hand so that you can use your thumb to "short" the the RCAs signal center pin and the RCAs outer signal return sleeve, listen at the sub and touch your thumb, [on and off on and off] to the RCA, if you hear nothing at all from the sub the amp is the problem, on the other hand if you hear a "hum" the problem is the HU or the RCAs.
If for any reason ground is "lost" from amp when its on and turned up even a little, the amp will get it's ground through the signal return and the signal return trace on the circuit board in the HU will blow like a fuse, check amp ground and plug RCAs into another set of RCA outputs if the HU has any, and try it. 94

nsxxtreme

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 02 accord &raquo;</TD></TR><TR><TD CLASS="quote">There is no way you will get enough power to the sub to do that. Ohm's law says it all:

12v / 4 ohms = 3 amps.
3 amps * 12v = 36 watts.

I don't see how that would burn the coil. Subs have 100+ watt power ratings, right? Even a 2 ohm coil should hold up. It will only dissipate 72 watts. Shouldn't be a big deal for a sub.


It's the same principle when you have an amp that puts out 2kw at 1 ohm, 1kw at 2 ohms, .5kw at 4 ohms, and 250w at 8 ohms. Let's say you connect an 8 ohm speaker to that amp. Yes, the amp can put out enough current to supply 2kw of power, but according to ohm's law, no more than 250 watts will be sent into the 8 ohm speaker due to the fixed max output voltage.</TD></TR></TABLE>
You will burn the sub up lol.

The value given is impedence. This is an AC characteristic.
The voltage you are suggesting to supply is DC. DC to an inductor is what?

I'll give you a hint it starts with an S.

khaosman

Do you have a multimeter? Verify that the amp is receiving signal on the RCAs and outputting power.

Perhaps your sub-out level on the head unit isn't turned up. I did that once and was kicking myself for feeling like an idiot :D

wrx-killer-Sti-eater

iTrader: (1)

whats the make and model of the amp?

02 accord

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxxtreme &raquo;</TD></TR><TR><TD CLASS="quote">The value given is impedence. This is an AC characteristic.
The voltage you are suggesting to supply is DC. DC to an inductor is what?</TD></TR></TABLE>

Inductors have dc resistance too. Subs, usually 3 ohms dcr for a 4 ohm sub.

Zhu962

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wrx-killer-Sti eater &raquo;</TD></TR><TR><TD CLASS="quote">whats the make and model of the amp?</TD></TR></TABLE>

Make: Directed
Model: 600d

nimbyfaygo

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 02 accord &raquo;</TD></TR><TR><TD CLASS="quote">
There is no way you will get enough power to the sub to do that. Ohm's law says it all:

12v / 4 ohms = 3 amps.
3 amps * 12v = 36 watts.

I don't see how that would burn the coil. Subs have 100+ watt power ratings, right? Even a 2 ohm coil should hold up. It will only dissipate 72 watts. Shouldn't be a big deal for a sub.
</TD></TR></TABLE>
Mega wrong! We used have contests and each of us connect a sub to a car battery. Even very high power subs will burn pretty quick.

ARMED

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Zhu962 &raquo;</TD></TR><TR><TD CLASS="quote">Hey I need some help with my amplifier because like in the title, it's receiving power but my sub woofers won't activate. I checked the fused on the amp and it's all clear and good. It's a Directed 600d Amplifier and as far as I can see all the wires and connections seem good. It used to work just fine but one day it just decided to give me a problem. I'm befuddled. Any help is greatly appreciated. Thanks for looking, and please help? </TD></TR></TABLE>make sure youre getting signal from the HU...if the AMP is good, signal and subs should be your only problem...

try and check if you have a subwoofer volume maybe its all the way down..or OFF

is the sub completely dead???

mrdeadman

You can take your amp somewhere and they will check it for you. Also, check your RCA outputs on your hu, mine quit one day, because my amp ground wasn't so great.

wrx-killer-Sti-eater

iTrader: (1)

on a funny note, Me and my mtx rep were dicking around with a 9500 12 sub. At the same time we decided to plug it into a wall socket. Do not do this at home. The dam thing went crazy for about 10 min. And ended life with a fountion firework style of sparks. I would not use anything over 9 volts to test a speaker. I seen this installer an cc test to see the phase of a speaker with a 18 volt drill battery. The sound blaaaaaaakak was the loudest sound I ever heard a stock speaker make

I know this was probably useless but owell we covered everything that could be wrong with his setup

fcm

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wrx-killer-Sti eater &raquo;</TD></TR><TR><TD CLASS="quote">on a funny note, Me and my mtx rep were dicking around with a 9500 12 sub. At the same time we decided to plug it into a wall socket. Do not do this at home. The dam thing went crazy for about 10 min. And ended life with a fountion firework style of sparks. I would not use anything over 9 volts to test a speaker. I seen this installer an cc test to see the phase of a speaker with a 18 volt drill battery. The sound blaaaaaaakak was the loudest sound I ever heard a stock speaker make

I know this was probably useless but owell we covered everything that could be wrong with his setup </TD></TR></TABLE> LOL, My question would be, why?
Also its, my MTX rep and I. 94

jz98ctr

maybe i missed it, but i haven't even seen anyone suggest just using the battery from a cordless drill....enough juice to make it pop good but not too much to fry it
just my $.02


Modified by jz98ctr at 9:23 AM 5/11/2007