Short Term & Long Term Power in Speakers

So what i think is that long term is when they operate at 8 ohms and short term is when they operate at 6 ohms.

Noooooo !

They operate at the SAME impedance, short term or long term.

Its just that 170 Watts for short bursts of Music power will not melt the voice coil and damage it permanantly !

You can feed it 120 watts, for as long as you like, without melting any voice coil !

[quote="Amp_Nut"][quote]

You can feed it 120 watts, for as long as you like, without melting any voice coil !

[/quote]

So if attach it an avr with an output of 130 w will it cause any damage.

secondly what is short bursts of power. it wasnt clear to me.

So if attach it an avr with an output of 130 w will it cause any damage. No problem at all. ENJOY ! secondly what is short bursts of power. it wasnt clear to me.

Its Nemulus to me too ! Guess will have to ask Jamo !

So if attach it an avr with an output of 130 w will it cause any damage. secondly what is short bursts of power. it wasnt clear to me.

No it wouldn't harm even if you would attach a 200 watts per channel AVR.

Short bursts are usually when you have some gun fights or bomb explosions. BTW you'll not damage your speakers if you use a 130 watt AVr unless you plan to drive em full volume always

Let me chip in with some technical facts :

1. Reproduced music contains most of its power in the low and mid frequencies.

High frquencies (5 KHz and above) usually carry less than 5% of the total power.

Hence a 100 watt (per channel) speaker will typically feed its tweeters less than 5 watts! As a result, tweeters are also design to handle about 10% to 20% of the total rated power.



2. A speaker rated at 150 watts has its cross-over, woofer and mid-range drivers capable of handling at least 150 watts continously, without burn out.

Like any peace of wire, the coil in the woofer and mid-range can take short bursts of power without melting.

How short ? Short enough so that heat does not accumulate and exceed the maximum voice coil operating temperature.



3. In a home environment, each speaker will rarely be driven with more than 10 watts of power continuously. Of course, short bursts of power will need to be delivered depending on the type of music.

Estimates of the ratio of the average power to the peak power bursts vary. Some estimated as highest 20 times to 100 times the average power.



4. If you have a 100 watt amplifier which is called on to deliver a power burst (for a few milli seconds) of 200 watts, it will distort i.e. the waveform will clip.

Tis clipped waveform is full of 'harmonics' or multiple of the basic frequency. This implies that the clip waveform is mainly high frequency energy.



5. The cross-over will divert all frequency energy to the tweeter.

The tweeter is designed to handle only a small amount of power and therefore may burn out !



6. As a result, a low power amplifier is more lilely to clip and glow the tweeter than a high power amplifier wich will not clip !

Hence, it is generally safer to drive your speakers with even a very high power amplifier than a low power amplifier, as long as you don't get carried away with feeding lots of continuous power such as during a party.

That was some techy stuff but very informative and helpful.

thanks amp_nut

Guys, if you find some of my posts toooo techie, let me know so I

Amp_Nut schrieb:

Let me chip in with some technical facts : 1. Reproduced music contains most of its power in the low and mid frequencies. High frquencies (5 KHz and above) usually carry less than 5% of the total power. Hence a 100 watt (per channel) speaker will typically feed its tweeters less than 5 watts! As a result, tweeters are also design to handle about 10% to 20% of the total rated power. 2. A speaker rated at 150 watts has its cross-over, woofer and mid-range drivers capable of handling at least 150 watts continously, without burn out. Like any peace of wire, the coil in the woofer and mid-range can take short bursts of power without melting. How short ? Short enough so that heat does not accumulate and exceed the maximum voice coil operating temperature. 3. In a home environment, each speaker will rarely be driven with more than 10 watts of power continuously. Of course, short bursts of power will need to be delivered depending on the type of music. Estimates of the ratio of the average power to the peak power bursts vary. Some estimated as highest 20 times to 100 times the average power. 4. If you have a 100 watt amplifier which is called on to deliver a power burst (for a few milli seconds) of 200 watts, it will distort i.e. the waveform will clip. Tis clipped waveform is full of 'harmonics' or multiple of the basic frequency. This implies that the clip waveform is mainly high frequency energy. 5. The cross-over will divert all frequency energy to the tweeter. The tweeter is designed to handle only a small amount of power and therefore may burn out ! 6. As a result, a low power amplifier is more lilely to clip and glow the tweeter than a high power amplifier wich will not clip ! Hence, it is generally safer to drive your speakers with even a very high power amplifier than a low power amplifier, as long as you don't get carried away with feeding lots of continuous power such as during a party.

Tum Kamaal ho yaar...
Few years back while partying hard at my place, I blew both my sonodyne speaker's tweeter (only tweeters), I was wondering why only the tweeters got affected...today I know I was also wondering what clipping is..your explanation is superb

BTW what is soft clipping ??
How do we know that the amp is clipping or about to clip ?????

..your explanation is superb

First of all, thanks for the Thumbs Up !

BTW what is soft clipping ?? How do we know that the amp is clipping or about to clip ?????

1. When an amplifier 'Clips' the output voltage , instead for rising, gets ABRUPTLY flattened out.

A 'soft clipping' circuit rounds off this sudden flattning of the waveform top. This reduces, somewhat, the amount of Very High freq harmonics, making the 'clipping' or distortion less objectionable.

On the other hand, when you switch in the 'Soft Clip' circuit, it actually starts rounding off the waveform, BEFORE the actual onset of (hard) clipping.

Hence a 30 Watt NAD will deliver, say 30 Watts with the soft clip switched OFF, but will have increased distortion, at even 28 Watts, with the 'Soft Clip' activated.

2. Sadly, no easy way to tell when the amp is about to clip.... just by ear, and that may not be too sharp with beer & friends around !

Some amps do have a small RED Light that glows to indicate clipping...

Most speakers will take a little abuse, eg when cliping under normal listning, but during a party, it could get too much for the tweeter to handle on a prolonged basis.

Soft Clipping - understood

But still, atleast there must nbe some hint that the amp is almost clipping
I mean say I am not partying, just playing it loud, what could be the most obvious indication of clipping ??

I have found that when I reach about 3 o clock position on my Plinius, my Audience52 tweeters strats showing some distortion (minly during Bass lines) is it what you call clipping ?

I have found that when I reach about 3 o clock position on my Plinius, my Audience52 tweeters starts showing some distortion (minly during Bass lines) Is it what you call clipping ?

YUP !

The bass lines demad max power, and the amp cant cope..

The 3 o'clock Volume postion can be a VERY Rough pointer, for your Source+Amp+Speakers+Room.

Will change CD to CD ( or record to record ), because some CDs are recorded at a low average volume level, and others at a higher average level.

Hi Amp_nut

I must have posted this question earlier in some other topic, but would like your view (in techy terms ;)).

eg. if my AVR has an output of 130 W RMS continous @ 6 ohms and my speakers are capable of handling 130W @ 8 ohms. Now in such a scenario what will happen :

1. will the AVR give the output @ 8ohms, if so then how much will it be.

or

2. will the speaker give the output @ 6 ohms (which i guess is not possible). if so then how much output will it be.

whichever case is true what will happen and the maximum output level of the AVR? will any clipping / distortion occur ??

Secondly, a dealer told me the speakers RMS handling power should me greater than the output of the AVR, but according to you it is better to keep a slight low power speakers with the AVR. which one will be correct??

Please advise.

1. will the AVR give the output @ 8ohms, if so then how much will it be.

Yes, an AVR rated @ 130 Watts into 6 Ohms, will Certainly provide a healthy output .... though less than 130 Watts, into 8 Ohms.

It will provide ( by calculation ) 97.5 Watts into 8 Ohms.

what will happen and the maximum output level of the AVR? will any clipping / distortion occur ??

It should Comfortably drive your 8 Ohm speakers.

The 8 Ohm rating of your speakers will suck Less current from the AVR, and in principle, your AVR will provide better sound into the lighter load presented by the 8 Ohm speaker load.

Secondly, a dealer told me the speakers RMS handling power should me greater than the output of the AVR, but according to you it is better to keep a slight low power speakers with the AVR. which one will be correct??

What the dealer told you, is IMHO the typical, less-thatn-fully-informed opnion, which is VERY common.

That is why I posted in great detail, why and how a limited power amp is More Likely to destroy a speaker ( particularly the tweeter) than a High Power Amp.

Ofcourse a monster amp pumping out full steasm to modest speakers will certainly blow the speakers. However, you will HEAR the spekers distorting hoplessly for a while before they actually blow due to excess power.

I personally used a 400 Watt ( @ 4 Ohms ) Power Amp, driving my 200 Watt speakers.... often driven to VERY LOUD sound levels, without a problem, for the past 4 years, until I shifted to a 40 Watt Valve Amp, recently, driving the same speakers. NOW I have to fear from my tweeters...

6 Ohms & 8 Ohms Speakers....

SUNILYO please consider the 6 or 8 ohm speaker ratings as Ball Park, INDICATIVE figures ONLY.

A 6 Ohm speaker's impedance will ACTUALLY vary, at different frequencies from maybe 3 Ohms to 8 or even 16 ohms !

The Higher impedance is easily handled by the amp, the low impedance dips are what seperates the men from the boys - amp wise...