woofer damage from low bass music?

[Sylar]

does music like this have the potential to damage woofers in speakers...ones which can play down to 30....40 Hz?
I bumped into this song while browsing and played this on my speakers. Even at average volumes the driver excursion was pretty high..., wasnt adventurous enough to push it further

 

[GranteedEV]

Depends on plenty of factors.

Does your sub have limiting circuitry to keep itself within its limits; and how much cone surface area and mechanical excursion does your sub have anyways?

For all I know your sub might have a vent tuned at that frequency tone, and it'll barely move at its tuning frequency.

Good subs are engineered to "take a hit".

DIY subs like mine with no high pass filter, low Q box, and 2500+ watts, are like being in vegas, ALL IN

When in doubt, just quadruple the number of subs. Not only will it improve headroom greatly but also improve in-room response.

 

[Pyrrho]

You can damage any speaker with too much power (though with self-powered speakers, there can be limiters to prevent this).

In general, you can find out how loud you can play something by gradually turning up the volume until you start to hear distortion, and then turn it down until it goes away, and you have found the maximum safe volume.

Of course, that does not mean that you will always be safe with that volume control setting, because a higher input signal will cause things to go louder.

It also is not going to work well for very dynamic pieces of music, like Tchaikovsky's 1812 Overture, as the cannon blasts toward the end are often much, much louder than the preceding music. So with something like that, one would want to find the loudest cannon blast, and play it at a low volume through one's speakers, and try that blast over and over, at slightly increased volume, until there is distortion (which may be hard to notice, as it is a cannon blast and not music; however, you had better notice it if you don't want to damage your speakers), and then turn it down until the distortion goes away.

 

[Sylar]

Depends on plenty of factors.

Does your sub have limiting circuitry to keep itself within its limits; and how much cone surface area and mechanical excursion does your sub have anyways?

For all I know your sub might have a vent tuned at that frequency tone, and it'll barely move at its tuning frequency.

Good subs are engineered to "take a hit".

DIY subs like mine with no high pass filter, low Q box, and 2500+ watts, are like being in vegas, ALL IN

When in doubt, just quadruple the number of subs. Not only will it improve headroom greatly but also improve in-room response.

By subs, do you mean subwoofers?
I was referring to the woofers within the front speakers alone.

 

[GranteedEV]

By subs, do you mean subwoofers?
I was referring to the woofers within the front speakers alone.

Woofers in front speakers can be damaged, yes. regular Amps don't have any limiting circuitry except for a subwoofer crossover, which you don't appear to be using. If it's got vents, the drivers will unload from any coupling below the vent tuning region. It might only take 30w at a low enough frequency to damage your mains.

 

[Sylar]

Woofers in front speakers can be damaged, yes. regular Amps don't have any limiting circuitry except for a subwoofer crossover, which you don't appear to be using. If it's got vents, the drivers will unload from any coupling below the vent tuning region. It might only take 30w at a low enough frequency to damage your mains.

I have the PSB T6 (2 woofers 6 1/2", with 2 front ports)
I do not have a sub with the mains and yes, I have not set the crossover. While playing, I did not hear the sounds corresponding to the *higher woofer excursion* that I was referring to. I know this because the music didnt sound any different when the high excursion happened, every time. (Pyrrho
had mentioned, keep an open ear for distortion) But, now there is no way for me to know, if the music/movie that I am playing is capable of damaging the woofer's within. So Crossing over to the subs such that mains dont play lower than 40Hz, is more or less necessary for me now...right?

If lower bass is capable of damaging the woofers, why wouldnt the manufacturers forcefully filter them at the speakers...or at least provide an option?

 

[GranteedEV]

II do not have a sub with the mains and yes, I have not set the crossover. While playing, I did not hear the sounds corresponding to the *higher woofer excursion* that I was referring to. I know this because the music didnt sound any different when the high excursion happened, every time.

Interestingly enough, you may have heard distortion, but it may have been masked by the music. The third harmonic of a 20hz tone is something like 60hz, right? How good are you at recognizing the difference between a true 20hz (virtually inaudible) and 60hz???

But, now there is no way for me to know, if the music/movie that I am playing is capable of damaging the woofer's within.

You've still got amp limitations and movie LFE is shelved by 10db if it is directed to your mains rather than your subs.

So Crossing over to the subs such that mains dont play lower than 40Hz, is more or less necessary for me now...right?

I would cross over the T6 closer to 100hz to maximize clean output, though the actual point is best determined by looking at room acoustics I suppose.

If lower bass is capable of damaging the woofers, why wouldnt the manufacturers forcefully filter them at the speakers...or at least provide an option?

Because

1) Such a high powered goal shouldn't be done passively and would be costly even if it was.

2) Would you buy speakers with a built in amplifier? I am a supporter of active speakers but not many people are.

3) Not much music has content below 30hz or so. It really takes test tones Electronik Music to blow a woofer like that. Anyone listening to electronik music should be using subs.

4) most people use subs anyways.

I'd expect something like a Seaton Catalyst or Genelec 8260A to have the features you suggest.

 

[Pyrrho]

I have the PSB T6 (2 woofers 6 1/2", with 2 front ports)
I do not have a sub with the mains and yes, I have not set the crossover. While playing, I did not hear the sounds corresponding to the *higher woofer excursion* that I was referring to. I know this because the music didnt sound any different when the high excursion happened, every time. (Pyrrho
had mentioned, keep an open ear for distortion) But, now there is no way for me to know, if the music/movie that I am playing is capable of damaging the woofer's within. So Crossing over to the subs such that mains dont play lower than 40Hz, is more or less necessary for me now...right?

If lower bass is capable of damaging the woofers, why wouldnt the manufacturers forcefully filter them at the speakers...or at least provide an option?

Upper bass can also damage the woofers, if it is loud enough. So do you want the manufacturer to filter out the upper bass as well? And high levels of treble can damage tweeters, too. Should the treble be filtered out also?

Basically, any speaker can be damaged by excessive power, at any frequency that is fed to it. Now, it is possible to have special circuitry to avoid damage, but that costs extra money, and does not improve the sound quality. Are you willing to pay extra for a speaker that does not sound any better? Most people are not.

Also, if one uses reasonable care, one will not blow a speaker, using the method I describe above. So it is not generally necessary to add such protective circuitry. In my case, I have never in my life blown a speaker, except in a case of a severely malfunctioning amplifier passing DC to the speaker, which had nothing whatever to do with volume setting; just hooking it up and turning it on blew the speaker.

Use the method I described earlier, and you should be fine, as far as speaker damage is concerned (assuming, of course, that you recognize what distortion sounds like when you hear it).

There is also a separate issue of damage to your hearing caused by loud sounds, and that will not be avoided merely by using the method I described for avoiding speaker damage.

 

[Pyrrho]

Interestingly enough, you may have heard distortion, but it may have been masked by the music. The third harmonic of a 20hz tone is something like 60hz, right? How good are you at recognizing the difference between a true 20hz (virtually inaudible) and 60hz???
...

Also, having 20Hz cleanly reproduced, but not at a high level, may not be audibly noticed when added to some music, so one might have high excursions sometimes that do not seem to correlate with a difference in sound.

If the woofers start "bottoming out" (i.e., reaching the limits of their excursion), one ought to notice unpleasant distortion, and one ought to turn down the volume immediately.

 

[Pat D]

does music like this have the potential to damage woofers in speakers...ones which can play down to 30....40 Hz?
I bumped into this song while browsing and played this on my speakers. Even at average volumes the driver excursion was pretty high..., wasnt adventurous enough to push it further

With ported speakers, there will be a point below which the ports no longer function so the woofer is unloaded and the driver can essentially flap freely back and forth. This is not much of a problem with acoustic suspension speakers because the box is closed and the larger the woofer excursion, the more the air in the box resists the woofer's movement.

As for damaging the woofers, with ported speakers, or speakers with a port substitute (passive radiator), if the woofers go past their excursion limits they may clang or bang against the metal frame. Certainly if that happens, you should back off the volume.

Record warps could sometimes cause woofers to flap around freely. I have low filters on the phono inputs which filter out the bass below about 30 Hz at 6 dB per octave. I used to have some full range speakers with a passive radiator and they could not handle large signals below 30 Hz or so.

There are some ways around this, I gather. One is to filter out the lowest frequencies that the speaker cannot reproduce, anyway. I have no idea whether PSB does this.

I have 2 pairs of ported monitor speakers, the old PSB Stratus MInis and the Paradigm Signature S2. I've never noticed a problem but then I use subwoofers with both and so the lower frequencies are filtered out from the main speakers.

You might ask PSB whether their speakers can take high levels of deep bass.

 

[Sylar]

How good are you at recognizing the difference between a true 20hz (virtually inaudible) and 60hz???

I would cross over the T6 closer to 100hz to maximize clean output, though the actual point is best determined by looking at room acoustics I suppose.

I have experimented a bit and I find 80Hz sounds the best, 40 & lower can get painful, 60 is not bad. I dont like higher bcos I dont have a sub and for some songs they sound *dull* as I cross over higher.

There is also a separate issue of damage to your hearing caused by loud sounds, and that will not be avoided merely by using the method I described for avoiding speaker damage.

Could you explain a bit on this, or if you could share a link or two would be great.

 

[Pyrrho]

There is also a separate issue of damage to your hearing caused by loud sounds, and that will not be avoided merely by using the method I described for avoiding speaker damage.

Could you explain a bit on this, or if you could share a link or two would be great.

Not only are their limits to what speakers can take, there are limits to what your ears can take. Many people do permanent damage to their hearing from exposing themselves to loud sounds. If your ears hurt from loud sounds, or you get a headache from loud sounds, it is too loud. Unfortunately, the reverse isn't true; sounds can cause damage without immediate pain, but you can be sure it is too loud if it causes pain or discomfort. How loud it takes to do permanent damage is also a function of how long one is exposed to the sounds; surprisingly low levels can do damage if the sound lasts for several hours. Very often, people have no idea that they are damaging their hearing, as the damage is often only noticed much later (though if the loud noises were loud enough, the effects would be immediate and permanent). Here are some links dealing with this issue:

http://www.nidcd.nih.gov/health/hearing/noise.asp

http://www.dangerousdecibels.org/education/information-center/noise-induced-hearing-loss/

http://www.medicinenet.com/noise_induced_hearing_loss_and_its_prevention/article.htm

http://www.asha.org/public/hearing/Noise/

http://www.abelard.org/hear/hear.php

I strongly recommend that you avoid trying to reproduce the loudest rock concert ever, as that will do permanent damage to your hearing.