troubleshooting, amplifier and subs Options

[pengsm]

hey peopleZ, anywho i got this JVC 600watt 2channel amplifier, and i hooked it up to 2 12'' Pioneer subwoofers, (800 watt each), and it is not hitting it right, but when i try wiring to only one sub, it's loud as hell, and then i went back and wiring it again to two subs, it does the same thing.

can anyone help me??

thnx.

[trdproven]

show me a picture of your wiring, sounds like you are not bridging it right or connecting it for that matter or defective amp.

[tonytutino]

also what gauge is your amp wiring?

[trdproven]

^ All wires must match the power handling. Remote wire is the only one that doesn't matter.

[crankyelbow]

This is most certainly an issue of phase.

Switch the + and - on one of the subs and they will match phase and be significantly louder than the one sub

To clarify your mistake...

You likely wired one sub correctly:
Positive from the amp to positive of the sub
Negative from the amp to negative of the sub

And one incorrectly:
Positive from the amp to negative of the sub
Negative of the amp to positive of the sub

What happening is with the one sub wired different than the other (called out of phase), one sub moves in while the other moves out - effectively cancelling the sound out almost completely! Furthermore, its irrelevant whether the amp + is to the + of the sub and so on, you can wire properly or inverted and it won't matter - all that matters is when you have more than one sub they be wired the same way.

If you want to understand these sorts of things, read up on ohms law and the differences between A/C and DC (your amp takes 12v DC from the vehicles charging system and converts it to A/C to power the speakers).


Additional not so sub related info on phase:

In a car it is sometimes a GOOD idea to wire say, the front speakers out of phase with the rear... or in some rare cases even the front speakers out of phase! Since your not sitting in the middle of the 2 speakers, the pressure waves are not going to be getting to your ears at the same time... hence there is phase distortion regardless of how you wire the speakers. Given the length of the wave of lower frequencies, wiring subs and/or any speakers providing bass frequencies of phase with eachother will cause cancellation at the ear... but when dealing with the shorter waves of high frequencies sometimes wiring the speakers out of phase will make the sound arrive at your ears IN phase!

Thats to say, its not likely that you will want to wire your midwoofers (front door speakers) out of phase... but there is a possible gain from wiring the tweeters out of phase.

I have yet to really toy with phasing in the celica, but I have noticed there is (in my hatchback) a pretty big phase issue between the front and rear speakers. With just the front speakers on, the bass is clear and well defined - they actually play pretty low! With all the speakers on, the bass becomes muddied and there is big cancellation in the lowest frequencies. Since the arrangement in my yaris is the same, I'd bet wiring the rear speakers out of phase with the front speakers will actually IMPROVE bass response! I urge anyone who may read this to due some critical listening (car off in a relatively quiet place) and see if you can tell the difference.

Some radios (kenwoods) invert the phase when the crossover is turned on or off... some have the option to invert the phase, but most will only have direct phase control of the sub (worth playing with for sure!)... this is all equivelant to switching both of the speakers (be it front or rear) + and -, so they are both in an inverted phase, but not OUT of phase (hopefully by now you understand what I mean ).

Playing with the phase, crossover settings, and fader can make ALL the difference in regards to sound quality

[pengsm]

This is most certainly an issue of phase.

Switch the + and - on one of the subs and they will match phase and be significantly louder than the one sub

To clarify your mistake...

You likely wired one sub correctly:
Positive from the amp to positive of the sub
Negative from the amp to negative of the sub

And one incorrectly:
Positive from the amp to negative of the sub
Negative of the amp to positive of the sub

What happening is with the one sub wired different than the other (called out of phase), one sub moves in while the other moves out - effectively cancelling the sound out almost completely! Furthermore, its irrelevant whether the amp + is to the + of the sub and so on, you can wire properly or inverted and it won't matter - all that matters is when you have more than one sub they be wired the same way.

If you want to understand these sorts of things, read up on ohms law and the differences between A/C and DC (your amp takes 12v DC from the vehicles charging system and converts it to A/C to power the speakers).


Additional not so sub related info on phase:

In a car it is sometimes a GOOD idea to wire say, the front speakers out of phase with the rear... or in some rare cases even the front speakers out of phase! Since your not sitting in the middle of the 2 speakers, the pressure waves are not going to be getting to your ears at the same time... hence there is phase distortion regardless of how you wire the speakers. Given the length of the wave of lower frequencies, wiring subs and/or any speakers providing bass frequencies of phase with eachother will cause cancellation at the ear... but when dealing with the shorter waves of high frequencies sometimes wiring the speakers out of phase will make the sound arrive at your ears IN phase!

Thats to say, its not likely that you will want to wire your midwoofers (front door speakers) out of phase... but there is a possible gain from wiring the tweeters out of phase.

I have yet to really toy with phasing in the celica, but I have noticed there is (in my hatchback) a pretty big phase issue between the front and rear speakers. With just the front speakers on, the bass is clear and well defined - they actually play pretty low! With all the speakers on, the bass becomes muddied and there is big cancellation in the lowest frequencies. Since the arrangement in my yaris is the same, I'd bet wiring the rear speakers out of phase with the front speakers will actually IMPROVE bass response! I urge anyone who may read this to due some critical listening (car off in a relatively quiet place) and see if you can tell the difference.

Some radios (kenwoods) invert the phase when the crossover is turned on or off... some have the option to invert the phase, but most will only have direct phase control of the sub (worth playing with for sure!)... this is all equivelant to switching both of the speakers (be it front or rear) + and -, so they are both in an inverted phase, but not OUT of phase (hopefully by now you understand what I mean ).

Playing with the phase, crossover settings, and fader can make ALL the difference in regards to sound quality

ey thanks for the info man, it reallie helps

[trdproven]

even though there are general knowledge for bridging and amp wiring, there are manufacturer specs for example like internal wiring inside the box, this will change the ohm power. and there are bridging combinations and same goes for ohms. There is also a optimal chart between speaker and amp. Tuning sounds take time because of sound preference, limitation of equipment, or compromise between different types of music (with this just create saved settings like user 1, user 2, user 3 for the different styles)

This post has been edited by trdproven: Feb 24, 2009 - 6:36 AM