Passive Speaker System - Underpowering It

[DJMaxG]

I have heard that if you Underpower speakers with a Passive systems, this can blow it.

Is this correct?

[Danno13]

Any clipped signal can blow a speaker, whether you're pushing the mixer, or the amp too hard. It's easier to blow speakers this way, than having headroom on your amp (i.e. overpowering the speakers) as you're far more likely to clip something if everything is running close to max.

[CRAZY K]

I have heard that if you Underpower speakers with a Passive systems, this can blow it.

Is this correct?

How did this conversation come about:confused:

Most of us run with manufacturer recommendations and if possible matched amps and speakers.:D

I spose if people buy off ebay and dont know what they are up to :eek:

Anything could happen.


CRAZY K

[Adam_F]

Customers think I'm mad when I tell them that if the amplifier isn't powerful enough they can still cause damage.

[Babybob]

So if you have a pair of 8ohm 350watt speakers and an amp which gives out 500w a side at 8ohm then would I be correct in saying that you should have the amp at about 2-3 o'clock in order for the speakers to work at just about their optimum.
If I had the amp at 12 o'clock could I damage my speakers by underpowering them?

Thanks in advance for any advice. :beer1:

[DJ Jules]

So if you have a pair of 8ohm 350watt speakers and an amp which gives out 500w a side at 8ohm then would I be correct in saying that you should have the amp at about 2-3 o'clock in order for the speakers to work at just about their optimum.
If I had the amp at 12 o'clock could I damage my speakers by underpowering them?

It's not so much about running an amp at less than full power, it's more about driving an Amp too hard to get the output you need to drive the speakers.

E.g. if you're running a 500w amp at 350w into 350w speakers then the amp will be running happily along and not at risk of distorting the signal it's giving as output - and it's the distortion/clipping which will destroy your speakers.

However, if you run a 350w amp at full power into 500w speakers, then you run a much greater risk of damaging your speakers because the output from the amp is likely to be distorting, or the output "clipping" - when that happens, you run the risk of burning out the coils in the speakers because you may be driving them with DC voltage instead of AC, which will quickly overheat the coil.

See here http://www.bcae1.com/2ltlpwr.htm for someone else asking the same question with pictures in the explanation (which makes it so much easier to understand!)

Julian

[DeckstarDeluxe]

amp same size as my speakers. The mixer is set up so it never clips but is usually hitting 3/4 up the outlevel and the amp is usually on 50%-60% power depending on room, people stood in front of them etc... Used this for years no proplems.

How can "underpowering" a speaker blow it?

[DJ Jules]

amp same size as my speakers. The mixer is set up so it never clips but is usually hitting 3/4 up the outlevel and the amp is usually on 50%-60% power depending on room, people stood in front of them etc... Used this for years no proplems.

How can "underpowering" a speaker blow it?

As mentioned in my other post, it's not so much underpowering a speaker, but underspec'ing the amp which is driving the speaker, and then drastically over-driving the amp. Running a speaker at less than it's rated power will never damage it.

Running as you are is the right way of doing it :D

[DeckstarDeluxe]

Wouldnt overdriving the amp into larger spec speakers though blow the amp before damaging the speakers? If the input is fairly low I cant see how the speakers would be damaged?

So what Max has said is if you drive an amp too hard it'll break?

[Tony Scott]

Yes a clipped signal that overdrives an underpowered amplifier's input stage can fry speaker drivers, particularly HF compression drivers.

This can happen with amps of any size but amplifiers at around a 1/3 of the driver's RMS rating or higher are most likely to blow a drivers coil when clipping.....amps below this 1/3 threshold are not really a threat. :)

i.e. a 100w amp is unlikely to damage a 300rms driver even if it is fed a clipped signal, this is because the driver's mechanical/electrical thresholds will not have been reached.

[spin mobile disco]

Ok the simple answer.#
If you do not allow your amp to clip you can:

1. under power your speakers and they will never blow. (other than poor workmanship that is)

2. Over power you speaker within accepted power ratings i.e more than rms but lower than the muic rating.

I have never blown a pair of speakers since I stated DJ'ing I never allow my amps to clip whatever I am doing its a warning light not a target.
If you need more volume buy better speakers / amp designed for it not low power speakers or amp you have to push hard.

[rob1963]

Assuming your mixer output isn't in the red, your amp isn't clipping and your speakers power rating is at least the same as the amp's output, I don't see how you can blow the speakers.

[CRAZY K]

Assuming your mixer output isn't in the red, your amp isn't clipping and your speakers power rating is at least the same as the amp's output, I don't see how you can blow the speakers.

Its a no brainer--get matched equipment.:bang:

CRAZY K

[DJMaxG]

Customers think I'm mad when I tell them that if the amplifier isn't powerful enough they can still cause damage.

Nathan (DJWilson) didn't believe it when I told him, and reccomended I asked on here, as I have never blown any speakers myself and still wasn't sure.

I have heard from someone, a user of Peavey, that systems have blown due to underpowering, and others have said similar things.


Wouldnt overdriving the amp into larger spec speakers though blow the amp before damaging the speakers? If the input is fairly low I cant see how the speakers would be damaged?

So what Max has said is if you drive an amp too hard it'll break?

I am asking, if you power a 500w speaker with a 200w amp, will it blow?

Some say it will, some say it won't.

[BeerFunk]

I am asking, if you power a 500w speaker with a 200w amp, will it blow?

Some say it will, some say it won't.That's because it may or may not! Now, if you send a clipped signal from the amp to the speakers - that's where you are far more likely to blow the speakers.

[rob1963]

I am asking, if you power a 500w speaker with a 200w amp, will it blow?

Some say it will, some say it won't.

That's a bit like asking "If you plug a 3 amp appliance into a 13 amp mains socket will it blow?"

Assuming your mixer output is not in the red and your amp is not clipping, a 200w amp will NOT blow a 500w speaker.

Edit: It won't run it very efficiently, though.

[Danno13]

But you're far more likely to run the amp into clipping when you don't have the headroom there. If you clip an amp, it can take out speakers instantly, whereas if your just overpowering them (above the rms I mean) you'll notice distortion and bad sound before any permenant damage is done.

[DJMaxG]

I would always keep my systems balanced, with the same wattage on both amps and speakers.

Just querying though.

[CRAZY K]

Nathan (DJWilson) didn't believe it when I told him, and reccomended I asked on here, as I have never blown any speakers myself and still wasn't sure.

I have heard from someone, a user of Peavey, that systems have blown due to underpowering, and others have said similar things.



I am asking, if you power a 500w speaker with a 200w amp, will it blow?

Some say it will, some say it won't.

Who says that Max? Name some some names;)

Crikey now were talking Peavey problems.

This is just a load of old cobblers Max.

You are talking to muppets:D :D :D

CRAZY K

[Excalibur]

So if you have a pair of 8ohm 350watt speakers and an amp which gives out 500w a side at 8ohm then would I be correct in saying that you should have the amp at about 2-3 o'clock in order for the speakers to work at just about their optimum.
If I had the amp at 12 o'clock could I damage my speakers by underpowering them?

Thanks in advance for any advice. :beer1:


It's not so much about running an amp at less than full power, it's more about driving an Amp too hard to get the output you need to drive the speakers.

E.g. if you're running a 500w amp at 350w into 350w speakers then the amp will be running happily along and not at risk of distorting the signal it's giving as output - and it's the distortion/clipping which will destroy your speakers.

However, if you run a 350w amp at full power into 500w speakers, then you run a much greater risk of damaging your speakers because the output from the amp is likely to be distorting, or the output "clipping" - when that happens, you run the risk of burning out the coils in the speakers because you may be driving them with DC voltage instead of AC, which will quickly overheat the coil.

See here http://www.bcae1.com/2ltlpwr.htm for someone else asking the same question with pictures in the explanation (which makes it so much easier to understand!)

Julian
Correctamundo. :approve:


amp same size as my speakers. The mixer is set up so it never clips but is usually hitting 3/4 up the outlevel and the amp is usually on 50%-60% power depending on room, people stood in front of them etc... Used this for years no proplems.

How can "underpowering" a speaker blow it?


As mentioned in my other post, it's not so much underpowering a speaker, but underspec'ing the amp which is driving the speaker, and then drastically over-driving the amp. Running a speaker at less than it's rated power will never damage it.

Running as you are is the right way of doing it :D
Again, correctamundo. :approve:


Wouldnt overdriving the amp into larger spec speakers though blow the amp before damaging the speakers? If the input is fairly low I cant see how the speakers would be damaged?So what Max has said is if you drive an amp too hard it'll break?
Probably not. I've seen some components fried beyond belief by an amp rated way below the soeakers it was feeding. ;) ;) :eek: :eek:


Yes a clipped signal that overdrives an underpowered amplifier's input stage can fry speaker drivers, particularly HF compression drivers.

This can happen with amps of any size but amplifiers at around a 1/3 of the driver's RMS rating or higher are most likely to blow a drivers coil when clipping.....amps below this 1/3 threshold are not really a threat. :)

i.e. a 100w amp is unlikely to damage a 300rms driver even if it is fed a clipped signal, this is because the driver's mechanical/electrical thresholds will not have been reached.
I'll bow to your knowledge on this Tony, but in my youth ( yes, I was young once, when Dinosaurs roamed the earth) I've blown cabs rated twice amp output. ;) Feed 'em rubbish, blow the drivers. :(


Ok the simple answer.#
If you do not allow your amp to clip you can:

1. under power your speakers and they will never blow. (other than poor workmanship that is)

2. Over power you speaker within accepted power ratings i.e more than rms but lower than the muic rating.

I have never blown a pair of speakers since I stated DJ'ing I never allow my amps to clip whatever I am doing its a warning light not a target.
If you need more volume buy better speakers / amp designed for it not low power speakers or amp you have to push hard.
Logical, Captain. ;) ;)


Assuming your mixer output isn't in the red, your amp isn't clipping and your speakers power rating is at least the same as the amp's output, I don't see how you can blow the speakers.
Rob may not be our technical guru, but I can't fault his logic in this case. :(


But you're far more likely to run the amp into clipping when you don't have the headroom there. If you clip an amp, it can take out speakers instantly, whereas if your just overpowering them (above the rms I mean) you'll notice distortion and bad sound before any permenant damage is done.
Abso:Censored:lutely.