Am I understanding receiver power and speaker power relationship correctly? - Page 2 - AVS Forum | Home Theater Discussions And Reviews
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post #31 of 54 Old 02-23-2016, 01:10 PM
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Originally Posted by ulyssis View Post
This would be my first option. Just need to think of a way to hide wires. I need it to be clean.
Here you go. Cut to length and you're good to go.

http://www.homedepot.com/p/Wiremold-...-C40/100554157
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post #32 of 54 Old 02-23-2016, 01:49 PM
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If the speaker is calibrated correctly and working correctly, the white cabinet is most likely your problem. That and the hard wood floor.


Picture how sound travels out of a speaker. Like a cone in all directions. Half of that cone is hitting the white cabinet and reflecting towards the ceiling. This will definitely affect the clarity of voices.


Find a wife approved way to move the speaker forward. Also, you can lift up the speaker closer to the screen. This will help as well. Last, find a nice throw rug, or carpet piece, or some sort of decretive fabric that will fit on top of the white cabinet.


Nice set up. Good luck!
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post #33 of 54 Old 02-24-2016, 03:48 AM - Thread Starter
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Originally Posted by GIEGAR View Post
... and lots of bare floor. Is a large rug or two on the cards? The mains are also a bit boxed in by the glass display cabinets. (Was I the only one to think the raised end units would make great spots for a pair of MTM monitors? )





Or just run Audyssey with it right at the front and do your serious watching with it in that position. For everyday/casual use it can reside back where it is.



I wouldn't spend any more money on speakers (or electronics) unless you can halt the encroachment of "décor" that seems to be enveloping the screen wall.



Perhaps you can work towards an ultimate plan of an LCR of specialist in-wall speakers (example) behind a wider aspect, acoustically transparent screen?

Yes all great ideas. This photo was taken while I was at the tail end of my construction so you don't see the area rug. But we do have one. Pretty thick too.

What is the purpose of monitor speakers? I googled them and I don't see how adding them will benefit the surround system? Do you mean to use as B speakers off the receiver and to use them for tunes?

Unfortunately, this room you see is on the main floor of the house and thus decor, colors, fabrics, and furniture trump any home theater electronics, positioning, and setup. This according to my better half. I consider myself this lucky that I was able to install a 120" screen and projector with a 5.1 surround (going to 7.1 soon, I ran 2 more speaker wires while she wasn't looking).

That being said, the unfinished lower portion of the house is my domain to do what I see fit. That dedicated home theater will be setup for Dolby atmos (or what ever latest technology is available at that time) and speaker placement and electronics will come first and any decor will work around the ideal placement of speakers, screens and projectors.
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post #34 of 54 Old 02-24-2016, 08:54 AM
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The monitor speakers they speak of are just yours spread out farther.


There is nothing wrong with the equipment you have. You do not need any more parts.


It is the room.


Do things in small steps. Disconnect the speaker from the wall. Wait a couple of days. Find a nice cloth that it can sit on. Maybe even ask your wife to find one for you.


Then, when you watch a movie move it out. When your done, move it back.
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post #35 of 54 Old 02-29-2016, 05:36 PM
 
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Originally Posted by jaddie View Post
Bill is right, though. What blows speakers is RMS power (heating power). You can get that from either higher undistorted power, or clipped, distorted power, but the result is the same at the same RMS power. Pop goes the speaker.

It turns out that pushing an amp 3dB into hard clipping raises it's RMS power output 3dB, just the same as if it was 3dB higher and wasn't clipped.
I'm a little confused.

I follow Jims thinking, but these other ideas seem little off the mark, from what Jim has presented.

When I think of audio power, I think of low distortion, unclipped signals, as being usable power. In fact as being defined as audio power. To me if the THD or IM increases above a certain point, for that sake of argument lets say 1% or the signal has entered clip and remains in clip, more often than not that I have ran out of usable (good - safe) musical power - wattage.

now it isn't lost on me that power is still present, but it's no longer musical, and therefore safe to assume it to be a safe waveform. to my mind, you are correct in a sense, as is Jim, as am I. when an amplifier exceeds its unclipped, undistorted power limits (more so unclipped power) that more power is actually being deliver to the speaker, as more of the waveform is pressed against the voltage rails. So yes, over powering is what will kill - but I think Jim and a good number of others, see this in a different context. One where the power is musical, and not just merely definable as power. In this context Jims thinking, approach and outcomes jives.

but again, I am assuming that I know what you and others are driving at, even jim for that matter.

Like jim, I'm keen to learn of new perspectives.

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post #36 of 54 Old 02-29-2016, 07:49 PM
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Fwiw, by definition 1% distortion means all the distortion products added together are 40 dB below the unclipped signal. (Google "thd dB" and you'll find calculators that make that conversion easy). aiui, that means the distortion adds a factor of 1/10,000 to the total power. IOW the clipped signal is 1.0001 the power it would be without the distortion products. Not enough to be relevant. One percent also is the level at which THD becomes audible to some folks with some test sounds, aiui.

Many musical instrument amps (like, say an amp for bass guitar) are rated at 10% distortion. I have read that guitar players generally will identify an amp running at 10% distortion as "clean." Fwiw.
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post #37 of 54 Old 03-01-2016, 04:52 PM
 
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Originally Posted by JHAz View Post
Fwiw, by definition 1% distortion means all the distortion products added together are 40 dB below the unclipped signal. (Google "thd dB" and you'll find calculators that make that conversion easy). aiui, that means the distortion adds a factor of 1/10,000 to the total power. IOW the clipped signal is 1.0001 the power it would be without the distortion products. Not enough to be relevant. One percent also is the level at which THD becomes audible to some folks with some test sounds, aiui.

Many musical instrument amps (like, say an amp for bass guitar) are rated at 10% distortion. I have read that guitar players generally will identify an amp running at 10% distortion as "clean." Fwiw.
In terms of THD - it can actually reduce the power factor, but to reduce it by even 2% I think the THD would have to be around 20%.

It's the waveform distortions and resulting increases in current transfer that occurs during clipping that I am thinking about. The true power calculation (useable power) are different for each type of waveform and vary by frequency, DC (0Hz) or very low frequencies being the simplest to calculate, such as -1Hz, to 1Hz, and also more capable of possessing greater sums in current transfer for a given period. But obviously have little to do with wattage outputs of properly functioning amplifiers, but, but are amplifier operating in heavy clip, thought to be functioning properly?

When an amplifier is pushed into a heavy state of clipping, the average output of the waveform, starts to strongly resemble that of a square wave, and the power calculations for determining the RMS power of a sine wave, can no longer accurately apply.

This is where we slip into some heavier stuff (please forgive me if I do a poor job here, I'm not a teacher).

The crest factor of a square wave is 1, as is it's RMS multiplier, a clean sine wave has a crest factor of 1.414 and an RMS multiplier of .707 (reducing power factor); to make my point more clear, the crest factor of DC is also 1 and the RMS multiplier is 1; in other words 100% power transfer (potential). Translated means that slipping out of sine into a square wave is tantamount to near DC or steady state current deliveries. The good news is that in reality, while the amplifier has most definitely slipped away from proper and full-time sinusoidal production, it has not in fact slipped into pure square wave production, but resides some where in between, but, but the in between produces higher current deliveries within a given period, so even though the Voltage rails have been maxed, increased current output can and does occur and that's were the bad power (non-musical) increase comes from: Volts x Current = Power and now with a greater power transfer, as a result of large signal compression; phase angle comes into play but I'm not going to go there.

Stated another way, when an amplifier enters into clipping, the waveform changes and with it the current transferring qualities. I think we all will agree that direct, DC (steady state) current transfers, will transfer the most current within a given period, followed by low cycle square waves, and so-on. Speaker VC ratings are based on pure sinewaves, over time, etc. RMS provides a decent idea of fulltime heating and cooling capabilities of the driver (tolerance). Changes from a sinewave, to any other wave, will actually lower the wattage rating because other waves pass more current within a given period (saw waves being very close, but still lower) and reduce the cooling capabilities of a driver. As an amplifier enters and remains in clip, the current transfer increases as the cooling capabilities of the driver decrease. Power is very much being transferred, albeit, not all of it musical power. When amplifiers are driven into a steady state of clip, the current transfer from the amplifier becomes more steady than it would when not in clip. So yes power is going up and it's power that is killing the VC, but it's not all musical power, I would contend that it's not definable as musical power at all, when the output signal is in a constant or mostly constant state, of clip.

Speakers are very tolerant to musical power - unclipped power. the peak current deliveries are highly cycled and the drivers cooling system is permitted to cool as designed. This permits speaker to handle momentary transients as high as twice it's max power rating for a few milliseconds.

Returning to amplifiers, their power ratings are not scored with clipped signals (well most anyway), but non-clipped signals. Most are scored using the CEA-2006 burst test, which is a measurement of dynamic power, which is limited to 1% THD, irrespective of clipping to a large degree. Dynamic power is not sustainable power, usually, 1/3 of dynamic power is actually available for continual output, often, not much past 50%, at best. So if you buy an amplifier that's rated using the CEA 2006 method, the rating is dynamic and one should maximally believe that they have 50% of the rating available to output 24/7. But most of us don't and we believe for example that we have 100-watts or so. When this happens most of us think we have a hundred watts and buy speakers that can handle at 100-watts, but more often than not, aim higher like 150-200-Watts (as the sales people tell us to do). In this common setting, most of us think it's perfectly safe to use more of the full dial to punch power to our speakers (remember THD sounds bad, but actually reduces the power factor - it's not really a speaker blower). As we do so, we punch the output into clip, and often keep it there, and after awhile, our voice coils, will in fact give up the ghost, from over powering, but the power isn't purely musical power (clean sinusoidal in nature).

So in this respect, the amplifier is in fact under powered musically. And it's musical power that we're all after, not clipped, current laced, compressed power.

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post #38 of 54 Old 03-01-2016, 05:54 PM
 
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Originally Posted by Bill Fitzmaurice View Post
That's the myth of under-powering. It's not true.
http://forum.qscaudio.com/forum/view...hp?f=29&t=2736
Again, when Jim said under powered I think he was / is talking about musical power - clean sinusoidal power, not power derived from any other waveform. such as clipped power / wattage, which will more quickly heat up voice coils, often to the point of failure, even in most modest AVR based systems.

I understood him to state that it was bad power - clipping that is the culprit, not musical power, in any quanity. That when the good stuff runs out (not having enough) we push into the bad stuff - clipping and that is what kills drivers. So he's saying that being underfunded in the good stuff, often forces a good number of us to push into the bad stuff. Therefore if we had more of the good stuff, instead of being underfunded in it, we would likely blow less drivers. (that's a lot of stuff - lol) - I believe that I get what's he's driving at and I agree with him, in this light.

I also completely agree that it's over powering that kills VC's - but we need to be clear about what type of power we're all talking about - the good stuff (clean sinusoidal), the bad stuff (clipped waveforms) or both, combined and durations specified. Obviously, visiting clip is no big deal, for the most part, as most of us visit it every time we get our system to or near 0dB attenuation, and our speakers survive.

I'm with him, having higher RMS power, helps keep bad power at bay (Clipping). With all of these weak (inflated) power specification afoot today, it's next to impossible for most of us to know how much safe, 24/7 power we actually have. Having more musical - clean power, is always a safer idea, than running short and entering into pushing clipped power into our speakers.

I have purchased underfunded amplifiers and pushed them into this region, as I am sure a great number of others have as well. That not longer happens in my home, as I have lots and lots of continuous power available, even enough to cook my vc's with clean power, but I know where the line is, as do all experienced users.

When Jim has referred to being 'under powered', I believe him to be referring to musical power, and not power in general. He clearly defines the two classes of power/signal quaility, and states which one is the culprit, and it's not musical power.

Clipping is bad, and sometimes deadly, so buy more power, learn how to safely use it, and you will never run out of good, clean musical power, or blow your speakers. heavy emphases on LEARN how to safely use it. A good rule of thumb in my opinion, is not to exceed 2x times the RMS rating unless you're a very experienced user: Speaker RMS 50-watts = Amp RMS 100-Watts. Matching at a ratio of 1:1 will more often than not result in us pushing the amplifier into clip; especially when an amplifiers wattage rating has been posted as dynamic, RMS power (CEA_2006). Just call it headroom, if you don't think you'll actually call upon it much, and there's nothing wrong with having at least 3dB of true headroom.

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post #39 of 54 Old 03-01-2016, 08:15 PM
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Originally Posted by Jady Jenkins View Post
In terms of THD - it can actually reduce the power factor, but to reduce it by even 2% I think the THD would have to be around 20%. It's the waveform distortion and resulting increase in current transfer that occurs during clipping that I am thinking about. The true power calculation (useable power) are different for each type of wave form and vary by frequency, DC or very low frequencies being the simplest to calculate, such as 1Hz, - 1Hz.
First, the term "Power Factor" is misused here. The term Power Factor is the ratio of real power to the load vs apparent power in the circuit, values from 1 to -1, with anything less than 1 resulting from reactance in the circuit. Pretty sure that's not what's being talked about here.

There is no such term as "true power" or "usable power". The RMS or "heating value" of any waveform is easily calculated, but has nothing to do with frequency. Power to a load in a DC circuit is easier to calculate, but any AC frequency demands the same RMS calculation regardless of frequency.

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Originally Posted by Jady Jenkins View Post
When an amplifier enters into clipping, the waveform changes and with it the current transferring qualities. I think we all will agree that direct, DC (steady state) current transfers, will transfer the most current within a given period, followed by the square wave.
What changes when an amp clips is the RMS voltage, and assuming a reasonably stiff power supply, power to the load will change proportionally.
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Originally Posted by Jady Jenkins View Post
Speaker VC ratings are based on pure sinewaves, over time.
VC ratings are RMS power ratings, usually determined with sine waves, but any wave form with the same RMS value will have the same effect over the same time.
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Originally Posted by Jady Jenkins View Post
RMS provide a decent idea of fulltime heating and cooling capabilities of the driver (tolerance).
Many of us think of RMS as exactly the heating value, because that is how it is defined.
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Originally Posted by Jady Jenkins View Post
changes from a sinewave, to any other wave, will actually lower the wattage rating because other waves pass more current within a given period (saw waves being very close, but still lower).
I may not be understanding what you're saying here. Waveforms other than sine waves also have easily measured or calculated RMS (heating)values. Just because it isn't a sine wave doesn't mean a speaker has to be derated. There are many non-sine waveforms that have peak values equal to a sine wave, but RMS values much lower.
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Originally Posted by Jady Jenkins View Post
As an amplifier enters and remains in clip, the current transfer increases as the cooling capabilities of the driver decrease.
The ability of any driver to dissipate power is a constant give constant ambient temperature.
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Originally Posted by Jady Jenkins View Post
Power is very much being transferred, albeit, not musical power. When amplifiers are driven in to a steady state of clip, the current transfer from the amplifier becomes more steady than it would when not in clip. So yes power is going up and it's power that is killing the VC, but it's not musical power.
Assuming we start with an undistorted sine wave, just below clipping, and measure it's RMS power to a load. Then we increase the sine wave signal so it is driven above the clipping threshold by 3dB, resulting in severe clipping and distortion, the measured RMS power at the load is also raised by 3dB. It's the same power increase as if no clipping occurred. This analysis holds true for most waveforms until we go to the extremes of clipping beyond where anyone would possibly tolerate the distortion.

There is no longer any generally accepted specification called "music power" or "musical power', though it is unfortunately still used, albeit ambiguously, in some driver specifications. The term assumes a certain crest factor in a musical signal, but the problem with using it in specifications is that the specific crest factor remains unspecified. Worse, crest factors in modern music have been steadily reducing for 20 years as a result of the "loudness war", making "music power" even more ambiguous. Better specifications define the test signal (such as IEC 2684 18.1).
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Originally Posted by Jady Jenkins View Post
Speakers are very tolerant to musical power - unclipped power. the peak current deliveries are highly cycled and the drivers cooling system is permitted to cool as designed. This permits speaker to handle momentary transients as high as twice it's max power rating for a few milliseconds.
Yes, there is a heating time constant in every driver, it is usually not specified. However, you can sort of back into it if a driver has a power specification with a defined signal.
Quote:
Originally Posted by Jady Jenkins View Post
returning to amplifiers, their power ratings are not scored with clipped signals, but non-clipped signals. Most are scored using the CEA-2006 burst test, which is a measurement of dynamic power, which is limited to 1% THD, irrespective of clipping to a small degree. Dynamic power is not sustainable power, usually, 1/3 of dynamic power is actually available for continual output, often, not much past 50%. So if you buy an amplifier that's rated using the CEA 2006 method, the rating is dynamic and one should maximally believe that they have 50% of the rating available to output 24/7. But most of us don't and we believe for example that we have 100-watts or so. When this happens most of us think we have a hundred watts and buy speakers that can handle at 100-watts, but more often than not, aim higher like 150-200-Watts (as the sales people tell us to do). In this common setting, most of us think it's perfectly safe to use more of the full dial to punch power to our speakers (remember THD sounds bad, but actually reduces the power factor - it's not really a speaker blower).
CEA 2006 is the Consumer Electronics Association's document, ""Testing & Measurement Methods for Mobile Audio Amplifiers." Mobile=car amps. You won't find this applied to AVRs.

Having a little problem with "most of us" here. The bulk of audio systems sold today are built around an AV receiver. Most AV receivers in the market have power output per channel that hovers within 2dB of each other. Most speakers designed for home theater application have efficiency factors in the very high 80s to mid 90dB/w/m. For the average home listening room with an average listening distance the average listener will be able to achieve peak SPL at over 105dB (mid-band), with sustained average levels at 85dB SPL. At that point the peak program content and the peak system capability is reasonably close, some dead on, meaning the system will clip at about 0dBFS. BUt most listen somewhere around 10 to 20dB below that because that level sounds too loud at home. Once we drop 10dB, our peak program content will land -10dB from amp clipping.
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Originally Posted by Jady Jenkins View Post
As we do so, we punch the output into clip, and often keep it there, and after awhile, our voice coils, will in fact give up the ghost, from over powering, but the power isn't musical power (clean sinusoidal in nature).
However, if we had a power amp with the ability to deliver the same RMS power to the speaker, but unclipped, we'd still do the same damage to the voicecoils.
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so in this respect, the amplifier is in fact under powered musically. And it's musical power that we're all after, not clipped, current laced power.
Again, the RMS power of a clipped waveform is exactly the same as an unclipped version at the same gain.

I agree that distortion is bad, and I agree that too much RMS power can toast a voice coil, but I think you have overstated the practical reality of the situation. Perhaps there is an orientation to automotive sound in your comments? That might explain the assumption that a user would drive his system into gross clipping.
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post #40 of 54 Old 03-01-2016, 09:15 PM
 
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Originally Posted by jaddie View Post
First, the term "Power Factor" is misused here. The term Power Factor is the ratio of real power to the load vs apparent power in the circuit, values from 1 to -1, with anything less than 1 resulting from reactance in the circuit. Pretty sure that's not what's being talked about here.

There is no such term as "true power" or "usable power". The RMS or "heating value" of any waveform is easily calculated, but has nothing to do with frequency. Power to a load in a DC circuit is easier to calculate, but any AC frequency demands the same RMS calculation regardless of frequency.

What changes when an amp clips is the RMS voltage, and assuming a reasonably stiff power supply, power to the load will change proportionally.
VC ratings are RMS power ratings, usually determined with sine waves, but any wave form with the same RMS value will have the same effect over the same time.
Many of us think of RMS as exactly the heating value, because that is how it is defined.
I may not be understanding what you're saying here. Waveforms other than sine waves also have easily measured or calculated RMS (heating)values. Just because it isn't a sine wave doesn't mean a speaker has to be derated. There are many non-sine waveforms that have peak values equal to a sine wave, but RMS values much lower.
The ability of any driver to dissipate power is a constant give constant ambient temperature.

Assuming we start with an undistorted sine wave, just below clipping, and measure it's RMS power to a load. Then we increase the sine wave signal so it is driven above the clipping threshold by 3dB, resulting in severe clipping and distortion, the measured RMS power at the load is also raised by 3dB. It's the same power increase as if no clipping occurred. This analysis holds true for most waveforms until we go to the extremes of clipping beyond where anyone would possibly tolerate the distortion.

There is no longer any generally accepted specification called "music power" or "musical power', though it is unfortunately still used, albeit ambiguously, in some driver specifications. The term assumes a certain crest factor in a musical signal, but the problem with using it in specifications is that the specific crest factor remains unspecified. Worse, crest factors in modern music have been steadily reducing for 20 years as a result of the "loudness war", making "music power" even more ambiguous. Better specifications define the test signal (such as IEC 2684 18.1).
Yes, there is a heating time constant in every driver, it is usually not specified. However, you can sort of back into it if a driver has a power specification with a defined signal.

CEA 2006 is the Consumer Electronics Association's document, ""Testing & Measurement Methods for Mobile Audio Amplifiers." Mobile=car amps. You won't find this applied to AVRs.

Having a little problem with "most of us" here. The bulk of audio systems sold today are built around an AV receiver. Most AV receivers in the market have power output per channel that hovers within 2dB of each other. Most speakers designed for home theater application have efficiency factors in the very high 80s to mid 90dB/w/m. For the average home listening room with an average listening distance the average listener will be able to achieve peak SPL at over 105dB (mid-band), with sustained average levels at 85dB SPL. At that point the peak program content and the peak system capability is reasonably close, some dead on, meaning the system will clip at about 0dBFS. BUt most listen somewhere around 10 to 20dB below that because that level sounds too loud at home. Once we drop 10dB, our peak program content will land -10dB from amp clipping.
However, if we had a power amp with the ability to deliver the same RMS power to the speaker, but unclipped, we'd still do the same damage to the voicecoils.

Again, the RMS power of a clipped waveform is exactly the same as an unclipped version at the same gain.

I agree that distortion is bad, and I agree that too much RMS power can toast a voice coil, but I think you have overstated the practical reality of the situation. Perhaps there is an orientation to automotive sound in your comments? That might explain the assumption that a user would drive his system into gross clipping.
Interesting form of reply:

Of the points that you have seemed to understand, but yet disagree with, I cannot find a path to agree with your attempts made at correction. As you have failed to produce the math or any form of citation to support your rebukes.

As to the points that you don't understand, yes it is clear that you don't understand.

I think by the nature of your point by point dissection that you wish to have me engage you the same way.

I'm not interested, I am merely presenting my opinions, you seem to be present yours comments as facts across the board, even though it is clear that you're making many assumptions, and have failed to provide any citations as you told me in another thread just earlier today that such is a must, when someone is presenting their position as fact(s).

Perhaps if you select one at a time to discuss, or even better just one that you really disagree with, I might be more willing to engage you, however, no promises.

Having said this - I would direct you to an easy correction. CEA-2006 while it originated within the 12-volt manufacturing communities, it has since made its way in to consumer, prosumer and pro-audio market segments. I am sure if you're interested that you will be able to find many consumer amplify products even AVR's with the rating. I merely presented the metric as one that measures dynamic power like many others. Perhaps i should have included others in my comments.


As for the rest, it is somewhat academic, and therefore available for yourself and others to measure and come to your own conclusions about, just as I have towards your many responses.


Well just one more thing - Power Factor is a term used to describe real power (P) and not apparent power (S) or reactive power (Q)... fairly alive and text book stuff, you should be able to look it up and slightly adjust your comments moving forward, regarding the subject. I intentionally left out discussing phase angles (and formulas for that matter), because i wanted to keep it light and as tight as I am able. Like I said, I am not a teacher. So my examples are likely to be clumsy as the next, but not necessarily incorrect.


As for the rest, as I said, I am not a teacher, and I don't wish to become one, as the only path to proving your larger error(s) is a mathematical one, and I didn't join here to get that heavy.

I am just saying the I agree with Jim, and I have stated why. Running out of clean power, often leads to the use of clipped power, which is very well known to have claimed a many of drivers, why because it results in excess, non-musical power production that typically exceeds the thermal tolerances of one or more drives within a speaker system. Also very academic

I pontificated, because of some brief, over the wall comments made by you and another that I felt were incomplete, out of context and misleading, to the OP's general question, and detracted from Jim's clear, useful and straight forward comments, in my opinion. If I have miss-stepped I apologize as I am just finding my way.

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post #41 of 54 Old 03-02-2016, 12:59 AM
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For crying out loud just turn the bass volume down and sit closer to the screen. The automatic setup adjusts it to be very bass heavy and very soft high frequency bits so that any system sounds very a lot bass-beefy.

cms, aka driver diaphragm suspension mechanical compliance: 0.000065 meter/Newton or in standard form 6.5e-05 m/N. (smaller number is better)
rms, aka driver diaphragm suspension mechanical resistance: 6.41 Newton.sec/meter. (higher number is better)
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post #42 of 54 Old 03-02-2016, 01:56 AM
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Originally Posted by Jady Jenkins View Post
I would direct you to an easy correction. CEA-2006 while it originated within the 12-volt manufacturing communities, it has since made its way in to consumer, prosumer and pro-audio market segments. I am sure if you're interested that you will be able to find many consumer amplify products even AVR's with the rating. I merely presented the metric as one that measures dynamic power like many others. Perhaps i should have included others in my comments.
Ok, sorry, I'll do one at a time. Lets start with the "easy one", CEA-2006. I was, in fact, interested, so I attempted to find one...just one...consumer or professional amplifier or AVR with the CEA-2006 rating. Now, I don't have time to be thorough and check every single manufacturer or every single product, so I picked out a few.

Denon - Checked specs on the AVR-X7200WA, their top-of-line AVR. Surely they'd use CEA-2006 in their power specs for that one. Nope, standard power specs, power into a specified load at a specified THD level. No mention of CEA-2006.

Onkyo - Looked at the TX-RZ900, again, a premier product. Nope, no CEA-2006, same power into a load at a distortion level.

Emotiva - a very popular brand of amplifiers around here - check their power output specs. Same sad song, no mention of CEA-2006, just the usual power > load @ THD.

What's interesting is the above three don't specify power at the same THD.

So I though, yikes, he can't really be wrong, I'd better check the pro market. So my two go-to pro brands that I install all the time, Crown and QSC. I'll save some space here, the ISA-1350 from QSC (happen to use that one frequently), no mention of CEA-2006. Crown CDi 1000 (also one I use a lot), no CEA-2006, just the usual power specs.

So, I struck out. I was uniformly flummoxed in my attempt to locate just one amplifier with power specs referencing CEA-2006. What I found was, specified power into a specified load at a random THD, anything from .1% up to 1%. The only thing that was consistent across all brands was that they all chose different distortion levels at which to specify output power. I found only two products, the Denon and Onkyo, that mentioned dynamic power, but they don't say how it was determined, so who cares.

Sorry, man. I tried to prove you right, it didn't happen.
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post #43 of 54 Old 03-02-2016, 02:02 AM
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Here's my next one-at-a-time for you.

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Well just one more thing - Power Factor is a term used to describe real power (P) and not apparent power (S) or reactive power (Q)... fairly alive and text book stuff, you should be able to look it up and slightly adjust your comments moving forward, regarding the subject. I intentionally left out discussing phase angles (and formulas for that matter), because i wanted to keep it light and as tight as I am able. Like I said, I am not a teacher. So my examples are likely to be clumsy as the next, but not necessarily incorrect.
If you read my reply, I actually linked to the definition of Power Factor. I do agree with the definition, or I wouldn't have linked to it in the first place. But you have not applied the parameter to the discussion of a clipping amplifier supposedly blowing up speakers. I would guess you mentioned it to be complete. However, if we are talking about an amplifier clipping to some degree that still remains somewhat listenable, I'm not sure why you mention it. If an amplifier/speaker circuit already has a power factor of less than 1, does clipping an amplifier improve the power factor, transferring more real power to the load, or degrade it? It was so out of context that I thought you might be misapplying the term. Perhaps not.

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So...I was wondering what happens to the RMS value when you clip a sine wave, and why do so many people begin sentences with "so"?

In an effort to answer the first part, I generated a test file with these signals:

400Hz sine wave at -6dBFS
400Hz sine wave at -3dBFS
400Hz sine wave at -6dBFS (again)
400Hz sine wave at -6dBFS clipped by 3dB
400Hz sine wave at -6dBFS
400Hz square wave at -6dBFS

Using the amplitude statistics function in Adobe Audition, which includes an true RMS function, I got these measurements (the RMS calculation references a sine wave at 0dBFS):

400Hz sine wave at -6dBFS = -6dB RMS
400Hz sine wave at -3dBFS = -3dB RMS
400Hz sine wave at -6dBFS clipped by 3dB = -4.66dB RMS
400Hz square wave at -6dBFS = -3dB RMS

From this I concluded that:
1. Clipping an amplifier by 3dB with a sine wave results in an output increase of only 1.34 dB.
2. it is impossible to get any more than +3dB more power out of a clipping amp.
3. A higher power, non-clipping amp will deliver more power to the load, and therefore be more capable of heat-damaging a driver than a clipping lower power amp.

4. Driving an amp into clipping will always produce less than twice it's rated output power because of 2. and because it is unlikely that an amplifiers power supply can deliver twice the amps rated power to a load for very long.

What about the spectrum of a sine wave clipped by 3dB? How about all them harmonics? Well, the attached spectrum plot shows the third harmonic around 17dB below the fundamental, and harmonics above that in frequency even farther down in amplitude.

I'd be happy to share the test file, but it's too big to attach to a post, so we'll have to find another way.
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Originally Posted by jaddie View Post
Ok, sorry, I'll do one at a time. Lets start with the "easy one", CEA-2006. I was, in fact, interested, so I attempted to find one...just one...consumer or professional amplifier or AVR with the CEA-2006 rating. Now, I don't have time to be thorough and check every single manufacturer or every single product, so I picked out a few.

Denon - Checked specs on the AVR-X7200WA, their top-of-line AVR. Surely they'd use CEA-2006 in their power specs for that one. Nope, standard power specs, power into a specified load at a specified THD level. No mention of CEA-2006.

Onkyo - Looked at the TX-RZ900, again, a premier product. Nope, no CEA-2006, same power into a load at a distortion level.

Emotiva - a very popular brand of amplifiers around here - check their power output specs. Same sad song, no mention of CEA-2006, just the usual power > load @ THD.

What's interesting is the above three don't specify power at the same THD.

So I though, yikes, he can't really be wrong, I'd better check the pro market. So my two go-to pro brands that I install all the time, Crown and QSC. I'll save some space here, the ISA-1350 from QSC (happen to use that one frequently), no mention of CEA-2006. Crown CDi 1000 (also one I use a lot), no CEA-2006, just the usual power specs.

So, I struck out. I was uniformly flummoxed in my attempt to locate just one amplifier with power specs referencing CEA-2006. What I found was, specified power into a specified load at a random THD, anything from .1% up to 1%. The only thing that was consistent across all brands was that they all chose different distortion levels at which to specify output power. I found only two products, the Denon and Onkyo, that mentioned dynamic power, but they don't say how it was determined, so who cares.

Sorry, man. I tried to prove you right, it didn't happen.
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Originally Posted by jaddie View Post
Here's my next one-at-a-time for you.



If you read my reply, I actually linked to the definition of Power Factor. I do agree with the definition, or I wouldn't have linked to it in the first place. But you have not applied the parameter to the discussion of a clipping amplifier supposedly blowing up speakers. I would guess you mentioned it to be complete. However, if we are talking about an amplifier clipping to some degree that still remains somewhat listenable, I'm not sure why you mention it. If an amplifier/speaker circuit already has a power factor of less than 1, does clipping an amplifier improve the power factor, transferring more real power to the load, or degrade it? It was so out of context that I thought you might be misapplying the term. Perhaps not.
Quote:
Originally Posted by jaddie View Post
So...I was wondering what happens to the RMS value when you clip a sine wave, and why do so many people begin sentences with "so"?

In an effort to answer the first part, I generated a test file with these signals:

400Hz sine wave at -6dBFS
400Hz sine wave at -3dBFS
400Hz sine wave at -6dBFS (again)
400Hz sine wave at -6dBFS clipped by 3dB
400Hz sine wave at -6dBFS
400Hz square wave at -6dBFS

Using the amplitude statistics function in Adobe Audition, which includes an true RMS function, I got these measurements (the RMS calculation references a sine wave at 0dBFS):

400Hz sine wave at -6dBFS = -6dB RMS
400Hz sine wave at -3dBFS = -3dB RMS
400Hz sine wave at -6dBFS clipped by 3dB = -4.66dB RMS
400Hz square wave at -6dBFS = -3dB RMS

From this I concluded that:
1. Clipping an amplifier by 3dB with a sine wave results in an output increase of only 1.34 dB.
2. it is impossible to get any more than +3dB more power out of a clipping amp.
3. A higher power, non-clipping amp will deliver more power to the load, and therefore be more capable of heat-damaging a driver than a clipping lower power amp.

4. Driving an amp into clipping will always produce less than twice it's rated output power because of 2. and because it is unlikely that an amplifiers power supply can deliver twice the amps rated power to a load for very long.

What about the spectrum of a sine wave clipped by 3dB? How about all them harmonics? Well, the attached spectrum plot shows the third harmonic around 17dB below the fundamental, and harmonics above that in frequency even farther down in amplitude.

I'd be happy to share the test file, but it's too big to attach to a post, so we'll have to find another way.
Well to start, you win! You are one very energetic individual, I will give you that. You completely outclass me in this particular regard, and to my amazement other areas as well.

Next I must say that I am thoroughly intrigued. You're the most gifted person that I've ever come upon. You clearly have an innate ability to present all of your own questions and answer them too (and with interesting narrative abilities, i might add). God bless you sir.

In light or you're unique skill-sets, I will leave you to your own vices.
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post #46 of 54 Old 03-02-2016, 08:01 AM
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Originally Posted by Jady Jenkins View Post
Well to start, you win! You are one very energetic individual, I will give you that. You completely outclass me in this particular regard, and to my amazement other areas as well.

Next I must say that I am thoroughly intrigued. You're the most gifted person that I've ever come upon. You clearly have an innate ability to present all of your own questions and answer them too (and with interesting narrative abilities, i might add). God bless you sir.

In light or you're unique skill-sets, I will leave you to your own vices.
Wow, what a snotty response. You have an experienced engineer take quite a bit of effort to explain your misunderstandings of audio and this is your reply?
Wanna prove him wrong? Do like you yourself asked and supply the worked math. Start with power into loads from clipped sinewaves.
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Originally Posted by A9X-308 View Post
Wow, what a snotty response. You have an experienced engineer take quite a bit of effort to explain your misunderstandings of audio and this is your reply?
Wanna prove him wrong? Do like you yourself asked and supply the worked math. Start with power into loads from clipped sinewaves.
Why are you minding someone else business for them, instead of your very own.

Feel free to offer what Jaddie has not, but don't feel free to beguile me into responding further than i have to him. His sarcasms were duly noted, and responded to in a gentler, kinder, and albeit sufficient manner.

There seem to be some tall grass growing in here and I am not feeling inclined to unsheathe my sword as to chop it down.

My god man, I just offerd my opinions and made a decent, light vernacular attempt at supporting them. If you disagree, no problem, noted. Move on please.

If you're altruistic and in someway concerned that my opinions and supporting argument while wrong (in your eyes), are some how, also persuasive enough to mislead others, then state your own opinions and support the best that you're able and leave them for others to ponder, and come to a decision about, just as I have, and I am sure tens of thousands of other have and will continue to do.

I am not sure what's going on in here, but it's not friendly sharing's that's for sure, so I think I will take my leave of this thread.

Peace be with you, and your!

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post #48 of 54 Old 03-02-2016, 09:03 AM - Thread Starter
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Hey everyone, I moved the center speaker forward and it's much better. Lol.
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post #49 of 54 Old 03-02-2016, 10:48 AM
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Hey everyone, I moved the center speaker forward and it's much better. Lol.


This post just made me laugh out loud. Glad to hear it is working better for you.

I turn the sharpness on my TV all the way up, because that's how I like my picture... real sharp.


Jumping into DIY - My 893, Volt 6, and UM18(x4) build
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post #50 of 54 Old 03-02-2016, 12:24 PM
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Hey everyone, I moved the center speaker forward and it's much better. Lol.
LOL!!! Glad we could help.

While the energetic discussions are prevalent in this thread now, do all well built amps sound the same? How about interconnects and speaker wire? Do they all sound the same?

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post #51 of 54 Old 03-02-2016, 01:07 PM
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Hey everyone, I moved the center speaker forward and it's much better. Lol.
I LOL'd so hard....Things were getting heated over here, expecting a pretty sassy reply back and BOOM, OP outta nowhere lol
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post #52 of 54 Old 03-02-2016, 08:10 PM - Thread Starter
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Excellent! Is the bride happy with the aesthetics?

I ran the cable in the cabinet and up through the top near the front. Speaker rests near the front. She couldn't even tell I made a change.
D Bone and GIEGAR like this.
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post #53 of 54 Old 03-02-2016, 10:33 PM
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She couldn't even tell I made a change.
Oh, she will! Be prepared for your response, as it will make or break whether or not it stays.
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post #54 of 54 Old 03-03-2016, 04:19 AM
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Iirc, the harmonics in a square wave would add up to 40 percent or so distortion. Moreover the harmonics must be only odd harmonics and must be in a precise mathematical and phase relationship. Change the phase and the resulting wave can get really wonky looking. Prat from a square wave. There is a headphone site that posts results of playing a square wave through non phase coherent phones and the results can be astonishing. Even more astonishing, the thing still sounds like a square wave, because the signal still is simply the fundamental plus odd harmonics in the appropriate descending levels.

Distortion adds higher harmonics. The amp is still producing, say, 100Hz and 300, 500, 700, 900, 1100 1300 Hz etc etc. the actual power delivered does not change if the harmonics are in phase to make a square wave or not. The picture of a square wave cases (me) confusion. The amp isn't producing alternating DC, but a harmonics-rich complex signal. Regardless of what the scope trace looks like.
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