how do i blow an amp and clip a sub ???

B

bal

Guest
ok so i bought my car and did some modifications to the sound system
1. kenwood hu
2. cheap and nasty 6x9s (maplin £12.50) then reinforced parcel shelf 18mm mdf
3. alpine door speakers
4. then got 200w amp and 12inch sub in boot and wired it up

it all sounds nice and the bass thumps quite well on most songs

but before i add my next amplifier i would like to know

1. how do you "blow" an amplifier?

2. how do you "clip" a sub?

3. how do you know if you have clipped your sub?

4. can you clip an amplifer or speaker?

i have managed to install my first am and sub without blowing anything up but i would still like to know for the future so i can avoid the mistakes.

any answeres are appreciated

thanks
 

NeX

You're after my robot bee
Club Member
don't know of those terms, but you'd blow an amp by putting too much power through it... Pendulum normally does this to my amps lol i have to replace the fuses every time i go out :)

the speakers will have to have a higher peek power than the amps or they will blow :)
 

59 bhp is more than enough

Deactivated Account
never heard of blowing an amp unless its incorrectly wired as the amount of power that goes in is minimal to that, that comes out. you can blow speakers nd subs by putting some much power through or by playing distorted music too loud. This can de bond your speakers or stuff your voice coils up etc
 
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B

bal

Guest
thanks so

to avoid blowing always use an inline fuse to your amp and
dont put the volume level above the point where music becomes distorted
and make sure your speakers have a higher watt rating than the amp


59 bhp is more than enough
can you explain the term "de-bond your speakers"

can anyone explain the term clip how its done, what it does and how you know
can amps/speakers get clipped?
 

NeX

You're after my robot bee
Club Member
ALWAYS use a fuse!!! it is very important, as i found out when my car caught fire lol,

i have 3 fuses on my amp wire and one per amp...

de-bond = where the coil comes unglued from the voice cone...

never heard of clipping mate,
 

Andrew

Club Member
Clipping means that the top and bottom part of the waveform is removed, changing a sine wave into a square wave. It happens when you drive an amplifier too hard. It sounds terrible.

It's a transient condition, which can cause damaged. So you can't say that an amp or speaker got "clipped".
 

NeX

You're after my robot bee
Club Member
there you go, learn something new every day :)

can't you get a square wave form if you box a sub incorrectly? where the sound bounces off the back of the box when the back of the box is exactly parallel with the sub?
 
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L

lewis

Guest
NeX said:
there you go, learn something new every day :)

can't you get a square wave form if you box a sub incorrectly? where the sound bounces off the back of the box when the back of the box is exactly parallel with the sub?

I think that would cause destructive/constructive interference, in simple terms the upper and lower parts would add/cancel each other and make it sound pants.
 

Ed

Fusion Motorsport
MSC Founder
Official MSC Trader
ARGHHH I just had a long post and hit back by accident!!!!!!

Ill say it again now but it won't be as good. Clipping your speakers actually refers to driving them with a clipped audio source. As Andrew said clipping turns the smooth audio AC waves to flat DC. This DC does nothing more than HEAT up the coils in your speakers, causing them to burn out. At the same time this heavy current load will heat up the Amp and is the no1 cause of amp failure.

NeX if your having to replaces fuses that often sooner or later youll fry your speakers/amps or both.....

Truly overloading a speaker is actually quite hard, and almost ALWAYS the cause for blown speakers is again an amp that was 1, not power full enough and two been driven to clipping. However in rare cases, with very very excess amp power it is possible to kill a speaker with a pure signal.
 

59 bhp is more than enough

Deactivated Account
im pretty sure you can kill a speaker through distortion. i know coz i did it. by the term de bond i just mean when you blow a speaker the actual speaker part comes "unstuck" as it were from the actual speaker
 
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B

bal

Guest
my sub box is perfectly square i will be changing it very soon
i made my own so its just very square and bare wood on the inside.
do i have to reshape the actually box or could i just stuff the inside with a sound material of some sort?

ok so running an amp too hard causes clipping

ed
can i run the amp too hard by turning the volume up to max?
or are you refering to a low power amp running a high power sub?
 

NeX

You're after my robot bee
Club Member
Ed said:
ARGHHH I just had a long post and hit back by accident!!!!!!
damn i hate that :)
Ed said:
NeX if your having to replaces fuses that often sooner or later youll fry your speakers/amps or both.....
nah its just when i put pendulum on i turn it up REALLY loud, fogetting that this blows the fuse :) and i use a low amp fuse anyway (20A)

Bal

if you put a bit of wood in the sub box that is at about 25 degrees and runs from the bottom of the box to the top then this will help to break up the sound. or stuffing it with toy stuffing should do it :)
 
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B

bal

Guest
nex
im gonna use loft insulation for my sub box cos i cant find any wool is this ok?
do you mean really stuff the sub box full of it or just coat the back of the box to stop the square signal

thanks
 

NeX

You're after my robot bee
Club Member
suff it with the loft insulation so when you bolt the sub in there is a slight resistance...

it needs to be full but not too much if you see what i mean.

insulation is dodgy stuff, so wear gloves :)
 
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B

bal

Guest
thanks mate its hard to find this info on google so you have saved me a lot of time
 
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W

wildti

Guest
get hold of a occilscope wire it to the speaker crank the system untill you see the waves cipping then turn the gain on the amp down untill it stops clipping , ive did this on all my speakers set up perfectly now
 

Retepetsir

King of Subsonic
WIDE_ARCHED_BOY said:
ive blown 3 amps up because the gain was turned up to much
or is it my bad luck :)

If its set up correctly you should never blow an amp.........

suff it with the loft insulation so when you bolt the sub in there is a slight resistance...

it needs to be full but not too much if you see what i mean.

Boxes dont have to be stuffed with wadding, its normally only used if you want to make the subwoofer 'see' a bigger box that its actually sitting in. If the box is around 1cuft, you should really need it!

It's easy to clip a signal when, basically, you overdrive an amp. If you are driving the amp too hard and say it is meant to put out 200wrms into 4ohm, but you're trying to drive a 500wrms subwoofer hard, you are more likely to push the amp into clipping (sine wave turning into more of a square wave) which speakers really do not like!

Either make sure the amp matches the power of the subwoofer, or more ideally, puts out more power than the subwoofer is rated for.....

The best way to setup the gains (which are NOT a volume control) on the amp is to use an oscilloscope and some sine wave test tones @ 0dB.

If in doubt, get someone who knows what they are doing to set it up :)

I've had my subwoofer for a few years now, driven from three different amps, starting at 300wrms, then 450wrms, to the now present 600wrms, and the subwoofer is rated at 300wrms.........

I have never once blown up any of the amps, or the subwoofers!
 
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