Axiom Home Page Forums General Discussion Technical Questions Question about sound frequency and speacker damage

Hello,


I would like to know if i will damage speackers from any brand like axiom playing a test tone signal, like a 20hz or 20khz oscillator sound ,-5dbfs up to -1dbfs ,on a scale up to 0dbfs.

I can't ask to my stereo amp to cut frequency below a certain frequency like a hc one.


My amp can reproduce sound spectrum :
(1W +1/-3dB) : 10 Hz -170 kHz

My sound card :
- D/A converter: AK4396
- Level: -10dBV nominal, 6dBV max (unbalanced)
- Frequency Response (20Hz - 20kHz): + 0.05/-0.10dB,
- Dynamic Range (1kHz, A-weighted): 116dB
- Signal-to-Noise Ratio (A-weighted): 116dB
- THD+N (1kHz at -1dBFS): -100dB (.001%)
- Stereo Crosstalk (1kHz at -1dBFS): < -109dB

I do mean:
Is the m80 crossover been good enough to reduce low frequency and high frequency bass/trebbles without any possible damage to the speacker ?

Thank you very much.

Well, I'm completely unqualified to answer this and probably shouldn't but my first thought was that I would be worried that if you do not get a perfect conversion of your analog signal that you might be in danger of clipping early as you approach 0 dbfs. How much or how dangerous this would be, I'm not sure.

I also do not believe it is the purpose of the crossover to protect you from such an effect.

That being said, ignore me because this is unqualified speculation.

i would never, never send a sine wave at -1 or -5 dBfs.
chances are your speakers will break down quite fast, specially the tweeters.
this has nothing to do with crossovers.

sine waves are not the same kind of animal as music or loud movies, they vary continuously in frequency and amplitude, contrary to sines waves.

sine waves are very dangerous IF you don't know what you're doing; they are continuous amplitude waves, and don't let the speaker breathe to cool down.

Why would you even want to do this anyway?

I don't want to do it but i saw a youtube channels where an user claim he found a sound that could damage your speackers playing it.



Actually My emu 0404 has pink noise white noise and oscillator generator with range 20hz to 20kz from -132db (mute) to 0dbfs.

I talked to someone who is a sound engineer that told me if i had a cd with pink noise inside or a program to generate it, he could use his mic to test the full spectrum range of my speackers.

I was wondering about oscillator that was shutting down my amp when switching to 20hz at -10dbfs or even louder.That's why i ask you in this forum before making any errors .

I thought oscillator could help me to test my bass driver or tweeter to see if they function well.It was my error.

a simple way to check if all the speakers work is by playing some music at a medium loudness level and then you put your ear within a couple of inches of each one.
you can also play pink noise at a moderate level; white noise will have relatively stronger high frequencies.
no sound = dead speaker or a loose wire inside.

i think that any kind of sound, if it's played too loud for the speaker to handle, will kill it

i think you can download pink noise from the internet and then just burn it to CD.

a speaker that shuts down means it's being overdriven; the shutdown is a protection. when it's overdriven, the sound distorts.

Or any modern receiver will have it built in for manual speaker leveling as well as pretty much any calibration disc such as Avia, Sound & Vision, Disney WOW etc...

Thanks for the answers.


I was looking for an amp like harman hk980 one or
NAD C356BEE which is really good.

Then i found a forum topic that lead to the creek evo 2.They claim sound really worth it for the price.

Atoll also make good amps so i have choice but this is another story :p

I received this answer from Alan:


Hello Adelin,

I saw your questions on the Axiom forums, which I monitor daily, as well as your PM, so here's what I suggest: the Axiom M80s do not have bass response to 20 Hz, so you shouldn't expect the woofers to reproduce loud output (or any output) at those frequencies. The M80 speaker has excellent deep bass to about 27 Hz, but no significant output at 20 Hz. You shouldn't feed test tones at 20 Hz to a speaker not designed to reproduce those tones, or damage may result. In fact, I'd suggest that if you are not familiar with lab testing procedures, don't use single test tones at all. You may use a pink noise signal, which I routinely use in speaker evaluation, as pink noise represents an equal amount of energy per octave across the audible spectrum. Single test tones may overstress any driver and cause damage.

If you want to reproduce energy at 20 Hz at high output, then a large powerful subwoofer is essential. I'd suggest Axiom's EP500 or a larger model.

By the way, there is almost no musical energy from any instrument, except very large pipe organs, below 30 Hz. Some movie soundtracks contain energy in the 20 Hz region or deeper, which is why large subwoofers are recommended for those signals, as well as pipe-organ reproduction.

The Axiom M80s are capable of very loud playback with no distortion of all music signals (not test tones!), ranging between 27 Hz and 20,000 Hz.

Regards,
Alan Lofft,
Axiom Audio

Some idiotphiles claims they burn new speackers by looping test tones.
I'm glad i never tryed it


Thanks

You don't need to break in speakers in any case.

don't listen to all those "know it all" people...

of course you need to burn-in new speakers!

when your amp sends something to those costly new speakers, any kind of signal, music or a movie, as soon as the speaker has reproduced some sound for a fraction of a second, it's done.

if you do it for a longer time than this, then you're an "audiophile".

audiophiles are a very funny bunch sometimes, like the guy who said that when he got his costly new amp during the winter, he let it stand at room temp for 2 weeks in order to get it stabilized.
apparently he forgot to think that when he started using the amp, it would warm up to a temperature higher than the room's temp and thus the amp would be destabilized.

Maybe slowly warm it up for a week under an adjustable heat lamp every time he turns it on? Then do the same thing in reverse after powering off?

terzaghi, like it says under your username, you're a connoisseur!
thanks for the tip. :-)

I would just bang it with a hammer a few times to get the oops, dropped it on the floor, part out of the way.

A speaker that has been sitting in a truck in the dead of winter could definitely sound different than one that has been set up at room temp.

Even the T/S parameters of your drivers can change during daily use of your speakers as the voice coils heat up. However under these circumstances, its insignificant audibly, and they revert back after use.

"Breaking in" your speakers will not prevent damaging your speakers either in future use.

If you live in a cold state or country, now that winter is coming along, just leave them in the box to get up to room temp for a couple of hours before you set them up.

Or if its too much effort to get a hammer, rub a little catnip on the speakers and let your cats do the heavy lifting...

Is it just me or does the first post make you think of Bbigwyres?

When i was 12 year old ;i remember about speackers that was siting on the cellar floor of my house for years.

I did a big mistake by cleaning the cellulose driver,with a wet duster.
There was that much dust that it was like glue.

One day later i played music on it. sound was ok.
hours later,boomer cone was unstuck.
I tryed to fix it myself using glue. what a bad idea i had.

What i'm thinking for myself:

Listen music and enjoy it my boy too much questions kill the music.

Uh-Huh!

Indeed.

Reflect!