The making of: The Two Towers (a 25 driver Full Range line array)

But the "seemingly" infinite array has other advantages. You get the -3 dB per doubling distance over a very wide frequency range. Meaning it actually has line array behaviour over that wide area. I'm sure we'll see something about that soon on a different thread.

As mentioned above, that data is up right now:
http://www.diyaudio.com/forums/multi-way/284371-corner-floor-ceiling-line-array-using-vifa-tc9-13.html#post4584879

(Keep in mind this is all raw line array response, no EQ is used)

I'm grateful to ra7 to show this data, which I knew to be true. It's always good to see it in clear data though to prove it. My room won't let me prove it in this clear cut way. I'd run out of space and stumble over the furniture. :p
 
Thanks for the plug, Wesayso!

I didn't know you were looking for a job. From our interactions, I can see that you are very detail-oriented, super analytical, like to solve problems and like to get to the root of things. You also enjoy teaching and guiding others, like you are guiding me with DRC. Have you tried finding a job in research? Or teaching perhaps? With your skills and dedication, I am sure you will find something soon. Good luck!
 
I've asked a friend of mine to do a review of my speakers. He's an avid music lover and in his spare time he's a musician and records and mixes his own music. He's used to hearing passages over and over again to make the right choices in his own mixing process. From our talks about music I know him to be at least as passionate about a musical experience as I am. Regularly going to live performances of his favourite Artists.
I've had more people come over and listen. But I wanted to get an honest review from someone that would be critical. For that you need to be passionate about it. I think I found the right person for the job and I promised to publish his piece as is. (whether I would like it or not :eek:)

Jan Fekkes said:
Hi Ronald. Here is my report :)


I will make apologies in advance for my English but I give it my best shot!

----He explained it all to me. The whole building process of his now grownup 7 ft twins. It is impressive, the way they gaze at me with each holding a long row of little speakers. I do not understand and comprehend everything Ronald told me about his project in a very enthusiastic way but I feel a lot of respect and admiration. Blood sweat and tears were shed to accomplish what is standing in front of me. “This is it, they produce sound and I think I did a good job” Well,….. a good job is a big understatement…because I have listened and they certainly produce sound. To call it just sound is way too simple to describe what is entering your ears. Tone colors is a better way to put it. Any color you like is there. Anyway, I was asked to give my honest and frank opinion about his tall and rank self-built stereo speaker set.

So, how do I do that? I asked myself. I don’t want it to become a lyrical piece of prose so people will doubt my honesty…..but I am lyrical. And that is because I am a critical listener, picking up details and can feel music to the bone. But anyway…at this my findings, while having a coffee on the ‘hotspot’ at Ronalds place.


Opeth, Windowpane from the album Damnation. I immediately feel like I’m on very right spot in the concert hall. The ultimate place to be, everybody is always looking for, I am experiencing now. Every instrument is clearly in place and it is very extraordinary, I can almost feel the space in between. It is a wide sound with room for everything that is going on. There is prominent clarity but the bass and deeper tones are perfectly present without domination. Hearing and feeling them in a very pleasant way as if sound and air cooperate to make it just right. This is how it should be. Like putting on 3D glasses. The musical landscape gets an extra dimension. It is warm and deep and I can’t help it so say….”Holy macaroni” (which is an old Dutch saying meaning: ….I’m flabbergasted) This is some hearing experience!!


Something completely different. He puts on the Sugababes. Hole in the head. It is not music I prefer but that is not the reason why I am sitting on the hotspot. So babes, let’s go J. I’m surprised that my ears tell me something different from my prejudgment. The extra dimension these speakers offer makes it very nice to listen to. While listening I made an image of a rectangle on my piece of paper. This rectangle is where this dominant kind of pumping song has its body. This was meant to be I guess…for the crowd….in your face…. But don’t get me wrong…everything is still on place and has its own distinctive position with clarity and warmth. And then there is out of the box… there is this nice tingling Ping-Pong panning effect which makes you happy… No other way to put it. It is hard to explain what makes these speakers so special but I think it has to do with a very nice wide stereo image without losing the natural reproduction. A sort of…the real thing!


David Bowie, Ashes to Ashes. I will confine myself to the striking details now. That I am very enthusiastic about the speakers needs no further explanation. I now notice how many tracks have been used for vocals in this song. There is a upper stream and a undertow with vocals and bizarre effects. These speakers apparently do have the distinctive character to reveal these details.


Blackfield – Blackfield. The clarity of the rhythm guitar is striking. Not that I couldn’t hear it on my own speaker set but over here, on the hotspot it comes more forward.


Blackfield – Hello. In a way a little shocking to find out about the honesty of these speakers. The high frequencies that are floating above it all in this song are too dominant in my opinion, it is really hurting a bit. Too bad….but a honest message. Didn’t notice this before, at least not as strong as now, not in a way it disturbed me like now.

Overall….

Like I said, I’m a devoted listener but not a technician. Don’t know about charts and measurements and why it should have this or that value. I know what I hear and I know it sounds great. Like I mentioned, I’m a critical listener but….. It was a revelation.

Ronald, for me, for what it is worth, you accomplished a great result. Thanks for being a little part of it!
 
Sounds like another convert to me! :)

Plus, the English is way better than most in English speaking countries!

I do believe he is... on his way out he said: "I think I'm going to have to order a set of these..." then paused a while and added: "if I ever win the lottery..."

Jan Fekkes and wesayso we thank review :)

Me also want coffee :eguitar:

I'll wait making the coffee until you get here, then it will be fresh, as fresh as the music.
 
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Hypothetical: If you moved, how much of the dsp would change? Almost all, i suspect. However, you would not have to reinvent the wheel. Any thoughts on tailoring your speakers to a different environment? The thread is a huge investigation into DSP, you could "write the book" at this point. Thanks for the accumulation of years of your work. Do you think most of the processing you have done is useable with most types of loudspeakers?
 
Thanks guys,

I value "outside listeners" more than giving you guys (just) my own opinion.
I was very pleased to read this review myself. I did ask Jan what he thought of the arrays in terms of: "Is this a they are here" or "You are there" kind of sound. His answer was very flattering. The hint to that answer was there already in the review. But the answer, if I can translate it well enough:

Jan said:
My best experience in sound so far has been at the North Sea Jazz Festival. I think it was a show from Steve Lukather playing with The Edgar Wintergroup. Best sound ever at a "live" gig. Happened to me before at North Sea Jazz. It's that kind of tickle... :)

That made me smile form ear to ear. Goal reached.

Hypothetical: If you moved, how much of the dsp would change? Almost all, i suspect. However, you would not have to reinvent the wheel. Any thoughts on tailoring your speakers to a different environment? The thread is a huge investigation into DSP, you could "write the book" at this point. Thanks for the accumulation of years of your work. Do you think most of the processing you have done is useable with most types of loudspeakers?

Hello marsupial,

I'd have to do most of it again, yes. But I have learned so much doing this project that I'm quite confident I know where to look now, if I had to redo all of it. Plus the recent updates in REW would make that work a lot easier.

These speakers would do (or at least have the potential to do) well in a wide variety of environments. The only draw back I can think of is running them without room gain, in other words "free standing" from the walls. They would need help in the first octave, maybe even 2 octaves to prevent them from running out of steam early. First reflection points would still be high on my agenda to treat. My own room is far from ideal. I promise I will show a map of it soon. Probably in 3D.

Would this DSP process work for other speakers? In basic view a lot of what I did would/could work for other type of speakers. I'm trying to help (where I can) others already in Greg's http://www.diyaudio.com/forums/full-range/275730-convolution-based-alternative-electrical-loudspeaker-correction-networks.html. But I do not see many designs with all the advantages that line arrays can have in a room. I firmly believe I made (one of) the right choice(s). The associated "comb filtering" that goes hand in hand with mentioning arrays has never felt like a compromise for me. None of my listeners ever even hinted at it. Not once. There have been male and female listeners. Some casual, others more intense. None ever hinted at any problem which could be tied to comb filtering problems. That's the only technical/theoretical drawback I see, far outweighed by all of the advantages. DSP is needed though, no doubt.
The one other design I see a lot of potential in right of the bat is any valid variation on Tom Danley's Synergy design.


Thanks that is very kindly offer within 6 months time will go south, in meantime will think over gift for friendly host.

I'd be happy to have you over.
 
Wesayso,
I think what many don't understand is that most of the older analysis done on line arrays was done with much larger diameter devices spaced much farther apart center to center. In those cases then comb filtering would still hold true. You have taken this to a different level and that seems to account for much lessor filtering effects. I would think it would have to be at a fairly high frequency before it could be measured, that is before you apply any dsp controls. I can understand your statement about the bottom one or two octaves dropping off if you moved the arrays away from the rear wall, even adding up all the surface areas of all those small drivers there isn't all that much surface area, but I can imagine as long as your not trying to run way over 110db your just fine. I'm impressed with your construction methods and your electronic controls, a far cry from when I first studied line arrays 40 years ago. Today most live events are done with some type of line array, whether a straight or curved line, but again much dsp processing is needed to make that work.

Steven
 
Thanks Steven,

I agree size matters, also driver choice is important, actually all the little details count. I see many projects on here come and go. But I'm convinced with a little effort (and a lot of time) we can make what we have as good as it can be. Whatever the concept may be. Maximise what you've got I say! These sleek arrays can be viewed as a 16" driver with 2.55 mm x-max (x-mech being a bit larger than that) and can handle up to 240 watt each.

To give the review a little more chance of an audience I'll copy it to this new page:

Jan Fekkes said:
Hi Ronald. Here is my report :)


I will make apologies in advance for my English but I give it my best shot!


----He explained it all to me. The whole building process of his now grownup 7 ft twins. It is impressive, the way they gaze at me with each holding a long row of little speakers. I do not understand and comprehend everything Ronald told me about his project in a very enthusiastic way but I feel a lot of respect and admiration. Blood sweat and tears were shed to accomplish what is standing in front of me. “This is it, they produce sound and I think I did a good job” Well,….. a good job is a big understatement…because I have listened and they certainly produce sound. To call it just sound is way too simple to describe what is entering your ears. Tone colors is a better way to put it. Any color you like is there. Anyway, I was asked to give my honest and frank opinion about his tall and rank self-built stereo speaker set.

So, how do I do that? I asked myself. I don’t want it to become a lyrical piece of prose so people will doubt my honesty…..but I am lyrical. And that is because I am a critical listener, picking up details and can feel music to the bone. But anyway…at this my findings, while having a coffee on the ‘hotspot’ at Ronalds place.


Opeth, Windowpane from the album Damnation. I immediately feel like I’m on very right spot in the concert hall. The ultimate place to be, everybody is always looking for, I am experiencing now. Every instrument is clearly in place and it is very extraordinary, I can almost feel the space in between. It is a wide sound with room for everything that is going on. There is prominent clarity but the bass and deeper tones are perfectly present without domination. Hearing and feeling them in a very pleasant way as if sound and air cooperate to make it just right. This is how it should be. Like putting on 3D glasses. The musical landscape gets an extra dimension. It is warm and deep and I can’t help it so say….”Holy macaroni” (which is an old Dutch saying meaning: ….I’m flabbergasted) This is some hearing experience!!


Something completely different. He puts on the Sugababes. Hole in the head. It is not music I prefer but that is not the reason why I am sitting on the hotspot. So babes, let’s go J. I’m surprised that my ears tell me something different from my prejudgment. The extra dimension these speakers offer makes it very nice to listen to. While listening I made an image of a rectangle on my piece of paper. This rectangle is where this dominant kind of pumping song has its body. This was meant to be I guess…for the crowd….in your face…. But don’t get me wrong…everything is still on place and has its own distinctive position with clarity and warmth. And then there is out of the box… there is this nice tingling Ping-Pong panning effect which makes you happy… No other way to put it. It is hard to explain what makes these speakers so special but I think it has to do with a very nice wide stereo image without losing the natural reproduction. A sort of…the real thing!


David Bowie, Ashes to Ashes. I will confine myself to the striking details now. That I am very enthusiastic about the speakers needs no further explanation. I now notice how many tracks have been used for vocals in this song. There is a upper stream and a undertow with vocals and bizarre effects. These speakers apparently do have the distinctive character to reveal these details.


Blackfield – Blackfield. The clarity of the rhythm guitar is striking. Not that I couldn’t hear it on my own speaker set but over here, on the hotspot it comes more forward.


Blackfield – Hello. In a way a little shocking to find out about the honesty of these speakers. The high frequencies that are floating above it all in this song are too dominant in my opinion, it is really hurting a bit. Too bad….but a honest message. Didn’t notice this before, at least not as strong as now, not in a way it disturbed me like now.


Overall….

Like I said, I’m a devoted listener but not a technician. Don’t know about charts and measurements and why it should have this or that value. I know what I hear and I know it sounds great. Like I mentioned, I’m a critical listener but….. It was a revelation.

Ronald, for me, for what it is worth, you accomplished a great result. Thanks for being a little part of it!

Ahh.. what can I say, I'm just so damn proud of it I wanted to see it again :D.
 
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If you look at post: http://www.diyaudio.com/forums/full-range/242171-making-two-towers-25-driver-full-range-line-array-92.html#post4269420
you will find a virtual recording. But that was before all of the processing was finished. Done quite a while ago for fun.
If I would offer a recording I'd like to do it with a reasonable stereo mic. I just don't have any. In the linked post I have chosen a song that matches two of Kenrick's recording.

The virtual audition uses the measurements at the listening position and a song gets convolved with those measurements. So you get to hear my room sound. More so on headphones than on a visit to my room I'd say as we adapt to a room more quickly. I'll see if I revisit the virtual recording with my more recent results.
 
Is there any way you can do a recording and link it here? With headphones I might just be able to tell the difference.

With you tube vids for example, I can tell a difference.

https://www.youtube.com/watch?v=z4EAnVq4BNU

https://www.youtube.com/watch?v=42AKTR-BaFs

By the way, just my honest view on this, both songs appear to be from the so called audiophile side of things. Probably chosen to make the speaker shine at what it is they do best. I'll tell you what. Provide me the song in FLAC format and I'll create a virtual version of it "how it would sound" in my room. I can upload an Opeth song to counter, but I'd rather give you a direct comparison.

The song is by Shanti Snyder and called Our Ballad Studio Live from the album Sunny and Blue, but I'm not prepared to pay for it on one of the Japanese forums. Any song of her would do really, if I look at Youtube: https://www.youtube.com/watch?v=FZ_npKe6VZo but I'd like to start with a flac original.
I don't have much of that kind of music in my library really, sorry...

Find it for me and I'll play along...
 
I had a reviewer over (Jan Fekkes) to tell you that only a few posts ago :).
I build these things, so to me that would mean I'm too biased to take my opinion for granted.
I'll try to get more people in to write a review. In my own words:
It does what I wanted it to do. Close your eyes and you feel like being there. A coherent sound with space for every instrument and singer. Convincing with all genres I throw at it. You forget you're listening to speakers and get pulled into the music. Highly musical sound, smooth and persuasive.
You forget about woofers and tweeters and crossovers, there's only music left to hear. An acoustical hologram, very life like, small when the recording is small. Huge if the recording is huge. Convincing even on old ~ 1950/1960's recordings. I'm no longer listening to songs. It feels like an acoustical event.
With your eyes closed it is impossible to trace where the sound comes from. With eyes open the speakers are hard to miss, our eyes do have influence on perception. I cannot deny that, but the sound field stays in place. The phantom image is rock solid, even with eyes open. Closing the eyes let you hear boundaries in the music, most of the time a bigger place than my living room. With my eyes open they try to confine that space to what I see, but still the ears place the sound somewhat the same, just not as easy.
It might be how my brain works but I do believe everyone suffers from that more or less.

Does this help?
 
Well yes, the description is great, I have never really experienced spatial Hi-Fi - of course I have lacked the speakers.

I am not sure how a large vertical array of speakers creates such a sound - maybe you should have a large spherical array of speakers? You must have explained it in a previous post.

Wikipeida says this "A line array is a loudspeaker system that is made up of a number of usually identical loudspeaker elements mounted in a line and fed in phase, to create a near-line source of sound. The distance between adjacent drivers is close enough that they constructively interfere with each other to send sound waves farther than traditional horn-loaded loudspeakers, and with a more evenly distributed sound output pattern."

Don't you need a lot of power to drive all those speakers? How did you decide on the size?