My amp is doing some wierd things.
What i had was the subs running off rears and the cabin speakers running off fronts (2 amps, 1 sub per amp, 2 front speakers per amp).
Then i was told to rig up 1 amp to play just the subs (as it's more powerful), and here is where the fun begins...
The amp has a switch, 2,3,4 channel mode. So obviously if i'm running 2 subs i'm gonna bridge them, ch1&2, ch3&4.
If i set them both to the same bass boost(eg. 12dB+) the subs play VERY softly, and distort with any decent volume. If i set the amp to 3 channel mode 1 sub sounds awesome, but the other one doesn't do anything (obviously cuz it's not picking up the channel).
Now with the amp in 2 channel mode, 1 sub will sound nice with it set to 12dB+, and the other one on 0, but then 1 sub is going alot harder than the other.
Now here's the part the sh!ts me the most, having them both set to LPF they play very softly, but if i set one to HPF they both go louder, but then once it hits a certain volume the sub playing HPF sounds horrible (as it would).

Sorry if i missed important information, if theres anything you need to know just ask. i need help asap!
Can anyone tell me what the hell is going on?

cheers!

is your amp even bridgeable? if so have u bridged it correctly?

i know on mine i have to Bridge channels 1-3 then 2-4.

if the amp has a switch for channel modes.....wouldnt u just put it on 2 and assume that its doing the bridging on its own? otherwise what is the point of the switch?

also why are u running Bass Boost as in (+12). always turn your gain up first.....Bass boost is just a bullsh|t thing designed to make your subs distort.

is your amp even bridgeable? if so have u bridged it correctly?

i know on mine i have to Bridge channels 1-3 then 2-4.
On 3 channel mode i bridge the 3&4 and have 1 and 2 on speakers. Now with 2 channel mode i've bridged 1&2 and 3&4. I did it this way as the settings on the amp are grouped by 1&2, 3&4. I'm at in class at the moment but after class i'll go have a look at trying to bridge them 1-3, 2-4.


if the amp has a switch for channel modes.....wouldnt u just put it on 2 and assume that its doing the bridging on its own? otherwise what is the point of the switch?
lol yeh my other amp just detects it, but this amp needs the switch for some reason :nuts: . Could be something i'm not doing properly.

The amp is a Boss Audio 1200w amp.

Are ur subs all 4 ohm Single Voice coil?

Or are you loading down 4 channel amps below 4ohm resistance?

Are ur subs all 4 ohm Single Voice coil?

Or are you loading down 4 channel amps below 4ohm resistance?
They are single voice coil, not sure on the ohmage, pretty sure it's 4.
How do i know if i'm loading down a 4 channel amp below 4ohm?

your Amp may not support low pass bridging on one channel..
This would explain why your Second sub would be going soft and the other going hard..

Can you set both to Full Range ??

there are 2 lots of controls, both identical, but one is for channels 1&2 and one is for 3&4.
Running the 1 sub bridged on 3&4 with 2 front speakers in 3 channel mode, the LPF worked fine on channels 3&4 and HPF on the fronts. It's when i set both channel to lpf with 1&2 bridged and 3&4 bridged is when it doesn't sound right. 1,2,3 & 4 can all be set to full, lpf or hpf.

set them to full range and see if it helps

set them to full range and see if it helps
Ok i will try that during my break but wont that make the subs distort quicker?

Ok i will try that during my break but wont that make the subs distort quicker?

In all possibility yes, You just have to set the Gains on your amp properly, take off the Bass boost this will reduce your distortion rate..

ok cool, the only thing i'm worried about is that setting them both to full will do the same as setting them both to lpf, but i'll try that and i'll try the 1-3 2-4 that samurai did, cant hurt :).

Were both subs wired with the correct polarity and to the correct speaker terminals?

Your amp "should" have markings next to your speaker terminals about which channels are the correct ones to bridge/wire together.

OK update, here is what has happened:
Cross over doesn't affect anything, so LPF, HPF or FULL the it doesn't change the situation (apart from the obvious frequency tuning). So let's rule that out.
Now, when i set the bass boost to 0dB on both subs, they are quiet, very quiet, and when turned up (which requires a huge volume change, i had to d/c the inside speakers) they just sound terrible and not loud at all.
When i set the bass boost to 12dB, 1 sub goes abit louder, but distorts real quick, and the other is just as soft as before. Putting them both at 12dB they both go quiet as before.

Now when i d/c a sub (either 1&2 or 3&4, it doesn't matter), the sub that is still plugged in goes well and very nice, the way it's suppose to! Then as soon as you connect the other sub, they both go quiet again :(.

Anyone have any ideas on what is happening?
Also tried the 1-3 2-4 and got no sound out of the amp, tried 1-4 and 2-3 though and that got the same result as above.

Also should mention that when i say they go "quiet" they are still working, just do jack all unless turned way way up, to which they arn't even loud and sound shocking.

It is a 4 channel Amp??
Does it have four Channels of RCA input running into it or only Two ??

It is a 4 channel Amp??
Does it have four Channels of RCA input running into it or only Two ??
Yes it is a 4 channel amp, it's a Boss 4x300watt (1200w total). It has 4 RCA channels input, i've got the 2 RCA's coming from the head unit, split into the 4 channels of the boss amp. Then the 2 channel output of the boss amp split into 4 again to go into my 800w amp.

The amp has a switch, 2,3 or 4 channel mode. My 800w amp just detects what mode it's in automatically.

Ok, I see, Now are the RCA's wired in Correctly?

Are the Gains set Equally ??
Make sure your gains are at 0.
Level set your System. To do this , Turn your Deck up to just before it distorts the Internal speakers, then adjust the gains on the Amp until the subs play cleanly and not distorting.


It is a Boss Amp, they have been known to cause big problems..
Does your Deck have a Sub out ??
Check your Head unit settings

Are your subs in one Big Enclosure or Two seperate ones??

Fault finding is a process of elimination..

I didn't think it mattered which way the RCA's are wired in???
What i might actually try is d/cing the output signal from the boss amp, that might be causing problems maybe?
Gains were at FULL when testing, with the HU at a lowish volume, i've tried with lower gains and it just makes the subs barely noticeable.
Pretty sure my deck only has 1 RCA output (as in 2 channels). The subs work fine, but they are in serperate boxes.
Headunit settings dont really affect whats happening here.

Ok, I see, Now are the RCA's wired in Correctly?

Are the Gains set Equally ??
Make sure your gains are at 0.
Level set your System. To do this , Turn your Deck up to just before it distorts the Internal speakers, then adjust the gains on the Amp until the subs play cleanly and not distorting.


It is a Boss Amp, they have been known to cause big problems..
Does your Deck have a Sub out ??
Check your Head unit settings

Are your subs in one Big Enclosure or Two seperate ones??

Fault finding is a process of elimination..


just to add to that.......

do u know what you're doing? :bowrofl: lol

OK Guys i kinda flukily fixed it.
Now i dont understand why hell this happened.
All i did was switch the + and - around on the 2nd sub and the thing kicked in and they sound sweet now. What i dont understand is why would this need to be done? Now i know the subs weren't in the wrong terminals because if you d/ced 1 sub the other would play fine. So i even tried switching the other terminals around and putting my newly fixed one around the "wrong" way and it kicked in as well. So in 2 channel mode for some reason 2 of the channels reversed their polarity, can anyone explain why????

Its a Boss amp.. no explaination needed.

OK Guys i kinda flukily fixed it.
Now i dont understand why hell this happened.
All i did was switch the + and - around on the 2nd sub and the thing kicked in and they sound sweet now. What i dont understand is why would this need to be done? Now i know the subs weren't in the wrong terminals because if you d/ced 1 sub the other would play fine. So i even tried switching the other terminals around and putting my newly fixed one around the "wrong" way and it kicked in as well. So in 2 channel mode for some reason 2 of the channels reversed their polarity, can anyone explain why????

I have this ****ing amp in my brothers car and it does the same thing. Only thing i can think if is they stuffed up when labelling the + and - symbols on the amp.

The reason they sounded ****ty was because they were phasing each other out i guess.

I have this ****ing amp in my brothers car and it does the same thing. Only thing i can think if is they stuffed up when labelling the + and - symbols on the amp.

The reason they sounded ****ty was because they were phasing each other out i guess.
Yeh but that cant be because if you just have 1 sub hooked up the + goes on + and - on -, but with 2 channels, 1 sub goes on + and+ - and -, and hte other + and -, - and +.
It's ****ing crazy :nuts: . Doesn't matter on which channels you do it on either lol!