I'm not talking about estimated output, but actual measured SPL at my listening position. The problem with estimates is that they don't take all factors into consideration. You must also consider power compression, which is not readily available information for hifi drivers.
My system is approx 90db efficient 1w1m and triamped with ~50w to the midbass and tweeter and 650w to each sub. It may be possible to measure 110db peaks if my meter were to take a small enough time window. I'm currently using the SPL meter function of Ultracurve with a measurement mic.
My system is approx 90db efficient 1w1m and triamped with ~50w to the midbass and tweeter and 650w to each sub. It may be possible to measure 110db peaks if my meter were to take a small enough time window. I'm currently using the SPL meter function of Ultracurve with a measurement mic.
While there might be some recordings out there that actually have this dynamic range I doubt that this is true for the largest part of recordings out there. Even with classical recordings some gain-riding is often used.
Even on a generously dimensioned system loud orchestral music has this annoying quality that a live orchestra doesn't have.
I don't know how to explain what I actually mean but a live orchestra still sounds dynamic and effortless in some way during fff passages while electronic reproduction sounds "jammed" in some way reproducing the same. And I assume that this is partially due to gain riding (apart from effects like IMD etc).
Apart from that: What quality would you expect from a 16 bit system that is used at 80 dB below maximum? There are just under 3 bits used - meaning a resolution of less than 8 steps. Even with tricks like noise-shaping this wouldn't be very good.
Regards
Charles
Getting back to the initial question about how loud is 105db. I have just been reading the JBL cinema design manual, which you can download here:
http://www.jblpro.com/pages/tech_lib.htm
Cinemas are designed for an average sound level of 85 db two thirds from the front, with peaks of 105db.
The JBL manual recommends an 18" vented pro sub driver with >97db sens and >400w power handling per 25,000 cu ft.
It's curious that most home theatre enthusiasts on this forum will probably use a lot more displacement per room volume than a comercial cinema.
Cinemas: 0.00012L of displacement (VD) / cu ft
In my setup I have 0.0029125L / cu ft (ie 24 x as much displacement)
This is achieved with 2 x 12" subs with a VD of 2.33L each.
I think the reason for the extra displacement is most of us like more bottom end than a cinema. My last visit to a cinema I noticed the bass was loud in the midbass, but felt bass below 40 Hz was lacking. Others who were there were surprised at my comments on the lack of low bass, subjectively to them it was very loud. Most people don't miss the bottom octave.
So to answer the first question, if you want to know how loud 105db is, go to the cinema!
http://www.jblpro.com/pages/tech_lib.htm
Cinemas are designed for an average sound level of 85 db two thirds from the front, with peaks of 105db.
The JBL manual recommends an 18" vented pro sub driver with >97db sens and >400w power handling per 25,000 cu ft.
It's curious that most home theatre enthusiasts on this forum will probably use a lot more displacement per room volume than a comercial cinema.
Cinemas: 0.00012L of displacement (VD) / cu ft
In my setup I have 0.0029125L / cu ft (ie 24 x as much displacement)
This is achieved with 2 x 12" subs with a VD of 2.33L each.
I think the reason for the extra displacement is most of us like more bottom end than a cinema. My last visit to a cinema I noticed the bass was loud in the midbass, but felt bass below 40 Hz was lacking. Others who were there were surprised at my comments on the lack of low bass, subjectively to them it was very loud. Most people don't miss the bottom octave.
So to answer the first question, if you want to know how loud 105db is, go to the cinema!
Paul,
The kind of setup in the JBL paper is wholly inadequate. How old is it? One of the local theatres has their large room THX certified. The bass isn't great but at least it's there. In their VIP rooms, the ones with reclining chairs, waitresses, etc (a great setup), they really screwed up and went with sound along the lines of the JBL paper. I went twice only because the first time, I had a long talk with the manager after having to walk out early. I should have brought my SPL meter, because they were running the system at somewhere near 90db and the peaks were just killing my ears. Without any real sub, there was simply no impact in the action sequences. The second trip was the same, only blasting the volume trying to generate action impact. What a waste of an otherwise great theatre setup.
The kind of setup in the JBL paper is wholly inadequate. How old is it? One of the local theatres has their large room THX certified. The bass isn't great but at least it's there. In their VIP rooms, the ones with reclining chairs, waitresses, etc (a great setup), they really screwed up and went with sound along the lines of the JBL paper. I went twice only because the first time, I had a long talk with the manager after having to walk out early. I should have brought my SPL meter, because they were running the system at somewhere near 90db and the peaks were just killing my ears. Without any real sub, there was simply no impact in the action sequences. The second trip was the same, only blasting the volume trying to generate action impact. What a waste of an otherwise great theatre setup.
Re: re loudness
Hi all
I have to agree. I try to listen at around max 80dB average , to save what's left of my hearing( it's nice to have a SPL meter nearby, to check levels once in a while) .
Still, I think a good system should be able to reach say 120dB peaks in an effortless manner, in order to preserve the dynamics and scale of orchestral music and grand opera.
Most direct radiators I've heard sound strained and compressed at those levels. On the other hand a good multiway hornsystem can be made to sound wonderful on that kind of music.
Which just goes to show that the current "audiophile" way of small power-hungry speakers and enormous amplifiers are a dead end.
Just my humble opinion, of course
cheers
Hi all
rcw said:
I have to agree. I try to listen at around max 80dB average , to save what's left of my hearing( it's nice to have a SPL meter nearby, to check levels once in a while) .
Still, I think a good system should be able to reach say 120dB peaks in an effortless manner, in order to preserve the dynamics and scale of orchestral music and grand opera.
Most direct radiators I've heard sound strained and compressed at those levels. On the other hand a good multiway hornsystem can be made to sound wonderful on that kind of music.
paulspencer said:
Which just goes to show that the current "audiophile" way of small power-hungry speakers and enormous amplifiers are a dead end.
Just my humble opinion, of course
cheers
re speakers
In my experience any system that has made the best choice of the engineering compromises that you have to make, regardless of the particular loading methods used, will win.
All to often you find people becoming obsessed by trivia that dosen't matter as far as the sound goes, whilst neglecting things that do matter.
Every audio nut of course thinks that he is special and can hear things that most people can't, double blind testing shows that is not true and there is as much variation between different groups of listeners as there is within a group.
To me this says that you take care of what objective tests indicate matters most first, then you are most of the way there, all too often designs you see on the net take care of the trivia and forget this, and sound like it.
In my experience any system that has made the best choice of the engineering compromises that you have to make, regardless of the particular loading methods used, will win.
All to often you find people becoming obsessed by trivia that dosen't matter as far as the sound goes, whilst neglecting things that do matter.
Every audio nut of course thinks that he is special and can hear things that most people can't, double blind testing shows that is not true and there is as much variation between different groups of listeners as there is within a group.
To me this says that you take care of what objective tests indicate matters most first, then you are most of the way there, all too often designs you see on the net take care of the trivia and forget this, and sound like it.
Of course it will win, as long as you compare a large multiway horn system to a small direct-radiator system.
If you compare a large multiway horn system to a large multiway direct radiator system the outcome won't be as clear anymore.
Just some experiences of mine:
I owned a three-way horn system for years that was consisting of a corner-horn (Klipschorn copy) and mid- and high-frequency horns. Xover between bass and mid-high was active and passive between mid and high. Being driven by a 300 Watts amp in the woofer section and 100 Watts in the mid/high I think it dind't lack in dynamics in almost anyone's terms. The setup was FUN and effortless to listen to. I assume that a direct radiator system of the same physical dimensions, using today's driver technology, would definitely beat it sound-wise.
One of the intermediate systems was using a 12" JBL woofer (bass-reflex) and a large JBL biradial horn. This was also fun and effortless to listen to and I even do listen to it every now and then, since I still own it.
The sytem I now mainly listen to is one of the smallest I have ever built. It is consisting of a Manger driver and a custom-built 8" woofer in a closed box. It is the most accurate of the three systems mentioned and I wouldn't want to go back except for the urge every now and then to crank the volume with some rock music. But I wouldn't want those back for listening to orchestral recordings, these ones handles the Manger system definitely better, even though it manages only about 110 dB peak.
The first REAL LIVE BASS (I.e. not only loud but going LOW as well !) I heard was from a DIRECT radiator P.A. system BTW.
Most P.A. systems nowadays are direct-radiators, at least in the low- and low-midrange. They offer much better sound than 70ies P.A. systems that used 40ies horn designs throughout.
Of course there is some divergence between the good SOUND of today's P.A. systems and the quality of today's CONCERTs but that isn't because of a technical reason.
Regards
Charles
RCW,
Once again you are referring to "Objective Tests". Did it ever dawn on you that in reality these tests weren't objective after all ? I'd bet that these tests where performed by someone trying to prove that "everything is the same as long as distortion is below a certain threshold" so in reality the result wasn't nearly as objective as you have been lead to believe.
First, audio is a very subjective thing just like music. Some people like some things and not others. It's all really a matter of how our brain interprets different things.
Ear and brain training makes a huge difference in whether differences can actually be heard and the general public doesn't really have a clue because their ears are so untrained to listen for the differences that you are trying to test for. It's not much different than taking a group of colorblind people and giving them a color test.
Lastly, were the people in these "objective blind tests" actually blindfolded? If there is visual stimulation in any form, it will significantly affect the audio perception and make the testing less valid.
I'm a Realist and have always had the tendency toward being objective, however, when it comes to audio, I've heard plenty of differences that the Objectivists, like yourself, tell me can't be there. Now I know for a fact that it's not some psychoacoustic effect, because I had to prove that to myself. Yet you guys continue to spout of the "results of objective tests prove....." and I say "those tests weren't nearly as objective as you think because some of the results are invalid". All they did was support the expected outcome of those performing the tests and that is very easy to do.
Let's get a group of blind people, who we test first to make sure they don't have hearing problems. Then let's give their ears some extra training with stereo signals to get their ears accustomed to sharp vs diffuse audio images and the different things that affect perception of width and depth in this counterfeit sound, along with training of sweeps of the audio spectrum so they have a better feel for what frequencies fall where. Then we'll play the live instruments for them, so they get a feel for what their real sound is. Now let's perform your "objective tests" and I'd be willing to bet that the results will be quite different than the crap you continue to spout about everything being the same, because it's not.
You seem to think you are some kind of scientist, yet you are like the scientists of their day who insisted the world was flat, so you go out and do a survey of the general public as your evidence that the world is flat. You seem intelligent enough to get past this mistake and learn to trust your ears more. You can hear the difference, so stop trying to explain that one is not there.
Once again you are referring to "Objective Tests". Did it ever dawn on you that in reality these tests weren't objective after all ? I'd bet that these tests where performed by someone trying to prove that "everything is the same as long as distortion is below a certain threshold" so in reality the result wasn't nearly as objective as you have been lead to believe.
First, audio is a very subjective thing just like music. Some people like some things and not others. It's all really a matter of how our brain interprets different things.
Ear and brain training makes a huge difference in whether differences can actually be heard and the general public doesn't really have a clue because their ears are so untrained to listen for the differences that you are trying to test for. It's not much different than taking a group of colorblind people and giving them a color test.
Lastly, were the people in these "objective blind tests" actually blindfolded? If there is visual stimulation in any form, it will significantly affect the audio perception and make the testing less valid.
I'm a Realist and have always had the tendency toward being objective, however, when it comes to audio, I've heard plenty of differences that the Objectivists, like yourself, tell me can't be there. Now I know for a fact that it's not some psychoacoustic effect, because I had to prove that to myself. Yet you guys continue to spout of the "results of objective tests prove....." and I say "those tests weren't nearly as objective as you think because some of the results are invalid". All they did was support the expected outcome of those performing the tests and that is very easy to do.
Let's get a group of blind people, who we test first to make sure they don't have hearing problems. Then let's give their ears some extra training with stereo signals to get their ears accustomed to sharp vs diffuse audio images and the different things that affect perception of width and depth in this counterfeit sound, along with training of sweeps of the audio spectrum so they have a better feel for what frequencies fall where. Then we'll play the live instruments for them, so they get a feel for what their real sound is. Now let's perform your "objective tests" and I'd be willing to bet that the results will be quite different than the crap you continue to spout about everything being the same, because it's not.
You seem to think you are some kind of scientist, yet you are like the scientists of their day who insisted the world was flat, so you go out and do a survey of the general public as your evidence that the world is flat. You seem intelligent enough to get past this mistake and learn to trust your ears more. You can hear the difference, so stop trying to explain that one is not there.
RCW,
Once again you are referring to "Objective Tests". Did it ever dawn on you that in reality these tests weren't objective after all ? I'd bet that these tests where performed by someone trying to prove that "everything is the same as long as distortion is below a certain threshold" so in reality the result wasn't nearly as objective as you have been lead to believe.
First, audio is a very subjective thing just like music. Some people like some things and not others. It's all really a matter of how our brain interprets different things.
Ear and brain training makes a huge difference in whether differences can actually be heard and the general public doesn't really have a clue because their ears are so untrained to listen for the differences that you are trying to test for. It's not much different than taking a group of colorblind people and giving them a color test.
Lastly, were the people in these "objective blind tests" actually blindfolded? If there is visual stimulation in any form, it will significantly affect the audio perception and make the testing less valid.
I'm a Realist and have always had the tendency toward being objective, however, when it comes to audio, I've heard plenty of differences that the Objectivists, like yourself, tell me can't be there. Now I know for a fact that it's not some psychoacoustic effect, because I had to prove that to myself. Yet you guys continue to spout of the "results of objective tests prove....." and I say "those tests weren't nearly as objective as you think because some of the results are invalid". All they did was support the expected outcome of those performing the tests and that is very easy to do.
Let's get a group of blind people, who we test first to make sure they don't have hearing problems. Then let's give their ears some extra training with stereo signals to get their ears accustomed to sharp vs diffuse audio images and the different things that affect perception of width and depth in this counterfeit sound, along with training of sweeps of the audio spectrum so they have a better feel for what frequencies fall where. Then we'll play the live instruments for them, so they get a feel for what their real sound is. Now let's perform your "objective tests" and I'd be willing to bet that the results will be quite different than the crap you continue to spout about everything being the same, because it's not.
You seem to think you are some kind of scientist, yet you are like the scientists of their day who insisted the world was flat, so you go out and do a survey of the general public as your evidence that the world is flat. You seem intelligent enough to get past this mistake and learn to trust your ears more. You can hear the difference, so stop trying to explain that one is not there by quoting "objective tests" that 1. You didn't perform and 2. Weren't objective at all.
Once again you are referring to "Objective Tests". Did it ever dawn on you that in reality these tests weren't objective after all ? I'd bet that these tests where performed by someone trying to prove that "everything is the same as long as distortion is below a certain threshold" so in reality the result wasn't nearly as objective as you have been lead to believe.
First, audio is a very subjective thing just like music. Some people like some things and not others. It's all really a matter of how our brain interprets different things.
Ear and brain training makes a huge difference in whether differences can actually be heard and the general public doesn't really have a clue because their ears are so untrained to listen for the differences that you are trying to test for. It's not much different than taking a group of colorblind people and giving them a color test.
Lastly, were the people in these "objective blind tests" actually blindfolded? If there is visual stimulation in any form, it will significantly affect the audio perception and make the testing less valid.
I'm a Realist and have always had the tendency toward being objective, however, when it comes to audio, I've heard plenty of differences that the Objectivists, like yourself, tell me can't be there. Now I know for a fact that it's not some psychoacoustic effect, because I had to prove that to myself. Yet you guys continue to spout of the "results of objective tests prove....." and I say "those tests weren't nearly as objective as you think because some of the results are invalid". All they did was support the expected outcome of those performing the tests and that is very easy to do.
Let's get a group of blind people, who we test first to make sure they don't have hearing problems. Then let's give their ears some extra training with stereo signals to get their ears accustomed to sharp vs diffuse audio images and the different things that affect perception of width and depth in this counterfeit sound, along with training of sweeps of the audio spectrum so they have a better feel for what frequencies fall where. Then we'll play the live instruments for them, so they get a feel for what their real sound is. Now let's perform your "objective tests" and I'd be willing to bet that the results will be quite different than the crap you continue to spout about everything being the same, because it's not.
You seem to think you are some kind of scientist, yet you are like the scientists of their day who insisted the world was flat, so you go out and do a survey of the general public as your evidence that the world is flat. You seem intelligent enough to get past this mistake and learn to trust your ears more. You can hear the difference, so stop trying to explain that one is not there by quoting "objective tests" that 1. You didn't perform and 2. Weren't objective at all.
Hi Charles
Good enough
We just have to agree to a different opinion, I think.
I have heard a lot of BIG systems, both direct radiator and horns,
some pretenders to the high-end throne and some not.
I'm sure you have similar experiences. Only big horns do it for me, I'm afraid
cheers
phase_accurate said:
Good enough
We just have to agree to a different opinion, I think.
I have heard a lot of BIG systems, both direct radiator and horns,
some pretenders to the high-end throne and some not.
I'm sure you have similar experiences. Only big horns do it for me, I'm afraid
cheers
re sound
The point is Johnin that science is not an individual activity.
We both know that we as individuals have a perception of what for want of a better word we can call reality, but if we agree that there is a world out there that it is like it is despite what our subjetive impression of it might be, and my experience is that the world is like that, then all that science does is ask the question, how can we find out what its like?
The very fact that we are able to do such things as record and reproduce music is based entirely upon the methods that have been developed to answer such questions.
The point is Johnin that science is not an individual activity.
We both know that we as individuals have a perception of what for want of a better word we can call reality, but if we agree that there is a world out there that it is like it is despite what our subjetive impression of it might be, and my experience is that the world is like that, then all that science does is ask the question, how can we find out what its like?
The very fact that we are able to do such things as record and reproduce music is based entirely upon the methods that have been developed to answer such questions.
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