Burst Ratings...

[1991_Vn2nV]

What exactly is a burst rating?

I always believed burst and peak/max power to be the same thing but my new subs give all 3 ratings.

RMS: 900
Max: 1300
Burst: 2600



So can someone tell me the difference between Max and Burst ratings? It makes little difference obviously but im just curious as to what exactly the difference is?

A few sites on the net have listed the RMS value for the subs as 900-1300rms (so they're giving max as the max reccomended RMS value) and then giving peak power as 2600 watts... Are they misreading the specs as I assumed? Or are they right and im wrong?

[Gillz]

burst is where the amp goes over its rated power for a split second. it should be disregarded.

[1991_Vn2nV]

You'll have to bear with me here:

So the sub can take 2600watts for a split second... But isnt that the same as peak/max power handling?

Or peak/max can be sustained for a longer period? Which makes it 2 useless power ratings they can put on a sub box to make people go wow if they don't understand what it is?

[wrx884]

WOW hahaha

[1991_Vn2nV]

lol looks like it works :-p

[Ra1d]

wow lol. sheet what sort of 15" is that...900wrms

[azkwazere]

Yeah, Max power in RMS and Watts are esentially the same thing.... differnt units of measuremnt and are meausred differntly...guess that made no sense lol. Burst would refer to the max amout the amp could handle in a burst period (0.5 of a sec?) without tripping fuses.... guess its a power spike rating...?

Its a wank factor... it goes well with flufy dice uleh.

aZk.

[Adelaideprosound]

Burst rating is the amount of power a subwoofer can take for a split second before it falls appart, it has nothing to do with the power an amp makes in a second (THIS IS CALLED CLIPPING not BURST). Also this shouldnt be disregarded, depending on the application you are using the woofers for ie SPL. Your woofers are actually designed for SPL purposes hence why they have a high FS of 38hz, although sometimes this is not the only indication.

Maximum power handling figure on some subwoofers means the maximum power you can apply to the subwoofer to reach its excursion limits XMAX. Your RMS or Root Mean Square power rating is your constant daily allowable power limit the woofer can take without risking damage and this measurement is presented in WATTS. RMS and WATTS are not two different things.

For your application please stick to your 900WRMS limit per woofer, or slightly above. Most woofers will handle more power than their true RMS rating but this also depends on box tuning if its a ported box, or box size if its sealed. Tarantula woofers should only be used in ported applications they dont perform well in sealed boxes.

What kills a woofer is an underpowered amplifier, and what i mean by this is you can go and buy the biggest whoopdy dooo bazillion watt amp but have you stopped to think about the electrical system of your vehicle and how much excess current it actually has available to drive such system.
Capacitors dont help so forget it they are a burden not a help. Also the amplifier output while playing music is dynamic which means it is not playing one frequency at the same time but a number of different frequencies. Each frequency loads the amplifier down differently as different notes means different coil impedance that the amplifier is seeing at its output terminals. Also with ported boxes impedance rise should be taken in effect. Just because your woofer handles 900WRMS and your amp makes 1000WRMS at a given impedance it doesnt mean it will make this power at maximum volume.

There you go

Hope that helps.


George

[azkwazere]

the power an amp makes in a second (THIS IS CALLED CLIPPING not BURST).

No, clipping is the process where the tops and bottoms of the sign waves are cut off hence "clip". That has nothing to do with power in a second.

Your first paragraph is contradictory actually... you said one thing then said it was wrong.

aZk.

[Adelaideprosound]

What power in a second mate? If you exceed the maximum output of an amplifier it will clip, it wont do BURST ratings. And yes you are correct when the sinewave reaches the DC rails if you turn up the gain any more on the amplifier it will exceed the rails and clip the tops of the sine wave. I am very well aware of what clipping is.

BURST RATINGS on a subwoofer have nothing to do with how much power an amplifier outputs in a second. If you didnt understand thats what im trying to say. A BURST rating is the absolute maximum a woofer will take before it reaches its mechnical limits or also known as XMECH.

And my first paragraph is not contradictory read it again. If you use the woofers in SPL competitions where you only stress the woofer for a couple of seconds, then the burst rating will give you an indication of what the most power that woofer will take for TONE BURSTS.

[azzfox]

sorry if this hijacks the thread but speaking of clipping.. they say that a clipped signal is more powerful and can do damage to drivers by overpowering them. but how is it more powerful? if the signal is clipped at a certain level.. how can the output be more powerful?

[Adelaideprosound]

Ok

An amplifier outputs a sinewave which is a nice curved wave that has peak to peak points. The maximum throw in a positive direction will make the drivers cone move forward, and the maximum throw in a negative direction pulls the drivers cone backwards. Imagine this nice curved wave now becomes cut off and it starts to mimick a square. Everytime the now called square wave moves towards the positive the cone moves outwards and then when it reaches the square bit instead of nicely rolling off it sits there untill the square part of the wave is finished and then drops down towards the negative, it does the same at this end pausing for a certain time. Also the driver relies on movement in order to cool itself down, but since the cone assembly which consists of the coil windings and spider used to control linear movement are now STATIONARY all the power from the amplifier is being fed into the coil and while the driver is not moving it cannot cool itself resulting in a cooked coil .

Anyway this is the best way i can explain it plain english without getting to technical.

[Adelaideprosound]

Also if this clipped signal is within the drivers RMS power rating, you are not really risking driver damage unless you are constantly clipping your amplifier.

If the clipped signal is more powerful than the drivers RMS rating this in turn will cook the driver very quickly and almost instantenously. This depends on quality of materials.

[azzfox]

ah k, was thinking something along those lines. thanks for clearing it up.

[1991_Vn2nV]

wow lol. sheet what sort of 15" is that...900wrms

They're Soundstream R1's... and im told they're the only 2 that Soundstream have and will bring into Aus as well

[1991_Vn2nV]

Burst rating is the amount of power a subwoofer can take for a split second before it falls appart, it has nothing to do with the power an amp makes in a second (THIS IS CALLED CLIPPING not BURST). Also this shouldnt be disregarded, depending on the application you are using the woofers for ie SPL. Your woofers are actually designed for SPL purposes hence why they have a high FS of 38hz, although sometimes this is not the only indication.

Maximum power handling figure on some subwoofers means the maximum power you can apply to the subwoofer to reach its excursion limits XMAX. Your RMS or Root Mean Square power rating is your constant daily allowable power limit the woofer can take without risking damage and this measurement is presented in WATTS. RMS and WATTS are not two different things.

For your application please stick to your 900WRMS limit per woofer, or slightly above. Most woofers will handle more power than their true RMS rating but this also depends on box tuning if its a ported box, or box size if its sealed. Tarantula woofers should only be used in ported applications they dont perform well in sealed boxes.

What kills a woofer is an underpowered amplifier, and what i mean by this is you can go and buy the biggest whoopdy dooo bazillion watt amp but have you stopped to think about the electrical system of your vehicle and how much excess current it actually has available to drive such system.
Capacitors dont help so forget it they are a burden not a help. Also the amplifier output while playing music is dynamic which means it is not playing one frequency at the same time but a number of different frequencies. Each frequency loads the amplifier down differently as different notes means different coil impedance that the amplifier is seeing at its output terminals. Also with ported boxes impedance rise should be taken in effect. Just because your woofer handles 900WRMS and your amp makes 1000WRMS at a given impedance it doesnt mean it will make this power at maximum volume.

There you go

Hope that helps.


George

Thanks heaps man, excellent post. The subs are soundstreams flagship SQ woofer, the R1's... Would you still reccomend a ported enclosure or am I alright to use a sealed encolsure? For the boot install im doing sealed would be alot easier to make and also fit into the install as it doesn't need to be as large.

[Adelaideprosound]

Oh sorry why did i think you had Tarantulas?

Well as far as the R1 goes considering there isnt many in Australia i would really need to have a look at the specs and that will tell me which size box they would require and whether they would be able to work in a ported or a sealed enclosure.

But as the saying goes with any SQ woofer provided the specs are correct they work best in a sealed environment, but i have been known to knock up a very good ported enclosure in an SQ environment also.