Ok to have speaker grounded to chasis???

[MrJollie 10+ year member]

here's what happened: i had to put on some speaker spacers for my rear speakers. after struggling to get them set right (only got the back left rear hooked up today), i turn on the HU and notice that i don't have any sound!! i then realize that somehow the speaker i just hooked up must have grounded itself. sure enough i disconnect the ground wire, and all of the speakers come to life. my question is though- now that only the positive wire is hooked up to the speaker, is it still all right to run it this way? i taped off the gound wire. thanks for the opinions. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

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[tommyk90 5,000+ posts]

Originally posted by MrJollie here's what happened: i had to put on some speaker spacers for my rear speakers. after struggling to get them set right (only got the back left rear hooked up today), i turn on the HU and notice that i don't have any sound!! i then realize that somehow the speaker i just hooked up must have grounded itself. sure enough i disconnect the ground wire, and all of the speakers come to life. my question is though- now that only the positive wire is hooked up to the speaker, is it still all right to run it this way? i taped off the gound wire. thanks for the opinions. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

What ground did you disconnect? I doubt it is safe to run the speaker on a chassis ground, in fact, whenever you get subs that clearly say not to chassis ground them. I don't know if it works the same way for regular speakers.

 

[80_Cutlass_mn 10+ year member]

Actually with newer h/u's and hte type of internal amps they have. If one of the speaker wire is grounded to the chassis then its instant death for that channel of the internal amp. Its hard to explain why but what it is that there is always a six volt diff between the speaker wire and the car's chassis. Ive never checked it before but I think I read that on the eatel.net site that so many ppl have the link in their sigs to.

 

[MrJollie 10+ year member]

well, maybe that myth is wrong. when i pulled away the ground from the speaker, all of the speakers came back on. i think i may have accidentally touched the ground again to cut the speakers off, and when i took it away, all of the speakers came back on, again. the back left also doesn't sound any different from the back right. tomorrow, i will "un ground" the "grounded" speaker. if you all think that this is a little dangerous, i guess i will fix the problem. (it's just so time consuming; the one thing i hate about car audio!!!) //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[maylar 10+ year member]

HU outputs are bridged amplifiers. There is no "ground" wire. Both neg and positive outputs are active. If you touch the neg speaker output to ground, you could instantly smoke the drivers on that side.

Running the speaker return to ground is not a good thing to do. Dunno if it'll damage anything, that depends on the HU amp design. You will definitely get only half the output voltage (1/4 the power) assuming nothing smokes.

 

[ChefJoe 10+ year member]

Basically, a voltage is the potential difference between two points. In your car battery, it's between the + and - end. The car uses the - of the battery as the "ground" but it's perfectly capable of being at a non-0 voltage compared to any other point in the car. Ground doesn't really mean the quantity of 0.

Ok, now, the speakers run with a voltage that's set for one speaker and the other can be set for the other speaker. In amp terms, it's a lot more difficult to make two +2 voltages compared to a common ground than it would be to make, say a +2 and a -2 compared to a common ground.

 

[MrJollie 10+ year member]

Well, hopefully i can get away from the dark side tomorrow, going to hook up all the speakers to the amp. so no more speaker grounded to the frame. i have an alpine cda-7892. the system didn't sound any different when i played it today. i kept it on for most of the time that i was out driving around. best buy didn't have any 4 gauge wiring or spade terminals, so i went to a&a auto, got four 2 guage ring terminals (cost $3 and change), and turned two of them into spade teminals using a pair of ajustable pliers and a dremel. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif