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Reply With Quotedepends... how did you tune your amps?.. you could be just hearinh them clip...
Well I know ****-all about Car audio, but I wanted to get rid of my head-unit. I got a 2-channel amp off the bay, and have just wired it up.
Anyway I know noise has lots of troubleshooting pages all about, and i'm working through them. I just wanted to know if it was possible that the problem is I am using the stock speakers in my Mondeo, and if I upgraded them it would be likely fixed........
Amp is VRX-VR1502C
Thanks,
Sam
depends... how did you tune your amps?.. you could be just hearinh them clip...
:sigh:... okay... an amplifier does exactly what it sounds like it does... it amplifies, the stereo's signal.
That gain setting, is actually just a little knob that lets you match up your amp, with your speakers... it is not a volume knob...
you're going to need an AC volt meter to tune the amp. Next you'll need to know how many watt's you want to tune it to, as well as at what ohm rating...
You take the square root of the watts times ohms... meaning sqrt(watts X ohms) if that helps...
This will tell you how many volts you would need, then next thing you do is hook up that ac volt meter to the amplifier, then pop in a cd with a test tone of 1khz, you can download this off line. Turn the stereo up about 3/4 of the way, then set the gain at that voltage that you figured out before...
Never turn your stereo past that point any more, for at that point, it is the max amount of watts that your amplifier should be pushing to your speakers...
So basically, lets say that your speakers are 25watts rms at 4 ohms...
Take the square root of 25X4... which is 10.
Pop that 1khz cd into your stereo, then set the gain on the amp so that it displays 10V AC...
done
Brilliant. Thanks for the info. I'll try it in the morning!
just make sure you find out what the rms watts and ohms are of the stock speakers are
Thanks loads for your help! I'm getting there! :-)
To simplify things i'm ignoring the whole serial/parallel config of my 4speakers->2 channels and i'm just working with one speaker.
20W rated speaker, measured at 4 and a bit ohms by my voltmeter. I'm struggling to find specs online, so i'm presuming that they are 4ohm speakers.
Firstly, why do you say put your stereo at 3/4, why not full? If that's the maximum?
Anyway, i'm turned my gain to give Sqr(80)=8.95V across the speaker when playing a 1khz tone in XP, and I still have crackling when no music playing....
The thing I don't get is it seems to be signal-dependant, in that when I move the mouse, the crackling intensifies. However the headunit doesn't pick this up at all. That would lead me to believe the usb cable for the mouse is interfering with the amp, and not the headunit. But the headunit is wired very similarly near the amp, and with much smaller, worse wires. (Headunit using a cassette-mp3 adapter).
This is all running from an external sound card, which is a bit rubbish, and could be the problem, but then again why does the headunit not have a problem?
I suspect the next thing would be to move the usb cables around, but that's a right pain
Help appreciated!
Thanks loads
If you put the volume at max, then you create clipping ( distortion ).
Can you record this "crackling" noise? Its hard to imagine something we cannot hear , might help us find the problem easier.
I have numerous things I could 'put at max'. Such as the external sound card volume, main windows volume, windows "wave" volume. Will I create distortion if say two are on max?
Crackling attached, in amr form (realplayer'll play it). After about 6 seconds you can hear the different tone which is when I move the mouse. I did try converting to wav but it buggered up.
I'm going to have to pack it in for the moment though, off to uni/college soon. Appreciate any ideas for when I have another go though. :-)
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Still a crackling when no
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