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phebus
08-17-2004, 07:32 PM
My woofer which is a JL-W7 has stopped working. I have an Alpine CDA-7893 head unit, which is going into a Rockford Fosgate Power bd1500 amp powering the JL-W7. I have checked all connections, with the exception of the RCA outputs on the back of the head unit (no rear access, must remove head unit to check), and all seems good and tight.
My problem is trying to find where the problem lies, the amp or speaker. Is there a way to meter the outputs off the amp, or do I need to get another speaker to hook up to find out where my problem is. And yes, before someone asks, the amp has power, and the power light is on. Also, the head unit is adjusted to power the sub.
Thanks

Havasu Hangin'
08-17-2004, 07:41 PM
You could put a voltmeter on the speaker sub wires (make sure it's on "AC"). Or, you could put a little 5.25" coaxle and see what happens...
If the amp is crossed over to the sub, you could put any signal into it to test it (just switch RCA's).
Does the sub pop or hum (even slightly) when switched on?

phebus
08-17-2004, 08:31 PM
The sub does absolutely nothing. It went from working to not, with no unusual sounds or anything. I need to check the connections on the back of the head unit, I suspect something is loose. Batteries are fully charged, and I had them load tested just recently, so I don't think it is a powere issue.
Now, I just have to figure out how to unlock the head unit so I can slide it out. :confused:

Havasu Hangin'
08-17-2004, 09:03 PM
Although it's not the healthiest thing for the sub, if you pull the RCA's on the amp (while the stereo is on), it should make a pop (turn the gains down if you can). If it doesn't, it's probably in the amp or sub.

ROZ
08-17-2004, 09:05 PM
Unless your RCA's are disconnected from your headunit, there's no reason to back it out. The amps are turning on, so the remote turn-on is operational....

phebus
08-17-2004, 09:17 PM
Yes, amp nis turning on, so remote is good, but what about the pair of RCA jacks that run from the head unit to the amp. If they are loose or not connected would it cause the no output problem?
I just figured the first thing to do to trouble shoot was to check all connections.

ROZ
08-17-2004, 09:17 PM
Since you obviously have more than one amp, you can test signal output from the headunit by switching the rca's between your rear channels and yor sub output. You can do it at the amps if you have enought rca length, or at the headunit if you have access there... I suggest turning the headunit's volume all the way down and thru the monoamp's crossover up to around 120-150hz so you can easily hear the amp's output through your rear channel speakers without blowing them... Making the switch at both the amp and headunit rca's will help rule out a bad RCA cable...

ROZ
08-17-2004, 09:20 PM
Actually the easiest thing to do is what HH suggested to do with a Voltmeter at the speaker output terminals on the amp if you have one.. Do what I suggested if you don't have one at your disposal...

phebus
08-17-2004, 09:59 PM
I'm in Havasu where I keep my boat, and my meter is back in Ca. I am going in the morning to buy another, i need one here to. If I meter the outputs, and get nothing, can I meter the RCA jacks where they come to the amp to see if they are delivering power? I assume I can, I just don't know what to set the meter to, and what values I should expect. That will let me know whether to pull the head unit and check the connections there.

ROZ
08-17-2004, 10:03 PM
Bummer... Instead of making th epurchase, just swap the RCA conections at the amps if they hapen to be close in location. Heck, Take it to CarToyz and ask for Mr. Naudio to do a basic troubleshoot...

phebus
08-18-2004, 02:20 PM
Haven't gotten to the bottom of the problem yet, but the woofer working/not working is an intermittent one. When I went out this morning the woofer did not work. After fiddling around with various things, it started working, and continues to work. This definitely makes me think I have a loose connection somewhere, now I just have to find it.
Secondly, I am not sure if the system is wired for the best performance or not. Off of a Rockford Fosgate Punch 800 amp, I am running a pair of Alpine 6x9 speakers at the back of the boat, and a pair of Alpine 6x9's in the mid section of the boat Then, at the bow of the boat, I have a pair of Alpine 6.5's wired off the head unit. You have to have the PWR IC set on for them to play.
Does this sound right? Since the boat is here in Havasu, I think a trip to Car Toyz is in my future, but I want to wait till after boating season so I don't have to miss a day on the water.
Thanks to all that have responded,
Rick

Mr. Naudio
08-20-2004, 09:53 AM
Does this sound right? Since the boat is here in Havasu, I think a trip to Car Toyz is in my future, but I want to wait till after boating season so I don't have to miss a day on the water.
Iam going to have to assume the boat is on the water.
In which case I apologize for not seeing this sooner as I just returned from 3 days on the water (little vacation).
Would have been more than happy to look at for ya.
If this is not the case though,I will be at the shop Saturday morning at seven.
We do not require an appointment for troubleshooting.(Or payment)
If the boat is on the water give me a call Sat. 928-680-0203

phebus
08-20-2004, 06:09 PM
I am back from Havasu, but will be back in a couple of weeks. The stereo was installed prior to me buying the boat, and I would like you to look it over, and suggest ways to improve on it. You ill be seeing me soon.
Thanks,
Rick

Havasu Hangin'
08-20-2004, 06:54 PM
I'm gonna lean toward the RCAs. In boats, I have had trouble in the past with the small wires in the center getting brittle and breaking (from flexing), causing what you are describing. I'd bring a spare RCA set, and try it out. You can test them with an ohmmeter, but if the problem is intermitant, it may not surface on the meter.
My second thought would be some broken solder...but that's tougher to find.
Make sure you zip-tie everything tight when you put it back together.
As for the speakers, if they are 4 ohm, wiring all six off the amp will give you a 1.3 ohm load...which will probably overheat that Rockford Hotplate amp.
For maximum performance, perhaps another amp?