98 v70: how to add a sub/1ch amp to sc901?

[CIK7]

I have the entire sc901 setup installed except the center channel speaker. I also have a JBL GTX500 mono amp, Skar 6.5" sub, and a complete Nissan double-sub-w/-amp donut box. I know how to hook up the subs to the JBL amp but how do I connect that to the sc901?

[RickHaleParker]

I also have a JBL GTX500 mono amp,

The GTX500 manual tells you to hook the GTX500 inputs to the head unit speakers. Use the included Wired to RCA adapters to connect the rear speaker in the car to the GTX500 inputs.

Watch the polarity audio wires so you don't get sound waves 180° out of phase. They would cancel each other out and nullify the bass output from the SC901. You would only get the difference between the SC901 and the GTX500. If you do the polarity right you get the sum of the SC901 bass and the difference between the SC901 and the GTX500.

When two wave forms of equal frequency are in phase, resulting amputate is the sum of the two as shown.

This shows 180° out of phase and equal amputate. If the amputate is not equal the resulting amputate is the difference between the two.

The different waves is expected. In music that is called mixing.

[CIK7]

I also have a JBL GTX500 mono amp,

The GTX500 manual tells you to hook the GTX500 inputs to the head unit speakers. Use the included Wired to RCA adapters to connect the rear speaker in the car to the GTX500 inputs.

Watch the polarity audio wires so you don't get sound waves 180° out of phase. They would cancel each other out and nullify the bass output from the SC901. You would only get the difference between the SC901 and the GTX500. If you do the polarity right you get the sum of the SC901 bass and the difference between the SC901 and the GTX500.

When two wave forms of equal frequency are in phase, resulting amputate is the sum of the two as shown.

This shows 180° out of phase and equal amputate. If the amputate is not equal the resulting amputate is the difference between the two.

The different waves is expected. In music that is called mixing.

I just finished hooking everything up except the Bose amp and the 'turn on' and 12v to the JBL amp. Ill do that tomorrow after installing 2 missing fuses.

[CIK7]

I also have a JBL GTX500 mono amp,

The GTX500 manual tells you to hook the GTX500 inputs to the head unit speakers. Use the included Wired to RCA adapters to connect the rear speaker in the car to the GTX500 inputs.

Watch the polarity audio wires so you don't get sound waves 180° out of phase. They would cancel each other out and nullify the bass output from the SC901. You would only get the difference between the SC901 and the GTX500. If you do the polarity right you get the sum of the SC901 bass and the difference between the SC901 and the GTX500.

When two wave forms of equal frequency are in phase, resulting amputate is the sum of the two as shown.

This shows 180° out of phase and equal amputate. If the amputate is not equal the resulting amputate is the difference between the two.

The different waves is expected. In music that is called mixing.

Would this create a high pitched squeal? I dont have static or buzzing. I have a high pitched squeal that has blown the factory radio/amp fuse #7 twice. What could this be?

[CIK7]

I will provide pictures of all connections tomorrow. BTW I disconnected the Bose donut box because it was causing echo booming any time I opened and closed a door. I might hook one of those subs to the center channel. The #7 fuse blew first time by turning up the volume a bit and bass down. Second time is when I disconnected one of the RCA connections.

[RickHaleParker]

Would this create a high pitched squeal? I dont have static or buzzing. I have a high pitched squeal that has blown the factory radio/amp fuse #7 twice. What could this be?

No.

Squeal: check your power grounds. If they are at different potentials that can cause squealing. For example one grounded to the metal chassis and another grounded through a small wire. Measuring the voltage from one ground to another ground will tell if you got this problem. Ideally the difference should be zero with the equipment turned on.

Too small of power cables on the amps can cause squealing and even damage a Amp when the amp is drawing a lot of current. The voltage drops across the cables .... or a bad ground.

[CIK7]

Would this create a high pitched squeal? I dont have static or buzzing. I have a high pitched squeal that has blown the factory radio/amp fuse #7 twice. What could this be?

No.

Squeal: check your power grounds. If they are at different potentials that can cause squealing. For example one grounded to the metal chassis and another grounded through a small wire. Measuring the voltage from one ground to another ground will tell if you got this problem. Ideally the difference should be zero with the equipment turned on.

Too small of power cables on the amps can cause squealing and even damage a Amp when the amp is drawing a lot of current. The voltage drops across the cables .... or a bad ground.

Pics attached of trunk connections. To connect the blue 'turn on' wire, I created a 3-wire branch for the ignition wire on the harness on back of radio (pin 13). I put the ground through the bolt that holds the left side of the third row seat down. If I cant figure this out, Im going to disconnect the amp/sub and wire the Skar sub to the center channel of the SC901.

[RickHaleParker]

Take the ground bolt out an clean the metal, frame, lug, bolt, washer and threads.It should be shiny bare metal. Any coating will increase the resistance. Solder the lug to the wire that, will decrease the resistance also. Flow the solder into the connection.

[CIK7]

Take the ground bolt out an clean the metal, frame, lug, bolt, washer and threads.It should be shiny bare metal. Any coating will increase the resistance. Solder the lug to the wire that, will decrease the resistance also. Flow the solder into the connection.

Im sorry but I gave up. I hooked up my Skar 6.5 Dual 2ohm VC sub with 4ohm to center channel. Embarrassingly, it took me switching to the dual Bose sub donut to realize the third channel was not activated under 'MODE'. My Skar sounds good, but Ive done some heavy speaker replacements to try to get the sound as close as possible to the 960 and Im still disappointed. Nothing comes close to the 960 sound system. Mozart and Bach sounded insanely crisp and clear. The Gittup, Wipeout (Fat Boys), Old Time Rock and Roll, and Lecrae were insane with the snaps and the lows. Mmmmmmm. Ill give Mozart a whirl tomorrow.

[abscate]

The best sound system in any car, ever was when Honda merged their Accord with the Saturn Ion for one year only car.