Member
Joined 2003
Scott,
I noticed you intentionally limited your (very good) description of beaming to the horizontal axis. Reason for the restriction? Is there a different/better term for the vertical?
Paul
I noticed you intentionally limited your (very good) description of beaming to the horizontal axis. Reason for the restriction? Is there a different/better term for the vertical?
Paul
First off, thankyou for answer my questions and posting the plots.
I was thinking of starting off with an experimental system that I can use as a proving ground. Driver budget would be around £300 for the horns & fullranges. Bottom end I could use my existing low end enclosures that I currently have for the perceive.
I usually only build once a year and that's thanks to my wallet, driver choices and lovely British weather. Each time I do so though I like to improve and go further than the last. So perhaps next year if I like what I hear, I could base that project around these design principles and take it to a more serious level.
I also very much like the idea of OB from a construtors point of view.
I was wondering about that when looking at the plots you posted, by 'bending wave'. I assume you mean a whizzer or similar?
Just out of curiosity more than anything, what brand and model are the subs? I like the JBL, Eminence and Beyma stuff. PHL whilst not strictly pro also make some nice high eff. ones too.
I fully agree, for recordings to actually come to life and take on a sense of realism, I really think that you need to listen at those upper levels, with low distortion and good dynamics. Fortunately I am blessed or cursed? With a smaller listening room than most which means I don't have to quite push the system as hard as a larger room would require.
Bigger rooms always tend to sound better though, my mum works for a local charity and they have a large lounge with plenty of soft furnishings, at around the Christmas holidays we have a get together up there for all the family and I'll often take whatever set of speakers I use at that time for background music but I'll go up and listen for a couple of hours before everyone arrives because its such a good acoustic space.
Sorry but did you say Rel Quakes? You don't strike me as the type to suffer the likes of that stuff.
Now you see, that's the type of thing that would be a possibilty on next years project. I'd have to down scale certain components to fit in with room compromises. Not married - too young for that yet, so no worries there.
You should work for the 'Department for promotion of London' if there is such a thing.
I live up north between Sheffield and Nottingham in a place called Chesterfield. So unfortunately its a little far for a demo so to speak.
I was thinking of starting off with an experimental system that I can use as a proving ground. Driver budget would be around £300 for the horns & fullranges. Bottom end I could use my existing low end enclosures that I currently have for the perceive.
I usually only build once a year and that's thanks to my wallet, driver choices and lovely British weather. Each time I do so though I like to improve and go further than the last. So perhaps next year if I like what I hear, I could base that project around these design principles and take it to a more serious level.
I also very much like the idea of OB from a construtors point of view.
I was wondering about that when looking at the plots you posted, by 'bending wave'. I assume you mean a whizzer or similar?
Just out of curiosity more than anything, what brand and model are the subs? I like the JBL, Eminence and Beyma stuff. PHL whilst not strictly pro also make some nice high eff. ones too.
I fully agree, for recordings to actually come to life and take on a sense of realism, I really think that you need to listen at those upper levels, with low distortion and good dynamics. Fortunately I am blessed or cursed? With a smaller listening room than most which means I don't have to quite push the system as hard as a larger room would require.
Bigger rooms always tend to sound better though, my mum works for a local charity and they have a large lounge with plenty of soft furnishings, at around the Christmas holidays we have a get together up there for all the family and I'll often take whatever set of speakers I use at that time for background music but I'll go up and listen for a couple of hours before everyone arrives because its such a good acoustic space.
Sorry but did you say Rel Quakes? You don't strike me as the type to suffer the likes of that stuff.
Now you see, that's the type of thing that would be a possibilty on next years project. I'd have to down scale certain components to fit in with room compromises. Not married - too young for that yet, so no worries there.
You should work for the 'Department for promotion of London' if there is such a thing.
I live up north between Sheffield and Nottingham in a place called Chesterfield. So unfortunately its a little far for a demo so to speak.
Konnichiwa,
In that case goole the web for my "Afterburner" project and search here for "JASD", the cheap Horn from Radioshack, if still available, plus a pair of the Ciare Drivers will give you a good idea what that kind of system does and what not. Of course, the "OB" Version of the Supravox Fieldcoil Driver I use has +/-6mm linear excursion (conservatively calculated from voicecoil length minus top plate) and nearly as much cone surface as the Ciare, so much more displacement for one....
No Whizzer, above the pistonic range any driver operates in "breakup" mode. Make the driver "break up" early so that in fact the whole thing is a bending wave trnasducer (not unlike manger) and while you get a lot of very narrow dips, overall the response is smooth and dispersion wider than it should be....
Basically a philosophy diametrically opposed to the modern paradigm of "stiff cone, widest pistonic range" which is invariably topped off with terible ringing at some high but audible midrange frequency and which no amount of filtering kills.
Eminence made OEM Drivers, similar to Delta 12LF.
I'm first and foremost a pragmatist, for filling in only one octave they are not bad and we got to borrow them for public demos, they work, what can I say?
Nah, go straight for the 24" Drivers, why muck around with compromises? ;-)
I doubt I'd keep the job for long.
If against better judgement you find yourself in London, drop me a line. As these speakers are becoming VERY SLOWLY a commercial reality with the more basic driver complement (a first series has been laid in, sadly promoting Hyperion took the focus of that) you may soon find them on demo here and there, but note that they are very stringent compromise, they give a glimpse of what can be done, not more than that.
The "Modest Proposal" is now slated for a rather cuter woofer/midrange plus HF Unit and the LF section will hopefully allow me to prototype the LF directivity steering I have in mind. Not that I suspect we'll sell many of either speaker, but what the heck.
Sayonara
ShinOBIWAN said:
In that case goole the web for my "Afterburner" project and search here for "JASD", the cheap Horn from Radioshack, if still available, plus a pair of the Ciare Drivers will give you a good idea what that kind of system does and what not. Of course, the "OB" Version of the Supravox Fieldcoil Driver I use has +/-6mm linear excursion (conservatively calculated from voicecoil length minus top plate) and nearly as much cone surface as the Ciare, so much more displacement for one....
ShinOBIWAN said:
No Whizzer, above the pistonic range any driver operates in "breakup" mode. Make the driver "break up" early so that in fact the whole thing is a bending wave trnasducer (not unlike manger) and while you get a lot of very narrow dips, overall the response is smooth and dispersion wider than it should be....
Basically a philosophy diametrically opposed to the modern paradigm of "stiff cone, widest pistonic range" which is invariably topped off with terible ringing at some high but audible midrange frequency and which no amount of filtering kills.
ShinOBIWAN said:
Eminence made OEM Drivers, similar to Delta 12LF.
ShinOBIWAN said:
I'm first and foremost a pragmatist, for filling in only one octave they are not bad and we got to borrow them for public demos, they work, what can I say?
ShinOBIWAN said:
Nah, go straight for the 24" Drivers, why muck around with compromises? ;-)
ShinOBIWAN said:
I doubt I'd keep the job for long.
ShinOBIWAN said:
If against better judgement you find yourself in London, drop me a line. As these speakers are becoming VERY SLOWLY a commercial reality with the more basic driver complement (a first series has been laid in, sadly promoting Hyperion took the focus of that) you may soon find them on demo here and there, but note that they are very stringent compromise, they give a glimpse of what can be done, not more than that.
The "Modest Proposal" is now slated for a rather cuter woofer/midrange plus HF Unit and the LF section will hopefully allow me to prototype the LF directivity steering I have in mind. Not that I suspect we'll sell many of either speaker, but what the heck.
Sayonara
Konnichiwa,
After all this heated discussion and also to keep alive the tread just a little longer, here a list (arguably selected by me) that helps for some more serious study into room acoustics and acoustics in general.
First something I found yesterday googeling when I wanted the Formula for converting beamwidth into DI to be able to rate my own speakers for DI (FWIW, the DI is around 5db to 500Hz...1000Hz and then increases to as much as 16db for the narrow pattern HF horn I use at 20KHz).
It is the JBL Professional Sound System Design Manual Part 1 which does (IMHO) a really good job of explaining the various issues and problems in usiong sound systems in rooms. While aimed at Pro-Sound installation constructors it covers the issues very well in an "advanced popular science" manner and inclused many excellent illustrations as well as nomograms and for hardcore math fans the key math behind things.
If you want to really understand what happens in rooms, what acoustic treatment can do and what nor and so on, start here. I learned all this stuff ages ago, but forgot some and I found it a nice refresher in some areas. There is a part 2 and there some other interesting publications in the JBL Professional Technical Library .
Further items worth reading are:
Harman Audio (Revel, Infinity et al) - Loudspeakers and Rooms Working Together
Harman Audio (Revel, Infinity et al) - The Acoustical Design of Home Theater
Art Dudlestone of Legacy Audio had a few good "summary level" documents about audio in a domestic settings, but sadly they have gone. Quite solidly in breach of copyright but in the spirit of educational use and general eludication I have reposted these documents and a few others I find usefull in one of my Yahoo groups, including a number of slides from german sound engineer course materials which cover a lot of ground on acoustic and psycho/physioacoustic fundamentals, which really help to understand what goes on.
This is not an attempt to get more members for my groups or promote them or Yahoo groups, it simply where I parked some of that stuff. The group is here:
http://groups.yahoo.com/group/Thunderstone_technical
You do need to subscribe to Yahoo in order to view the files available and please make sure to opt out from all the spam. Then log onto Yahoo Groups and select the Group, then Files and then Acoustical Foundation Classes.
The requirement to sign up for Yahoo Groups is enforced by Yahoo, not by me. I'd prefer to have the Files readily available.
Sayonara
After all this heated discussion and also to keep alive the tread just a little longer, here a list (arguably selected by me) that helps for some more serious study into room acoustics and acoustics in general.
First something I found yesterday googeling when I wanted the Formula for converting beamwidth into DI to be able to rate my own speakers for DI (FWIW, the DI is around 5db to 500Hz...1000Hz and then increases to as much as 16db for the narrow pattern HF horn I use at 20KHz).
It is the JBL Professional Sound System Design Manual Part 1 which does (IMHO) a really good job of explaining the various issues and problems in usiong sound systems in rooms. While aimed at Pro-Sound installation constructors it covers the issues very well in an "advanced popular science" manner and inclused many excellent illustrations as well as nomograms and for hardcore math fans the key math behind things.
If you want to really understand what happens in rooms, what acoustic treatment can do and what nor and so on, start here. I learned all this stuff ages ago, but forgot some and I found it a nice refresher in some areas. There is a part 2 and there some other interesting publications in the JBL Professional Technical Library .
Further items worth reading are:
Harman Audio (Revel, Infinity et al) - Loudspeakers and Rooms Working Together
Harman Audio (Revel, Infinity et al) - The Acoustical Design of Home Theater
Art Dudlestone of Legacy Audio had a few good "summary level" documents about audio in a domestic settings, but sadly they have gone. Quite solidly in breach of copyright but in the spirit of educational use and general eludication I have reposted these documents and a few others I find usefull in one of my Yahoo groups, including a number of slides from german sound engineer course materials which cover a lot of ground on acoustic and psycho/physioacoustic fundamentals, which really help to understand what goes on.
This is not an attempt to get more members for my groups or promote them or Yahoo groups, it simply where I parked some of that stuff. The group is here:
http://groups.yahoo.com/group/Thunderstone_technical
You do need to subscribe to Yahoo in order to view the files available and please make sure to opt out from all the spam. Then log onto Yahoo Groups and select the Group, then Files and then Acoustical Foundation Classes.
The requirement to sign up for Yahoo Groups is enforced by Yahoo, not by me. I'd prefer to have the Files readily available.
Sayonara
Paul W said:
Yes. (..and thank you.)
People occasionally use this term for vertical attenuated dispersion, and it is functionally the same as traditional beaming, but in the vertical axis. The thing is though that most people are not bothered by what would be considered "normal" vertical beaming, (at least what would be normal for horizontal dispersion leading to the term beaming), whereas they are bothered by it (for very good reasons) in the horizontal axis. What you will typically find then is the term beaming (in the vertical plane) used to describe massive vertical attenation - virtually always with reference to a linesource (like a ribbon or a planar) that is more than 3 inches in length. So although beaming is essentially the same vertically or horizontally, people generally don't mean precisely the same thing.
Another reason I didn't include it is that the response for why it may or may not be desireable is also a bit different (and would likely lead to confusion).
As for a better term (at least for those massivly vertically attenated drivers), I'll "guess" with: "limited high freq. vertical dispersion".
directivity?
Anyone have any more thoughts on this?
I had a long conversation with someone the other day about directivity. He (thoroughly qualified) said directivity, narrow directivity at that, was a must above the schroeder (sp?) frequency in a room.
He said you need a significant delay between direct sound and the first reflections. Period. No arguments.
I, like I think most people, had always heard drivers should have as wide dispersion as possible. Of course, I trust the bulk of the audio industry as far as I can throw it.
He uses waveguides, but the first thing I thought of was to use a wide range, large diameter ( > 8 inches) driver from the top down, for the sake of simplicity when building. That would allow you to cross as low as you want to LF drivers (I'm currently looking at 15 inch units for bass). I believe Thorsten suggested that at the beginning of this thread. Anyone else have any experience with that?
I once cobbled (?) together a system with two high quality, 8 inch pro audio drivers. I knew absolutely nothing about speaker design at the time, so I had to EQ them within an inch of their lives to get them to work, but once I did there was a level of detail that was almost disturbing. The drivers couldn't manage too much on the top end, so they were rolled off a bit, but there was an ease to their presentation that I haven't been able to pull off in any other (properly designed) system since.
I had always thought it was the fact that it was a full range driver, sans crossover, but recent experiments with small (3 inch) wide range drivers don't quite get there.
After the conversation I had, I've been wondering if it was the directivity of the 8 inch drivers that made imaging so precise. Is that possible?
Does anyone know how directive an 8 inch driver is? Is there simple math to estimate it or is it something that would have to be modeled for an individual driver?
Is it possible to get a spell checker on this board? Typos drive me nuts but I don't have time to edit these.
Peace
Anyone have any more thoughts on this?
I had a long conversation with someone the other day about directivity. He (thoroughly qualified) said directivity, narrow directivity at that, was a must above the schroeder (sp?) frequency in a room.
He said you need a significant delay between direct sound and the first reflections. Period. No arguments.
I, like I think most people, had always heard drivers should have as wide dispersion as possible. Of course, I trust the bulk of the audio industry as far as I can throw it.
He uses waveguides, but the first thing I thought of was to use a wide range, large diameter ( > 8 inches) driver from the top down, for the sake of simplicity when building. That would allow you to cross as low as you want to LF drivers (I'm currently looking at 15 inch units for bass). I believe Thorsten suggested that at the beginning of this thread. Anyone else have any experience with that?
I once cobbled (?) together a system with two high quality, 8 inch pro audio drivers. I knew absolutely nothing about speaker design at the time, so I had to EQ them within an inch of their lives to get them to work, but once I did there was a level of detail that was almost disturbing. The drivers couldn't manage too much on the top end, so they were rolled off a bit, but there was an ease to their presentation that I haven't been able to pull off in any other (properly designed) system since.
I had always thought it was the fact that it was a full range driver, sans crossover, but recent experiments with small (3 inch) wide range drivers don't quite get there.
After the conversation I had, I've been wondering if it was the directivity of the 8 inch drivers that made imaging so precise. Is that possible?
Does anyone know how directive an 8 inch driver is? Is there simple math to estimate it or is it something that would have to be modeled for an individual driver?
Is it possible to get a spell checker on this board? Typos drive me nuts but I don't have time to edit these.
Peace
Depends what you mean by narrow!
I think it is fairly well established that sudden changes in directivity should be avoided, that they should be smooth and gradual. This is a good reason to use a waveguide on a tweeter to restrict its directivity to match the mid at the xo point and get a good transition. Say you cross a 12" driver to a 1" dome tweeter @ 2k. The dome will have wide dispersion but the 12" will be very narrow at 33 degrees. This won't be good, and there will also be off axis lobing due to driver spacing.
With a 1.1k xo point the 12" will now have 60 degrees dispersion, and putting the tweeter in a WG with matching angle of radiation would be better, although crossing this low probably requires a CD.
If you used an 8" driver then for 60 degrees coverage a 1.6k xo point would be ok and a dome in a WG could handle that. I think you could get a good result with some efficient mids in an MTM with a WG loaded tweeter like the Vifa XT (non ring) tweeter which is 93.5 db sensitive.
This is the Haas effect. With sufficient delay between direct and reflected sound, the brain can interpret the delayed sound as ambience, and it does not confuse imaging. Early delays can't be distinguished and so the image becomes less clear. I don't recall how much delay is considered necessary for this to occur, but I believe this is fairly well established.
I recall Linkwitz discussing this.
I have tended to think the opposite, that sound should be focused where you want it. It seems there are two approaches that work well:
1. wide dispersion (typical hifi) and considerable room treatment
2. narrower and controlled polar response and dispersion in a more live room
1 sprays the room then tries to absorb and diffuse
2 concentrates the sound where it is needed but also seeks to control the character of off axis sound reflected around the room
I believe a more live room is desirable if you have 2
I have also heard a comparison of a JBL home theatre speaker based on horn loaded CD tweeter and a 15" midbass and the B&W Nautilus as representing the two approaches. I have heard it described that wide dispersion puts the musicians in the room but narrow directivity gives a window on the performance. I'm still trying to figure out exactly what that means!
I have been asking myself the last few days about exactly how polar response, directivity and other factors determine imaging.
OB speakers are interesting in this regard. They supposedly have a well behaved polar response, even in the bass. A cone driver has a wider dispersion in an OB. They radiate less to the side. To the rear they radiate more, but in a controlled way. If correctly placed, the first reflections from the front and rear walls are cancelled. This works if the distance the panels are out from the front wall matches that of the listener to the wall behind. It's shown here:
What does this mean? Early side wall and ceiling reflections are reduce firstly due to dipole cancellation. Early floor reflections can be absorbed with a rug. The more prominent early front and rear wall reflections are cancelled. This means the reverberant sound field will damage imaging less in a dipole speaker, and cause less coloration.
Larger drivers and waveguides and horns will improve polar response and increase directivity, reducing the reflected sound and the coloration caused by it. My current take, however, is that dipoles do a better job at dealing with these issues.
dipoles and wgs
Hi Paul,
Thanks for the detailed response.
How do you know / can you calculate the off axis pattern of a given (cone) driver and the frequency of interest? It's my understanding that any given size cone will narrow as you go up in frequency, and that the narrowing is fairly linear. Is there a rule of thumb for estimating that?
You seem to know, so isn't it just a matter of comparing the off axis patter of driver X in IB and OB configs? My only thoughts on it are that I've read the driver's basket creates a complex low pass that's pretty much impossible to model and will cause irregularities in the cancellation / off axis pattern.
You would also have to factor in the arrival times of the rear wave in order to figure out of it's delayed enough for the brain to be able to distinguish it as ambience. In my conversation the question was brought up whether or not the space behind a dipole and the rear wall in a 'typical' room setup was enough for the brain to consider it ambience. The answer then was no, or probably not. I'm not in a position to say.
I agree that dipoles seem ideal for this - directivity is controlled over most or all of the frequency range, they are not impossible to build (bass horns?) and there are other benefits (no box resonances, etc). But just because they're attractive doesn't mean other ends shouldn't be explored - I'm talking to myself here.
Whenever I play around with a driver, I'm always happiest with it OB.
I have noticed that dipoles sound 'diffuse' in addition to their other traits. I would imagine this is the amount of reflections or the strength of the reverberant field caused by the rear wave - which must be higher than monopoles as you go up in frequency - and certainly higher than horns. They sound very good in general (natural, detailed, etc) but I wonder if too much is being added to the sound, even if it's pleasant.
Unfortuntately, I haven't heard a good domestic horn setup, so it's hard to know what I'm missing.
Another question that's come up: It's widely accepted that horns have colorations. Can a cone driver suffer from this as well? Or is a cone more a WG? Are WGs typically free from this type of distortion - possibly because they're not used as gain devices? I'm guessing here.
Hi Paul,
Thanks for the detailed response.
How do you know / can you calculate the off axis pattern of a given (cone) driver and the frequency of interest? It's my understanding that any given size cone will narrow as you go up in frequency, and that the narrowing is fairly linear. Is there a rule of thumb for estimating that?
You seem to know, so isn't it just a matter of comparing the off axis patter of driver X in IB and OB configs? My only thoughts on it are that I've read the driver's basket creates a complex low pass that's pretty much impossible to model and will cause irregularities in the cancellation / off axis pattern.
You would also have to factor in the arrival times of the rear wave in order to figure out of it's delayed enough for the brain to be able to distinguish it as ambience. In my conversation the question was brought up whether or not the space behind a dipole and the rear wall in a 'typical' room setup was enough for the brain to consider it ambience. The answer then was no, or probably not. I'm not in a position to say.
I agree that dipoles seem ideal for this - directivity is controlled over most or all of the frequency range, they are not impossible to build (bass horns?) and there are other benefits (no box resonances, etc). But just because they're attractive doesn't mean other ends shouldn't be explored - I'm talking to myself here.
Whenever I play around with a driver, I'm always happiest with it OB.
I have noticed that dipoles sound 'diffuse' in addition to their other traits. I would imagine this is the amount of reflections or the strength of the reverberant field caused by the rear wave - which must be higher than monopoles as you go up in frequency - and certainly higher than horns. They sound very good in general (natural, detailed, etc) but I wonder if too much is being added to the sound, even if it's pleasant.
Unfortuntately, I haven't heard a good domestic horn setup, so it's hard to know what I'm missing.
Another question that's come up: It's widely accepted that horns have colorations. Can a cone driver suffer from this as well? Or is a cone more a WG? Are WGs typically free from this type of distortion - possibly because they're not used as gain devices? I'm guessing here.
I think it was earlier in this thread that someone gave a rule of thumb for driver radiation angle. I used that rule of thumb formula to create a spreadsheet in Excel. How it was worked out I don't know. Obviously a particular radiation angle would be a point where the SPL drops a given amount relative to the on axis response.
Keep in mind with the OB that if set up correctly (according to the diagram) the first reflection off front and rear wall will cancel. Only a dipole can do this. Thus a dipole should in fact be better than all other speakers in this regard, when it comes to reflections confusing imaging. Whatever you can do with other speakers to improve imaging, you can probably do it with OB as well. At least, this is my current understanding on the matter.
Some of us want to get the best sound we can for the least cost/effort/time. Others want to try everything and care more about experimentation than result. I'd say most of us are in the middle. Building and trying things out is half the fun.
A waveguide is a short horn which is designed more for optimising radiation angle than for efficiency. I think in some cases horn and waveguide might be interchangeable terms. I understand that a problem with HF horns is that they have reflections and resonances which colour the sound. I have heard of one speaker designed for home theatre, the Summa, which has a waveguide with foam inside. The idea is that coloration is reduced as it absorbs the reflections more than the sound which propagates in a more direct path. It is claimed to have hifi transparency with pro sound SPL.
I'd like to hear some accurate and efficient speakers, especially horns ...
Keep in mind with the OB that if set up correctly (according to the diagram) the first reflection off front and rear wall will cancel. Only a dipole can do this. Thus a dipole should in fact be better than all other speakers in this regard, when it comes to reflections confusing imaging. Whatever you can do with other speakers to improve imaging, you can probably do it with OB as well. At least, this is my current understanding on the matter.
Some of us want to get the best sound we can for the least cost/effort/time. Others want to try everything and care more about experimentation than result. I'd say most of us are in the middle. Building and trying things out is half the fun.
A waveguide is a short horn which is designed more for optimising radiation angle than for efficiency. I think in some cases horn and waveguide might be interchangeable terms. I understand that a problem with HF horns is that they have reflections and resonances which colour the sound. I have heard of one speaker designed for home theatre, the Summa, which has a waveguide with foam inside. The idea is that coloration is reduced as it absorbs the reflections more than the sound which propagates in a more direct path. It is claimed to have hifi transparency with pro sound SPL.
I'd like to hear some accurate and efficient speakers, especially horns ...
hello paul, what do you think of the summa loudspeaker ?
you will find a LOT of information on waveguides on the site of the designer of this loudspeaker : http://www.gedlee.com
you will find a LOT of information on waveguides on the site of the designer of this loudspeaker : http://www.gedlee.com
A good friend of mine, career recording engineer, said he heard the Summa and it's incredible. He said the horn technology + CD isn't a subtle thing, he said it's night and day.
Re: Re: What exactly is beaming and why does it matter?
Some of the best sounding commercial speakers I'd heard in years are the Revel Salons, they have an additional rear firing tweeter. I would be surprised if you disliked those speakers if you listened to them in a blind test.
I listened to a "Holographic Recording" of various different places/events on a pair of small speakers tha are omni up to about 1 Khz and it was as if we were transported to the venues, the experience was remarkable, if you closed your eyes it was really like being there, simply amazing. I've never fully experienced that effect listening to "conventional" speakers.
OMAI WA MO SHIN DE ERU!
Oh, I don't mean to say room reflections are never a significant problem ~ floor bounce cancellations are the most bothersome ones to my ears.
It seems that your ideal system would require the listener to have their head in a clamp to hold it precisely in the very narrowsweet spot, because if you moved a few inches to either side you would loose imaging and the frequency response would be off?Kuei Yang Wang said:
Some of the best sounding commercial speakers I'd heard in years are the Revel Salons, they have an additional rear firing tweeter. I would be surprised if you disliked those speakers if you listened to them in a blind test.
I listened to a "Holographic Recording" of various different places/events on a pair of small speakers tha are omni up to about 1 Khz and it was as if we were transported to the venues, the experience was remarkable, if you closed your eyes it was really like being there, simply amazing. I've never fully experienced that effect listening to "conventional" speakers.
OMAI WA MO SHIN DE ERU!
Oh, I don't mean to say room reflections are never a significant problem ~ floor bounce cancellations are the most bothersome ones to my ears.
NIHONGO GA SUKI DESU
Was the salon in a treated room? You mean head in a vice - like Wilsons? =)
Was the salon in a treated room? You mean head in a vice - like Wilsons? =)
Will anybody be so kind to give me a "Directivity Index" definition? All says about DI, nobody defines it 🙂
Konnichiwa,
Typing Directivity Index definition into google yields as hit #3:
http://www.jbl.com/home/technology/glossary.aspx?language=ENG&country=USA®ion=act=glossary&term=D
From there:
"A numerical representation of the sound dispersion characteristics of a loudspeaker, expressed in dB.
It is the difference between the measured on-axis frequency response and the sound power.
0 dB describes an omnidirectional loudspeaker, radiating sound equally in all directions.
Increasing numbers describe an increasing bias for sound radiated in the forward direction."
Sayonara
anli said:
Typing Directivity Index definition into google yields as hit #3:
http://www.jbl.com/home/technology/glossary.aspx?language=ENG&country=USA®ion=act=glossary&term=D
From there:
"A numerical representation of the sound dispersion characteristics of a loudspeaker, expressed in dB.
It is the difference between the measured on-axis frequency response and the sound power.
0 dB describes an omnidirectional loudspeaker, radiating sound equally in all directions.
Increasing numbers describe an increasing bias for sound radiated in the forward direction."
Sayonara
Re: Re: Re: What exactly is beaming and why does it matter?
Konnichiwa,
Clearly you do not think things through before posting. What you describe requires omnidirectional speakers.
Correctly implemented and used directivity will make sure that the image remains stable and centered as the Level difference compensates time difference (look at any basic text on sound perception), if you arrange the speakers such that the speaker to wich you move closer places you further off axis. This implies the main acoustic axis's crossing in front of the listener.
And note, CONTROLLED DIRECTIVITY implies a flat off axis reponse as well as a flat on axis response, BUT CRUCIALLY, one that becomes progressively attenuated as you move further off axis.
Sayonara
Konnichiwa,
critofur said:
Clearly you do not think things through before posting. What you describe requires omnidirectional speakers.
Correctly implemented and used directivity will make sure that the image remains stable and centered as the Level difference compensates time difference (look at any basic text on sound perception), if you arrange the speakers such that the speaker to wich you move closer places you further off axis. This implies the main acoustic axis's crossing in front of the listener.
And note, CONTROLLED DIRECTIVITY implies a flat off axis reponse as well as a flat on axis response, BUT CRUCIALLY, one that becomes progressively attenuated as you move further off axis.
Sayonara
- Status
- Not open for further replies.