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Tunnel Vision
07-19-2006, 07:27 AM
I bought my DCB last year (used) and noticed that while listening to a CD it would play seven songs and then crap out and all you would hear is some base from the woofers.
So I thought I had a battery(s) going on vacation and had them both tested and was assured they were fine.
So my next find was the amp(s) 1-base & 1- 4 channel were hot enough to fry an egg on and DCB mounted them under the bow so I added fans, nope still craps out at seven songs.
So this last weekend I was talking to a friend that is much more savvy than I about audio systems and he noticed that there was next to nothing coming from the rear speakers, he had me fade it to the rear speakers, adjust the volume up were it sounded fine and then fade it a little to the fronts and WOW it sounds like I thought it should and we probably listened to 10-12 CD's without any issues.
So here are my questions:
1) Why would I have to set the head unit to bias mostly to the rear with very little fade to the fronts? Should'nt I be able to set the fader in the middle of the range?
2) Could this have been my problem last summer, I was over working the 4-channel and it would go into a safe mode therefore I could only hear base thump?
The components are all DCB installed:
Sony head unit
Rockford Fosgate amps and (2)10" woofers
Crystal (4)6.5"
Thank you in advance
TV

T-56
07-19-2006, 08:11 AM
Sounds like a partial short in either the head unit or in the ... uhm... something. As if the head unit (or it's output transistors) is overheating from too low of an OHM load and is shutting down to protect itself.
$0.02....

rivercrazy
07-19-2006, 08:20 AM
Your problem is probably the fact that your using Rockford Hotplates. They are notorious for heat/shutdown problems....

phebus
07-19-2006, 08:34 AM
You should check the gains. It sounds like you have more gain to the front channels, then the rear.

h2oski2fast
07-19-2006, 10:27 AM
You should check the gains. It sounds like you have more gain to the front channels, then the rear.
That is definately the problem. The gain is set too high on the front half of the amplifier which is causing the front speakers to clip (do to having to compensate for the rear gains being set too low). After the amp heats up it's more susceptible to going into protection from a clipped signal. Set the head unit to controls (bass, treble, fader, and balance) to zero just the gains from there. If you don't know how to set the gains properly, take it to a professional (it will help in getting the most out of the system).

Tunnel Vision
07-19-2006, 11:06 AM
Thank you guys,
I do have the manuals on the amps I will check to see if they tell me anything. The hardest part is going to be getting to the amps thru the small bulk head opening in a mach22.
The sub amp adjustments should be fine the way it is, right? So adjust the four channel only?

Jesster
07-19-2006, 12:13 PM
Adjust all the gains correctly, including the sub amp. Dont assume it is correct because it wasnt shutting down, sub amps are far more efficient and probably wont be forced into shutdown.
For the 4 channel amp set everything to zero including the gains on the amps. Disconnect the front or rear RCA cables (not both) bring the volume up to a few clicks below max, turn the gain up on the amp that has the RCA's still connected until you hear the speakers clip and back it of slightly. Reconnect the other RCA's and disconnect the ones you just did. Repeat the steps.
There is a lot more that needs to be addressed like crossover points and HP, LP filters so it would be best to take it to a Pro or find one of the experts on the water sometime and offer a case of their favorite beverage to hook you up.