Testing Pre-Outs

[kdhorne73]

More problems with my stereo. How do I test RCA Pre-Outs. The 2 that go to my Infinity Bass Link Powered Sub must not be working, or my Amp is blown in the Infinity Bass Link Powered Sub. The light go's on but there is not sound now. It worked fine the past few days. If it is in deed the RCA pre-outs I am getting a little bit concerned with the Pioneer Brand Head Units. I am on my second head unit now due to Pre-Out issues. May have to change over to Alpine like I had before. I picked Pioneer because I was told they produced a more detailed sound. Anyhow if someone can tell me how to test RCA pre-outs that would help me out a lot. Thanks for your time again.

[Perry Babin]

Meter set to AC volts.

One probe on the shield, the other probe on the center conductor

Volume set high (1 notch from maximum with all tone controls set flat and all equalization and crossovers off)

All RCAs unplugged from amplifiers

If you don't have an auto-ranging meter, set it to 20v (or something close).

Play a low frequency test tone (~60Hz). If you don't have a test tone CD, burn the following file onto a disc.
http://www.bcae1.com/temp/60hz60seconds.zip

The head unit will produce 2v or more if it's working properly.

There's nothing wrong with Pioneer head units. If the fuse blew, there was a reason. They do NOT blow for no reason. The fuses are there to prevent fires in case voltage is applied to the RCA shield. Without this protection (or similar protection), it's possible for the RCAs to burn the length of the vehicle if the shield is allowed to contact the main 12v wire feeding the amps (which happens often).

[kdhorne73]

Perry thanks again for your reply. I have not tested anything as far as output on the RCA outs. I have no experience with testing anyting electrical. The only thing I know is how to somewhat hook components together. It has been a couple of days since my Infinity Basslink stopped working. It was weird because today I was really cranking up the volume on a Lenny Kravitz song and the sub started to work again. It worked for about 2 more songs and then it cut in and out and just quit all together again. Not sure what the heck is going on. Maybe the ground is not as good as I thought. Will the Red LED light still go on if the ground is not good. I have it attached to the top side of the bracket that bolts to the floor board. This is what bolts the back seat to the floor. It is painted black and the floorboard has paint on it as well. I'm just not sure what the problem is. It is hard to find a good ground in this car since it is a 2003 Toyota Camry that is a uni body constructed car. Any thoughts on this Perry. Hope to hear back from you. By the way like I said I no nothing about testing electrical current. Is it called a DB meter that you were talking about? Please give me input if you get a chance. Thanks for your help.

[Perry Babin]

meter = multimeter

Sand down to bare metal on the floorpan of the vehicle and ground the amp with a 1/4" bolt and nut and you will have a good ground. Be sure to drill through where there are no fuel lines, brake lines and no wiring. Be careful not to drill through the gas tank.

If you use the same ground point you're currently using, you should sand down to bare metal where the ring terminal contacts the floor of the vehicle.

You can check your ground by setting your multimeter to DC volts, powering up the amp and measuring from the ground terminal of the amplifier to a known good ground. You should read well under 0.1v DC.

Dies this basslink have a remote turn on wire or does it turn on via a signal from the RCAs?

[kdhorne73]

This sub does have a remote turn on wire to it. It is turning on or powering up just fine and it stays on the whole time my stereo is on. The remote turn on wire is ran in conjuntion with the power wire. Would this still power on and not produce sound if the ground is in deed not a good ground? Thanks again Perry I really do appreciate you time and your knowledge. I wish you were my next door neighbor then I could have you come over and look at this for me. Thanks Again!

[Perry Babin]

It's possible that the light would come on with a bad ground.

Using your multimeter... if you place the black probe on the ground terminal of the amp and the red probe on the B+ or remote turn on and you get 12+v on both the B+ and remote and they never fall below 12v, the supply voltage and the ground connection are OK.

Did you test the output of the head unit?

[kdhorne73]

I have not tested the head unit yet. I need to buy a test meter or borrow one from somone here at work if I can find someone who has one. I am assuming that the 60 Hertz thest would be at the head unit on two RCA's that are coming out for the sub outs. The head unit only has two outputs for the sub but the Infinity Basslink Sub has 4 RCA inputs. I think they are a left and a right on the Basslink Amplified Sub. Both the left and the right on the Basslink have a pair of RCA's going into the unit. Sorry for my lack of knowledge Perry. I will try to get some testing done on both the head unit and the Basslink this coming weekend. THANK YOU SO MUCH FOR YOUR HELP! I just want to be able to enjoy nice sounding music in my car again. It is the only time I get to enjoy music at higher volumes since I have a wife and two kids.

[kdhorne73]

Didn't get a chance to test the pre-outs yet. I will be doing this in the next week or so. I am going to borrow a meter to do the testing.

[kdhorne73]

OK I tested the pre-outs on with test meter set to AC volts. Actually all I had to borrow for now was an AC tester. At the end of the RCA cables going to the Infinity Bass Link with the 60 Hertz tone test I received 3.9 to 4.0 Volts. I guess the head unit is putting out the signal. Trying to figure out if I should take apart the Infinity Bass Link Sub and investigate the issue. I know that I only have 2 Sub outs and there are 4 low level inputs on the Basslink unit. I think I had one pre out to the left and one on the right. It hit really hard this way. I think maybe this was what may have messed up the unit. I think I should have had either the left or the right hooked up and not one pre out to the left and the right. I'm not sure though. Maybe I need to split each pre-out to to connect all four pre ins on the Infinity Bass Link. Any suggestions. I can't afford a new Basslink or a new Amp and Sub. Any help would be greatly appreciated at this point. Thanks again for your help Perry.

[Perry Babin]

Is the basslink under warranty?

If not, what is the exact model number?