no vocals

[bob zee]

i just installed a crunch 4 channel amp in a 2007 toyota tacoma.

there are no vocals coming through. the balance left to right doesn't
do anything - the volume stays the same in all speakers. i have
obviously crossed something, but what?

i have the amp set to 3 channel. the third channel is driving a sub.
the other two channels are driving the door speakers.

i pretty much suck at life, so....
:~)>

bob z.

[e-nigma]

"bob zee" > wrote in message
oups.com...
>i just installed a crunch 4 channel amp in a 2007 toyota tacoma.
>
> there are no vocals coming through. the balance left to right doesn't
> do anything - the volume stays the same in all speakers. i have
> obviously crossed something, but what?
>
> i have the amp set to 3 channel. the third channel is driving a sub.
> the other two channels are driving the door speakers.
>
> i pretty much suck at life, so....
> :~)>
>
> bob z.
>

Do you have the xover set to high pass for the channels going to the door
speakers?

[Matt Ion]

bob zee wrote:
> i just installed a crunch 4 channel amp in a 2007 toyota tacoma.
>
> there are no vocals coming through. the balance left to right doesn't
> do anything - the volume stays the same in all speakers. i have
> obviously crossed something, but what?
>
> i have the amp set to 3 channel. the third channel is driving a sub.
> the other two channels are driving the door speakers.
>
> i pretty much suck at life, so....
> :~)>

You sure you have the proper inputs and outputs matched? What's
happening is a cancellation effect caused by combining the two inputs
out of phase... if you have the inputs set to "mono" or "bridged" for
the front speakers' channels, it could do this.

[bob zee]

On Aug 4, 7:09 pm, "e-nigma" > wrote:

>
> Do you have the xover set to high pass for the channels going to the door
> speakers?

yes, i did play with most of the settings for the amp. i don't think
i have given enough info in my original question and i will try to add
more info.

thank you for the reply!!!

bob z.

[bob zee]

On Aug 4, 7:16 pm, Matt Ion > wrote:

> You sure you have the proper inputs and outputs matched? What's
> happening is a cancellation effect caused by combining the two inputs
> out of phase... if you have the inputs set to "mono" or "bridged" for
> the front speakers' channels, it could do this.

i am not sure if i have the inputs and outputs correct. i just went to
the garage after reading yours and e-nigma's replies.
i double-checked my ground. it seems to be pretty good. i double-
checked the switch on the amp. it can be set to 2, 3, or 4 channel
mode. i had it set on 3 channel. i unplugged the hi-level input
harness that is feeding channels 3 and 4 (bridged to one channel, i am
assuming when the switch is set to 3 channel). after i unplugged the
harness and switched the amp to 2 channel mode, the audio is perfect
and the balance works properly in the door speakers. a little too
many adult beverages to work on it much more this evening, but i am
now guessing from your input, Matt, i might have the mono third
channel wired wrong - could i have pulled a positive feed from the
right and from the left? the sub was hitting really hard.

thank you, everyone for the replies.

bob z.

[Matt Ion]

bob zee wrote:
> On Aug 4, 7:16 pm, Matt Ion > wrote:
>
>> You sure you have the proper inputs and outputs matched? What's
>> happening is a cancellation effect caused by combining the two inputs
>> out of phase... if you have the inputs set to "mono" or "bridged" for
>> the front speakers' channels, it could do this.
>
> i am not sure if i have the inputs and outputs correct. i just went to
> the garage after reading yours and e-nigma's replies.
> i double-checked my ground. it seems to be pretty good. i double-
> checked the switch on the amp. it can be set to 2, 3, or 4 channel
> mode. i had it set on 3 channel. i unplugged the hi-level input
> harness that is feeding channels 3 and 4 (bridged to one channel, i am
> assuming when the switch is set to 3 channel). after i unplugged the
> harness and switched the amp to 2 channel mode, the audio is perfect
> and the balance works properly in the door speakers. a little too
> many adult beverages to work on it much more this evening, but i am
> now guessing from your input, Matt, i might have the mono third
> channel wired wrong - could i have pulled a positive feed from the
> right and from the left? the sub was hitting really hard.
>
> thank you, everyone for the replies.

Hard to say for sure without knowing more specifics on the amp.

As an example, we used to set up "simulated" surround systems on home
amps by disconnecting the rear speaker grounds from the amp and just
connect them to each other, so basically you'd have (left amp +) to
(left speaker +), (left speaker -) to (right speaker -), (right speaker
+) to (right amp +). Even just connecting one speaker between the two +
terminals on the amp would achieve the same effect: anything that's the
same in both channels (vocals, much of the bass) gets canceled out; the
more a sound exists to one side or the other, the more noticeable it is.

You can't do this with car amps because of their floating ground design,
but depending on the input configuration, you may be getting a similar
occurrence on the incoming signal. Check your connections on your input
harness, make sure they're all solid and working, and that the polarity
of everything is right. I assume you're using the high-level inputs
because your deck doesn't have line outputs?

[bob zee]

On Aug 4, 10:50 pm, Matt Ion > wrote:

> I assume you're using the high-level inputs
> because your deck doesn't have line outputs?


yes, i have no line outputs. it is a factory deck.

i am using a crunch 4 channel amp and i just this morning found the
instruction booklet. (i had this amp in my other car for a while - no
problems there, just driving a couple subs)

in the amp instructions (for my scenario), it says to run the left
speaker signal to channels 1 & 3 and the right signal to channels 2 &
4. it does not say to switch from or to 3 or 4 channel mode. i am
assuming that it is supposed to be on 4 channel mode. its not like i
can't hit that switch when the time comes (already hit it a couple
times while things were running).
these instructions are not what i did. i split the right signal and
ran it into channels 3 & 4 to bridge and drive the sub.

i set the outputs from the amp according to the instructions (before i
read the instructions this morning. how lucky am i?) :~)>

i am going to change my wiring to what the instructions show and i
will report back.

Thanks everyone!

bob z.

[Matt Ion]

bob zee wrote:
> On Aug 4, 10:50 pm, Matt Ion > wrote:
>
>> I assume you're using the high-level inputs
>> because your deck doesn't have line outputs?
>
>
> yes, i have no line outputs. it is a factory deck.
>
> i am using a crunch 4 channel amp and i just this morning found the
> instruction booklet. (i had this amp in my other car for a while - no
> problems there, just driving a couple subs)
>
> in the amp instructions (for my scenario), it says to run the left
> speaker signal to channels 1 & 3 and the right signal to channels 2 &
> 4. it does not say to switch from or to 3 or 4 channel mode. i am
> assuming that it is supposed to be on 4 channel mode. its not like i
> can't hit that switch when the time comes (already hit it a couple
> times while things were running).
> these instructions are not what i did. i split the right signal and
> ran it into channels 3 & 4 to bridge and drive the sub.
>
> i set the outputs from the amp according to the instructions (before i
> read the instructions this morning. how lucky am i?) :~)>
>
> i am going to change my wiring to what the instructions show and i
> will report back.
>
> Thanks everyone!

Okay, now it makes sense... typically, when you switch to bridged mode
on a set of inputs, it will invert one input (ie. switch the phase 180
degrees, same idea as reversing the positive and negative). If you do
this on a stereo signal, you end up with the same form of cancellation.

A couple other things you could try: if the deck has separate front and
rear outputs, try running the fronts to channels 1 & 2, and the rears to
3 & 4, to allow you to separate the front speakers from the sub.

The PREFERABLE option would be to use a line-level converter to properly
drop the deck's output to separate line-level feeds. Something like this
is what you want:
http://www.scosche.com/scosche_caraudio.aspx?CategoryID=229&ItemID=SLC4

[bob zee]

On Aug 5, 1:23 pm, Matt Ion > wrote:


> Okay, now it makes sense... typically, when you switch to bridged mode
> on a set of inputs, it will invert one input (ie. switch the phase 180
> degrees, same idea as reversing the positive and negative). If you do
> this on a stereo signal, you end up with the same form of cancellation.
>
> A couple other things you could try: if the deck has separate front and
> rear outputs, try running the fronts to channels 1 & 2, and the rears to
> 3 & 4, to allow you to separate the front speakers from the sub.
>
> The PREFERABLE option would be to use a line-level converter to properly
> drop the deck's output to separate line-level feeds. Something like this
> is what you want:http://www.scosche.com/scosche_caraudio.aspx?CategoryID=229&ItemID=SLC4


putting this amp and sub in ended up being done pretty much on a
whim. i thought i had everything i needed to get it done and mostly
did.
the line-level converter would've been something on the list if i had
planned beforehand to do this. :~)>

i have everything hooked up by the book now and the system sounds
really good. (factory head unit, factory door speakers, 1000w crunch
amp, and 10" pioneer sub in a sealed box).

of course, now i have a new problem. there is a tone that is almost a
buzz that is coming from behind the dash. it is like the seatbelt
buzzer, but is only getting half of the voltage, so it sounds sick.
the fun is neverending!
:~)>

bob z.