you could maybe tried the system with another home psu and with a pair of headphone ...to see if there is noise again...
frist...conecte the home power suply to the computer with the atx hack (you could get it on the site) and see if is there noise in the head phone....
after this...try to coenct the psu directly on the motherboard...if there is still noises...your psu is not the problem.....
400W of audio output takes MORE than 400W of power input to generate, sometimes significantly more.Quote:
I thought watts of audio output were different than watts of power draw? It provides 400 watts of audio output, but I don't know the power input, because as I said earlier, there's no label that tells me, nor can I find any information about it online.
As soundman said, it's probably not a 400W amp, or its 400W peak to peak, measured at 24V input with a perfect sine wave at 200hz, only with a frequency response of 20-350hz, into 2 ohms, bridged.
In reality, a 400W amp with a cigarette lighter to power it - is probably more like a 30w per channel amp.
As for the noise - you have a ground loop because you aren't meant to use an amplifier through a cigarette lighter. You get a wall of noise that way.
WHy did the manufacturer make it that way, because it looks easy and you bought it because of that. Thats why. Electrically its friggin retarded.
It was likely made that way since it was made for use on a motorcycle. They don't expect people to hook it up to their onboard audio systems, but rather just plug in their MP3 players (which I've verified works beautifully) as a cheap and easy way to listen to music on the go.
I have been in battle with noise for a while. I run my setup using a 400W inverter and a Pioneer head unit. So as some may know inverters are very noisy. I recently have eliminated 99% of the noise in my system ( yes EMI and RFI ). What I did is very simple. I ran the power line for the inverter on the underside of the vehicle and took pre-cautions against it becoming rubbed through and or damaged. The +12V was ran on the underside of the vehicle to keep it away from all other low voltage lines ( speaker cables, rca lines etc. ). I then ran a very short ground to the vehicle body. Both lines were 8 gauge wire.
A few lessons I learned were the shorter the ground the better. The ground line has to be a larger and or same size guage than the largest +12V line you use in your system. If your setup is in a really modern vehicle you must find a ground point other than the body because most modern vehicles are designed around the uni-body method and it's componets are tack welded together at the factory. So my point is tack welds or other mechanical junctions will cause poor grounding so go after frame rails or the like.
As a final thought in regards to running heavy +12V lines. Always use a fusable link at the battery and use grommets where the line may pass through holes in the body and or frame of the vehicle. Make no exceptions, the last thing you want is this line to short to the frame without a fuse, all you have left of your car is copper and a frame!
^^ didn't quote for the sake of space, but i dissagree with the fusible link statement-- i think using fuses are much better, becasue they will blow around the amperage, and not anything more. i really don't like fusible links becasue you are basically using a small wire as a current limiting device-- so that wire must heat up, and if it is long enough, and hot enough, it will burn something else-- a fuse has a very small area that gets hot/burns up, so there is much less chance of things around it burning up...and it is easier to replace...
that fuse block is fine, but just remember any other device you tapp into that wire (say, radio, carpc or whatnot) still must be fused on their own with a much smaller fuse. what you have there is a lot of current still able to pass through, while it will keep your car from burning it wont protect many devices from damage.