Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 5 1 2 3 4 5
Clipping
#133513 03/27/06 02:47 PM
Joined: Mar 2006
Posts: 66
R
Rapmon Offline OP
old hand
OP Offline
old hand
R
Joined: Mar 2006
Posts: 66
I'm new to this so please don't LOL. I didn't know I had a crappy system till I started researching for new speakers. What exactly does clipping sound like? Is it similar to the sound of a kazoo? And if not, what could be causing that; A cracked woofer? Also, do blown speakers still work or do they just sound bad? One more question. Why do home theater receivers have two options for attaching speakers and is one option better than the other? Thank you for curing my ignorance in advance.


".....We don't need no thought control..." Axiom M60's CSW m60's HK avr 240
Re: Clipping
#133514 03/27/06 04:25 PM
Joined: Dec 2005
Posts: 3,301
connoisseur
Offline
connoisseur
Joined: Dec 2005
Posts: 3,301
I can't help you on the cliping, never heard it before. As far as your receiver having options for connecting speakers, there are actually three, bare wire, spades or banana clips. The latter two are just a personal choice for convenience, no difference in sound quality, the banana's are just easier to connect in tight spots.


A computer once beat me at chess, but it was no match for me at kick boxing.
Re: Clipping
#133515 03/27/06 05:35 PM
Joined: Feb 2004
Posts: 845
aficionado
Offline
aficionado
Joined: Feb 2004
Posts: 845
A KAZOO?.............(LOL).


Sorry.




LIFE: "Choices, balance, and timing"

(Larryism)
Re: Clipping
#133516 03/27/06 06:42 PM
Joined: Jan 2006
Posts: 71
old hand
Offline
old hand
Joined: Jan 2006
Posts: 71
Unless I'm badly mistaken, clipping is what you get when you try to get too much volume from not enough power. In other words, the amplifier can't keep up with the demand for power, and the louder parts of the signal get flattened out (picture a sine wave that's flat on the top and bottom...) because there's no more juice. This is really bad for speakers, besides sounding distorted. Speakers driven too hard with a weak amp tend to get burned out faster than when driven to the same level with a powerful amp because of this signal distortion.

Damaged speakers also sound bad, (Understatement!!) but I'm not sure how to describe the sound. Maybe like paper fluttering in the wind?


Success is not the result of spontaneous combustion: you must set yourself on fire!
Re: Clipping
#133517 03/27/06 07:27 PM
Joined: Apr 2005
Posts: 1,155
connoisseur
Offline
connoisseur
Joined: Apr 2005
Posts: 1,155
You may be onto something with clipping sounding like a Kazoo.

The problem with clipping is that it tends to blow your tweeters.

I have had "blown" speakers in a car system and they would still work. They just sounded bad.

If you can look inside your speakers, see what sort of drivers are in them. Maybe you can listen to each individual driver and see how it sounds.


The Rat. M80s, VP-150, QS8s, SVS PC 20-39+, OPPO, Onkyo 703s, Harmony 880 Sony 60" SXRD HDTV
Re: Clipping
#133518 03/27/06 07:32 PM
Joined: Dec 2003
Posts: 3,602
B
connoisseur
Offline
connoisseur
B
Joined: Dec 2003
Posts: 3,602
There are actually two "sounds" of clipping... hard (digital) clipping and soft (analog) clipping... both are types of distortion.

In the digital world, there is an absolute hard maximum after which a signal gets clipped, it's at 0dBFS, if you're familiar with computers, every CD sample at 1/44,100th of a second can be an amplitude (loudness) of between 0 (00000000 00000000 - digital "black") and 65,535 (11111111 11111111 - the highest value a 16 bit sample can hold) what happens if the engineer screws up and makes everything on the disc too loud? Say it's twice full scale, that means a sample at 50% of the full amplitude is recorded as 65,535... now what's written to the disc when a sample is at 75% of full amplitude? The same value, 65,535... there is nowhere higher to go, the waveform can't be correctly approximated and distortion results. What does that sound like? This clip should help. This first half of the clip is very much clipped (then attenuated to match levels), the second is as the album cut sounds.

Now, soft clipping, in the analog world (like your receiver) is similar, but it's "softer"... there is more "headroom" in an analog signal. As the signal reaches full saturation, it starts sounding more compressed - which is an odd term for most to come to grips with - compressed sound actually sounds "bigger"... new pop/rock music uses a lot of compression, it makes the quiet parts louder and the loud parts quieter, it kind of removes the dynamics, so guitar fret noise, breath sounds, etc sound louder in relation to the music. Why do they do it? It's that Wall of Sound... gotta be big, and loud. Anyway, so as your receiver approaches clipping, it will "roll off" those high bits of amplitude, which actually doesn't sound as bad as digital clipping. I tried to look for a CD without compression already added at the mixing stage so I could show an example, but I couldn't find one in my collection here. I'll have to look through Lisa's collection for something classical.

So as your receiver approaches clipping, it compresses the waveform, and shortly after that it starts behaving like digital clipping, by distorting the sound.

Is clipping bad? Not necessarily for everyone, the entire "tube sound" that guitar players strive for is the sound of the tubes being pushed into clipping... a tube overdrive is the same idea, only taken a bit further... then if you take that even further you get the fuzzbox sound.

Clipping - great for guitars, bad for home or mobile audio.

Hope that helps, more info than asked for, but... felt like giving a discertation.

Bren R.

Re: Clipping
#133519 03/27/06 08:37 PM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
...because there's no more juice...

____________________

So, if there is no more juice than why is there a concern of blowing the speaker?

The fear of blowing a speaker with a weak amplifier is often overblown . If you have a 300 W or 400 W rated speaker what harm can be done from a 50W amplifier? A 50W amplifier can not put out more than 50W, period. The speaker woun't even break a sweat.

A real danger comes from 'matching' amplifier and speaker. For instance, if you have a 200W rated speaker and 200W amplifier than you have to watch for clipping. Clipping distorts the waveform and add tons of higher harmonics. That's why clipping sounds raspy. These harmonics are re-directed by the crossover circuits to the tweeters and there is enough juice to burn them.

Re: Clipping
#133520 03/27/06 09:32 PM
Joined: Apr 2005
Posts: 1,155
connoisseur
Offline
connoisseur
Joined: Apr 2005
Posts: 1,155
Gena: just because you have a speaker rated for 100 watts does not necessarily mean that all the drivers in the speaker are rated for 100 watts. Somewhere I recently saw an article/ post on this. It could have been on this board. Bottom line, because of the actual musical power spectrum, the tweeters are rated quite a bit less than the actual speaker rating by most manufacturers. Wish I could remember how much.


The Rat. M80s, VP-150, QS8s, SVS PC 20-39+, OPPO, Onkyo 703s, Harmony 880 Sony 60" SXRD HDTV
Re: Clipping
#133521 03/27/06 10:07 PM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
First, I didn't say 100W speaker, I said 400W speaker and 50W amp. Second, if the tweeter is weak, it is usually blown just by increasing the total volume level and the corresponding increase in the high frequency component. Doesn't have to do anything with clipping. Sure, clipping will give some extra power due to distortion, but the tweeter will be blown by the high level non-distorted part just due to the high volume.

Re: Clipping
#133522 03/27/06 10:35 PM
Joined: Jun 2003
Posts: 6,833
W
Wid Offline
axiomite
Offline
axiomite
W
Joined: Jun 2003
Posts: 6,833

Gena I hate to tell you but you are wrong here. You are far more likely to blow the tweeters out of a speaker that can handle 400 watts with a 50 watt amp than a 200 to 300 watt amp. Clipping can fry tweeters fairly quick.

From Ian

"The key is in amp clipping. Very small amplifiers driven into clipping can damage very high-powered speakers. It is like sending little dead shorts to the voice coils, which cause them to heat up and melt down. If the power is clean the M60s will take ridiculous sized amplifiers with no problem. In our power testing we use Bryston 7Bs, which are putting out close to 700 watts. The test involves both modified pink noise continuous for 100 hours at 250 watts followed by another 100 hours of heavy rock and roll. This is way above the standard rating methods of 5 to 8 hours of modified pink noise at the rated power."

Ian Colquhoun
President & Chief Engineer




Rick


"A fear of weapons is a sign of retarded sexual and emotional maturity." Sigmund Freud

Re: Clipping
#133523 03/27/06 10:54 PM
Joined: Aug 2004
Posts: 6,379
Likes: 7
axiomite
Offline
axiomite
Joined: Aug 2004
Posts: 6,379
Likes: 7
Exactly. If you run at normal levels with (say) a 50W amp only a small amount of the power is in the frequency range which gets through the crossover into the tweeter.

If you take that same 50W amp and drive it into hard clipping, the flat top and sharp edges of the resulting signal drive relatively more of the power into the high frequency ranges (that "kazoo" sound) and so you can easily get MORE power into the tweeter with a clipping 50W amp than you can with a non-clipping 100W or 200W amp.

The big issue is that if you have a 500W amp and turn it up to the point where tweeter damage could occur it's going to be REALLY FREAKIN' LOUD but if you have a 50W amp and drive it into clipping you can fry your tweeters but the overall sound is not going to be that loud.

That's the problem with a small amp. You turn it up... it's not loud enough... you turn it up more... it doesn't seem to be getting any louder... you turn it back down a bit... and the next day you notice that one of your tweeters isn't working.


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8
Re: Clipping
#133524 03/27/06 11:20 PM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
If you take that same 50W amp and drive it into hard clipping, the flat top and sharp edges of the resulting signal drive relatively more of the power into the high frequency ranges

__________

It's only partially correct and often over-exagerated because it's frequently quoted.

First the flat top does not contain high frequencies. Flat is associated with low frequencies.

Sharp edges indeed, contain high frequencies but their contribution is very small. If you do actual Fourier transform you'd be amazed how small the power increase in the high f domain is due to distortion. It's not even that you make a pure square wave out of a sinusoidal signals. You just clip the very top of the sin.

The danger is that by driving an amp to clipping the overall power increases and exceeds the amp rms rated power. That, in turn increases the power in high f which delivered to tweeters. The wave distortion by itself has only a small contribution.

Re: Clipping
#133525 03/27/06 11:22 PM
Joined: Dec 2003
Posts: 3,602
B
connoisseur
Offline
connoisseur
B
Joined: Dec 2003
Posts: 3,602
In reply to:

...because there's no more juice...
(...)
So, if there is no more juice than why is there a concern of blowing the speaker?


I think you're confusing power side and signal side here. When he says "no more juice" he means on the power side of the amp circuit, not the signal side. When the power side sags, you end up with a distorted signal.

In reply to:

If you have a 300 W or 400 W rated speaker what harm can be done from a 50W amplifier? A 50W amplifier can not put out more than 50W, period. The speaker woun't even break a sweat.


Except all 50W pushes aren't created equal. As clipping increases, the wave starts to resemble a pulse (or square) wave... the best naturally occuring type of wave to freeze voice coils. You can probably push a 400W rated speaker many times past it's rating with a 200Hz sine wave, feed the same speaker a fast pulse and it'll do a Vesuvius impression rather quickly.

In reply to:

A real danger comes from 'matching' amplifier and speaker. For instance, if you have a 200W rated speaker and 200W amplifier than you have to watch for clipping.


You do have a point here, indirectly. A higher (amp rating:speaker rating) ratio will either increase the damage done in a period of time, or drop the period of time required to do the damage.

Bren R.

Re: Clipping
#133526 03/27/06 11:24 PM
Joined: Mar 2006
Posts: 66
R
Rapmon Offline OP
old hand
OP Offline
old hand
R
Joined: Mar 2006
Posts: 66
Thanks for the info to you all. That link you sent, BrenR, is most like what I hear only louder. A cd I bought by Doyle Bramhall II sounded like that because it must have been recorded too loudly. But the sound I get is probably due to the cheap components I own. I have a Technics receiver and Infinity RS525 speakers. They are getting a bit old anyway. Of course, the speakers sound fine till I try to play them too loud. Again thanks to everyone.


".....We don't need no thought control..." Axiom M60's CSW m60's HK avr 240
Re: Clipping
#133527 03/27/06 11:57 PM
Joined: Dec 2003
Posts: 3,602
B
connoisseur
Offline
connoisseur
B
Joined: Dec 2003
Posts: 3,602
In reply to:

The danger is that by driving an amp to clipping the overall power increases and exceeds the amp rms rated power. That, in turn increases the power in high f which delivered to tweeters. The wave distortion by itself has only a small contribution.


Again, everyone's picking on you, and I don't want to add to that, but it looks like you bring up good points, then aim them at the wrong targets.

Yes, clipping drives up RMS power... by definition, the root-mean-square of a compressed (or companded) signal will be higher.

Low frequencies CAN become saturated more quickly than high frequencies. Take this Rane page for instance. It seems to be an absolute smoking gun for your side of the argument. And the author HAS made sure to use examples that will support his theory perfectly.

I have taken issue in the past on a lot of Rane's corporate theories.. especially their clinging to damping factor as the be-all end-all in wire choice.

I gotta split, though... can't finish my train of thought until later.

Bren R.

Re: Clipping
#133528 03/28/06 03:10 AM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
That Rane's link that you gave proves my point exactly. I might have a problem to express it well in English (not my native language) but, once again:

The waveform distortion from clipping does not kill tweeters. It's just another internet myth perpetuated all over again. There is just not enough power from the extra high f harmonics.

Thanks for the link
Gena

Re: Clipping
#133529 03/28/06 03:57 AM
Joined: Jan 2004
Posts: 13,840
Likes: 13
shareholder in the making
Offline
shareholder in the making
Joined: Jan 2004
Posts: 13,840
Likes: 13
I think I'll trust what the founders of Axiom tell me with 30 years at the NRC.


M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85


Re: Clipping
#133530 03/28/06 03:59 AM
Joined: May 2002
Posts: 10,654
shareholder in the making
Offline
shareholder in the making
Joined: May 2002
Posts: 10,654
Gena, the following discussion which I've linked previously is possibly the most complete examination of possible clipping damage which is available online. Both the compression and harmonics theories are examined along with brief mention of other possibilities. As you'll note, it reaches no definite conclusion. This is part of the material which Dr. Lesurf originally prepared for introductory use by his students in electronics and physics at St. Andrews.


-----------------------------------

Enjoy the music, not the equipment.


Re: Clipping
#133531 03/28/06 04:12 AM
Joined: Dec 2003
Posts: 3,602
B
connoisseur
Offline
connoisseur
B
Joined: Dec 2003
Posts: 3,602
I had to drop this one mid-stream.

I was suggesting that it's not the whole story on either side.

Fourier says there's not enough POWER to blow a tweeter. And there isn't. There are MANY other forces at work. One is also, as you mentioned, that this forces the tweeters to take on more of their share of power - though that Rane article is suspect since it intentionally uses a low amplitude hi-freq with a burst of high amplitude lo-freq modulation for the author to prove his point... if you were to reverse the amplitudes, I could prove that low frequency drivers (ie: woofers) would blow first.

Damn, we're back to square one and haven't proven anything... except even "professional" companies (and Rane's one of the respected ones) may be trying to oversimplify.

So if I were to rebuild his Figures with the amplitudes reversed, I could prove that woofers would blow before tweeters... though that hardly ever happens. So what else do we look at?

Heat. So when you really overdrive a tweeter (even a ferrofluid cooled one like Axiom uses, which DOES help) as the wattage sent to the tweeter rises, so does the amount of heat generated, ever taken apart a tweeter? They're not nearly as easy to cool as a woofer with it's large basket.

So now that everyone's dug in their heels and given their side, the answer seems to be "nobody knows"... I like to hear others' opinions, many heads are better than one, but when trying to shed light on another's partial answer, suggesting another partial answer is the whole canonical truth is probably counter-productive.

Even Ian's quote is somewhat vague on what exactly it IS about clipping that melts down tweeters. But in the end, clipping kills drivers, what part of clipping it IS that kills them is still open for discussion it would seem.

I do agree with you that it's tough for the harmonics to generate enough extra power to fry a tweeter, but as others have said, it's easier for a lower powered amp to clip at a reasonable listening level (you originally said a 200W amp & 200W rated speaker would be a worse combination than a 50W amp and a 200W rated speaker; I contend it would be much harder and louder to push a 200W amp to clip than a 25W one, making the danger a low powered amp)

Bren R.

Re: Clipping
#133532 03/28/06 04:16 AM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
Excellent link, John.

Again, the modeling shows that even with the amplifier of the 'matched' power (speaker 100W, amplifier 100W) the damage from the distorted waveforms is, well, questionable. However, there's a firm belief that even a very low power amplifier can damage a high power speaker if clipped - see the quote from Ian. I think it's way off. Well, I can understand him - they are about to start selling new, 'powerful' amplifiers

Re: Clipping
#133533 03/28/06 04:22 AM
Joined: Feb 2004
Posts: 1,703
connoisseur
Offline
connoisseur
Joined: Feb 2004
Posts: 1,703
Clipping in a very simplistic way is like running DC power thru your speaker (for short periods of time). And since speakers (esp tweaters) can't cool down effectively when presented with a DC signal the voicecoil melts.

Re: Clipping
#133534 03/28/06 04:27 AM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
Bren,

Interesting discussion. Spent quite some time today doing Fourier analysis. I've forgotten so much since college

___________

So if I were to rebuild his Figures with the amplitudes reversed, I could prove that woofers would blow before tweeters...
_________________

That's correct. And the 'heat' answer is on the right track, I think. Just the shear mass of woofers, much stronger mechanically and thermally.

As for the Ian's quote... - see my comment above

Re: Clipping
#133535 03/28/06 04:33 AM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
Clipping in a very simplistic way is like running DC power thru your speaker (for short periods of time). And since speakers (esp tweaters) can't cool down effectively when presented with a DC signal the voicecoil melts.

_______

Very popular explanation but it's wrong.

First, DC power doesn't hurt tweeters (unless you intentionly disable the crossover circuits).

Second, you can run DC power thru a speaker.

Third, there is no DC componet that results from clipping. It's at worst a square wave. If you severely clip a 1 kHz sinusoid at 10V, it will be alternating +/- 10 V, no DC component.

Re: Clipping
#133536 03/28/06 04:58 AM
Joined: Apr 2003
Posts: 16,441
shareholder in the making
Offline
shareholder in the making
Joined: Apr 2003
Posts: 16,441
Here is the original post from Ian. Notice the date. Axiom wasn't about to release amps back in 2002. You're insinuating a bias that I don't think exists.

Re: Clipping
#133537 03/28/06 05:03 AM
Joined: Dec 2003
Posts: 3,602
B
connoisseur
Offline
connoisseur
B
Joined: Dec 2003
Posts: 3,602
In reply to:

Interesting discussion. Spent quite some time today doing Fourier analysis. I've forgotten so much since college


Wandering mathematician?

Bren R.

Re: Clipping
#133538 03/28/06 05:06 AM
Joined: Dec 2003
Posts: 3,602
B
connoisseur
Offline
connoisseur
B
Joined: Dec 2003
Posts: 3,602
In reply to:

You're insinuating a bias that I don't think exists.


Whoops, I missed that part of his post.

Nah, I don't think there is any bias based on the offered products, if so, the Axiom corporate line would be that their interconnects and speaker cable made listening orgasmic.

Bren R.

Re: Clipping
#133539 03/28/06 05:15 AM
Joined: Dec 2003
Posts: 3,602
B
connoisseur
Offline
connoisseur
B
Joined: Dec 2003
Posts: 3,602
In reply to:

That link you sent, BrenR, is most like what I hear only louder.


Whoops... got mixed up in the rest of this and forgot about you. Much love, man. That's 9dB of gain added in order to clip to that level, by the way.

Bren R.

Re: Clipping
#133540 03/28/06 05:17 AM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
You're insinuating a bias that I don't think exists.

______

C'mon! How many more smilies do I need to put so it's clear that it was a joke. I have a great respect for Ian.



Re: Clipping
#133541 03/28/06 05:18 AM
Joined: Feb 2004
Posts: 1,703
connoisseur
Offline
connoisseur
Joined: Feb 2004
Posts: 1,703
In reply to:


Third, there is no DC componet that results from clipping. It's at worst a square wave




I know, I was really generalizing... I was saying a square wave is a lot closer to DC then a true signal is (which would be closer to AC). And if a speaker is rated for say 200watts... I can't believe it could handle 200watts of DC as well as if it was a nice sine wave. There has to be some cool down period while the AC-like signal changes direction. The power presented to the coil is not constant in that senerio.

Re: Clipping
#133542 03/28/06 05:27 AM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
There has to be some cool down period while the AC-like signal changes direction
____________

True. However, it's not a big deal, at most it's a factor of 2 between a pure square wave and a pure sinusoid. Given that's never a square wave it's even less. Not a big deal.

Re: Clipping
#133543 03/28/06 11:52 AM
Joined: Jun 2003
Posts: 6,833
W
Wid Offline
axiomite
Offline
axiomite
W
Joined: Jun 2003
Posts: 6,833
Ian isn't the first to say clipping will distroy drivers. He may not have given the exact account as to why it does but I really don't see what that would have accomplished in the first place.

What some of you forget to understand is that the majority of the folks here and that visit here are not scientist. When Bren makes a reply he does so that everyone can understand not just the folks with 100 years of collage, same goes for Chess. There are times when JohnK posts a link or gives a theory that might as well be from mars, it would be better for most if when we try to explain some of the most technical stuff to keep the talk in layman’s terms. That, to me, is what Ian did in the original reply.



Rick


"A fear of weapons is a sign of retarded sexual and emotional maturity." Sigmund Freud

Re: Clipping
#133544 03/28/06 01:27 PM
Joined: Feb 2006
Posts: 120
veteran
Offline
veteran
Joined: Feb 2006
Posts: 120
Wid,

I agree. Interesting that the original question was not scientific at all. It was almost Zen-like - "What does clipping sound like?" And then it went sideways.

Some of the folks (looking in the mirror) just don't know when to stop

Re: Clipping
#133545 03/28/06 02:17 PM
Joined: Jan 2004
Posts: 13,840
Likes: 13
shareholder in the making
Offline
shareholder in the making
Joined: Jan 2004
Posts: 13,840
Likes: 13
I think I'll just go back to enjoying the sound.


M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85


Re: Clipping
#133546 03/28/06 02:31 PM
Joined: Apr 2003
Posts: 16,441
shareholder in the making
Offline
shareholder in the making
Joined: Apr 2003
Posts: 16,441
In reply to:

I think I'll just go back to enjoying the sound


of your own voice?



Re: Clipping
#133547 03/28/06 11:16 PM
Joined: May 2003
Posts: 18,044
shareholder in the making
Offline
shareholder in the making
Joined: May 2003
Posts: 18,044
No, of clipping, dummy.


I am the Doctor, and THIS... is my SPOON!
Re: Clipping
#133548 03/30/06 01:35 AM
Joined: Feb 2004
Posts: 1,703
connoisseur
Offline
connoisseur
Joined: Feb 2004
Posts: 1,703
Back in my youth when all I really cared about was car stereo clipped bass was prefered because it definite sounds louder. Tweaking our systems we definitely drove the amps into some clipping to get the sound we wanted.

Re: Clipping
#133549 03/30/06 03:30 AM
Joined: Apr 2005
Posts: 1,155
connoisseur
Offline
connoisseur
Joined: Apr 2005
Posts: 1,155
You're probably right. I have replaced multiple speakers in the cars that my kids drive. I think that I know why!

LOL!!!


The Rat. M80s, VP-150, QS8s, SVS PC 20-39+, OPPO, Onkyo 703s, Harmony 880 Sony 60" SXRD HDTV
Re: Clipping
ratpack #133550 08/31/06 04:15 PM
Joined: Aug 2006
Posts: 33
C
enthusiast
Offline
enthusiast
C
Joined: Aug 2006
Posts: 33
I wish I could get my friends to realize that! They'll have me listen to their "1000 watt" amp and check out how loud it is. Then I hook up the oscilloscope and show them what they are sending to their speakers and that they can really only get 1000/8 watts of power cleanly (we're talking crap amp here). Too bad clean sound isn't loud enough. Even after I warn them, they continue to keep the gain way up and blow both amps and subs every other month. Sad...

Re: Clipping
cava #133551 08/31/06 08:25 PM
Joined: Aug 2004
Posts: 6,379
Likes: 7
axiomite
Offline
axiomite
Joined: Aug 2004
Posts: 6,379
Likes: 7
There was a link posted a while back to an article which talked about "dynamic compression" (their term, I think) being a more significant contributor than hard clipping to speaker damage when the amp is overdriven. The gist of it was that most of the damage happens before the levels are so high that you get square waves -- there is a period in between where the signal clips at the extremes of the low frequency cycles, but during the rest of the cycle the high frequencies can keep getting louder even if the bass is limited. The result is that you can crank the volume maybe 10-20dB higher than the onset of clipping without the signal SEEMING to be all that loud.

If you had a more powerful amp and were playing at the same volume control setting, the result would be much louder and you would probably not turn the volume up so high -- and so the HF signal levels would not be so high either.

The two views seemed pretty compatible to me but I thought this article was important... bottom line is that overdriving the amp results in relatively more high frequency power than the speakers are designed to handle, resulting in unhappy speakers.


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8
Re: Clipping
bridgman #133552 07/02/07 07:46 AM
Joined: Jul 2006
Posts: 12,077
Likes: 7
C
CV Offline
Founder, Axiom Upgrade Club
shareholder in the making
Offline
Founder, Axiom Upgrade Club
shareholder in the making
C
Joined: Jul 2006
Posts: 12,077
Likes: 7
Interesting thread on clipping! I just had to comment to revive it.

Re: Clipping
CV #133553 07/02/07 03:50 PM
Joined: Jan 2007
Posts: 10,490
Likes: 116
M
shareholder in the making
Offline
shareholder in the making
M
Joined: Jan 2007
Posts: 10,490
Likes: 116
Very interesting indeed.

I'd like to add something from my own practical experience. If you are not hard of hearing, are in a "normal" sized, "quiet" room, sit a "reasonable" distance away from your speakers and have relatively efficient speakers like the M80s, a 90W/channel amp should never cause you any problems.

Take my case. I'm in a 4,000 cubic foot, relatively live room (with considerable leakage due to my staircase) that has an ambient noise level of about 50dB with the lights off and 60dB with the lights on. I sit 8 feet away from the fronts. My right ear is not as sensitive as my left (but I don't know by how much). When listening to music, my receiver typically pumps a quarter to a half watt into my M80s. This gives my amp headroom of 22dB to 25dB which is 10dB to 15dB more than recommended.

So let's say you are in a room of similar size, have some hearing deficiency like me but have significantly more furnishings. Let's be generous and say that you will use 4 to 8 times more power than me (1W to 2W). That still gives your amp 16dB to 19dB of headroom!

Page 1 of 5 1 2 3 4 5

Moderated by  alan, Amie, Andrew, axiomadmin, Brent, Debbie, Ian, Jc 

Link Copied to Clipboard

Need Help Graphic

Forum Statistics
Forums16
Topics24,940
Posts442,457
Members15,616
Most Online2,082
Jan 22nd, 2020
Top Posters
Ken.C 18,044
pmbuko 16,441
SirQuack 13,840
CV 12,077
MarkSJohnson 11,458
Who's Online Now
0 members (), 386 guests, and 4 robots.
Key: Admin, Global Mod, Mod
Newsletter Signup
Powered by UBB.threads™ PHP Forum Software 7.7.4