Thread: Induced noise/Ground loop trouble shooting guide.

good to hear you got it all worked out!!

it sounds like you really want a 5 channel amp.. those are usually not to cheap, it will probably be cheaper to keep your 2ch amp for the sub, and get a 4ch amp for the rest of the speakers.. i have heard of good things from people that have used amps listed as "motorcycle amp" on ebay..

I found earlier a 4-channel amp brand : FELIX FX-4110 :P which costs 62euros (about 75dollars) in a local store and i'm thinking of buying it. Can i bridge the woofer to the amp? Can you give me a schematic?

i cannot find enough info on the felix amp to know if it is bridgable.. so i must assume that it is not... if you can find some clear pics of the sides of the amp, or a manual with similar info, i should be able to help.

yeah i assume that too! i found this : http://www.denver-electronics.com/denver-cap-4100/ for 7 euros more (69euros)

This must be great for my purpose right? What about connections then?

according to the specs, the denver model is bridgable-- only into 4 ohms. for a diagram, i would need the speaker model numbers, or for you to test the resistance of every speaker/sub. and i would also need to know what amps you choose to use with it..

hm i guess i have to learn a lot for car audio In fact i have no idea what are you talking about! hehe! Can you give me some details for the Ohms of the speakers/sub, how to find these details or measure them!

More ohms (more resistance) the better or the worse? And if this amp is 4 ohms what amp should i buy?

the terms 'Ohm' and 'resistance' mean the same thing, they are just used in different ways. if you connect a digital multi meter to the terminals on the speakers(while set to the Ω, or ohm setting--this is the symbol for the omega, or ohm reading) it will tell you what the resistance of the speaker is.


95% of all cars and car speakers use 4 ohm speakers. but it is always that 5% that messes everything up..

there is no 'perfect' resistance value for speakers. most car audio speakers are 1 of 3 values. 8Ω, 4Ω, or 2Ω.

the way that speakers become a specific resistance is the thin voice coil wire-- the more wire gets wound around the voice coil, the higher the resistance.

because there is more wire in the voice coil of a 8Ω speaker then a 2Ω speaker, it also changes the way it sounds.

the 8Ω speaker will have more inductance, and so it will be much more sensitive to the audio signal-- so it will require less power to move the speaker and emit sound.

the 2Ω speaker will have less inductance, so it will be less sensitive to the audio signal, but it will be louder then the 8Ω speaker at the same cone movement level because it allows more power to go through the voice coil.. hence the reason so many people use 2Ω subs-- because they rock the town louder..


of course all of this is extremely simplified-- if you want more detail, a site like diymobileaudio.com will have more in-depth info on why speakers are that way..

Wow thanks for these info.