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bob ludwig and loudness
Old 28th January 2009 | Show parent
  #61
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Quote:
Originally Posted by MAzevedo ➡️
Sound pressure (dBSPL) and voltage (dBV) are both 20log functions, and double every 6dB.
That's true. If we were doubling the pressure, then absolutely we would see an increase of 6dB. This is where you guys are going astray. When we combine two identical sound sources of equal power and equal pressure, then we get a doubling of power, but we do NOT get a doubling of pressure!

In order to achieve a doubling of actual sound "pressure" we need to apply 4 times the power, or 4 sources of equal power, (watts) to get to 6dB. This is regardless of whether the devices are in 2pi or 4pi space, or the Q of the device, etc., etc. A watt is a watt.
Old 28th January 2009 | Show parent
  #62
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Fader8,

read my post #59 carefully and think about it over a cup off coffe.


/Peter
Old 28th January 2009 | Show parent
  #63
kjg
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Quote:
Originally Posted by Audiop ➡️
Fader8,

read my post #59 carefully and think about it over a cup off coffe.


/Peter
consider a 3dB increase on the coffee power/intensity
Old 28th January 2009 | Show parent
  #64
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heh


/Peter
Old 29th January 2009 | Show parent
  #65
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Quote:
Originally Posted by Audiop ➡️
heh

/Peter
See! Now you guys are laughing at me!tutt But I'll show you, gosh darnit! I'll have the last laugh! MUHUHAHAHAHAHA!!!

Allow me to just repeat one thing that I'd like you all to chew on over a Martini:

"If we were doubling the pressure, then absolutely we would see an increase of 6dB. This is where you guys are going astray. When we combine two identical sound sources of equal power and equal pressure, then we get a doubling of power, but we do NOT get a doubling of pressure."

Let that be the olive that you roll around on your tongue for a while. In time, you too shall be one of the enlightened ones! Until then, I rest my case.

Now, back to my padded cell to finish some work!
Old 29th January 2009 | Show parent
  #66
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Here is a pic of a measurement showing some graphs of a two way loudpseaker by Seas Norway.

At the crossover frequency (aprox. 2.3kHz) you can see that the summed output of both drivers are +6dB.

bob ludwig and loudness-bifrost_woof_twt.jpg


/Peter
Old 29th January 2009 | Show parent
  #67
kjg
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Quote:
Originally Posted by fader8 ➡️
See! Now you guys are laughing at me!tutt But I'll show you, gosh darnit! I'll have the last laugh! MUHUHAHAHAHAHA!!!
I wasn't laughing at you! Just making at little joke.

Imagine a super deluxe coffee machine in your studio.. With a control to scale coffee power/intensity, in dB!
The control would have to be stepped in 0.5 dB steps of course, for recallability, but that goes without saying :P
Old 29th January 2009 | Show parent
  #68
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A good paper with some examples and calculations.

All interesting but pg.4-5 being most relevant to the discussion.

The author is unknown to me but the references are long time legends in the field.

http://www.interdomain.net.au/~bodzio/Article5.pdf

edit: duh, the author is very well known even to me. He is the designer of (amongst other programs) Sound Easy, a speaker design software used by many many amateurs and pros.


/Peter
Old 29th January 2009 | Show parent
  #69
kjg
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Quote:
Originally Posted by Audiop ➡️
At the crossover frequency (aprox. 2.3kHz) you can see that the summed output of both drivers are +6dB.

/Peter
That's probably just caused by IM distortion from a ultrasonic partial around 63k Peter... You should know that.

EDIT: but seriously.. Thank you for the link! I'll read it later tonight.
Old 29th January 2009 | Show parent
  #70
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Quote:
Originally Posted by kjg ➡️
IImagine a super deluxe coffee machine in your studio.. With a control to scale coffee power/intensity, in dB!
The control would have to be stepped in 0.5 dB steps of course, for recallability, but that goes without saying :P
Lets make that .2dB increments. I'm pretty sure we can distinguish that, eh?

Quote:
Originally Posted by Audiop ➡️
A good paper with some examples and calculations.
I remember this article well. Allow me to quote from it because what I'm talking about is woven all through that paper:

Quote:
Two drivers connected in-parallel.
. . . . . . Each driver will generate 100dB SPL, so that total SPL of the system is now 103dB.
Notice the term "total" in that sentence. Peter, for the purposes of this discussion, loudspeaker design isn't really relevant. We could be discussing Mole farts, as long as they were the same. Ironically, that paper should give you a lot of insight to explain why you have a 6dB increase at your crossover frequency, instead of just 3dB.

Quote:
Originally Posted by Audiop ➡️
The author is unknown to me but the references are long time legends in the field.
And a walk down memory lane, for me. I studied with John Eargle when he taught at Eastman, (his alma mater too) and he was one of the guys (along with Melvin Sprinkle) who used to beat our heads around about exactly the decibel stuff we're discussing here. Believe me, I was just as stubborn about it then as you guys are now! I had some dealings with him later due to his association with Harman/JBL, and at AES. He passed on a couple years ago, but he's sorely missed. (Mel too).

I studied with Don Keele too, back when I first started using TDS. I was an original TEF10, 12 and 20 user and he would co-teach the TEF seminars at Crown. Gee, I hope he's still alive!

OK, I digress, on to the point . . .

Whenever we talk about the decibel in the context of acoustics, it is ALWAYS about power. The Bel is an expression of power ratio, 10:1 in fact. In order to apply it to pressure, we first have to convert to the power ratio. So:

10Log (P1/P2) gives us our basic power ratio in dB. To convert that to pressure, we simply use 20Log (P1/P2) because, as I said earlier, it takes four times as much power if you want to achieve twice as much pressure. Going from 10Log to 20Log is simply a convenient way to double your answer and make it relate to a pressure ratio. 6dB when you double the pressure instead of 3dB when you double the power.

Now we can't directly measure the sound power of things, (we can calculate it but it's awfully, awfully difficult) we instead conveniently measure the pressure, (force) at a given point in the sound field. If two devices both measure the same, the power ratio between both running and one running, is 2:1. That's the nice thing about watts, you can add them directly.

Since the decibel is not a unit value, but only an expression of ratio, and in acoustics only ever an expression of power ratio, then the only way we can express the ratio between two pressures in decibels is with a power ratio. Phew.

Now we all know from Audio 101 that when we double the power of anything, it's 3dB. Since the decibel is only ever capable of expressing a power ratio between two sound pressures, then the answer must be 3dB.
10Log (2/1) = 3.

What's confusing for many is that when we apply it to different mediums, like voltage, current, impedance or pressure, it's no longer a power ratio. It's been mutated for these mediums to express their own ratios. That is when we can use the 20Log equation, eg 10V/20V is a 6dB voltage ratio. 20uPascal/1 Pascal is a 94dB pressure ratio.

Quote:
Originally Posted by Audiop ➡️
If you take two identical sources, say speakers, and add them as proposed you WILL get +6dB SPL and also quadrupled (sp?) power.
Think about your statement, Peter. If I have 2 speakers each outputting 1 acoustic watt, where would I get quadruple the power from?

Quote:
Originally Posted by Audiop ➡️
This is really basic physics that anyone involved with audio engineering should understand IMO.
/Peter
Which is exactly why I'm trying to make the effort to help you understand it!

This isn't so much about physics as it is about convenient mathematical notation and how we name things. For example, a Pascal is a unit of sound pressure but we never use it to describe Sound Pressure Level. Likewise, Sound Intensity refers to the absolute intensity in watts per square meter whereas Sound Intensity Level is the magnitude of the sound intensity relative to a reference intensity.

OK, I'll stop there before Gearslutz crashes again! LOL.
Old 29th January 2009 | Show parent
  #71
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Quote:
Originally Posted by fader8 ➡️
Lets make that .2dB increments. I'm pretty sure we can distinguish that, eh?
...
For which signal? It is borderline.
for 1 kHz on a good day maybe
for 100 Hz even on a good day unlikely.
Old 29th January 2009 | Show parent
  #72
kjg
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Quote:
Originally Posted by audio ergo sum ➡️
For which signal? It is borderline.
for 1 kHz on a good day maybe
for 100 Hz even on a good day unlikely.
that was about the coffee.
what a confusion...

intensity/power >> log10 >> 3dB >> a -3dB to 3dB range in quarter dB steps would require a 25 step switch? Maybe VCG (voltage controlled grinder) control would be more cost effective?

Which unit? dB Beans?

Old 29th January 2009 | Show parent
  #73
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Quote:
Originally Posted by kjg ➡️
that was about the coffee.
what a confusion...

intensity/power >> log10 >> 3dB >> a -3dB to 3dB range in quarter dB steps would require a 27 step switch? Maybe VCG (voltage controlled grinder) control would be more cost effective?

Which unit? dB Beans?

Maybe his coffee "sings" to him?

We'd need to hire a culinary expert, come up with the values, parameters and ranges for them . . . Of course, we'll need various plug-in algorithms to compensate for Colombian Supreme, French Roast, Kona, etc. But it's do-able.
Old 29th January 2009 | Show parent
  #74
kjg
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Quote:
Originally Posted by fader8 ➡️
Maybe his coffee "sings" to him?

We'd need to hire a culinary expert, come up with the values, parameters and ranges for them . . . Of course, we'll need various plug-in algorithms to compensate for Colombian Supreme, French Roast, Kona, etc. But it's do-able.
You are right... This will require some serious DSP and a dedicated research team of international specialists!
Old 29th January 2009 | Show parent
  #75
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Quote:
Originally Posted by fader8 ➡️
Notice the term "total" in that sentence. Peter, for the purposes of this discussion, loudspeaker design isn't really relevant. We could be discussing Mole farts, as long as they were the same. Ironically, that paper should give you a lot of insight to explain why you have a 6dB increase at your crossover frequency, instead of just 3dB.
You quoted a small part of one of my earloer posts and missed the boat because of that. Now you quoted a (badly written unfortunately) part from the article and made a big mistake again.

Quote:
Two drivers connected in-parallel.
Being the ideal voltage source, the amplifier will cope well with the 2ohm load
impedance being now presented to it ( two 4ohm loudspeakers connected in-parallel). Each
driver will generate 100dB SPL, so that total SPL of the system is now 103dB. The
diffraction effect will add on the top of it +6dB in the upper end of the operating frequency
6
range and the mutual radiation impedance effect will add +3dB in the lower end of the

operating frequency range. The final SPL gains curve is shown on Figure 4.


You are mistaken fader8. :-)

But you're not the first one having problem with understanding this and ojne can choose differend explanation models for the fact that two equal sources do indeed sum to +6dB.

Quote:

Plainly speaking, when testing in the anechoic chamber, at high frequencies the

speaker is radiating into "half space" (2π) i.e. it is only radiating into the forward hemisphere.
At low frequencies the speaker radiates into "full space", (4π) exhibiting a loss of bass when
implemented in typical speaker enclosures. The difference in the SPL is 6dB and is referred



to as the "6 dB baffle step" or the enclosure’s "diffraction loss".
Above the 2pi vs. 4pi is described.

With the same speaker and same power you can increase SPL with 6dB by changing the acoustic impedance. Surely this must give you a hint?

By adding a surface you gain 6dB and adding a second speaker will do the same.

If one speaker is placed up in free air and measured at one meter we will see +6dB by placing the speaker on the ground. The energy that would spread like a sphere is pushed into a half sphere hence the pressure doubles=6dB. Where else would the air go?


Quote:
Believe me, I was just as stubborn about it then as you guys are now!

Since you refuse to unlearn and learn again I must say that you are the one being stubborn here. :-) No offense. ;-)

I am 100% sure that the coin will fall down soon for you. You seem to be an intelligent man but I guess it's hard to let go of something you have seen as a fact or reality for a long time.

Quote:
Whenever we talk about the decibel in the context of acoustics, it is ALWAYS about power.

Yes and no. We deal with a fluctuating pressure in my book but of course that takes energy.. and a certain amount of energy in a certain time span is "power".



Quote:
as I said earlier, it takes four times as much power if you want to achieve twice as much pressure.



Yes and you get that when paralelling two speakers. The electric power in transformed into acoustic power with the means of a magnetic motor. When you double up on motors you gain efficiency in the system. Everything is explained by my earlier posts and the article + the picture I posted. It's so obvious for me but I don't know how to help you understand.



The best for you would probably to measure two speakers and see for yourself that the SPL will sum to +6dB and then you just have to accept it. ;-)


Quote:

Now we all know from Audio 101 that when we double the power of anything, it's 3dB. Since the decibel is only ever capable of expressing a power ratio between two sound pressures, then the answer must be 3dB.
10Log (2/1) = 3.

But that's not the way it is. The dB thing can be used as a comparative log measure of anything, not only power.

Quote:

What's confusing for many is that when we apply it to different mediums, like voltage, current, impedance or pressure, it's no longer a power ratio. It's been mutated for these mediums to express their own ratios. That is when we can use the 20Log equation, eg 10V/20V is a 6dB voltage ratio. 20uPascal/1 Pascal is a 94dB pressure ratio.

Exactly, you can use dB for anything, such as voltage or pressure.

Quote:

Think about your statement, Peter. If I have 2 speakers each outputting 1 acoustic watt, where would I get quadruple the power from?


Radiation impedance and system efficiency explains this.


Quote:

Which is exactly why I'm trying to make the effort to help you understand it!


A sweet but I have a grip on it which you don't.


Ok, I'm sure we will get this into your head sooner or later.



Let's start with one loudspeaker. We feed it 1W electrical power and measure 90dB SPL at one meter.



Now, let's feed 2W into the same speaker, that is twice the electric power and we will measure 93dB SPL at one meter.



Let's add a 2nd speaker and feed 1W into each of them. Now, we know that one speaker with 1W input gave us 90dB SPL and it's safe to assume that the 2nd added speaker will pump as much air as the first.



Now we will effectively move twice as much air.. and where do that air go if not the same direction adding two times the pressure?



According to your erroneus explanation there must be some huge 3dB loss somewhere if the double amount of air that is pumped from the cones add to less than 6dB. Get it?



Another way to look at it:
Upping the power from 1W to 2W in a single speaker WILL only give +3dB SPL, yes?



BUT if we instead let the cone move twice as much, pumping the same amount of air as the two driver case with 1W fed into each, then we will get +6dB right?



To increase the output from one speaker from 90dB to 96dB takes four times the power just as you think but adding a second speaker will give the same 96dB with only 2W input to the system.



Head hurts? heh

I promise you that what I present to you is correct.




/Peter
Old 29th January 2009 | Show parent
  #76
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Quote:
Mutual Radiation Impedance
When two loudspeakers are mounted on the same baffle and fed the same signal, one
driver starts to produce additional pressure on the other, increasing its radiation impedance.
The next logical step is therefore to determine power radiated by two sources mounted on the
same baffle. Vanderkooy and Lip****z [3] examined a simple case of two pistons mounted in
an infinite baffle and proposed an elegant formula for expressing radiated power into the farfield
taking into account self and mutual radiation impedance of source1 (piston1) coming
from itself and from piston 2 as:
where d, is the distance between the pistons and a, is the radius, identical for both pistons and

ω
=2πf, with f being the frequency of the applied signal.
4
For low frequencies, the above formula reduces to:
The above result is four times (or 6dB SPL) the single source result.



/Peter

Old 29th January 2009 | Show parent
  #77
kjg
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Peter, your explanations are very clear and I have no doubt that they are 100% correct. They correspond with everything I learned in the past as well as with my own reasoning.

I missed correlated and assumed uncorrelated before (which is why fader8's lawn hypothesis seemed correct), but since that got cleared up I see absolutely nothing wrong with your reasoning.

fader8, maybe take a little time?

Quote:
Originally Posted by Audiop ➡️
Let's start with one loudspeaker. We feed it 1W electrical power and measure 90dB SPL at one meter.

Now, let's feed 2W into the same speaker, that is twice the electric power and we will measure 93dB SPL at one meter.

fader8, this is the 3dB increase resulting of a doubling of power.

Quote:
Let's add a 2nd speaker and feed 1W into each of them. Now, we know that one speaker with 1W input gave us 90dB SPL and it's safe to assume that the 2nd added speaker will pump as much air as the first.
and this is a doubling of SPL or 6dB. Try it. I just did with my speakers. I put uncorrelated pink noise first which added just under 3dB to the SPL, then identical (100% correlated) pink noise which added just under 6dB. The reason they don't get to exactly 6dB is because they are not on the same baffle but two separate speakers.

Quote:
Upping the power from 1W to 2W in a single speaker WILL only give +3dB SPL, yes?

BUT if we instead let the cone move twice as much, pumping the same amount of air as the two driver case with 1W fed into each, then we will get +6dB right?
making the cone move twice as much > doubling of amplitude. Think of how you double the amplitude from 0.5 to 1 in your wave editor: by adding 6 dB..

Quote:
To increase the output from one speaker from 90dB to 96dB takes four times the power just as you think but adding a second speaker will give the same 96dB with only 2W input to the system.

... makes total sense ...

Quote:
I promise you that what I present to you is correct.

/Peter
fader8, I wouldn't mind betting a little money he is indeed right, especially since I just verified it again for myself, or at least I think I did

regards,
Klaas-Jan
Old 29th January 2009 | Show parent
  #78
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Yes and the room may play tricks with the measurement as well. Measuring outdoors or in an anechoic chamber or in a big hall with better diffuse field will likely get closer to theory.

What's even cooler from a loudspeaker designing perspective is that four drivers in series paralell connection will give +6dB SPL with the same power input as the single speaker gives 0dB.

1W into single 8ohm speaker = 90dB SPL.

Connect two identical speakers in paralell and two such pairs in series for a 8ohm load (of four drivers total) and feed 1W and we have 96dB SPL.

One single Watt by the help of a little magic gives us four times the acoustic power for "free".

The cone travel for a given output SPL will be 1/4 (less distortion) and the thermal compression will be decreased a lot since each speaker/driver only need to handle 1/16 of the power that the single driver needs to handle for the same SPL.


/Peter
Old 29th January 2009 | Show parent
  #79
kjg
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Quote:
Originally Posted by Audiop ➡️
Yes and the room may play tricks with the measurement as well. Measuring outdoors or in an anechoic chamber or in a big hall with better diffuse field will likely get closer to theory.

What's even cooler from a loudspeaker designing perspective is that four drivers in series paralell connection will give +6dB SPL with the same power input as the single speaker gives 0dB.

1W into single 8ohm speaker = 90dB SPL.

Connect two identical speakers in paralell and two such pairs in series for a 8ohm load (of four drivers total) and feed 1W and we have 96dB SPL.

One single Watt by the help of a little magic gives us four times the acoustic power for "free".

The cone travel for a given output SPL will be 1/4 (less distortion) and the thermal compression will be decreased a lot since each speaker/driver only need to handle 1/16 of the power that the single driver needs to handle for the same SPL.


/Peter
Wow, that is good stuff. Still I don't see many speakers with four woofers?
What you see a lot is pairs. Woofers, mids, subs. They are mostly parallel then, I guess?

BTW, in your earlier example we already got a 6dB increase in SPL from feeding 1W into two speakers instead of one, but we did this in parallel so that would be a 4ohm load then, right?
While with this series/parallel wiring, we get the same 6 dB increase, but from 4 speakers while the load stays 8ohm. Am I getting this?
+6dB from 2 speakers @ 4 ohm VS +6dB from 4 speakers @ 8 ohm.

PMC just released new a dual woofer speaker, looks pretty nice.. I guess the reason for the two woofers would be gaining 6dB in the lows, less distortion, higher peak SPL etc. For a given SPL the cone travel would be half, right? But what about the power requirement in this case? 1/4 for a given SPL compared to one woofer? But the load has doubled compared to 1 woofer? That's all good as long as the amp can deliver the current? Is that how it works?

Thank you for any enlightenment,
Klaas-Jan
Old 30th January 2009 | Show parent
  #80
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Quote:
Originally Posted by kjg ➡️
Wow, that is good stuff. Still I don't see many speakers with four woofers?
$$$ and size. :-) But that's a must for high performance.

Quote:
What you see a lot is pairs. Woofers, mids, subs. They are mostly parallel then, I guess?
Paralell is most common but series connection is used as well but can be problematic if the drivers are poorly matched and especially in bassreflex speakers. If the drivers are operated above the fundamental resonance there's no problem.

Quote:
BTW, in your earlier example we already got a 6dB increase in SPL from feeding 1W into two speakers instead of one, but we did this is parallel so that would be a 4ohm load then, right?
If we start at 1W and one 8ohm speaker and let the volume control stay the same while we connect another identical speaker we get a 4ohm load and the current draw will double for a total of 2W delivered to the combo. We will see a 6dB SPL increase.

Quote:
While with this series/parallel wiring, we get the same 6 dB increase, but from 4 speakers while the load stays 8ohm. Am i getting this?
Yes, so life will be a little easier for the amp and we are likely to see a tad lower distortion from the amp driving 8ohm instead of 4ohm for a given power level.

Quote:
PMC just released new a dual woofer speaker, looks pretty nice.. I guess the reason would be gaining 6dB in the lows, less distortion, higher peak SPL etc. For a given SPL the cone travel would be half, right?
Yes!

Quote:
But what about the power requirement in this case? 1/4 for a given SPL compared to one woofer?
Yes, a 1/4 in total which means 1/8 the power to each woofer.

Quote:
But the load has doubled compared to 1 woofer?
The impedance will be cut in half, but I think that is what you meant.

Quote:
That's all good as long as the amp can deliver the current? Is that how it works?
Yes! But for a given SPL the current will drop to 1/2 with two drivers in paralell. So it's not like the amp has to push more current to the dual woofers, but it will see a lower impedance. Most decent modern solid state amps can drive 3-4ohm without problems and many can handle 1-2ohm.

Quote:
Thank you for any enlightenment,
Klaas-Jan
Thank you! Learning and sharing is what we're here for.


/Peter
Old 30th January 2009 | Show parent
  #81
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Peter,
There is nothing wrong with your logic. A doubling of pressure does indeed represent a 6dB power ratio. Your discrepancy has been with your understanding of the mathematical use of the decibel. You cannot interchange power and pressure, just as you cannot interchange power and voltage, within the same equation string. Yes, you can use the decibel to describe the ratio of anything as long as you provide the reference unit and that unit stays the same.

Here's the crux of the biscuit:
With pressure and voltage, the whole reason we multiply the answer times 20 is to convert the answer back to a convenient power ratio. We don't need to do that if we're talking about power in the first place. We only need to multiply it by 10 because we like to use decibels, not bels.

The sole and rigid purpose of the decibel is to represent a power ratio. In many writings we'll see the use of dB as unitless, which is fine as we already know what it represents. Pressure does not in itself define a unit of work. You cannot convert any unit of pressure, eg Pascals, bars, into any unit of actual power/work performed, like the watt. The same is true for voltage in that we can't determine what actual work its's performing until we know the load and see the current flowing. But the decibel gives us a convenient way of predicting what a parameter will do even when we don't know what the other conditions are.

Rereading the thread, I realized that you were using terms without regard to their underlying mathematical principals. This always leads to the kind of misunderstanding we're having here. One of the best books for clearly distinguishing these mathematical concepts and their application in audio is Don & Carolyn Davis's Sound System Engineering. Few books have suffered the peer review by audio engineers that this one has over the years.

Quote:
Originally Posted by Audiop ➡️
One single Watt by the help of a little magic gives us four times the acoustic power for "free".
Thus the 6dB. Pressure can be multiplied many times with various loading techniques. Let's look at this statement you quoted from the description of mutual radiation impedance:
The above result is four times (or 6dB SPL) the single source result.
Here the author correctly states that there is a 6dB ratio in power between the 2 test conditions. We know that the measurement parameter was pressure due to the use of the suffix SPL, but the ratio is expressed in dB, so we know that the ratio between the two pressures is being expressed as power.

Regarding these references to baffle and multi-driver coupling techniques, while interesting and have a lot of their basis in Keele's work with Bessel arrays, have little to do with the combining of sound sources in free air, which could be several meters apart, not mounted in the same baffle. It clouds the original issue we were discussing here as you then must mathematically treat the multi-driver array as a single sound source.

Peter, I appreciate, as much or more than anyone else on this forum, your passion for experimenting with loudspeakers and their related acoustics. It's a fascinating vocation. But because many of the concepts and variables are so complex, the terms we use, both textually and mathematically, become tremendously important when communicating them. So lets bury the hatchet and move on from here. In addition to the book I recommended above, I'd also suggest you read Bob McCarthy's "Sound Systems: Design and Optimization". Many of the concepts you're describing have long been hashed out by the guys who do stadium and concert sound systems, where dB is dollars. But often these tricks don't come without a price, but we'll leave that for the subject of a different thread.
Old 30th January 2009 | Show parent
  #82
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*cough cough* so much smoke here, can hardly see or breath!

;-)


fader8,

I know the difference between power and voltage, I know what dB is and how to use it and describe certain phenomena. I even know when to hit 10log or 20log on my Casio.

I know Ohms law and some more about that stuff and I have spent a respectable amount of time on studying acoustics and physics.

Yes, things get complicated when putting several sound sources in this or that environment, don't assume I don't know that BUT before we can even start to discuss about that (in another thread of course ;-) we must sort out the basic stuff we have been discusing the latest day/days.

I'm cool but why not drop the prestige and admit that you were wrong instead of making up things about me being confused about this or that and recommend books that you probably need to read more than I?


/Peter
Old 30th January 2009 | Show parent
  #83
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Quote:
Originally Posted by Audiop ➡️
I'm cool but why not drop the prestige and admit that you were wrong . . .
LOL, Peter, I just did!:
Quote:
Originally Posted by fader8 ➡️
Peter,
There is nothing wrong with your logic. A doubling of pressure does indeed represent a 6dB power ratio.
My post was merely to explain why I misunderstood you. If that wasn't clear, I apologize. Sometimes the casual format of a discussion forum doesn't lend itself to precise language. We're all guilty of this. And even when it is precise, sometimes we don't read it carefully enough. I know I'm guilty of this!

So yeah, I'm cool too. On with life.
Old 30th January 2009 | Show parent
  #84
Lives for gear
 
🎧 10 years
Well then, seems like we can have a nice weekend and think of something else for a while. heh

Take care, talk to you later!



/Peter
Old 31st January 2009 | Show parent
  #85
Gear Addict
 
Dale's Avatar
 
🎧 15 years
the end

and they all lived happily ever after
enjoying multiple Grammies and platinum records each!!!

thanks to Mr Katz

Last edited by Dale; 31st January 2009 at 12:05 AM.. Reason: kudos was needed
Old 1st February 2009 | Show parent
  #86
Gear Addict
 
🎧 10 years
I just bookmarked this thread. Great discussion.

Firstly I'm concerned that the original poster is a mastering engineer when he/she states the everyone should know that 10dB is 10 times louder.

I find it amazing how many times I thought audioOp was correct and then fader 8 was correct. I appreciate you are both very knowledgable but I think audioOp did hit it on the head with the Loudspeaker reference.
My explanation in layman's terms is that if you have one speaker producing 90dB SPL and then you push up the fader for equivalent loudspeaker and pull down the previous, you have 90dB SPL. 90dB SPL plus 90dB SPL equals 96dB SPL.
Old 2nd February 2009 | Show parent
  #87
Here for the gear
 
🎧 15 years
Loudness Wars

Hi,

First time poster, but I have a question. With respect to mastering with extreme loudness, how much weight does the way something sounds on the radio carry these days? I know they wrestle with the same loudness issues, with air-chain processors adding intense loudness to everything so they can dominate with volume on their respective bands. I would think that radio is probably mattering less and less in these decisions, but would like to know what you all think and what your experiences are.

Thanks,
Bob Martin
Old 2nd February 2009 | Show parent
  #88
kjg
Lives for gear
 
🎧 10 years
what was that song again?chorus went something like this:

"you can't see tits on the radio-o"


anyway...

I never listen to radio. Ever. I think it is obsolete. Almost as obsolete as cd's are Internet radio/broadcasting will be the new am/fm, I guess? Not that I care much. I like to choose what I listen to.
But for pop it is still a big deal I guess. Then again, making it too loud makes it quieter and completely mangled on the radio.

I do buy cds, but never listen to them. I rip them to flac, and that is it. Disc goes on the shelf. I might as well have downloaded the music, skip the physical package. But I'll have to wait a few years, I guess. I don't buy mp3s online, rather get the physical disc then.
Old 2nd February 2009 | Show parent
  #89
Here for the gear
 
🎧 15 years
Quote:
Originally Posted by kjg ➡️
what was that song again?chorus went something like this:

"you can't see tits on the radio-o"


anyway...

I never listen to radio. Ever. I think it is obsolete. Almost as obsolete as cd's are Internet radio/broadcasting will be the new am/fm, I guess? Not that I care much. I like to choose what I listen to.
But for pop it is still a big deal I guess. Then again, making it too loud makes it quieter and completely mangled on the radio.

I do buy cds, but never listen to them. I rip them to flac, and that is it. Disc goes on the shelf. I might as well have downloaded the music, skip the physical package. But I'll have to wait a few years, I guess. I don't buy mp3s online, rather get the physical disc then.
Thanks for that. More than personal listening preferences, I am wondering what the pros here encounter when mastering for clients. Do CLIENTS take radio into consideration any more? And if they do, is there ever a dialog about "dual loudness" - ie: Loudness added in mastering vs. loudness the air-chain processor ads. OR, for that matter, on TV, for the compression and limiting that's put into the broadcast audio.

Thanks,
Bob
Old 2nd February 2009 | Show parent
  #90
kjg
Lives for gear
 
🎧 10 years
Quote:
Originally Posted by uburoibob ➡️
Thanks for that. More than personal listening preferences, I am wondering what the pros here encounter when mastering for clients. Do CLIENTS take radio into consideration any more? And if they do, is there ever a dialog about "dual loudness" - ie: Loudness added in mastering vs. loudness the air-chain processor ads. OR, for that matter, on TV, for the compression and limiting that's put into the broadcast audio.

Thanks,
Bob
Sorry Bob, can't really help you with that. I generally work for people that are more "underground"/realistic (i.e. don't care much about radio/tv broadcast as long as their disc/mp3 sounds great).

Like I said though, if loudness is pushed too much, it will come out worse and quieter when played back through additional radio/tv multiband compression. Being in the ballpark (for the style) but slightly quieter seems to be the safest (and relatively best sounding) way to go. You have to educate your clients in that regard. That "radio" sound will come after radio processing, when it is actually being broadcast. If you already make the master sound like that before broadcast, it'll probably sound wimpy on radio.

I am sure there are people here with more experience it dealing with clients aiming for the mainstream though, and I'd be interested to hear their thoughts on this subject also.

regards,
kjg
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