ZZ13
Well-Known Member
I have a 9-year old Clarion APX400 2/3/4 channel amp driving the four cockpit speakers on my boat. The wiring is such that the amp receives only the rear RCA output from the head unit (Clarion XMD3) and the amp has the "Rear Channel Input Select" set on in order to drive the 2-channel input to all four speakers. The speakers are Polk MM6501 component speakers with a passive crossover for each speaker set (midrange and tweeter). They have a rated impedance of 2.7ohm. The amp will handle as low as 2 ohm speakers. The amp also has a "rear crossover frequency multiplier" switch" which when depressed increases the crossover frequency of the 2 rear speaker outputs by 10x.
The problem is that occasionally one of the two right speakers will go completely out because the amp stops driving it. I have tried everything to get the sound back (including disconnecting it from the battery power, turning it on/off with the remote on, etc), and I have found that only one thing brings the sound back (and it works everytime), and that is to change the state of the "rear crossover frequency multiplier" (don't need to toggle it - just change its state). I have no idea why this would work.
My only theory is that it is impedence related since the amp is driving 4 outputs from only 2 inputs. If the amp creates the additional outputs by simply internally connecting the front and back channels in parallel, then the amp is effectively seeing 1.35ohm impedance from the speakers, which is under the 2 ohm minimum. Again, even with this theory I don't know why that magic switch brings the sound back. I was thinking of wiring the front and back channels externally in series off the front channel outputs to effectively get 5.4ohm impedence, yet sound on all four speakers.
Anyone have any good explanations and ideas? - trying to avoid buying a new amp if possible.
The problem is that occasionally one of the two right speakers will go completely out because the amp stops driving it. I have tried everything to get the sound back (including disconnecting it from the battery power, turning it on/off with the remote on, etc), and I have found that only one thing brings the sound back (and it works everytime), and that is to change the state of the "rear crossover frequency multiplier" (don't need to toggle it - just change its state). I have no idea why this would work.
My only theory is that it is impedence related since the amp is driving 4 outputs from only 2 inputs. If the amp creates the additional outputs by simply internally connecting the front and back channels in parallel, then the amp is effectively seeing 1.35ohm impedance from the speakers, which is under the 2 ohm minimum. Again, even with this theory I don't know why that magic switch brings the sound back. I was thinking of wiring the front and back channels externally in series off the front channel outputs to effectively get 5.4ohm impedence, yet sound on all four speakers.
Anyone have any good explanations and ideas? - trying to avoid buying a new amp if possible.
