Re: Infocomm???
That looks fantastic Mark – I’ve taken a guess at the rest of the specs; want some of those drivers J
That looks fantastic Mark – I’ve taken a guess at the rest of the specs; want some of those drivers J
Infocomm???
- Thread starter David Nickerson
- Start date
Re: Infocomm???
The late great Dave Wenger and I would do all testing outdoors. He had a great method for this that I still use to this day. It cost a ton of cash to make a room work as well.
his secret, and I am not sure it was, was in the quiet field outside his home and workshop in Stevens PA was to point the speaker straight up in the air. A long cable was strung across to hold the mic hanging down. No ground reflections.
The late great Dave Wenger and I would do all testing outdoors. He had a great method for this that I still use to this day. It cost a ton of cash to make a room work as well.
his secret, and I am not sure it was, was in the quiet field outside his home and workshop in Stevens PA was to point the speaker straight up in the air. A long cable was strung across to hold the mic hanging down. No ground reflections.
Re: Infocomm???
Thanks Ivan. That is what I was looking for. I agree with your 10 to 15 DB over the tops for pop as well. Maybe 2 212 per SBH20 would be better for those pesky pop stars. That way I'd get better transient and lower freq response and be a bit modular if only 2 are needed.
Thanks Ivan. That is what I was looking for. I agree with your 10 to 15 DB over the tops for pop as well. Maybe 2 212 per SBH20 would be better for those pesky pop stars. That way I'd get better transient and lower freq response and be a bit modular if only 2 are needed.
Re: Infocomm???
After all that stuff about people not actually specifying a correct -3dB point, you recommend the TH118. Its -3dB point is 40Hz with reference to its nominal efficiency 108 dB @2.83 volts or 105 dB @ 2 volts to match Mark’s plot, which BTW is 105 dB and -3dB at 32.
... also the nominal operating range of the TH118 is quoted as 35Hz - 250Hz - 4dB ... to me it looks more like +/- 10 dB !!!!!!!
However despite the awful impulse response of a tapped horn, I do like the way it sounds
http://www.danleysoundlabs.com/danley/wp-content/uploads/2012/04/TH-118-spec-sheet.jpg
After all that stuff about people not actually specifying a correct -3dB point, you recommend the TH118. Its -3dB point is 40Hz with reference to its nominal efficiency 108 dB @2.83 volts or 105 dB @ 2 volts to match Mark’s plot, which BTW is 105 dB and -3dB at 32.
... also the nominal operating range of the TH118 is quoted as 35Hz - 250Hz - 4dB ... to me it looks more like +/- 10 dB !!!!!!!
However despite the awful impulse response of a tapped horn, I do like the way it sounds
http://www.danleysoundlabs.com/danley/wp-content/uploads/2012/04/TH-118-spec-sheet.jpg
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Re: Infocomm???
I don't understand the remark about impulse response, Peter.
Respectfully
However despite the awful impulse response of a tapped horn, I do like the way it sounds
I don't understand the remark about impulse response, Peter.
Respectfully
Re: Infocomm???
Some time later the sound from that first movement of the cone makes its way around the horn and emerges (depending on the length of the horn) about 7ms latter but opposite in polarity.
Because we are dealing with a very low frequencies and a limited band width, in practice its not as huge of an issue as it appears from a quick look at the impulse response. i.e. only really compare / look at the spectrogram below about 100Hz. In comparison a real horn or reflex enclosure has a much better looking impulse response.
When you model it the impulse pulse looks like this - The top impulse response and spectrogram is a 21" reflex enclosure, the bottom is the same driver in a tapped horn
What happens with a tapped horn when you subject it to a step function is that the cone immediately starts more. Sound is produced from the back exposed driver.
Some time later the sound from that first movement of the cone makes its way around the horn and emerges (depending on the length of the horn) about 7ms latter but opposite in polarity.
Because we are dealing with a very low frequencies and a limited band width, in practice its not as huge of an issue as it appears from a quick look at the impulse response. i.e. only really compare / look at the spectrogram below about 100Hz. In comparison a real horn or reflex enclosure has a much better looking impulse response.
When you model it the impulse pulse looks like this - The top impulse response and spectrogram is a 21" reflex enclosure, the bottom is the same driver in a tapped horn
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Mark DeArman
Junior
Re: Infocomm???
Well, I know some people who put a lot of weight into impulse response analysis. I'm not sure I agree with its practicality for measuring loudspeakers. One big issue which I have seen trip people up, is measuring the box outside of its usable bandwidth, and then trying to visually analyze the impulse response. For a front loaded HP enclosure, typically the usable bandwidth where the box behaves as a LTI-minimum phase system, is quite large, say 10-500Hz. You then look at a more complicated system like a tapped horn, bandpass enclosure or something else on the same bandwidth, and try to visually inspect the impulse response? This makes no sense to me, and I've seen people make some pretty wild claims about boxes (having serious problems), when their entire measurement methodology is flawed.
There are other techniques of decomposing the impulse response into pieces vs. frequency which make this type of analysis much easier, but they are not really common in audio analysis yet. In fact, Peter in his DIY thread had posted a link to one of the first programs I have ever seen which starts to venture into this type of thing.
Anyway, I keep going way off topic here,
Mark
Well, I know some people who put a lot of weight into impulse response analysis. I'm not sure I agree with its practicality for measuring loudspeakers. One big issue which I have seen trip people up, is measuring the box outside of its usable bandwidth, and then trying to visually analyze the impulse response. For a front loaded HP enclosure, typically the usable bandwidth where the box behaves as a LTI-minimum phase system, is quite large, say 10-500Hz. You then look at a more complicated system like a tapped horn, bandpass enclosure or something else on the same bandwidth, and try to visually inspect the impulse response? This makes no sense to me, and I've seen people make some pretty wild claims about boxes (having serious problems), when their entire measurement methodology is flawed.
There are other techniques of decomposing the impulse response into pieces vs. frequency which make this type of analysis much easier, but they are not really common in audio analysis yet. In fact, Peter in his DIY thread had posted a link to one of the first programs I have ever seen which starts to venture into this type of thing.
Anyway, I keep going way off topic here,
Mark
Re: Infocomm???
Timo.
I was talking about live performances.
The mixing technician (producer) is making many, many decisions in the mix that makes the instruments or voices sound different than they would unamplified.
I think it's a good idea for most people in the audience to hear the same results of those decisions.
Timo.
I was talking about live performances.
The mixing technician (producer) is making many, many decisions in the mix that makes the instruments or voices sound different than they would unamplified.
I think it's a good idea for most people in the audience to hear the same results of those decisions.
Re: Infocomm???
Maybe I am not seeing what you are seeing, but the -4dB point IS 35Hz. As referenced to the nonimal sensitivity.
I have no idea where you are getting -10. The response is STATED as -4 and -10, NOT +/- anything. If you want to "read something else into it" then feel free to-that is why we provide measured freq responses and impedance curves-so the user can make up their own minds as to what the specs should be from from the data. MUCH better than a simple number that comes from "who knows where"
That is the ONLY way to do it (in my-and other respected people who measure for a living).
The -4dB point was chosen because it more realistically represents the actual freq response.
Remember that the scale is LOG not linear-so 35Hz is not in the middle between 30 and 40, but rather a good bit closer to 40.
The numbers ARE correct.
... also the nominal operating range of the TH118 is quoted as 35Hz - 250Hz - 4dB ... to me it looks more like +/- 10 dB !!!!!!!
However despite the awful impulse response of a tapped horn, I do like the way it sounds
http://www.danleysoundlabs.com/danley/wp-content/uploads/2012/04/TH-118-spec-sheet.jpg
Maybe I am not seeing what you are seeing, but the -4dB point IS 35Hz. As referenced to the nonimal sensitivity.
I have no idea where you are getting -10. The response is STATED as -4 and -10, NOT +/- anything. If you want to "read something else into it" then feel free to-that is why we provide measured freq responses and impedance curves-so the user can make up their own minds as to what the specs should be from from the data. MUCH better than a simple number that comes from "who knows where"
That is the ONLY way to do it (in my-and other respected people who measure for a living).
The -4dB point was chosen because it more realistically represents the actual freq response.
Remember that the scale is LOG not linear-so 35Hz is not in the middle between 30 and 40, but rather a good bit closer to 40.
The numbers ARE correct.
Re: Infocomm???
The problem is that many sound people have no idea what the REAL instrument is supposed to sound like-having listened to samples and such.
I was "classically trained" (my Dad was a Doctor of Music), I started playing clarinet when I was 5. I played clarinet-violin-piano-sax and my primary instrument was oboe, which I stated playing when I as 11.
Of course I "discovered" the electric guitar in HS, and well-here I am------------------
But I still have the appreciation of real music, instruments etc and try to translate that whenever I mix them.
Having a varied music upbringing (with many different styles) really has helped me in my career.
And another good example of why people need to LISTEN to the instrument-to get an idea of the way it is SUPPOSED to sound-so they can do their best to bring that sound to the audience.
The problem is that many sound people have no idea what the REAL instrument is supposed to sound like-having listened to samples and such.
I was "classically trained" (my Dad was a Doctor of Music), I started playing clarinet when I was 5. I played clarinet-violin-piano-sax and my primary instrument was oboe, which I stated playing when I as 11.
Of course I "discovered" the electric guitar in HS, and well-here I am------------------
But I still have the appreciation of real music, instruments etc and try to translate that whenever I mix them.
Having a varied music upbringing (with many different styles) really has helped me in my career.
Re: Infocomm???
Ooops - sorry Ivan I meant to write +/- 5 dB (10dB total) re: 108 its 3 dB down @ 40Hz, 4 dB down @35Hz plus 6 dB @138Hz.
To me if you are going to quote a frequency range 35 to 250Hz your specifications should say +/- 5 dB, if you want to use +/- 4 dB then it should be 35 to 120Hz in this case, and the SPL should be referenced to 2 volts given that its a 4 ohm driver ... like every one else, but I know you disagree on this last point.~~:smile:
Ooops - sorry Ivan I meant to write +/- 5 dB (10dB total) re: 108 its 3 dB down @ 40Hz, 4 dB down @35Hz plus 6 dB @138Hz.
To me if you are going to quote a frequency range 35 to 250Hz your specifications should say +/- 5 dB, if you want to use +/- 4 dB then it should be 35 to 120Hz in this case, and the SPL should be referenced to 2 volts given that its a 4 ohm driver ... like every one else, but I know you disagree on this last point.
~~:smile:Attachments
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Re: Infocomm???
I did not suggest the TH212-because it starts to roll off a bit higher than your "specification".
Re: Infocomm???
We never know where the low pass filter will be set is a particular situation, and the peaks can always be eqed down.
It is simpler just to state the -dB pints, THAT is what is important.
The reason we ONLY use 2.83V is that allows for easy comparison between boxes.
The problem with "switching voltages" is that what is the voltage REFERENCED TO?
Many refer to 2.83V=1 watt @ 8 ohms.
HOWEVER-You DO NOT APPLY WATTS to a loudspeaker-ONLY voltage. The watts are the resultant of the applied voltage and the impedance. Since the impedance varies at different freq, the "wattage" will also. So the term "watts" is COMPLETELY WRONG, and then if you are trying to adjust voltages to make the "Watts" work out, then that can result in errors as well.
In MANY cases the ACTUAL impedance is NOT the "nominal" impedance. ESPECIALLY when you start putting drivers on horns-as most of ours are. The ACTUAL impedance is often higher. So what voltage should be used them? The rated? the minmum-some sort of "average" (over what freq range?)?
To keep it simple-we use only 2.83V. And by supplying the freq and impedance curves the user can easily figure out what THEY fell the cabinet is capable of.
Of course we do not measure the subs with 2.83V-that is what they are referenced back to.
We use 28.3 and measure at a distance of 10M. 28.3V is a 20dB gain, and 10M is a 20dB loss-so they "equal".
As far as I am concerned, the IMPORTANT thing about specs is to give the user the information they need to figure out how a particular product will perform.
Many manufacturers rely on confusion and deception on what the numbers mean and where they come from.
At least we supply the measurement condition and the measured responses, so you can make whatever adjustments you need to see about the suitability for a particular usage.
Without this data-you can only "hope" that the product will perform as stated-many do not follow the "simple numbers"-EVEN when both are supplied.
The +/- spec on a sub does not really tell much in the terms of "usability"Ooops - sorry Ivan I meant to write +/- 5 dB (10dB total) re: 108 its 3 dB down @ 40Hz, 4 dB down @35Hz plus 6 dB @138Hz.
To me if you are going to quote a frequency range 35 to 250Hz your specifications should say +/- 5 dB, if you want to use +/- 4 dB then it should be 35 to 120Hz in this case, and the SPL should be referenced to 2 volts given that its a 4 ohm driver ... like every one else, but I know you disagree on this last point.
We never know where the low pass filter will be set is a particular situation, and the peaks can always be eqed down.
It is simpler just to state the -dB pints, THAT is what is important.
The reason we ONLY use 2.83V is that allows for easy comparison between boxes.
The problem with "switching voltages" is that what is the voltage REFERENCED TO?
Many refer to 2.83V=1 watt @ 8 ohms.
HOWEVER-You DO NOT APPLY WATTS to a loudspeaker-ONLY voltage. The watts are the resultant of the applied voltage and the impedance. Since the impedance varies at different freq, the "wattage" will also. So the term "watts" is COMPLETELY WRONG, and then if you are trying to adjust voltages to make the "Watts" work out, then that can result in errors as well.
In MANY cases the ACTUAL impedance is NOT the "nominal" impedance. ESPECIALLY when you start putting drivers on horns-as most of ours are. The ACTUAL impedance is often higher. So what voltage should be used them? The rated? the minmum-some sort of "average" (over what freq range?)?
To keep it simple-we use only 2.83V. And by supplying the freq and impedance curves the user can easily figure out what THEY fell the cabinet is capable of.
Of course we do not measure the subs with 2.83V-that is what they are referenced back to.
We use 28.3 and measure at a distance of 10M. 28.3V is a 20dB gain, and 10M is a 20dB loss-so they "equal".
As far as I am concerned, the IMPORTANT thing about specs is to give the user the information they need to figure out how a particular product will perform.
Many manufacturers rely on confusion and deception on what the numbers mean and where they come from.
At least we supply the measurement condition and the measured responses, so you can make whatever adjustments you need to see about the suitability for a particular usage.
Without this data-you can only "hope" that the product will perform as stated-many do not follow the "simple numbers"-EVEN when both are supplied.
Re: Infocomm???
On surprisingly many occations I have seen confusion and even delight on a musician's face, when I have left FOH and gone up on stage and just asked if I can listen for a while before I start "doing something"...
On surprisingly many occations I have seen confusion and even delight on a musician's face, when I have left FOH and gone up on stage and just asked if I can listen for a while before I start "doing something"...
Re: Infocomm???
+1 i do this all the time. i find that the good will generated often makes my final result sound that much better to the musician, regardless of what i do....
+1 i do this all the time. i find that the good will generated often makes my final result sound that much better to the musician, regardless of what i do....
Re: Infocomm???
Hello
I agree completely with both aspects, that were brought up
- one should listen to instruments without sound system to have an idea of how they sound naturally.
- everyone in audience should be able to hear the mix equally.
On first aspect - there have been plenty of occasions, where I was complimented for achieving natural sound - not "let´s show how this rig kicks..." - unfortunately not always, but the goal was to be reproducing natural sound.
Sometimes you have artist with peculiar sound - you go to stage, listen directly and ask if that is the sound he/she wants - you might get the answer : "Why - is there something wrong with it?" - "No - just to know how to reproduce it." OK - later in audience someone comes to me yelling "Do something, that guitar sounds like shit!" - "That´s how he wants it, I asked him." - "Oh - well - quite interesting actually" - sometimes the answer is "No, but I have no idea of how to make the right sound" - then we work that out together.
Acoustic instruments have their particular natural sound - then microfone selection and positioning becomes most important.
On second aspect - as we all know, real life dictates, that only small part of most audiences ever get the great sound - rest have whatever - this all being due to inferior acoustics, crappy house systems, unreasonable expectations of the organizers, too limited resourses etc. But if we strive to do the best we can with instruments given to us and manage to get the performers co-operate, then there might be success.
Then there is the social aspect of a party - as I wrote in "Tall skinny speakers"-thread ( where this all begun with Ivan ) - there is always great number of people who are there regardless of who is on stage, because their friends are there - they could not have less interest, stay in the background or far side, and generally do not give a d.. of how it sounds as long it is not too loud to prevent them discussing with each other.
Concerts are naturally other story - people com to listen, and usually things are better organized anyways.
Finally - YES - the more we learn, the better we understand how little we actually know.
Hello
I agree completely with both aspects, that were brought up
- one should listen to instruments without sound system to have an idea of how they sound naturally.
- everyone in audience should be able to hear the mix equally.
On first aspect - there have been plenty of occasions, where I was complimented for achieving natural sound - not "let´s show how this rig kicks..." - unfortunately not always, but the goal was to be reproducing natural sound.
Sometimes you have artist with peculiar sound - you go to stage, listen directly and ask if that is the sound he/she wants - you might get the answer : "Why - is there something wrong with it?" - "No - just to know how to reproduce it." OK - later in audience someone comes to me yelling "Do something, that guitar sounds like shit!" - "That´s how he wants it, I asked him." - "Oh - well - quite interesting actually" - sometimes the answer is "No, but I have no idea of how to make the right sound" - then we work that out together.
Acoustic instruments have their particular natural sound - then microfone selection and positioning becomes most important.
On second aspect - as we all know, real life dictates, that only small part of most audiences ever get the great sound - rest have whatever - this all being due to inferior acoustics, crappy house systems, unreasonable expectations of the organizers, too limited resourses etc. But if we strive to do the best we can with instruments given to us and manage to get the performers co-operate, then there might be success.
Then there is the social aspect of a party - as I wrote in "Tall skinny speakers"-thread ( where this all begun with Ivan ) - there is always great number of people who are there regardless of who is on stage, because their friends are there - they could not have less interest, stay in the background or far side, and generally do not give a d.. of how it sounds as long it is not too loud to prevent them discussing with each other.
Concerts are naturally other story - people com to listen, and usually things are better organized anyways.
Finally - YES - the more we learn, the better we understand how little we actually know.
Re: Infocomm???
It is NOT the number of people OR the size of the room, but INSTEAD, the INTENDED area of coverage.
Sometimes this is the whole room. Sometimes bars want the bar aread to be quieter so the bartenders can hear orders better and faster.
You should always ask "What am I here to do or accomplish".
It will sometimes be different than what you think or what you have done in other places.
Different shows have different needs. The better you understand the needs. the better the chance you have to do what the customer wants.
And THAT is another part of "sound system design".
It is NOT the number of people OR the size of the room, but INSTEAD, the INTENDED area of coverage.
Sometimes this is the whole room. Sometimes bars want the bar aread to be quieter so the bartenders can hear orders better and faster.
You should always ask "What am I here to do or accomplish".
It will sometimes be different than what you think or what you have done in other places.
Different shows have different needs. The better you understand the needs. the better the chance you have to do what the customer wants.
Re: Infocomm???
Ops - That was a typo - The TH212 is too large. I meant 2 TH112's.
Ops - That was a typo - The TH212 is too large. I meant 2 TH112's.
Re: Infocomm???
I'd talk with John Janowitz at Acoustic Elegance about this. He's been doing this for years.
http://aespeakers.com/
Best regards,
John
I'd talk with John Janowitz at Acoustic Elegance about this. He's been doing this for years.
http://aespeakers.com/
Best regards,
John
Re: Infocomm???
It would also make a great sounding home setup. Something you can't say for "professional" type products.
That would be a great sounding setup-deep, full, smooth etc.
It would also make a great sounding home setup. Something you can't say for "professional" type products.