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How to distinguish between clipping and overdriven speakers

Dimitrov

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How does a newbie determine if distortion is caused by amp clipping or because the speakers have been overdriven? If I listen to music quite loudly I notice voices and higher frequencies start to distort.

Is that a function of the amp clipping or because the speaker is not capable of sustaining these volumes? I assumed if the speaker was being overdriven I would notice it more in the bass sections and not in the higher frequencies.

Is that a correct assumption? To those more knowledgeable please help me explain what might be happening.
 

solderdude

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What speakers and what amp is used ?
 

solderdude

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You should be able to reach 110dB peak at a few meter distance in a room.
This means about 90-100dB average SPL (Less in Phon) with well recorded music before clipping starts.
 
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Dimitrov

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Are you suggesting the amp is underpowered for my needs?
 

solderdude

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That could depend on how loud you listen, what the distance to the speakers is and speaker positioning in the room is.

I would suggest turning the balance to Left (and later to right) and check if both speakers sound less desirable around the same volume as a first test.

A second test could be to use a low power amp and see if similar-ish distortion starts at a lower volume.
 

raindance

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What we need to know is how you listen. Tone control settings? Audyssey settings? Audio source? How loud is the volume setting on the Marantz when this occurs?
 

pma

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How does a newbie determine if distortion is caused by amp clipping or because the speakers have been overdriven? If I listen to music quite loudly I notice voices and higher frequencies start to distort.

Put an oscilloscope onto amplifier output. If you do not have it, make a voltage divider (to reduce amplitude for a soundcard input) and use a soundcard to record the sound e.g. with Audacity free SW. Inspect the recorded file to see if there are clipped samples. Also inspect the music data if they do not contain clipped samples.
It may be not only amplifier clipping, but also DAC intersample overs, if the music is over-compressed as a result of loudness wars.
 

miero

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Also your ears might be overdriven/clipping.
 

SIY

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It may be not only amplifier clipping, but also DAC intersample overs, if the music is over-compressed as a result of loudness wars.

Then wouldn't it be audibly distorted at lower volumes as well?
 

DonH56

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How does a newbie determine if distortion is caused by amp clipping or because the speakers have been overdriven? If I listen to music quite loudly I notice voices and higher frequencies start to distort.

Is that a function of the amp clipping or because the speaker is not capable of sustaining these volumes? I assumed if the speaker was being overdriven I would notice it more in the bass sections and not in the higher frequencies.

Is that a correct assumption? To those more knowledgeable please help me explain what might be happening.

When the amplifier clips, whether due to a large bass signal or at some other frequency, harmonics "spray" across the entire audible bandwidth. That creates a more "harsh" sound that can be fatiguing across the audio spectrum (not just the bass).

When a speaker is overdriven several things can happen. The worst case is the cone or spider hitting its mechanical limits and buzzing or rattling. Before that distortion will rise due to several factors, including cone breakup or flexing that generates standing waves and thus frequency tones not in the music, thermal compression that limits the excursion and again causing distortion similar to an amplifier clipping (though usually "softer"), etc. Different speaker drivers react differently, so cones and horn diagraphams may sound different than ESL or planer-dynamic and ribbon drivers. Port noise can also occur, a "chuffing" or airy "woofing" sound from the port rather than the drivers themselves.

I am not sure I have a good way to distinguish speaker from amplifier clipping without instruments. Generally the harsher sounds are from amplifier clipping IME while speaker clipping tends to be not as obnoxious. The catch is that means upping the amplifier power may simply destroy the speaker if it cannot handle the extra power, often before the listener realizes it.

It may be worthwhile to remember that 1 dB is a very minor change in volume, about what most of us might do when asked to bump it "just a hair", and requires about 25% more power. A noticeable increase ("Turn it up a little, would you?") is about 3 dB and that takes twice the power. Doubling the perceived volume (in the midrange) takes about a 10 dB increase and that is ten times the power (!) If you are clipping your amplifier, chances are you need to more than double the power to prevent it. Many years ago studies showed peak-to-average power in music was around 17 dB, meaning you nee about 50 times the average power to handle the loudest peaks. If you use about 1 W at typical volume then you need 50 W on tap. 10 W, get a 500 W amplifier, and so forth. Modern recordings, at least some of them, exceed 20~25 dB, and some movies are pushing 30 dB (1000 times the average power). Chances are the lowest levels are below average, so hopefully you do not need a 1 kW (or 10 kW) amplifier.

Moving closer to the speakers (or moving them closer to you) helps a lot, and of course you can buy more sensitive speakers that do not require as much power to play loudly.

HTH - Don
 

pma

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Then wouldn't it be audibly distorted at lower volumes as well?
If we speak about DAC output clipping due to intersample overs, i.e. digital oversampling reconstruction filter is clipping, and volume is digitally controlled in the DAC, then lowering volume cures intersample overs.
 
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Dimitrov

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When the amplifier clips, whether due to a large bass signal or at some other frequency, harmonics "spray" across the entire audible bandwidth. That creates a more "harsh" sound that can be fatiguing across the audio spectrum (not just the bass).

When a speaker is overdriven several things can happen. The worst case is the cone or spider hitting its mechanical limits and buzzing or rattling. Before that distortion will rise due to several factors, including cone breakup or flexing that generates standing waves and thus frequency tones not in the music, thermal compression that limits the excursion and again causing distortion similar to an amplifier clipping (though usually "softer"), etc. Different speaker drivers react differently, so cones and horn diagraphams may sound different than ESL or planer-dynamic and ribbon drivers. Port noise can also occur, a "chuffing" or airy "woofing" sound from the port rather than the drivers themselves.

I am not sure I have a good way to distinguish speaker from amplifier clipping without instruments. Generally the harsher sounds are from amplifier clipping IME while speaker clipping tends to be not as obnoxious. The catch is that means upping the amplifier power may simply destroy the speaker if it cannot handle the extra power, often before the listener realizes it.

It may be worthwhile to remember that 1 dB is a very minor change in volume, about what most of us might do when asked to bump it "just a hair", and requires about 25% more power. A noticeable increase ("Turn it up a little, would you?") is about 3 dB and that takes twice the power. Doubling the perceived volume (in the midrange) takes about a 10 dB increase and that is ten times the power (!) If you are clipping your amplifier, chances are you need to more than double the power to prevent it. Many years ago studies showed peak-to-average power in music was around 17 dB, meaning you nee about 50 times the average power to handle the loudest peaks. If you use about 1 W at typical volume then you need 50 W on tap. 10 W, get a 500 W amplifier, and so forth. Modern recordings, at least some of them, exceed 20~25 dB, and some movies are pushing 30 dB (1000 times the average power). Chances are the lowest levels are below average, so hopefully you do not need a 1 kW (or 10 kW) amplifier.

Moving closer to the speakers (or moving them closer to you) helps a lot, and of course you can buy more sensitive speakers that do not require as much power to play loudly.

HTH - Don

Hi Don, and thank you for the very long, informative reply! Are you saying that it's possible that the distortion I'm hearing (in the higher frequencies) is due to the speaker exceeding it's limits and that it's possible adding a more powerful amp won't help me?

I have B&W 683 speakers and a Marantz SR-5013 amp.

People I've spoke to in the past have told me that if bass starts to distort that it's usually a function of the speaker exceeding it's clean limits and if the mids and highs start to distort that it's more a function of clipping. I don't know enough to know whether that wisdom is true or fictional. Or maybe it just depends.
 

DonH56

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I am not a speaker expert. In my experience, speaker distortion before hitting mechanical limits tends to be exhibited as breakup modes, usually low order, or "soft" clipping due to thermal compression. Neither sounds as bad to me as amplifier clipping which tends to affect the entire spectrum. I would not call it "wisdom", more a rule of thumb. So, I think it is more likely amplifier clipping, but without measuring could not say for sure.

Another reason for fatigue is simply playing too loud. You might want to consider how well you want to hear in later life. I have tinnitus that is at times very annoying and I am sure largely due to all the years playing in and listening to loud bands. Of course my day job exposes me to high noise levels as well, and I like to shoot, a triple whammy.

Without looking up the speakers and amp, which as others have said needs to be taken in the context of how loudly you listen and how far you are from the speakers (see e.g. Peak SPL Calculator ), I'll just note that B&W often presents a challenging load to an amplifier. It may be your combination of power demands and taste in music is simply overworking the Marantz. Most of the time folk are using far less power than they think, but there are always exceptions. Without measurements it may be hard to tell but you can use the peak SPL calculator to get an idea. If you don't have a cheap SPL meter you might want to get one just to get a ballpark idea of how loud you are listening just so you'll know.

HTH - Don

Edit: A quick search yielded the impedance chart for the 683's; it is essentially a 4-ohm'ish speaker, residing in the 3 to 4 ohm range for the critical 100 - 1000 Hz range, with ~88 dB/2.83 Vrms/m sensitivity (middling) so I don't find it totally crazy that it could be taxing your Marantz at your listening levels.

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