Problem: Speaker Cut Out at Low Volume

Tesla

Tesla

Tesla

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Joined
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I posted this over on the TalkAudio forums and cannot be bothered to retype it all out:

Hi guys,

Hope you all had an excellent Christmas.

Around 2 months ago I purchased a set of Infinity 6510c Component Speakers to use in my Mondeo Mk2. The rear speakers are stock paper-coned Fords but I do not use them at all.

My other equipment consists of an Alpine 9851R Head Unit and the very popular budget (£150) JBL amp and Sub package from CAD.

I run a Home Cinema installation business so I would like to think I am competent with the cabling side of things and also setting up the equipment, optimising the various settings of the HU and Amp. Obviously Car Audio is proving a little different

The problem I am having is that at relatively low volumes- below 8 on the HU the drivers door speaker is cutting out. When I turn the ignition the HU obviously powers up and usually at a low volume so I only have one speaker working, passenger door. I can overcome the problem by turning the volume up. If I turn the volume back down then the speaker works. I am not 100% sure but I think it is still intermittent at low volumes even after turning the volume up and then back down.

I have tried a few things to resolve or pin point the problem.

When the speaker was not working I faded the audio to the rear, stock ford speakers. Both channels worked fine, fade back to the front and only have the one, passenger side channel.

So I thought that perhaps the Amp in the HU is knackered. I swapped the pins in the ISO block around making the front the rear and vice versa.

I have the same problem. I therefore think that this proves it's a not a problem with the HU?

Any ideas where the problem could lie? The Crossover? Somebody advised me that if it's the crossover then the problem would occur at all volumes.

I bought the speakers brand new off of an ebay powerseller with a store up north. It may be easier for me to contact Infinity if the speaker proves faulty, what are they like in the customer service department?

Any other ideas of things to try?

Many thanks,

Chris
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Any ideas wise OcUK'ers?

EDIT - I should add that when the fault occurs both the tweeter and driver do not produce any sound.
 
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Phil W said:
Sounds like a HU problem to me, have you got a spare/borrow one to see if it makes a difference?
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Why do you think this?

I do not have a spare I can try.

Is it possible to test the speaker outputs with a multimeter at all?
 
I am going to swap the crossover boxes over today as I think that's what is faulty. If I am correct then the problem should switch over to the passenger door.

It's possible that it's the Mondeo speaker wire. If this is the case then how do I get a new speaker cable into the door from the chassis?

Obviously currently it uses the cars original loom which has these funny twisty plugs which connect all the cables from the door to the car at once.
 
With some stereo amps, the output isn't exactly perfect at low levels. If you've got the speakers amped and the gain isn't particularly high, one may appear to work before the other when turning the sound up because in effect it's two seperate amps for a stereo system.

So, running at low levels might be enough to get the signal through one side, but the other hasn't got enough to feed it.. it's difficult to explain. :/

Try balancing the levels between the HU and the amp a bit. If you're relying more on the amp, then reduce the output of the amp a bit, meaning you've got to turn the HU up more. That should hopefully sort the problem unless it's a crossover or cable issue :)
 
I am not using an external amp, the HU is powering the speakers. The HU has 4 x 45W RMS internal amps.

The faulty speaker does not gradually come to life, just bang, comes on at abover a certain volume. I can then turn it back down and it will continue to work.
 
I have received an excellent reply from a chap called Mick at Inifinty/Harmon with lots of things to try and multi meter readings I should get from each component. I think I will have time tomorrow afternoon to have a play around.

However, Mick seems to think it's with the wiring loom in my car. So, I could really do with some advice on how to get a new speaker wire between the chassis and door.

Cheers,

Chris
 
I have this problem, my headunit only supplies 1v when my subs need like 2v at least maybe 4v. So it sounds like the same problem. I need to be above 10 on my Head unit out of 30 for the amp to turn on to get any bass at all.

Josh
 
Chris, regarding running cable... if it's just for testing, just run some cable under the carpet and fix it in place between the door and body of the car making sure it doesn't get trapped.

When you're looking for a more permanent fixture, just run it through with the cables that already run into the door, probably protected in a rubber sleeve.

To get to this on my car, you need to remove the front wing.
 
Chers Andy.

I should have some pics of the Mondeo loom somewhere, I am not sure how your idea would work... Give me a minute to have a look through my HDD.

Also, I would be looking for a permanent fixture, after testing of course for which I will just leave the door card off.

EDIT- Here is a high-res pic of the door loom (identical) from my Ghia X.
http://www.avconnections.co.uk/cjackway/mondeo/doorloom.jpg

The rubber circles on the left are what stick out of the door facing the a pillar.
They are sort of special multiplugs.

The speaker cable is the bit with the yellow plug on, near the centre but to the right.

How can I thread a new cable through with these funny plugs in the way?

For real Mondeo fanboyism the plug immediately to the right of the yellow speaker plug is for Power folding mirrors. Something only the Japs had :(
 
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As you mentioned most Fords use locking connectors to join chassis to door. To wire straight through I use the grommit that is on the chassis side above the door connector and wire though the rubber Ford tubing (carrying the wires) in to the door.
 
splitz said:
As you mentioned most Fords use locking connectors to join chassis to door. To wire straight through I use the grommit that is on the chassis side above the door connector and wire though the rubber Ford tubing (carrying the wires) in to the door.
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Cheers Ben, which tubing, the black tube that connects into the locking connector, do you cut into it then? This OK to do, no water ingress problems?
 
Yeah, the existing rubber tubing. Here's a couple of pictures I took of my install.

P1010053.JPG


P1010054.JPG


Now my big assumption is that your Mondeo has a similar plastic grommit. I sealed the tubing with silicone grease, no ingress apparent.
 
Damn, looks like splitz beat me to it. That's exactly what I was going to suggest... cut into the rubber tubing to feed a cable through. At least the tubing will stop the speaker cable from getting trapped or caught in the door hinge.

I'm not sure, but I think the Rover just has the rubber tubing containing all the wires, no fancy plugs or plates for me :p

On another note, Ben did you get my e-mail?
 
I did however when I tried to reply it bounced back. I was going to tell you but I forgot. Anyway I can wait until the 10th and it's in good condition, I rarely played it :)
 
Sorry if I missed it but did you actually try swapping over the crossovers? I wouldn't even do that, bypass the x-over completely and try your woofer to see if it works at low volumes.
 
splitz said:
Sorry if I missed it but did you actually try swapping over the crossovers? I wouldn't even do that, bypass the x-over completely and try your woofer to see if it works at low volumes.
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No I haven't. I received a good reply from Infinity, from somebody obviously in the know and not a customer support desk worker, well if they are then it was apparent they had a keen interest in car audio. Basically they said that the problems I am having are highly unlikely to a faulty cross over. My problem is something he has come across several times but never related to the cross over.
 
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