Amp issues

[[email protected]]

Ok, i have a 4 ch 2000 wat (max) Legacy amp. It powers 2 10" subs, and
a set of mid ranges with tweeters. I have a panasonic head unit and a
legacy equilizer.

first; when i have music at moderat volumes, i get a loud cracks from
the left sub, and that sub only. I have replaced my old subs with new
ones that have a much higher wattage rating ( 1200 ) than my old ones (
800 ), since the amp can only put out 500 wats per chanal, i dont think
the subs are bottoming out. it kinda sounds like the speaker
connections are too close and arcing is occuring, though non of the
wires are touching or even close to each other!

second; the amp runs fine when the engin is running, (exept for the
first problem) but when the engin is off and the battery power drops to
about 12.5 volts, the speakers start making static and hissing noises,
along with a few clicks and crackles, this is annoing and should not
happen at voltages above 12 V

i dont know what the ishue is, i have tried to fix it, but nothing so
far has worked.
please help!

[MOSFET]

> wrote in message
oups.com...
> Ok, i have a 4 ch 2000 wat (max) Legacy amp. It powers 2 10" subs, and
> a set of mid ranges with tweeters. I have a panasonic head unit and a
> legacy equilizer.
>
> first; when i have music at moderat volumes, i get a loud cracks from
> the left sub, and that sub only. I have replaced my old subs with new
> ones that have a much higher wattage rating ( 1200 ) than my old ones (
> 800 ), since the amp can only put out 500 wats per chanal, i dont think
> the subs are bottoming out. it kinda sounds like the speaker
> connections are too close and arcing is occuring, though non of the
> wires are touching or even close to each other!

First, it would be helpful if we had more information, like exactly what
model amp and what model speakers, and then how have you got the subs wired.
If the impedance is too low, it might be creating problems.

But the fact that it is happening to only one speaker makes me think it
might be what I call "lead slap". This is when the leads that go from the
connection terminals to the voice coil slap the back of the cones when they
are operating at higher volumes. I had this problem once with a pair of
Soundstream SPL12 12" subwoofers. What I did was just use some electrical
tape to tape the leads a little closer to the connection terminals. That
completely fixed the problem. Of course, if YOUR leads are woven into the
spider (as MANY subwoofers are these days) then this is obviously not your
problem.

If "lead slap" is not your problem, give us more info and we will likely
have a better chance of helping you.
>
> second; the amp runs fine when the engine is running, (except for the
> first problem) but when the engine is off and the battery power drops to
> about 12.5 volts, the speakers start making static and hissing noises,
> along with a few clicks and crackles, this is annoing and should not
> happen at voltages above 12 V
>
> i dont know what the ishue is, i have tried to fix it, but nothing so
> far has worked.
> please help!

Does this happen ONLY when you play music or ALL THE TIME as soon as the
voltage drops below 12.5. So, if I understand you, your system is
completely quite (even if playing is nothing) until the voltage drops below
12.5, then all hell breaks lose? Hmmmm. I'm wondering if the hissing is
ALWAYS there, it's just you don't notice it when the engine is running (the
engine noise overpowers the hissing noise). Please clarify this. Is the
hissing there when NOTHING is playing? Is it silent JUST BEFORE the voltage
drops below 12.5 with the engine off?

MOSFET



>

[Kyle]

Ok, The amp is a Legacy - LA1038
The 2 subs are Max Pro - MAXP104D
Since the subs are DVC subs, I wired the coils on each sub in parallel
to give me two 2ohm subs, and each sub has its own channel on the amp,
Ch 3 and Ch 4. the first two are for the mid to high range speakers.

I had the same cracking problem with my old 4ohm subs, so I don't
think that it is the ohms or "lead slap". I got the new subs for
more power, and I was hopping that I would find some wiring issues, but
I found no problems.

And about the lower voltage thing, (all voltage readings so far are
from my cap's display)
The amp is completely quiet when the voltage is above 12.5, it plays
fine, (except for the first thing), and sounds good. This is true with
the head unit on or off. This is not a quiet noise that can be
overridden by the engine or music, it is so loud that it can be heard
inside the house! The noise goes from 0 to insane in a mater of
seconds! When I shut the jeep down, the voltage drops from 14.5 to 12.3
in about 30 seconds, once below 12.5, the amp freaks out! I can put my
battery charger on it, and it brings the voltage up to about 13.2, and
the amp is fine. I tried to adjust the gains but they have no effect on
the noise.

And for your questions;
All hell dose break lose when voltages are below 12.5
There is hissing when nothing is playing (when below 12.5 V)
And it is silent just before dropping below 12.5

By the way, the noise kinda sounds like a staticky hiss with a noise
that sounds like someone ripping an old cloth too close to a microphone
Hope this helps

[winkenstein]

your not helping BOB, your annoying and unwanted here.
i wish i knew where you lived.
so i could have a nice friendly fist to mouth talk with you.

[bob wald]

the reason i say go extra cheap is only he wasted so much on that
legacy...
even i wouldnt try those...
''boss'' is a million times above ''legacy''
i have boss.

[e-nigma]

> wrote in message
oups.com...
> Ok, i have a 4 ch 2000 wat (max) Legacy amp. It powers 2 10" subs, and
> a set of mid ranges with tweeters. I have a panasonic head unit and a
> legacy equilizer.
>
> first; when i have music at moderat volumes, i get a loud cracks from
> the left sub, and that sub only. I have replaced my old subs with new
> ones that have a much higher wattage rating ( 1200 ) than my old ones (
> 800 ), since the amp can only put out 500 wats per chanal, i dont think
> the subs are bottoming out. it kinda sounds like the speaker
> connections are too close and arcing is occuring, though non of the
> wires are touching or even close to each other!
>
> second; the amp runs fine when the engin is running, (exept for the
> first problem) but when the engin is off and the battery power drops to
> about 12.5 volts, the speakers start making static and hissing noises,
> along with a few clicks and crackles, this is annoing and should not
> happen at voltages above 12 V
>
> i dont know what the ishue is, i have tried to fix it, but nothing so
> far has worked.
> please help!
>

1st thing I would do is swap the speakers on the amp. put left speaker on
right channel and right speaker on left channel.
if the noise stays with the same speaker, then it's a speaker problem. If it
changes to the other speaker, then it's an amp of something before the amp
problem

[Kyle]

Ok I tried each sub channel individually on each amp channel and even
flipped the inputs to the amp, the cracking was there every time, so I
guess that I was wrong about only one side having the issue.

[KU40]

did the crackling stay with the same sub when you flipped outputs or did
it change to the other sub?


--
KU40

[Kyle]

both sides had the issue when i was testing them, i guess that i just
couldent tell that it was both channels cracking, so both crack.

[MOSFET]

"KU40" > wrote in message
...
>
> did the crackling stay with the same sub when you flipped outputs or did
> it change to the other sub?
>
EXACTLY. This will tell you whether it's a problem with your sub or your
amp.

As far as the 12.5 volt issue, did you say that the noise was there even
when the HU was off (and I assume your feeding the blue REM wire with 12
volts to keep the amp on with the HU off)? If you have not tried this test,
I would CERTAINLY try it to establish that it is NOT your HU. Or, of
course, you can just unplug the RCA's that go into the amp, this will check
for the same thing. If there is STILL static with the HU not connected then
I would move on and check the grounds to your amp. You might want to try
moving your grounding location, though this is a long shot (a poor ground
MIGHT work with a higher voltage as this means less current, but NOT at a
lower voltage).

And if all that does not work, I'm afraid you have a problem with your amp.
Of course there is ONE expensive solution: a Jacobs Accuvolt. This device
keeps your voltage at a CONSTANT 14.4 volts NO MATTER what voltage it
receives (up to a point, of course, like 10.5 volts). But these device are
not cheap and probably would not be worth the expense.

Sorry I couldn't be more help.

MOSFET

[Kyle]

Ok, I flipped and changed the wires, i discovered that the cracking was
coming from both channels on thee amp, and through both subs

I sent the amp back one time for a broken power supply (or that's
what they said) and it took them almost a month and a week to send it
back. I don't plan to send it back again, I would rather just get a
good amp. Do you guys have any recommendations on good reliable amp
brands? I would like to have music. And reliable music. I have a soft
top jeep, and the radio just doesn't have the power to overpower the
wind noises.

[KU40]

what's your budget


--
KU40

[Kyle]

$1000

[KU40]

oh dang, for a grand you can get a crazy amp. I'd say look at zapco,
kicker ZR, or other high end lines like that. Or are you wanting to
upgrade the subs and other speakers as well?


--
KU40

[bob wald]

go either Infinity or Alpine amp.if it were me.
buy a 4yr service agreement with your extra money.