ive seen a sub-box with two ready mounted 8" subs (400w) i think the watts is for both of them not too sure. if it is will i be able to run them without an amp??
sub help
- Thread starter charlieboy
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sub help
If it isn't a active subwoofer you WILL need amps and a HU capable of powering an amp. Subwoofers can't be run directly from a headunit.
Bit rnadom, telling him how to wire half an amp? If ur gonna bother typin that u might as well tell him he'll need an earth... And yes you can run it of most head units as a speaker, but the problem is it wont be very loud and u will still need to buy a frequency filter. Its not worth running it off the head unit, you would be better with 6x9's. The amp you want will probably be around 300w (depending on how they rate the RMS) as you dont want to push it too hard.
You can actually run a subwoofer from a HU offering say 4x50w output?! You learn something new every day, sorry for giving incorrect advice!
You CAN, but it will be sooooooooooo crap its not worth doing. 50 w into a 150w sub!!!!!!!!!!!!!!!!! 6x9's will give better bass. 
you can run a sub off a head unit and it will be good not crap like other people are saying. im running a 10"jbl 1000 watt sub and id like people to come say its crap when i turn it up. id say try it before running it off the battery, its personal opinion.
There is no way it can sound any good. I have a JBL too, it simply cant compete with an amp. where do you live. Then i can prove you wrong!
I had my sub running from the HU basically acted as a giant 50w speaker... was quite funny
You mean u didnt use a frequency blocker!!!!!!!!!!!!!!!! How long did it last? but then again it would have been ok with 50w.
It's the same one i have running now... I only wired it up fro a few days to make sure the thing worked.Lol
if you wanted to run the sub off your head unit then there aint much point in you having the sub. It will be majorly underpowered and end up frying the amp in your HU.
And from previous posts... You want to get an amp that exceeds the subs wattage - or try to match the RMS but ensure the amp has plenty left to give. My reasoning for this is most amp's output quality degrades as the volume pumps up - so its better to have an underused amp than an overworked one. becuase in the end if you use an overworked amp you'll end up with a fried voice coil on your sub. You WILL have to make sure the gain is turned down on teh amp and the volume adjusted properly to the sub (mine are on a seperate channel from the HU) so when you crank it up you wont blow the sub into next week.
The wiring of the amp is a simple process and has been mentioned already above
And from previous posts... You want to get an amp that exceeds the subs wattage - or try to match the RMS but ensure the amp has plenty left to give. My reasoning for this is most amp's output quality degrades as the volume pumps up - so its better to have an underused amp than an overworked one. becuase in the end if you use an overworked amp you'll end up with a fried voice coil on your sub. You WILL have to make sure the gain is turned down on teh amp and the volume adjusted properly to the sub (mine are on a seperate channel from the HU) so when you crank it up you wont blow the sub into next week.
The wiring of the amp is a simple process and has been mentioned already above
lol... I understand what you're getting at, but a high-pass filter isn't strictly needed, because the subs can not produce high frequencies. anyway my point was, you have to run a few cables up and down the car to get it all to work... but yes, you probably already knew that.D4NS said:
Luke, your right, you'll need to get a slightly more powerful amp because clipping starts to occur at higher gains.
P.s. Oh and by the way you'll need an earth, use an existing earth point, or make sure that your earth is toutching bare metal.
You do really need a filter as higher frequencies will harm the sub and shorten its life. The main thing im trying to say is DONT USE THE HEAD UNIT!
Alex said:lol... I understand what you're getting at, but a high-pass filter isn't strictly needed, because the subs can not produce high frequencies. anyway my point was, you have to run a few cables up and down the car to get it all to work... but yes, you probably already knew that.
Luke, your right, you'll need to get a slightly more powerful amp because clipping starts to occur at higher gains.
P.s. Oh and by the way you'll need an earth, use an existing earth point, or make sure that your earth is toutching bare metal.
Most Fiats have a grounding point near one of the rear lights in the boot ideal for amps (LHS for my uno). You just need to unbolt it and slip the eyelet over the hole with teh rest of the wires and bolt it back down again. You may need to solder a new eyelet to the grounding wire though as the size of the bolts can be excessive.
No offence intended, I was being facesious. I was trying to write quality advice, and obviously crap was produced. (no doubt that will appear in somebodys sig!).D4NS said:
Why do high frequencies harm the sub? I always thought because such a large speaker couldn't move quick enough high frequencies were effectively not produced.
Luke: Its almost as if FIAT planned for people to put subs in the back!!!
Alex said:
It harms the voice coil inside the sub. The little peaks can kill it after long use at volume, just like the distortion from the amp. It wouldnt if driven from the headunit due to the low driving power, but that fed through the amp then you've got yourself a problem.
And yea, i think they must have done. Shame they didnt make the boot about 5" wider so i could fit both my subs in properly with my amp
defo need a amp mate prob would be ok on low volume off your headunit but when you turn it up it would drain your amp inside your stereo and after abit it would burn out id say for 400 watt box you would need bout 300watt amp have the gain (volume) on the amp about quarter to half way on full sub setting. then run some 6x9s off your headunit should sound ok. like i said try your gain on it on a quarter first sit in your car pump it up then turn the gain up to half way and see whitch sounds better. does your headset have pre outs for a amp?
id say for 400 watt box you would need bout 300watt amp have the gain (volume) on the amp about quarter to half way on full sub setting. then run some 6x9s off your headunit should sound ok. like i said try your gain on it on a quarter first sit in your car pump it up then turn the gain up to half way and see whitch sounds better. does your headset have pre outs for a amp?
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