DVD Talk
How easy is it to BLOW your speakers? [Archive] - DVD Talk Forum
 
Best Sellers
1.
2.
3.
4.
5.
6.
7.
8.
The Longest Day
Buy: $54.99 $24.99
9.
10.
DVD Blowouts
1.
2.
3.
4.
5.
6.
7.
Alien [Blu-ray]
Buy: $19.99 $9.99
8.
9.
10.

PDA
DVD Reviews

View Full Version : How easy is it to BLOW your speakers?


RaZorBlade
02-19-01, 08:46 PM
I always want to put the volume pretty high when I'm watching a dvd - especially in DTS (not extremely high, but high enough for the things in the room to vibrate a bit), and my dad tells me to turn it down, because I will blow the speakers.

Is this true? How easy is it to blow the speakers in a HT system?

edclem
02-19-01, 10:05 PM
It really depends on your amplifier. If your amplifier goes into clipping, you can blow speakers at normal listening levels. However, if you have a clean high powered amp (or amp stage of your receiver) you can drive your system to the point of causing both pain and damage to your ears without damaging your speakers, provided they are designed for producing very elevated sound levels.

At some point, your speakers will begin to over-exert themselves, noticeable as distortion in the sound. This is most noticeable in mid and upper frequencies. Woofers usually distort by "bottoming out".

A few general rules: If there's any distortion, it's too loud for your system. If your amp is clipping, it's too loud for your system. If it hurts: it's WAY too loud for your ears.

As someone who has permanent low level tinnitus from too many rock shows without earplugs, take care of your hearing. You only get one set of ears. :)

Centurion
02-20-01, 03:37 AM
WHAT?

Sorry.
Couldn't resist. ;)

tommy28
02-20-01, 07:49 AM
i blew a pair of nht super1 with a citation 7.1 bridged(450 watts):)and YES i did it on purpose....

ts

clemente
02-20-01, 03:23 PM
What's clipping?

stevevt
02-20-01, 03:30 PM
Originally posted by clemente

What's clipping?

from http://www.aspen-media.com/surroun1.htm

"The biggest single cause of loudspeaker driver failure is the high frequencies generated by an amplifier when it is driven into clipping. When the output signal of an amplifier is clipped (i.e. the output voltage, if unrestricted, would exceed the power supply voltage of the amplifier) the result is a signal that increasingly resembles a squarewave. A square wave, unlike a sinewave of a similar frequency, contains high frequency harmonics at a much higher level than would normally present in most audio signals. Hence the HF drivers in a loudspeaker, which are only designed to accept normal audio signals, have their coils burned-out by these high frequency harmonics generated by amplifier clipping. Therefore, whenever possible install an amplifier that matches or exceeds the power-handling of your loudspeaker."

PoorBoy
02-20-01, 04:00 PM
It's not volume that blows a speaker. It's distortion. Clipping (as defined above) is that crap sound your speakers make when you turn it up WAY too high. You'll start hearing audible distortion. A good way to think about it is like a car. When you're just driving along the car is using only a certain level of gas and it's doing great. Now imagine you flooring the car but not feeding the engine any more gas than when you were cruising. The car will choke and sputter but keep running. Kind of the same thing with an amp. If the amp doesn't have enough gas to power the speaker at a higher volume clipping occurs. Most of the time it's not the wattage rating in your amp that causes clipping, it's the current. I think that's a good analogy. I'm terrible at electronics.

Sin/Square wave: The signal coming out of your wall is a Sin wave, now when clipping occurs the tops of the sin wave start getting cut off making it look flat at the top, so the response isn't consistant with the signal.

Kromax
02-20-01, 05:13 PM
Originally posted by edclem
As someone who has permanent low level tinnitus from too many rock shows without earplugs, take care of your hearing. You only get one set of ears. :)

I feel your pain. My tinnitus probably results from years of loud concerts, car stereos and home systems, but one severe traumatic incident from my home theater is what brought it on.

I ruined my ears watching the credits on BLADE too loud and too close. :brickwl: How did this happen? I thought I heard clipping, which should not have been the case (and ultimately wasn't), so I kept getting progressively closer to the front speakers and kept turning the volume up. Stupid, I know. But it is done. . .it won't destroy my life, as it has done to others (my ENT doctor said that the only medication for tinnitus is an antidepressant. People have been known to lose their minds. :()

Goblincat
02-21-01, 01:44 PM
If I take MP3's and turn them to .WAV files and burn them to a CD, the CD causes the clipping light on my receiver to flash, no matter what volume level. Normal CD's don't cause this. Why does this occur, and is this damaging?

Patman
02-21-01, 01:48 PM
Your recording levels are too high.

SINGLE104
02-21-01, 02:18 PM
Originally posted by RaZorBlade
I always want to put the volume pretty high when I'm watching a dvd - especially in DTS (not extremely high, but high enough for the things in the room to vibrate a bit), and my dad tells me to turn it down, because I will blow the speakers.

Is this true? How easy is it to blow the speakers in a HT system?

it's not really necessary to play it that loud, unless you just want the whole entire neighborhood to hear it. but eventually, it'll do some damage to your speakers,and ears after a long period of time.

RaZorBlade
02-21-01, 07:24 PM
Originally posted by SINGLE104
Originally posted by RaZorBlade
I always want to put the volume pretty high when I'm watching a dvd - especially in DTS (not extremely high, but high enough for the things in the room to vibrate a bit), and my dad tells me to turn it down, because I will blow the speakers.

Is this true? How easy is it to blow the speakers in a HT system?

it's not really necessary to play it that loud, unless you just want the whole entire neighborhood to hear it. but eventually, it'll do some damage to your speakers,and ears after a long period of time.

But I like to have the full experience - to be engulfed in the sight and sound of the movie. So I want to be able to hear everything.

Can you tell if you're listening to something too loud? Often when I turn my headphones too loud I can tell, and I turn it down. I dont get this feeling when I'm in my HT, so I usually just leave the volume where it's at.

Fhrx
02-21-01, 07:37 PM
It's so hard to explain to people that their system sounds dreadful because their amp is clipping, not their speakers dying.

The most common problem we face is that customers hear their speakers distorting and think the amp is too powerful for them or the driver is not big enough to handle the power so they get a smaller amp or bigger speaks.

This is the total opposite to the real remedy.

Centurion
02-21-01, 07:43 PM
Fhrx,
You're right.
That's what the quote from Stevevt's post was trying to convey.

tdamico
02-22-01, 06:47 AM
First you give them a few drinks to get them in the mood. They you slowly pull off their covers, take out their woofers...

Goblincat
02-22-01, 07:40 AM
Originally posted by Patman
Your recording levels are too high.

How can I lower them? I use Winamp to convert, and Adaptec CD Creator 4 to burn.

SINGLE104
02-22-01, 09:25 AM
I see your point, but to me, it would make the movie sound more unnatural. i usually listen to my DVD's at a moderate volume, and when the volume seems too high for me, it get's distracting.but then again, it depends on the type of movie your watching, and the size of the room as well. the sound is more realistic when it's listen to at a moderate volume, to me it does. digital sound is tremendously powerful, and that's what home theaters are for to enjoy it :)



[Edited by SINGLE104 on 02-23-01 at 07:27 AM]

vlad
02-22-01, 04:51 PM
One of the easies ways to determin the listening levels is to go to Radio Shack and buy a SPL meter. This should be around 30 bucks. This will also allow you to balence your system.

I have a very powerfull amp and nice speakers. When I saw 117db on my SPL meter during GoldenEye; I turned it down. I did not think it was that loud.... I don't go that loud any more :) Good, clean sound is louder that you realize.

Goblincat, the wave file you have may be crap and that could cause clipping. Remember you are taking a digitized wave and turning it into a analog signal for the speakers. If the wave "compressed" or left out to many samples from the original, the resulting wave will not be the same; clipping may occur.

Patman
02-22-01, 09:00 PM
You move right up close to the speaker and exhale. Q.E.D. :)

BigStinky
02-23-01, 12:29 AM
Kind of a stupid question - more of a clarification needed:

Supposing I have a 100 Watt receiver and speakers that are rated for 100W ...

1. Is the halfway point on my receiver volume dial equivalent to 50 watts of output? And the maximum volume equivalent to 100W of output?

2. Will I only ever run the risk of damaging the speakers when the dial is turned way up? 70-100 Watts?

OR did i miss something? Is wattage not really a factor in damaging your speakers?

[i can't comfortably turn up this kind of system past the 1/2 way point anyway so i doubt i'll ever hear its full potential volume]

BigStinky
02-23-01, 03:17 AM
that's helpful,
thanks, stevevt, phil

stevevt
02-23-01, 08:34 AM
Originally posted by Clint Eastwood
Kind of a stupid question - more of a clarification needed:

Supposing I have a 100 Watt receiver and speakers that are rated for 100W ...

1. Is the halfway point on my receiver volume dial equivalent to 50 watts of output? And the maximum volume equivalent to 100W of output?

1. Not really.

Originally posted by Clint Eastwood
2. Will I only ever run the risk of damaging the speakers when the dial is turned way up? 70-100 Watts?
[/B]
2.) No. You will run the risk of damaging the speakers whenever you ask the receiver to put out more power than it is capable of. Although when this happens isn't completely independent of where your volume control is, the volume level on the receiver is only one factor. Others include: the input level, impedence of your speakers, the way the amplifier section of your receiver was built, etc.

Originally posted by Clint Eastwood
OR did i miss something? Is wattage not really a factor in damaging your speakers?

[i can't comfortably turn up this kind of system past the 1/2 way point anyway so i doubt i'll ever hear its full potential volume]
You missed something. At any given time, your receiver is doing more or less work, depending on many more factors than the volume knob.

Use your ears. If you hear your speakers begin to distort, turn the volume down.

Phil I
02-23-01, 02:24 PM
FYI: From JBL-Pro website: Danger: Low Power (http://www.jblpro.com/pub/technote/lowpower.pdf) Information on one of the most common causes of speaker failure.

JBL - Technical Note

Danger: Low Power

. . . The Nature of Amplifier Power
The power output specification of an amplifier is not absolute. Under certain operating conditions, such as when the volume control is set too high or when the input signal is too great, the amplifier can exceed its published output. The power output of an amplifier is rated with reference to a given level of total harmonic distortion (THD). If required to produce more power, the amplifier will do so, but at considerably greater distortion levels. For example, an amplifier rated at 10 watts (20 to 20,000 Hz into an B-ohm load) at no more than 0.5% THD could be overdriven to produce 20 watts of output power to the loudspeakers. Under these same adverse conditions, an amplifier rated at 20 watts could deliver 40 watts to the loudspeakers; a 35-watt amplifier could deliver 70 watts and a 50-watt amplifier could be overdriven to deliver 100 watts. This distorted output could very well be in the treble region, as we shall soon see.


Hereís The Killer: Distortion Generally Affects High Frequency Drivers
The additional power generated by overdriving the amplifier is rich in harmonics (distortion). These harmonics can be particularly dangerous to high frequency drivers. Harmonics are higher frequency multiples of the original signal; therefore, the high frequency component of a loudspeaker system must bear the brunt of the distortion - even though the original signal may have been generated by a bass guitar.

What Can the User Do?
There are no hard and fast rules. Very few amplifiers have meters that are capable of accurately indicating when an amplifier is being overdriven to the point that it could damage loudspeakers. Even the volume control position is not a clue - half rotation often produces considerably more or less than 50% of an amplifierís power. There are no absolutes. We wish there were.

However, we can offer a few guidelines:

1. Purchase an amplifier that will provide more power than you will need.
Remember, a loudspeaker can require up to ten times the average power level for those instantaneous bursts of sonic power known as transients. If the amplifier has enough reserve power, transients will be clear and crisp. If not, the transients will be muddy or dull. When an amplifier runs out of undistorted power, it is forced to exceed its design capabilities, producing dangerous power levels rich in high frequency distortion.

2. Do not drive the amplifier into clipping
Clipping sounds something like a stylus mistracking. and generally occurs on loud passages when the system is played at loud volume levels. If clipping occurs regularly, turn down the volume level or install a larger amplifier that can deliver the required power without distortion.

Summary
JBL loudspeaker systems are efficient, they will produce reasonable volume levels in a room of moderate size with very little amplifier power. However. if a small amplifier must be overdriven to obtain the desired volume levels in a listening room, thus generating high power and distortion levels, the user would be better advised to purchase a larger amplifier capable of producing the required power with negligible distortion. In any case, an amplifier should be selected with an output power rating that is greater than the maximum power that will be used. This margin of reserve power will ensure that the amplifier will not attempt to deliver more power than its design allows. The net result will be distortion-free sound reproduction and virtually unlimited loudspeaker life.

So, to quote Tim the Tool Man, . . ."More Power"!!

There is more INFO in the PDF document, click the link above to access the copy.

Phil

[Edited by Phil I on 02-23-01 at 03:40 PM]