Yes, a single driver would suffer from one strong reflection off of the floor and one off of the ceiling. For an array of drivers, every driver has a unique position and that makes it act different, the effect of the reflection of each driver is very small. Let's see it in a graph:
The orange line is the combined result (direct sound and floor+ceiling reflections) at the listening spot of a single driver vs an array. The restlessness of the output above 5KHz is due to the lobing of an array with this particular center to center spacing. We can see that lobing in a vertical directivity graph:
(I have limited this graph to about 45 degree to show where the ceiling would be approximately. You see the energy that is directed towards the floor and ceiling. The lobes are caused by the center to center spacing. Using smaller drivers, packed closer together would raise the frequency where that lobing starts.)
Attachments
Many thanks for answers already.
The room is not ideal, that's clear and there is more, although it may (?) help.
The left front corner is really a wall pillar 270 by 230mm, the right corner is a real corner but just 495 away is a window, and then the fire place sticks out, so listening height first reflections will be window and fireplace influenced, the little bit of wall (495) will have little opportunity to first reflect, a scale drawing is attached.
Wesayso asked about computer aptitude, clearly i don't do CAD...........
The listening positions at 1 and 2 are not perfect, but seem like they may have a reasonable chance, 3-5 are less important.
At the moment I continue to like the idea of identical FR drivers, no crossover and the tall vertical line, absence of floor and ceiling effects and tolerant listening height
The room is not ideal, that's clear and there is more, although it may (?) help.
The left front corner is really a wall pillar 270 by 230mm, the right corner is a real corner but just 495 away is a window, and then the fire place sticks out, so listening height first reflections will be window and fireplace influenced, the little bit of wall (495) will have little opportunity to first reflect, a scale drawing is attached.
Wesayso asked about computer aptitude, clearly i don't do CAD...........
The listening positions at 1 and 2 are not perfect, but seem like they may have a reasonable chance, 3-5 are less important.
At the moment I continue to like the idea of identical FR drivers, no crossover and the tall vertical line, absence of floor and ceiling effects and tolerant listening height
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Tight quarters. I can understand why you are doing line arrays.
I've done the corner line array thing, or I started out in that direction but ended up using my arrays out from the walls in a large garage. But I analyzed the heck out of the corner position and tested them there. One conclusion is that the corner walls need to be padded to avoid a reflection null at the frequency corresponding to the distance to the side wall from the array baffle. The further you pull them out from the walls, the lower that frequency and the thicker the padding needed to absorb it. The open doorways aren't a problem, except for lack of bass support. Fill the remaining wall space with fiberglass panels, or equiv, and you are golden. Morphy had a nice construction in which you could butt an absorber panel up against each sidewall and take care of that problem (which existed but he didn't acknowledge.)
You should design your in-corner arrays to aim at seat 2. That results an asymmetrical shape. Their beamwidth will be wide enough for 1 and 3. In seats 4&5 there won't be much high treble and in fact combing might be audible in seat 5 due to proximity to the left array. Don't let a critic sit there
Make the arrays as close to floor to ceiling as you can. You aren't limited to 24 or 25 drivers; 32 and 36 are numbers that work. With 32 8-ohm, connect drivers in 8 parallel sets of 4 drivers in series for a net Z of 4 ohms...
I've done the corner line array thing, or I started out in that direction but ended up using my arrays out from the walls in a large garage. But I analyzed the heck out of the corner position and tested them there. One conclusion is that the corner walls need to be padded to avoid a reflection null at the frequency corresponding to the distance to the side wall from the array baffle. The further you pull them out from the walls, the lower that frequency and the thicker the padding needed to absorb it. The open doorways aren't a problem, except for lack of bass support. Fill the remaining wall space with fiberglass panels, or equiv, and you are golden. Morphy had a nice construction in which you could butt an absorber panel up against each sidewall and take care of that problem (which existed but he didn't acknowledge.)
You should design your in-corner arrays to aim at seat 2. That results an asymmetrical shape. Their beamwidth will be wide enough for 1 and 3. In seats 4&5 there won't be much high treble and in fact combing might be audible in seat 5 due to proximity to the left array. Don't let a critic sit there
Make the arrays as close to floor to ceiling as you can. You aren't limited to 24 or 25 drivers; 32 and 36 are numbers that work. With 32 8-ohm, connect drivers in 8 parallel sets of 4 drivers in series for a net Z of 4 ohms...
Thanks for joining nc535,
Height, 28 x83.7 =2343.6, if they really butt together, room is 2400, just 56 mm left, half each end, is that a benefit over the 25 or does that take the top end of the line into some reflecting mess behind the cross beam?
Do i understand that the null is a first reflection null at the listening positions? If they are tight into the corners of the walls at say 15cms (centre of driver?) that's going to be around 2300Hz? there isn't much wall space there........and i forgot to mention the radiator under the window........! what would absorb that sort of frequency, fairly thin panels? the corner position is all about aesthetics so i cannot go too far with panels etc..........
Aim, just aim the baffle at the head of seat 2?
Height, 28 x83.7 =2343.6, if they really butt together, room is 2400, just 56 mm left, half each end, is that a benefit over the 25 or does that take the top end of the line into some reflecting mess behind the cross beam?
Do i understand that the null is a first reflection null at the listening positions? If they are tight into the corners of the walls at say 15cms (centre of driver?) that's going to be around 2300Hz? there isn't much wall space there........and i forgot to mention the radiator under the window........! what would absorb that sort of frequency, fairly thin panels? the corner position is all about aesthetics so i cannot go too far with panels etc..........
Aim, just aim the baffle at the head of seat 2?
Its a boundary freflection null, sometimes called boundary interference and it is a result of a (first) reflection from sound wrapping around the side of the cabinet and to the side or front wall and then out to the LP/mic. The frequency depends on the path length difference which is roughly half the width of the baffle plus the length along the cabinet side wall. Null occurs where this is half a wavelength (as you know) and could end up being circa 2300 Hz. that is a good thing that it is that high as an inch or two of absorber will likely make it vanish. Make the cabinet deeper or wider than it needs to be and all of a sudden, you are wondering if you can get enough absorber in there.
Somewhere in Wesayso's thread, he talks about how he chased down all the big early reflections and treated them. As he says, any long vertical edge that sticks out is going to show up in the frequency response.
To approximate an infinitely long array and thus get a response that is independent of elevation, we depend on multiple floor and ceiling reflections and reflections of reflections, as expounded in the Murphy paper. I don't know what your Xbeam situation is, I probably skimmed past that part of your post. I can only hope that at LF, where each driver has wide vertical dispersion, the Xbeam doesn't matter because its thickness is a small fraction of a wavelength and at HF where its dimensions are significant, the driver is beaming so not much energy hits it. Undoubtedly, there will be a range where it causes ripples. If you do have a number of crossbeams breaking up the ceiling, it would make sense to keep the top of the array somewhat below them. Its been shown that if the array reaches at least 75% of the way to the ceiling, it will work fairly well. More than75% is better, unless you have crossbeams to contend with.
To speak somewhat precisely, a normal to the baffle at the head's elevation should pass through the center listener's head. All I'm saying is angle the baffle to center the listening window on the primary chair(s). It didn't look like 45 degrees would do that
Somewhere in Wesayso's thread, he talks about how he chased down all the big early reflections and treated them. As he says, any long vertical edge that sticks out is going to show up in the frequency response.
To approximate an infinitely long array and thus get a response that is independent of elevation, we depend on multiple floor and ceiling reflections and reflections of reflections, as expounded in the Murphy paper. I don't know what your Xbeam situation is, I probably skimmed past that part of your post. I can only hope that at LF, where each driver has wide vertical dispersion, the Xbeam doesn't matter because its thickness is a small fraction of a wavelength and at HF where its dimensions are significant, the driver is beaming so not much energy hits it. Undoubtedly, there will be a range where it causes ripples. If you do have a number of crossbeams breaking up the ceiling, it would make sense to keep the top of the array somewhat below them. Its been shown that if the array reaches at least 75% of the way to the ceiling, it will work fairly well. More than75% is better, unless you have crossbeams to contend with.
To speak somewhat precisely, a normal to the baffle at the head's elevation should pass through the center listener's head. All I'm saying is angle the baffle to center the listening window on the primary chair(s). It didn't look like 45 degrees would do that
I took a picture on the line from seat 2 to the problem corner, it shows the small amount of wall available, or causing problems and the window, radiator and fireplace. my current thought for this is to have learnt it may be a problem but assume it can be resolved and continue to address other matters.
M
M
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Firstly, I wont express thanks to each reply, so hope my enormous appreciation to all of you goes without saying!
Thoughts and answers to date…….suggestions in italics, followed by answers
As mayhem13 said, arrays with the TC9 driver have a pretty wide horizontal dispersion.
If I were in your shoes, I wouldn't completely cram the speakers in the corners. I'd build them free-standing and get an absorbing panel on that right side beside the array.
But I understand that further away from the wall lowers the wavelength to worry about the reflection and I would like them to be as insignificant visually as possible, I shall draw up some cabinet sections to trial.
Free standing speakers have the advantage that you can play with toe in (believe me it's worth it) and have a little play with distances to walls.
I understand this, free standing in the corner could be practical?
Look for 2 about liters per driver for the TC9 if you want to extend it (pretty) low)
Each enclosure sealed? If so, the vertical centres can be at 83.7mm which is the front plate depth according to the drawing I found, so the height is that minus a material thickness, say 15mm? – leaves 68.7mm internal height, which for 2000cc’s requires a plan area of 291 square cms, say a 25 cm triangle in the corner or more probably a pentagon shape with the baffle angled to suit the direction of aim. More thoughts to follow here…..
Further, you'll have to find a way, suitable to your wishes, to apply EQ.
Currently thinking mini DSP like, apart from anything else it has to be family user friendly. All ideas welcome!
As far as shading goes, you don't need shading for starters (most satisfied users don't use any shading, to my knowledge).
I did read about intensity and divergence shading and as I don’t currently understand shading……I shall believe that for now I can do without!
There's always options if you end up wanting something different, like sticking a tweeter in the center.
One appeal is to have no crossover.
You'll get an idea of how much EQ is needed to run these arrays. It isn't a huge problem if the array does not extend all the way to the ceiling. Vituixcad can visualize that for you.
I don’t expect me to grasp this area!
A tall array is a must if you like seated and standing enjoyment. Personally, I'd never build a small array, taller ones work so much better.
So, as reported elsewhere, 25 units butted will leaves 300mm “unoccupoied”, 28 units leaves 56mm……..25 seems fine with most of the gap at the top
Maybe a panel that is easy on the eyes that absorbs most higher frequencies.
But to have a shot at good sound, that right side really does need some help.
White room, white panels like these in my “office” /listening room, where I play with my Radial arm experiments. These are 300mm wide and would fill a gap between the speaker cabinet and the window recess if the cabinet was 195mm which all seems around feasible.
Thoughts and answers to date…….suggestions in italics, followed by answers
As mayhem13 said, arrays with the TC9 driver have a pretty wide horizontal dispersion.
If I were in your shoes, I wouldn't completely cram the speakers in the corners. I'd build them free-standing and get an absorbing panel on that right side beside the array.
But I understand that further away from the wall lowers the wavelength to worry about the reflection and I would like them to be as insignificant visually as possible, I shall draw up some cabinet sections to trial.
Free standing speakers have the advantage that you can play with toe in (believe me it's worth it) and have a little play with distances to walls.
I understand this, free standing in the corner could be practical?
Look for 2 about liters per driver for the TC9 if you want to extend it (pretty) low)
Each enclosure sealed? If so, the vertical centres can be at 83.7mm which is the front plate depth according to the drawing I found, so the height is that minus a material thickness, say 15mm? – leaves 68.7mm internal height, which for 2000cc’s requires a plan area of 291 square cms, say a 25 cm triangle in the corner or more probably a pentagon shape with the baffle angled to suit the direction of aim. More thoughts to follow here…..
Further, you'll have to find a way, suitable to your wishes, to apply EQ.
Currently thinking mini DSP like, apart from anything else it has to be family user friendly. All ideas welcome!
As far as shading goes, you don't need shading for starters (most satisfied users don't use any shading, to my knowledge).
I did read about intensity and divergence shading and as I don’t currently understand shading……I shall believe that for now I can do without!
There's always options if you end up wanting something different, like sticking a tweeter in the center.
One appeal is to have no crossover.
You'll get an idea of how much EQ is needed to run these arrays. It isn't a huge problem if the array does not extend all the way to the ceiling. Vituixcad can visualize that for you.
I don’t expect me to grasp this area!
A tall array is a must if you like seated and standing enjoyment. Personally, I'd never build a small array, taller ones work so much better.
So, as reported elsewhere, 25 units butted will leaves 300mm “unoccupoied”, 28 units leaves 56mm……..25 seems fine with most of the gap at the top
Maybe a panel that is easy on the eyes that absorbs most higher frequencies.
But to have a shot at good sound, that right side really does need some help.
White room, white panels like these in my “office” /listening room, where I play with my Radial arm experiments. These are 300mm wide and would fill a gap between the speaker cabinet and the window recess if the cabinet was 195mm which all seems around feasible.
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My advise for aiming the arrays (when the position is fixed) would be slightly different from @nc535 as I would aim the left speaker at the left ear position of seat 1, the right speaker at the right ear position of seat 3. It will provide some intensity trading to create a broad listening area.
You could create a round shaped speaker (with a flat baffle for ease) and place it in the corner. That way you can play with aiming while having a shape that provides less diffraction off of the speaker itself. That round shape taken to the extreme gets you something like this: https://www.stereonet.com/uk/news/ruel-r-modular-line-source-loudspeakers
I'd opt to use something that's round already (for instance a huge cardboard shape covered with fiberglass+epoxy) and fabricating a flat baffle for it.
See here: https://www.vandermill-audio.nl/smooth-curves-to-avoid-diffraction/ how the shape of the speaker itself is of influence for smooth off axis output.
Should the cabinet front width be as small as possible to take the driver, like i think i see in Koldby and Wesayso? - or can it have space either side. if its free standing i can imagine a hexagon section would be similar to those but made of flat pieces..........
M
Or as you suggest a round something that aim can change, could possibly be laminated wood.
out of interest i took a pic of a 2 litre section sat on the proac in the corner........it can also be round with a baffle flat - for changing aim, plastic pipe?
M
Or as you suggest a round something that aim can change, could possibly be laminated wood.
out of interest i took a pic of a 2 litre section sat on the proac in the corner........it can also be round with a baffle flat - for changing aim, plastic pipe?
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So for me as a pragmatist, I’ve stopped asking the could I question first…….the should I always wins in the end anyways….
I feel the same about arrays in a home environment…..I just can’t see a use case scenario for them in most typical home settings…..yours included and even more so now that you’ve given us some drawings to look at.
Working in the industry for many many years as a live sound/mix/recording engineer, I’ve come to some conclusions based on thousands of observations…….the bass/midbass foundation which has the most profound interactions with the room is the rock of which any stereo room installation should be built upon…..without exception. Many designs and DIY designers look at it as an afterthought……and instead end up with ‘I’ll add a sub’ or something like that. But in essence, that bass/midbass impact zone is just as important if not more so than the MT section.
Line arrays are a LOT of work to build too…..just ask Wesayso or look through his massive thread…….cabinet build…..all those holes…..all that wire and wiring…….I get cramps just thinking about it. And that’s NOT to say the effort was not well rewarded…..clearly it was after years of prototyping, building, tweaking, tuning via DSP and room treatment and sub addition…….jeez….now i‘m itching and scratching too………but I know when to stop scratching and let the itch subside.
While I share your enthusiasm and creative drive, I can say this for sure…….placing a case full of small drivers in two long towers is not going to end well without an exponential amount of effort to make it work…..and having those towers fixed to a ‘desired’ yet visually appealing location with the need to ‘tune’ the room around it?…….that goes against every DIY principle I can imagine. Build to suit your space instead…..that’s where DIY shines brighter than any commercial speaker offering……that’s the call of duty so to speak.
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Aimability is a good thing. You won't be sure of where to aim until you have something to listen to, which is a catch-22 re' a simple triangular or murphy style cabinet. A flat front, round back would work. It would be easy to build if you came up with a safe way to slice a plastic pipe. I would also suggest keeping the volume per driver small, say for a Qtc=1 instead of optimizing for maximum bass extension. You can make up the difference on the low end with EQ, extra amp power, and subwoofers.
Line arrays can be a lot of work but they won't be as labor intensive as Wesayso's
if you get the baffles CNCed. It took less than a day to wire mine up.
I am not at all in agreement with this. A line array is not more difficult to build than a conventional enclosure. You can make it in a more or less difficult way , but thar holds true for any type of enclosure. My first, based on Roger Russels IDS 25 article, was very easy
and , because of their shape, easy to resonans control. Remember this is a speaker system that can reach 20 Hz.... And no crossover ... Where it is a bit demanding is in the roomcorrection/eq departement, but constrution wise it is perhaps the most easy wide bandwith enclosure I have made. The arrays I have now was even easier, as they are only a square alu tuning with 25 holes... Then comes some resonans control but if you chose to fasten the drivers with screws, then that's it
fasten eac
Thanks for all those responses folks, and i like to have both the agreeing and disagreeing ones, it helps me understand the reasoning.
I can put one thing out the equation, i don't mind the work, as long as i am comfortable with the techniques and i see nothing to put me off in that department.
But i am not seeking over employment, so whatever i make i will find some simple enough routes, 100% for sure i will not put in the amazing work that Wesayso has done (admiration!) that's why i am tapping all your knowledge and experience first.
A few years ago i made some quite substantial double skinned and veneered boxes for my 3 ways so the labour intensiveness isn't a problem, although 50 times the same thing could well be boring!
More important is to achieve a result i am happy with in that room, i could move my 3 way system in there but i would not like the space taken up that way, and i am sure my wife would not!
Hence arrays in the corner do appeal, as they will take up pretty much zero useful space.
I see from others measurements that with good EQ, it can go down to 20-30Hz ok, and i don't listen very loud.
From what i have read i look forward to hearing a full range, no crossover loudspeaker as well.
So a sub doesn't appeal and knowing the bass of my 3 ways is tapering in the 30's and 20's but sounds deep to me, i feel that suitable EQ should give me a suitable result in the bass.
So, i cannot/will not(!) put conventional speakers out in the room, (full range open baffle would appeal if i would) i already have a soundbar and sub that works to an adequate level of performance, i would like to do better, i enjoy making things, particularly working things. By the way, i am of an age when i wont do loads more big projects.
Clearly i could do this, and i value the discussion of whether i should enormously.
I feel i am learning and getting some good answers already.
But what might i do instead i wonder within the limitations?
I can put one thing out the equation, i don't mind the work, as long as i am comfortable with the techniques and i see nothing to put me off in that department.
But i am not seeking over employment, so whatever i make i will find some simple enough routes, 100% for sure i will not put in the amazing work that Wesayso has done (admiration!) that's why i am tapping all your knowledge and experience first.
A few years ago i made some quite substantial double skinned and veneered boxes for my 3 ways so the labour intensiveness isn't a problem, although 50 times the same thing could well be boring!
More important is to achieve a result i am happy with in that room, i could move my 3 way system in there but i would not like the space taken up that way, and i am sure my wife would not!
Hence arrays in the corner do appeal, as they will take up pretty much zero useful space.
I see from others measurements that with good EQ, it can go down to 20-30Hz ok, and i don't listen very loud.
From what i have read i look forward to hearing a full range, no crossover loudspeaker as well.
So a sub doesn't appeal and knowing the bass of my 3 ways is tapering in the 30's and 20's but sounds deep to me, i feel that suitable EQ should give me a suitable result in the bass.
So, i cannot/will not(!) put conventional speakers out in the room, (full range open baffle would appeal if i would) i already have a soundbar and sub that works to an adequate level of performance, i would like to do better, i enjoy making things, particularly working things. By the way, i am of an age when i wont do loads more big projects.
Clearly i could do this, and i value the discussion of whether i should enormously.
I feel i am learning and getting some good answers already.
But what might i do instead i wonder within the limitations?
It’s important to distinguish between bass response and in room response……..you could show me in room measurements of 20hz response at 95db all day long, and it still won’t present anything like a 12-15” long excursion woofer through the bass and midbass region……..as the saying goes these days…..they are not the same.
That being said, most important….have fun and enjoy the project! For me, this isn’t a max performance value venture so I don’t have anything else to offer. Best of luck!
That being said, most important….have fun and enjoy the project! For me, this isn’t a max performance value venture so I don’t have anything else to offer. Best of luck!
For me, a DIY effort always has to start with some clear goals in mind……..designing and creating a solution where a commercial solution does not exist. I haven’t approached DIY as a cost saving measure for a very long time as I’ve found when we’re talking about reasonable folk, where we exclude the audiophoolery…….DIY rarely wins if one values their own effort and time.
That being said, if you’d be so kind as to establish your goals individually with a little explanation of each I’m 100% convinced there’s a better solution than a floor to ceiling full range driver array.
That being said, if you’d be so kind as to establish your goals individually with a little explanation of each I’m 100% convinced there’s a better solution than a floor to ceiling full range driver array.
Some goals and ambitions, itemised and explained, in addition to those in post #1.
To undertake a project that I find interesting and satisfying and that I can use and be pleased with long term, this is a motivating interest for me and mentally stimulating as well. So building a kit or exact replica has less interest for me than developing or evolving something. However I need to develop confidence that the results will be satisfactory, it's not blue sky development for the sake of it, hence I started this thread.
To produce a sound reproduction result for our living room that family and visitors can enjoy, whereas my other projects, arms, turntables, amplifiers, speakers are limited, largely by size, to my office/den, and aren’t in regular use by the family.
To achieve sound that seems a bit magical, consequently better than I hear regularly, makes me smile and attracts me to listen. I have never heard what people describe as magical totally life like reproduction, and I don’t realistically expect it is possible (for me), particularly with the space limitations I have, but would like to get closer. Everything is a compromise, and I would like to choose a good one. i want to turn it on and be caused to smile! - encouraged to listen some more, pull out the old records and listen again! - which i do with my other system.
I don’t expect to repeat this project, so wish to start on a good path, with evolution opportunities built in if necessary.
To build something good at a cost I consider reasonable, for which purpose I am different to Mayhem, in that, as I don’t now charge anyone else for my time, being retired, and I have it freely available, the only real cost is materials or bought in services, so, I hope I can build for a few £K cost of material, something that I wouldn’t otherwise consider worth or justify spending the money on. So, if a commercial equivalent were available, then these would need to have a market value several times the material cost at least.
To suit our room, which is a living room with an entertainment system in it, not a separate music room, the speakers cannot dominate the room. If the ProAcs in the first picture were of adequate performance they would meet this requirement but to perform at their best they need to come out into the room and that’s not what I want. When music isn't playing, 4-6 people might sit in their chatting.
For example, the sound bar and its sub is unobtrusive enough but doesn’t produce any real stereo image etc.
Consequently the corners placement seems ideal, but to avoid predetermination, I give an example that a wall panel could also be fine, inevitably I don’t know of anything else or I would perhaps have started there.
To achieve a reasonably tolerant image/soundstage impression, currently we have none, my 3 way in the office is quite position critical, vertically and horizontally. I understand the arrays should be almost non critical vertically which is a good start and horizontally the suggestion is I should get three good seats and some impression elsewhere, that would be fine for me.
For the sound to seem realistic across the frequency range, I would have been interested in both OB and other types, but all these seem to not work in the corners.
A full range without crossover appeals because of convincing things I have read.
Whilst bass is important for all this, I don’t watch, for example, sci fi with effects, so the rumbling of sound effects is less important than a good bass drum.
What else can I add, I don’t know, apart from I started the thread having read widely about speaker projects including the arrays and developments and concluded that was a suitable start point for me.
To undertake a project that I find interesting and satisfying and that I can use and be pleased with long term, this is a motivating interest for me and mentally stimulating as well. So building a kit or exact replica has less interest for me than developing or evolving something. However I need to develop confidence that the results will be satisfactory, it's not blue sky development for the sake of it, hence I started this thread.
To produce a sound reproduction result for our living room that family and visitors can enjoy, whereas my other projects, arms, turntables, amplifiers, speakers are limited, largely by size, to my office/den, and aren’t in regular use by the family.
To achieve sound that seems a bit magical, consequently better than I hear regularly, makes me smile and attracts me to listen. I have never heard what people describe as magical totally life like reproduction, and I don’t realistically expect it is possible (for me), particularly with the space limitations I have, but would like to get closer. Everything is a compromise, and I would like to choose a good one. i want to turn it on and be caused to smile! - encouraged to listen some more, pull out the old records and listen again! - which i do with my other system.
I don’t expect to repeat this project, so wish to start on a good path, with evolution opportunities built in if necessary.
To build something good at a cost I consider reasonable, for which purpose I am different to Mayhem, in that, as I don’t now charge anyone else for my time, being retired, and I have it freely available, the only real cost is materials or bought in services, so, I hope I can build for a few £K cost of material, something that I wouldn’t otherwise consider worth or justify spending the money on. So, if a commercial equivalent were available, then these would need to have a market value several times the material cost at least.
To suit our room, which is a living room with an entertainment system in it, not a separate music room, the speakers cannot dominate the room. If the ProAcs in the first picture were of adequate performance they would meet this requirement but to perform at their best they need to come out into the room and that’s not what I want. When music isn't playing, 4-6 people might sit in their chatting.
For example, the sound bar and its sub is unobtrusive enough but doesn’t produce any real stereo image etc.
Consequently the corners placement seems ideal, but to avoid predetermination, I give an example that a wall panel could also be fine, inevitably I don’t know of anything else or I would perhaps have started there.
To achieve a reasonably tolerant image/soundstage impression, currently we have none, my 3 way in the office is quite position critical, vertically and horizontally. I understand the arrays should be almost non critical vertically which is a good start and horizontally the suggestion is I should get three good seats and some impression elsewhere, that would be fine for me.
For the sound to seem realistic across the frequency range, I would have been interested in both OB and other types, but all these seem to not work in the corners.
A full range without crossover appeals because of convincing things I have read.
Whilst bass is important for all this, I don’t watch, for example, sci fi with effects, so the rumbling of sound effects is less important than a good bass drum.
What else can I add, I don’t know, apart from I started the thread having read widely about speaker projects including the arrays and developments and concluded that was a suitable start point for me.
The above is exactly what started my journey. I never expected to save money by going the DIY route, I had different goals in mind.
What I wanted is something that could work with my room, give me an advantage to obtaining (my definition of) good sound. Basically every normal 2 or 3 way did not come to mind, only a few concepts could fill the requirements I had set. Those being a coincidental source (coax), a MEH, which quite frankly does the same thing as the coax, or use an array.
Those three concepts are the only ones that I could see to work well with the room. At least my relatively tiny room where all of the space savings is important. It is there that the array had the most benefits. As a concept, it can, for all practical purposes, avoid floor and ceiling reflections and it has the smallest footprint. The horizontal pattern is that of the driver chosen, which in my case would mean a 3.5" driver if I were to expect any low end from it and make it a true full range solution. Absorbing panels do the rest, helped out by FIR filtering and other DSP tricks.
So why those other two concepts? I think the MEH might very well be the best of them (if you have the space, they can get large if pattern control matters to you). But I would like to start with a different (more optimized) shape than the usual conical builds. Both the MEH and the Coax each have pretty much the same dispersion horizontally as wel as vertically (*). This often gets brushed off, but to me this is the most important part of these concepts.
The more I play within my room, where I pretty much avoid the floor and ceiling reflections and absorb the strong early reflections, from the start of the tone out till about 20 ms, the more I'm convinced how important the part of smooth directivity is. With my ambience speakers I pretty much dial in my own space, and its baffling the differences that can get me. How very little tweaks can have a large influence on perception.
The teachings of Toole may preach that vertical dispersion is of less importance than horizontal dispersion, but I don't quite believe it's that simple. Not for what I wanted to achieve anyway. I wanted a clear shot at hearing a clean, mostly undisturbed first wave front before the room messes with it. Seemingly impossible, but with a bit of work we can get close. Even in a regular living room, if we have the option of some tweaks to the room to make it possible.
But that's my personal journey, I went all out in an effort to try and achieve it. However I can imagine not everyone having the same goals. My goal of that undisturbed first wave front, followed by the room response, much like a Haas kicker, came from looking at Studio setups. (where Haas kickers fell out of grace, because they tend to make every song sound a bit more pleasing) Most regular rooms place you on the other end of Stereo perceptions, depending on the room size one has. If you have plenty of space, things are quite different compared to a more, let's call it European sized, modest room. In a large room, you get to pull the speakers out in the room and still have space left to place the listening seat away from boundaries. The amount of speakers available to sound nice in such a room is quite a bit bigger than the ones that can do the same in a small room.
So when cramped for space, you need to pick your poison. Do you choose a speaker that, with a little help, avoids the early stuff to get you closer to that first wave front? Or do you choose a wider dispersion and let that dispersion render the spaciousness. That last option requires way less investment in room treatment etc. And, judging from ASR and Toole's findings, is pretty popular by a large audience. That's the Toole school of thought. One that I personally don't follow in detail. My findings line up way more with the works from David Griesinger, who spend most of his career trying to figure out how to manipulate the perception of sound.
If one is looking for an all round solution with good sound, I'm pretty sure you can stick to that second way of thought. Be sure to pick speakers with smooth directivity. For instance, look at what Kef did with the Blade. A smaller similar solution following the same guide lines could work too if SPL requirements are reasonable. I'm pretty sure that this could work and bring the joy of listening to the entire family. Not to say that I don't have that, but my efforts were based upon a whole different goal. I'm pretty sure that's not for everyone.
So what one wants to achieve within the room should be the most important guide to determine what speaker would actually have a shot of achieving that. For me, Arrays ticked most of the boxes. I got what I wanted. I wanted to "be transported into the recording", be it a true recording or one created in the Studio. I wanted the song to create the environment. I got what I wanted, by avoiding/absorbing those early reflections and introducing late lateral ones (like a Haas kicker) to take it's place. There's nothing wrong with enjoyment of the other ways, having the room create the spaciousness. It's just not what I was after.
Figure out what you want and build the speakers to get you there. The above is my view, my opinion, no need to agree with me
.(*) = not saying their patterns are alike, just saying that they each are symmetrical in pattern, on the horizontal and vertical axis. The horn shape or waveguide or even speaker shape (think Kef Blade or even my arrays) determine their pattern control.
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What I love the most about the line arrays is that anywhere I go, the sound is there. Stand up, sit down, side to side, other side of the room. I want play for the other side of the house and when I walk back to the listening room it doesn't murder my ears as I walk closer like my horns do.
I have been experimenting with line line arrays in a much different way than everyone else. I believe that good imaging is all about speaker placement. With that I've finally gotten myself to try moving them into the room. The location that worked best for imaging for me was 1/3rd of the way into the room. It's very extreme and easily 8 ft from the front wall. Wesayso's shading idea would probably be ideal with this positioning. It probably wouldn't need to be this extreme if I had effective room treatment. That's one of my future goals. My current project is to build a pair of woofer towers and row behind the couch with 16 x JBL 2226 drivers to better support the bass with the line arrays, especially with them that far into to room. I also plan to incorporate 2 JBL 2" throat horns with the line arrays to almost act like the hf shading that Wesayso is doing. I'm using a MiniDSP with Dirac and with basically set all of these speaker systems flat and them merge them all together in a very gradyal way, whether it be shallow crossover slopes or let that combined with Dirac reducing the sum of the speakers to flat.
I highly endorse the TC9 drivers.