help :( speakers burning...

[beau]

ok, my alpine amp arrived today, wired it all up, all good, very good, sound is mental!! gains are at about 3 quarters up, stereo volume is about 3 quarters up, sound is crisp no distortion, i played it for about 20 mins, and disaster struck, one of the speakers started burning! stunk the whole car out just one, (but i think the left one is getting slightly more power than the right one, this may be due to the left one is on thick rca cable, the one on the right is on thin stuff?) but yes, it started burning, i quickly turned it off, i hope i havent done any damage? it still works fine, but why did it do it? it wasnt distorting at all, the amp is rated at 100w rms at 14.4v, i was running it at 11-12v, the speakers are 75w rms.

whats gone wrong

 

[chaos]

It sounds like the voice coil's protesting.

Push the cone down gently and listen for a scratching sound.

 

[beau]

It sounds like the voice coil's protesting.

Push the cone down gently and listen for a scratching sound.

i did, and its fine, it still works fine too but it just smells of burning.

 

[jug]

the problem is too much juice. you cant use distortion to tell you if you've got it right.

for a start your speakers should always be able to take more than the amp can give. if each speaker is on a 100wRMS channel i'd want 150wRMS speakers.

 

[beau]

the problem is too much juice. you cant use distortion to tell you if you've got it right.

for a start your speakers should always be able to take more than the amp can give. if each speaker is on a 100wRMS channel i'd want 150wRMS speakers.

well i did ask, if 75w rms speakers will be ok on 100w rms amp, and everyone said yes

 

[chaos]

for a start your speakers should always be able to take more than the amp can give. if each speaker is on a 100wRMS channel i'd want 150wRMS speakers.

Nope, not necessarily. Plenty of people run amps that are rated to put out more than a speaker's rated to be given to take.

I think the gain sounds too high - but without listening to it you can't really say for certain. Beau, knock the gain down to absolute minimum and try it.

 

[beau]

well the gains were high, and the stereo volume was high, i was pushing them hard imo, but not so bad i thought one would start burning.

with regards with what i said earlier, the one which was burning, appeared to be louder than the other one, only thing i can think of which is different is one speaker runs on front pre out, the other on the rear pre out (the amp has preout input for 1+2 channels (front) then another for 3+4 (rear) but im running bridged so both front, so would this make a difference? only other difference is the phono cables, one is some thick stuff, the other one is thin cheap stuff, would it make a difference in loudness? cos i swear the left one was louder, but thought i was imagining it, but maybe i was right when it started burning!

il try turning the gains down a bit then! there at about 3/4ish, 1 notch back from when they distorted, i thought that was about right?

 

[Rampage94]

never heard of working speakers in? i would never go to full blast on a new set of speakers.

 

[beau]

never heard of working speakers in? i would never go to full blast on a new set of speakers.

its all second hand gear

 

[Rampage94]

ohh me ohh my, maybe you got a set of highly abused speakers....

 

[Neuroticus]

About the left one sounding louder, since your using the front and rear preouts for left and right speakers are u sure u havnt got your headunit faded more to the front/rear?

 

[beau]

About the left one sounding louder, since your using the front and rear preouts for left and right speakers are u sure u havnt got your headunit faded more to the front/rear?

yeah im sure on that

right, might of found a possible reason, i just presumed the speakers would be 4 ohm's like every other bloody speaker, but they are 2 ohm, my amp is 2 ohm stable, it apparently gives 180w rms at 2 ohms! so does that mean im giving these 75w rms speakers 180? not really sure about this! but the speakers are 2 ohm, the amp runs at 2x100w rms at 4 ohm or 2x180w rms at 2 ohm, so is that right? that im maybe running them at double what i should? how does the amp know what ohm the speakers are to give out 100w or 180w ?

 

[jug]

Nope, not necessarily. Plenty of people run amps that are rated to put out more than a speaker's rated to be given to take.

sorry let me rephrase that, if you want to be able to use the amp's full output you need a speaker that is more than capable of taking that outout. if you use a speaker that has a smaller rating you must reduce the output of the amp to compensate for the deficit.

basically, a 75w speaker cant take your amp's 100w output so either turn down the amp or cook the speaker.

 

[x Alex x]

hmm, i'll be using an 1800w amp lol, better be carful

 

[jamesgamby1989]

hmm, i'll be using an 1800w amp lol, better be carful

1800 rms????? or max?

 

[BenW]

First off, don't use front for one side and rear for the other side. See if the amp has a switch to how all outputs the same input, so that all 4 channels get the input from one RCA. Therefore you only use the front RCA. If not then get RCA splitters (be careful, make sure they have the correct plugs).

Seconly, 100W RMS or even 180W RMS is fine on 75W RMS speakers as long as you're sensible. I'm almost certain your gain shouldnt be at 3/4, sounds very high and no doubt you're sending a distorted signal. You need to be careful or you WILL get fried speakers.

I used to give my 100W RMS speakers 200W RMS and the gain was set at about 1/4 IIRC. No problems there

 

[beau]

hmm, i'll be using an 1800w amp lol, better be carful

its probably got less power than my amp though

 

[beau]

First off, don't use front for one side and rear for the other side. See if the amp has a switch to how all outputs the same input, so that all 4 channels get the input from one RCA. Therefore you only use the front RCA. If not then get RCA splitters (be careful, make sure they have the correct plugs).

Seconly, 100W RMS or even 180W RMS is fine on 75W RMS speakers as long as you're sensible. I'm almost certain your gain shouldnt be at 3/4, sounds very high and no doubt you're sending a distorted signal. You need to be careful or you WILL get fried speakers.

I used to give my 100W RMS speakers 200W RMS and the gain was set at about 1/4 IIRC. No problems there

right well iv ripped it all out now cos i plan to sell the car, but when i put it back in in another, il have to get a picture, cos its got alot of settings, which kinda went straight over my head it sounded good though just i couldnt work out why one of the speakers was louder.