Hello,
After a couple of (imho) quite successful builds a few years back I am now planning a new loudspeaker build.
I hope for some help in deciding what kind of loudspeaker to choose.
Drivers and filters should not cost much more than $1000, and I find it much more exciting to try something new rather than a proven traditional design.
The speakers are going to be used in a fairly small room, and I appreciate tight "dry" bass before anything blurry. Quick response is more important than deep bass. I really like a clear, transparent sound.
Up until now i have preferred sealed boxes with two way systems, and very simple crossovers. I don't like small speakers that are made to "sound bigger than they are" since I believe it often leads to a blurry slow bass. Deep bass is of course not bad, as long as it is tight!
So, does anyone have any suggestions? Should I perhaps not give up the traditional vented box?
How about a "transmission line"?
Quarter wave pipes??
or perhaps an open baffle dipole? I am for instance very curious about the budget types suggested by S. linkwitz (cheaper variants of the "phoenix".)
thanks in advance,
Magnus
After a couple of (imho) quite successful builds a few years back I am now planning a new loudspeaker build.
I hope for some help in deciding what kind of loudspeaker to choose.
Drivers and filters should not cost much more than $1000, and I find it much more exciting to try something new rather than a proven traditional design.
The speakers are going to be used in a fairly small room, and I appreciate tight "dry" bass before anything blurry. Quick response is more important than deep bass. I really like a clear, transparent sound.
Up until now i have preferred sealed boxes with two way systems, and very simple crossovers. I don't like small speakers that are made to "sound bigger than they are" since I believe it often leads to a blurry slow bass. Deep bass is of course not bad, as long as it is tight!
So, does anyone have any suggestions? Should I perhaps not give up the traditional vented box?
How about a "transmission line"?
Quarter wave pipes??
or perhaps an open baffle dipole? I am for instance very curious about the budget types suggested by S. linkwitz (cheaper variants of the "phoenix".)
thanks in advance,
Magnus
I designed this speaker using Aurum Cantus 8" woofer and 5 1/4 " drivers both carbon fiber. Tweeter is an Usher 9950-20.
My best sounding speaker so far, it achieves what you are looking for.
The cabinet is tapered front to rear and is canted 5 degrees rearward. I have a few construction pics along with crossover details and would be glad to help with any other info if you're interested.
My best sounding speaker so far, it achieves what you are looking for.
The cabinet is tapered front to rear and is canted 5 degrees rearward. I have a few construction pics along with crossover details and would be glad to help with any other info if you're interested.
Attachments
Fostex Fe206E in a Bruce? Look at spawn of Frugalhorn. Phase plugs are essential. No crossovers to mess with, amazing vocals, 95dB/W/m so not a lot of power required. Plenty of cheap tweaks around for the fostex drivers.
That will cost you about $500 with wood and some basic finishing paid for.
then spend the other $500 on a 12 inch Sealed Rythmik servo sub for 40Hz to 20Hz. ($450 for speaker and amp, $50 on an ugly cabinet shaped to hide under the couch.)
Is that different enough for you?
That will cost you about $500 with wood and some basic finishing paid for.
then spend the other $500 on a 12 inch Sealed Rythmik servo sub for 40Hz to 20Hz. ($450 for speaker and amp, $50 on an ugly cabinet shaped to hide under the couch.)
Is that different enough for you?
What about... a non-standard alignment, such as: a centre tweeter surrounded by a circular array of 6 low-cost midranges? It would be like a co-axial design but with the option of using a decent tweeter, the speed and accuracy of small midrange units, and the imaging qualities of a large wave-front all rolled into one design 
Edit: however, I am actually in the middle of writing up some plans for a traditional 3-way design. I plan on using 10" woofers in sealed boxes, as I think that the roll-off from that size would blend quite well with the room gain of a typical living room.
Anything larger and room nodes are accentuated or the room is unnaturally pressurized, whereas an 8" doesn't go low enough unless it's in a ported box.
Edit: however, I am actually in the middle of writing up some plans for a traditional 3-way design. I plan on using 10" woofers in sealed boxes, as I think that the roll-off from that size would blend quite well with the room gain of a typical living room.
Anything larger and room nodes are accentuated or the room is unnaturally pressurized, whereas an 8" doesn't go low enough unless it's in a ported box.
Attachments
CeramicMan said:What about... a non-standard alignment, such as: a centre tweeter surrounded by a circular array of 6 low-cost midranges? It would be like a co-axial design but with the option of using a decent tweeter, the speed and accuracy of small midrange units, and the imaging qualities of a large wave-front all rolled into one design
Now this is interesting!! I really like that idea. I'm thinking cast concrete box, perhaps spherical... closed or vented?
What could I expect from such "fly eye" speakers? Could someone with better knowledge than me judge the qualities of the design? Theoretical pros and cons?
This one got me excited!
Thanks,
/Magnus
Practical Nearfield Line Arrays
I'm extremely biased to line arrays. Having gone to arrays, everything is JUST MINIATURE DANCING FROG MUSIC......to me.
Near Field Line Array
Dr. James Griffin has done much to advance the line array concept. His original white paper was the definitive line array theory resource. Jim has recently completed an updated, revised edition of his Design Guidelines for Practical Near Field Line Arrays white paper.
Those wishing to explore the inner workings of the line array concept in detail are encouraged to download Dr. Griffin's White Paper (306kb).
http://www.audiodiycentral.com/awpapers.shtml
No one currently even considers building line arrays for in house sound reproduction without following Dr. Griffin's paper.
I built one of these:
http://pub48.bravenet.com/photocenter/album.php?usernum=4095425731&album=48032
I'm extremely biased. Been to most other stuff. Wanted something that was as realistic to a real performance as possible.
Design Guidelines:
The Calipso Array has been developed on a model that includes the following essential characteristics:
Two 12 inch 15mm Xmax GoldSOund Woofers
34 Sammi 3.3mm X-max, Copper coils, composite paper/fab cone, mid woofers
60 Dayton ND20FA tweeters with flanges cut to a .9 inch Center-to-center distance
Rane Ac-23 Analog Electronic Crossovers, at 165 & 2600
Tri-amplification: 60 w/ch for tweeter array, 150 w/ch mid/woofer array, 350 w/ch woofers
1. Three-Way design.
In point source speaker systems, a two way design is often considered to be an inadequate compromise. Much of audio has gone to two way designs with a single sub woofer. Vance Dickason in his 6th Edition of The Loudspeaker Cookbook has indicated that the use of dual woofers that are capable of subwoofer frequencies produces a significantly better sound image than a subwoofer. In this design a large 12 inch, high mm Xmax woofer is used with each side, and it crosses to the mid ranges at about 165hz. While mine are not currently in the correct size box, the correct size is a 6-8 cu ft vented box.
2. No Crossover in the most sensitive areas of human hearing.
Rod Elliot at Southwest Audio( http://sound.westhost.com/bi-amp2.htm ) makes the case better than I:
“It is not at all uncommon to see systems where the crossover frequency is set right in the middle of what I call the "intelligence band". This is the range of frequencies from 300Hz to 3600Hz, and is extremely important from a psycho-acoustic point of view.
“It is no accident that this is the range of the telephone system (and has been for many years). If we are only to hear a limited range, then this band of frequencies is by far the most important. Just from this we can recognize a person's voice, which musical instrument is being played (even bass instruments!), and - more importantly - what is being said. It contains nearly all the "intelligence" of the sound, which is to say that if this band is "corrupted", intelligibility is greatly reduced.
“So why do speaker manufacturers insist on placing their crossover frequencies within this band of frequencies? The public address (PA) systems used by many rock bands are a case in point - how often does one find that the vocals are completely unintelligible? Mind you, it may also be the case that the band's lyrics just don't make sense, but that's another story altogether.
“Often this occurs because the system is so loud that the amplifiers are clipping badly, but even at lower levels it is quite common. Place a common-or-garden crossover filter right in the middle of the "intelligence band" and this is exactly what will (and does) happen. With phase aberrations and cancellations, this most important frequency range becomes muddied and indistinct causing loss of intelligibility - not only on voice, but instruments as well.
“The effect is also noticeable with some hi-fi speaker systems, except that it usually less pronounced, and it is far less likely that the amplifier will be driven to clipping. Reviewers will often say of a speaker that the vocals seem veiled, or that there is noticeable coloration of either male or female vocals. These effects are often caused by the effects of phase shift around the crossover frequency, coupled with the fact that the crossover frequency falls right in the middle of the intelligence band.”
This very hard to do with point source speakers, but with line arrays, the midrange speakers are often loafing along, and if they have the range, pulling the wagon as a group of horses, they can do the job admirably.
3. Use Electrical Crossovers.
Again, passive crossovers are, IMO, a DATED TECHNOLOGY. Passive’s introduce so much negative into the sound that they should not be there. And the cost of a top of the line passive cross(with the increased cost of copper) and a electronic is almost the same. Read Rod Elliot’s papers on Bi-Amplification and electronic crossovers at http://sound.westhost.com
The only reason for not using them is that you’ve spent years learning how to design them and you aren’t giving that up, or you are in the business of selling speakers and you aren’t willing to sell amps and crossovers too.
4. Separate the midrange speakers from all other influences.
Bad coloration of sound, in my opinion, is caused by other sound that the direct radiation coming through the speakers. This means that you have to eliminate ANYTHING that goes out the back of the speaker, and anything that might be in the box behind the speaker from coming forward through the speaker again and muddying the sound clarity. (Some people don’t believe that this is impactive.)
To do this, this design uses SEALED separate 4 inch PVC tubes for each of the 34 midrange/mid bass speakers. Each tube is physically separates from its peers by ¾ inch of open air space.
On page 35 of the Dickason 6th Edition Loudspeaker Cookbook, there is an empirical study on the efficiency of various stuffing materials. The greatest attenuation was determined to be at the 4 lb/cu ft density level. Frequencies within the range of the mid/midbass speaker are right within the range of attenuation. Only by using tubes can the appropriate density be achieved, since the insulation can be stuff tightly against the walls of the tube and not push up against the speaker itself. The part closest to the speaker is protected by a layer of sheet pillowfill from the fiberglass threads that might otherwise get into the voice coil.
A recent study by Rod Elliot showed that the smaller the diameter of the fiber the more effective the attenuation. Pillow fill= .01 in, regualr fiberglass=.005 in, Acoustical fiberglass= .001 inch
Additionally there are some benefits of the tube’s inability to make even ordered harmonics, or even ordered harmonic distortion, but that will not be addressed here.
This design is labor intense but it helps make the 3 inch midrange speaker process viable.
5. Keep the cost down below $1400 for the speakers, and the required electronics.
6. Keep Comb distortion in the mid and high frequency drivers below Griffin minimums, and use dome tweeter SOUND rather than ribbons or planars, for their flatter frequency response.
The only dome tweeters that I know which have a center to center distance small enough, and at the same time can be crossed low enough, are Dayton Neo ND20FA’s. These have their flanges cut so that the c-to-c is .9 inch, and the comb filter distortion doesn’t start until more than half way into the last octave, or more than 15,000Khz.
All statements except for referred to studies or references are my opinion.
Zarathu
I'm extremely biased to line arrays. Having gone to arrays, everything is JUST MINIATURE DANCING FROG MUSIC......to me.
Near Field Line Array
Dr. James Griffin has done much to advance the line array concept. His original white paper was the definitive line array theory resource. Jim has recently completed an updated, revised edition of his Design Guidelines for Practical Near Field Line Arrays white paper.
Those wishing to explore the inner workings of the line array concept in detail are encouraged to download Dr. Griffin's White Paper (306kb).
http://www.audiodiycentral.com/awpapers.shtml
No one currently even considers building line arrays for in house sound reproduction without following Dr. Griffin's paper.
I built one of these:
http://pub48.bravenet.com/photocenter/album.php?usernum=4095425731&album=48032
I'm extremely biased. Been to most other stuff. Wanted something that was as realistic to a real performance as possible.
Design Guidelines:
The Calipso Array has been developed on a model that includes the following essential characteristics:
Two 12 inch 15mm Xmax GoldSOund Woofers
34 Sammi 3.3mm X-max, Copper coils, composite paper/fab cone, mid woofers
60 Dayton ND20FA tweeters with flanges cut to a .9 inch Center-to-center distance
Rane Ac-23 Analog Electronic Crossovers, at 165 & 2600
Tri-amplification: 60 w/ch for tweeter array, 150 w/ch mid/woofer array, 350 w/ch woofers
1. Three-Way design.
In point source speaker systems, a two way design is often considered to be an inadequate compromise. Much of audio has gone to two way designs with a single sub woofer. Vance Dickason in his 6th Edition of The Loudspeaker Cookbook has indicated that the use of dual woofers that are capable of subwoofer frequencies produces a significantly better sound image than a subwoofer. In this design a large 12 inch, high mm Xmax woofer is used with each side, and it crosses to the mid ranges at about 165hz. While mine are not currently in the correct size box, the correct size is a 6-8 cu ft vented box.
2. No Crossover in the most sensitive areas of human hearing.
Rod Elliot at Southwest Audio( http://sound.westhost.com/bi-amp2.htm ) makes the case better than I:
“It is not at all uncommon to see systems where the crossover frequency is set right in the middle of what I call the "intelligence band". This is the range of frequencies from 300Hz to 3600Hz, and is extremely important from a psycho-acoustic point of view.
“It is no accident that this is the range of the telephone system (and has been for many years). If we are only to hear a limited range, then this band of frequencies is by far the most important. Just from this we can recognize a person's voice, which musical instrument is being played (even bass instruments!), and - more importantly - what is being said. It contains nearly all the "intelligence" of the sound, which is to say that if this band is "corrupted", intelligibility is greatly reduced.
“So why do speaker manufacturers insist on placing their crossover frequencies within this band of frequencies? The public address (PA) systems used by many rock bands are a case in point - how often does one find that the vocals are completely unintelligible? Mind you, it may also be the case that the band's lyrics just don't make sense, but that's another story altogether.
“Often this occurs because the system is so loud that the amplifiers are clipping badly, but even at lower levels it is quite common. Place a common-or-garden crossover filter right in the middle of the "intelligence band" and this is exactly what will (and does) happen. With phase aberrations and cancellations, this most important frequency range becomes muddied and indistinct causing loss of intelligibility - not only on voice, but instruments as well.
“The effect is also noticeable with some hi-fi speaker systems, except that it usually less pronounced, and it is far less likely that the amplifier will be driven to clipping. Reviewers will often say of a speaker that the vocals seem veiled, or that there is noticeable coloration of either male or female vocals. These effects are often caused by the effects of phase shift around the crossover frequency, coupled with the fact that the crossover frequency falls right in the middle of the intelligence band.”
This very hard to do with point source speakers, but with line arrays, the midrange speakers are often loafing along, and if they have the range, pulling the wagon as a group of horses, they can do the job admirably.
3. Use Electrical Crossovers.
Again, passive crossovers are, IMO, a DATED TECHNOLOGY. Passive’s introduce so much negative into the sound that they should not be there. And the cost of a top of the line passive cross(with the increased cost of copper) and a electronic is almost the same. Read Rod Elliot’s papers on Bi-Amplification and electronic crossovers at http://sound.westhost.com
The only reason for not using them is that you’ve spent years learning how to design them and you aren’t giving that up, or you are in the business of selling speakers and you aren’t willing to sell amps and crossovers too.
4. Separate the midrange speakers from all other influences.
Bad coloration of sound, in my opinion, is caused by other sound that the direct radiation coming through the speakers. This means that you have to eliminate ANYTHING that goes out the back of the speaker, and anything that might be in the box behind the speaker from coming forward through the speaker again and muddying the sound clarity. (Some people don’t believe that this is impactive.)
To do this, this design uses SEALED separate 4 inch PVC tubes for each of the 34 midrange/mid bass speakers. Each tube is physically separates from its peers by ¾ inch of open air space.
On page 35 of the Dickason 6th Edition Loudspeaker Cookbook, there is an empirical study on the efficiency of various stuffing materials. The greatest attenuation was determined to be at the 4 lb/cu ft density level. Frequencies within the range of the mid/midbass speaker are right within the range of attenuation. Only by using tubes can the appropriate density be achieved, since the insulation can be stuff tightly against the walls of the tube and not push up against the speaker itself. The part closest to the speaker is protected by a layer of sheet pillowfill from the fiberglass threads that might otherwise get into the voice coil.
A recent study by Rod Elliot showed that the smaller the diameter of the fiber the more effective the attenuation. Pillow fill= .01 in, regualr fiberglass=.005 in, Acoustical fiberglass= .001 inch
Additionally there are some benefits of the tube’s inability to make even ordered harmonics, or even ordered harmonic distortion, but that will not be addressed here.
This design is labor intense but it helps make the 3 inch midrange speaker process viable.
5. Keep the cost down below $1400 for the speakers, and the required electronics.
6. Keep Comb distortion in the mid and high frequency drivers below Griffin minimums, and use dome tweeter SOUND rather than ribbons or planars, for their flatter frequency response.
The only dome tweeters that I know which have a center to center distance small enough, and at the same time can be crossed low enough, are Dayton Neo ND20FA’s. These have their flanges cut so that the c-to-c is .9 inch, and the comb filter distortion doesn’t start until more than half way into the last octave, or more than 15,000Khz.
All statements except for referred to studies or references are my opinion.
Zarathu
line array or "cluster"
I read the paper about line arrays, and it seems more and more interesting.
I'm just curious... in line arrays I now understand the importance of having as short distance as possible between the drivers in the array (no more than one wavelength) to avoid cancellations.
Isn't this a problem in simpler speakers with "D'appolito" configuration of two drivers?
For instance if I choose to go with the "circular array" idea with a tweeter in the middle, that wouldn't be very much like a line array at all, but would I still have to worry about cancellations?
I read the paper about line arrays, and it seems more and more interesting.
I'm just curious... in line arrays I now understand the importance of having as short distance as possible between the drivers in the array (no more than one wavelength) to avoid cancellations.
Isn't this a problem in simpler speakers with "D'appolito" configuration of two drivers?
For instance if I choose to go with the "circular array" idea with a tweeter in the middle, that wouldn't be very much like a line array at all, but would I still have to worry about cancellations?
The answer to your question is yes. Also, You have to pay attention to vertical and horizontal comb filter distortion with multiple speakers each covering the same frequency range.
As to the circular versions, they were tried in the early 60's and found to be rather wanting in quality. Lobing was quite noticable and all the special characterisitcs of a line array, especially the sound stage was lacking.
There is no nearfield with the lack of reflections. The Bose 901's were a kind of example of that.
Zarathu
As to the circular versions, they were tried in the early 60's and found to be rather wanting in quality. Lobing was quite noticable and all the special characterisitcs of a line array, especially the sound stage was lacking.
There is no nearfield with the lack of reflections. The Bose 901's were a kind of example of that.
Zarathu
which drivers?
OK,
Perhaps I sould try a line array! It sure sounds interesting.
My just thought up idea is to make line arrays with 5,25" mid/woofers and as small (outside diameter) tweeters as I can find. In my dreams, this combo would be OK without a subwoofer.
Any comments on this? I believe it was said in another thread that mid/woofers weren't any good choice for line arrays, is that right?
I only found a couple of interesting drivers here in Sweden:
Zachry HR-017: , 5,25", 80 W, Känsl. 88 dB. Frekv. 38-7000 Hz. Imp 16 Ohm. Qts 1,05. Vas. 5,56. Fs 69 Hz. Ytterm. 136 mm.
Rila RW 5048: 5", Impedans : 6 Ohm Frekvensomfång : 55-10000 Hz, Effekt: 40 W, Känslighet: 89 dB/SPL, Fs: 40 Hz /Vas and Fs unknown)
Zachry BX-2015: 0,5", 100 Watt. Känsl. 90 dB. Frekv. omf. 3500 - 25000 Hz. Imp. 4 Ohm. Outer dia. 40 mm.
Any comments on the drivers? High Qts... I was thinking sealed boxes, but perhaps not.
How low could a combo like this play? Or is it plain unwise to make a 2 way line array for full frequency range?
OK,
Perhaps I sould try a line array! It sure sounds interesting.
My just thought up idea is to make line arrays with 5,25" mid/woofers and as small (outside diameter) tweeters as I can find. In my dreams, this combo would be OK without a subwoofer.
Any comments on this? I believe it was said in another thread that mid/woofers weren't any good choice for line arrays, is that right?
I only found a couple of interesting drivers here in Sweden:
Zachry HR-017: , 5,25", 80 W, Känsl. 88 dB. Frekv. 38-7000 Hz. Imp 16 Ohm. Qts 1,05. Vas. 5,56. Fs 69 Hz. Ytterm. 136 mm.
Rila RW 5048: 5", Impedans : 6 Ohm Frekvensomfång : 55-10000 Hz, Effekt: 40 W, Känslighet: 89 dB/SPL, Fs: 40 Hz /Vas and Fs unknown)
Zachry BX-2015: 0,5", 100 Watt. Känsl. 90 dB. Frekv. omf. 3500 - 25000 Hz. Imp. 4 Ohm. Outer dia. 40 mm.
Any comments on the drivers? High Qts... I was thinking sealed boxes, but perhaps not.
How low could a combo like this play? Or is it plain unwise to make a 2 way line array for full frequency range?
Re: line array or "cluster"
Probably, but there are different issues to think about. For example, for 6 drivers placed at a distance of 10cm from each other, it wouldn't be a simple 10cm, 20cm, 30cm... calculation. Their relative distances would be: 10cm, 10cm, 10cm, 18.6cm, 18.6cm, and 20cm.
At a listening position of 30 degrees off-axis, the relative distances between opposite speakers would be around 10cm (20*sin(30) = 10), with several speakers in between.
The problem with line arrays is that at some frequencies they produce a cylindrical wave-front, while at others it is spherical. If you move closer to the speakers, the midrange SPL will only increase proportionally, while the SPL from a dome tweeter or single subwoofer would increase with the inverse square of the distance.
This explains why people often go crazy with an "all or nothing" approach to line arrays. They use ribbon tweeters and floor-to-ceiling arrays of subwoofers... Or, you could just try a simpler T-MMM-W design and see if you like it?
maghen said:
Probably, but there are different issues to think about. For example, for 6 drivers placed at a distance of 10cm from each other, it wouldn't be a simple 10cm, 20cm, 30cm... calculation. Their relative distances would be: 10cm, 10cm, 10cm, 18.6cm, 18.6cm, and 20cm.
At a listening position of 30 degrees off-axis, the relative distances between opposite speakers would be around 10cm (20*sin(30) = 10), with several speakers in between.
The problem with line arrays is that at some frequencies they produce a cylindrical wave-front, while at others it is spherical. If you move closer to the speakers, the midrange SPL will only increase proportionally, while the SPL from a dome tweeter or single subwoofer would increase with the inverse square of the distance.
This explains why people often go crazy with an "all or nothing" approach to line arrays. They use ribbon tweeters and floor-to-ceiling arrays of subwoofers... Or, you could just try a simpler T-MMM-W design and see if you like it?
I cannot speak to the speaker choices you've given me since they are available to you in europe, and mine are probably only avaialbe in the USA. I'd like to be in Europe. Three weeks shy of a year ago, I spent 11 wonderful days visiting my son in Karlsruhe Germany(he's a nuclear astrophysicist, and is always spending a month here and there in Germany).
But here are two bais choices:
Two inexpensive Array designs:
How cheap can you go when you design an array?
Lets first look at the electronics. You need a pre-amp, three power amps, a 3 way electronic crossover, a sound level meter, and possibly a constant Q minimum stereo 2/3 octave equalizer.
On eBay you can find a pre-amp for about $30, three 150 watt/ch amps for $60 each, a Rane crossover for about $130, and sound level meter for about $40. If you want to throw in the equalizer, about $130. All US$, I've no idea how it works on EBAY Europe.
But speaker wise there are two basic directions to go:
1. 24 6.5 inch speakers
2. 12 Planar or ribbons
3. two woofers or a subwoofer.
Or
1. 64 3/4 inch domes that you can cut the flanges to less than an inch between them center to center
2. 34 3 inch mind woofers
3. two woofers
-------------
I used 3 inch mid woofs, but I did need 34 of them, and I did need a real woofer to get down below 165hz.
But here are two bais choices:
Two inexpensive Array designs:
How cheap can you go when you design an array?
Lets first look at the electronics. You need a pre-amp, three power amps, a 3 way electronic crossover, a sound level meter, and possibly a constant Q minimum stereo 2/3 octave equalizer.
On eBay you can find a pre-amp for about $30, three 150 watt/ch amps for $60 each, a Rane crossover for about $130, and sound level meter for about $40. If you want to throw in the equalizer, about $130. All US$, I've no idea how it works on EBAY Europe.
But speaker wise there are two basic directions to go:
1. 24 6.5 inch speakers
2. 12 Planar or ribbons
3. two woofers or a subwoofer.
Or
1. 64 3/4 inch domes that you can cut the flanges to less than an inch between them center to center
2. 34 3 inch mind woofers
3. two woofers
-------------
I used 3 inch mid woofs, but I did need 34 of them, and I did need a real woofer to get down below 165hz.
Ceramic Man,
Simple Question: Do you have a full size line array in your house that you actually listen to?
Line arrays have four significant differences over other speakers . if you don't care about these things, then you shouldn't build a line array. if they are very important to you, then you should consider them:
1. A very large sound stage
2. Very low distortion
3. Very high levels of fine detail
4. Very wide dynamic range
To get these benefits, you have a very labor intensive system. You have to cut a lot of holes(My baffle required thirty four holes in 3/4 inch red oak, and 2 - 1 inch x 35 inch line holes). I believe in separate enclosures for every midrange speaker, and tri-amplification with electronic crossovers.
For this labor(took me more than 18 months of week end days), I have a system that beats out ANY point source I've every heard anywhere in the four areas listed above.
I can't guarantee that others will get the same results as me if they don't use all the same details I have.
But it would be simpler to build anything else...anything else.
Now to your comments.
1. "The problem with line arrays is that at some frequencies they produce a cylindrical wave-front, while at others it is spherical." This is not true except for the woofers. As long as you have built the line array according the Dr. Griffin's procedures you will remain in the nearfield for all the listening, and you will be within the cylindrical wave.
Woofers are not a nearfield event unless you use two of them on each side. Tweeters are not if you only use one per side. The nearfield is slightly longer than three times the actual length of the speaker line. For my system, I'm in the nearfield up to about 10 feet from the speakers for the tweeter part, and up to 24 feet for the mid ranges. I listen at about 9 feet.
I have found that the woofer operating at 165hz and below is essentially omnidirectional enough so that there is no feeling of a farfield experience. Real line arrays don't have just one tweeter.
2. "If you move closer to the speakers, the midrange SPL will only increase proportionally, while the SPL from a dome tweeter or single subwoofer would increase with the inverse square of the distance." This sounds important. In real listening its not an issue. You don't hear this technical phrase. The woofer non nearfield experience is not an issue in actual hearing, and you design so that you have an array of both mids and tweeters. THIS IS HOW IT IS DONE. Of course if you skimp and do it some other way, then you won't have a practical nearfield line array.
3. "This explains why people often go crazy with an "all or nothing" approach to line arrays. They use ribbon tweeters and floor-to-ceiling arrays of subwoofers..."
This is also wrong. There is no "going crazy". What there is, is following the specific guidelines of making a REAL LINE ARRAY, which has parameters different than point source speakers. Its not going any more crazy than following the technical and appropriate guidelines for any quality item.
While you may call this "going crazy", i call it: Either building a real nearfield line array, or building a point source speaker with a bunch of sepakers instead of one. A WWTW or a MTMW or a WMTMW, is still just a large point source speaker.
Its not a line array. Read James Griffin, PhD's white paper.
Zarathu
Simple Question: Do you have a full size line array in your house that you actually listen to?
Line arrays have four significant differences over other speakers . if you don't care about these things, then you shouldn't build a line array. if they are very important to you, then you should consider them:
1. A very large sound stage
2. Very low distortion
3. Very high levels of fine detail
4. Very wide dynamic range
To get these benefits, you have a very labor intensive system. You have to cut a lot of holes(My baffle required thirty four holes in 3/4 inch red oak, and 2 - 1 inch x 35 inch line holes). I believe in separate enclosures for every midrange speaker, and tri-amplification with electronic crossovers.
For this labor(took me more than 18 months of week end days), I have a system that beats out ANY point source I've every heard anywhere in the four areas listed above.
I can't guarantee that others will get the same results as me if they don't use all the same details I have.
But it would be simpler to build anything else...anything else.
Now to your comments.
1. "The problem with line arrays is that at some frequencies they produce a cylindrical wave-front, while at others it is spherical." This is not true except for the woofers. As long as you have built the line array according the Dr. Griffin's procedures you will remain in the nearfield for all the listening, and you will be within the cylindrical wave.
Woofers are not a nearfield event unless you use two of them on each side. Tweeters are not if you only use one per side. The nearfield is slightly longer than three times the actual length of the speaker line. For my system, I'm in the nearfield up to about 10 feet from the speakers for the tweeter part, and up to 24 feet for the mid ranges. I listen at about 9 feet.
I have found that the woofer operating at 165hz and below is essentially omnidirectional enough so that there is no feeling of a farfield experience. Real line arrays don't have just one tweeter.
2. "If you move closer to the speakers, the midrange SPL will only increase proportionally, while the SPL from a dome tweeter or single subwoofer would increase with the inverse square of the distance." This sounds important. In real listening its not an issue. You don't hear this technical phrase. The woofer non nearfield experience is not an issue in actual hearing, and you design so that you have an array of both mids and tweeters. THIS IS HOW IT IS DONE. Of course if you skimp and do it some other way, then you won't have a practical nearfield line array.
3. "This explains why people often go crazy with an "all or nothing" approach to line arrays. They use ribbon tweeters and floor-to-ceiling arrays of subwoofers..."
This is also wrong. There is no "going crazy". What there is, is following the specific guidelines of making a REAL LINE ARRAY, which has parameters different than point source speakers. Its not going any more crazy than following the technical and appropriate guidelines for any quality item.
While you may call this "going crazy", i call it: Either building a real nearfield line array, or building a point source speaker with a bunch of sepakers instead of one. A WWTW or a MTMW or a WMTMW, is still just a large point source speaker.
Its not a line array. Read James Griffin, PhD's white paper.
Zarathu
One more thing....anf then, I'll shut up.
I like to listen to music as close to the actual performance in impact and volume as possible.
There are three kinds of music my other speakers could never approach realism for:
1. Full Orchestral
2. Organ
3. solo or orchestral solo piano
Excluding the fact that my sound stage while as high as the orchestra is not 40 feet wide, orchestra, well recorded sounds like I'm really there.
Organ sounds like I'm actually in the church(you could close your eyes and swear you'd been teleported to the church.) Bach Tocatta and Fugue is unbelievable
Piano sounds like I have Andre Watts playing a grand piano right in my music room just for me. The bass string and the high treble have a sound that my other speakers could never produce. Often i can even hear the hammers hitting the strings.
For me, anything else is miniature music. It may be clear and accurate, but there's no denying that there are a couple of small speakers that its coming out of. I want the real thing, not just a good small reproduction of the sound. I want to be convinced there are no speakers just real performers in my music room.
Now I'll be quiet.
Zarathu
I like to listen to music as close to the actual performance in impact and volume as possible.
There are three kinds of music my other speakers could never approach realism for:
1. Full Orchestral
2. Organ
3. solo or orchestral solo piano
Excluding the fact that my sound stage while as high as the orchestra is not 40 feet wide, orchestra, well recorded sounds like I'm really there.
Organ sounds like I'm actually in the church(you could close your eyes and swear you'd been teleported to the church.) Bach Tocatta and Fugue is unbelievable
Piano sounds like I have Andre Watts playing a grand piano right in my music room just for me. The bass string and the high treble have a sound that my other speakers could never produce. Often i can even hear the hammers hitting the strings.
For me, anything else is miniature music. It may be clear and accurate, but there's no denying that there are a couple of small speakers that its coming out of. I want the real thing, not just a good small reproduction of the sound. I want to be convinced there are no speakers just real performers in my music room.
Now I'll be quiet.
Zarathu
Zarathu, just to clarify, I don't have anything against line arrays in particular. I was just trying to point out certain theoretical things that Maghen might want to keep in mind, whatever he decides to make.
Re: my earlier comment about people going crazy with an "all or nothing" approach, I wasn't implying any actual "madness" as such... It's just that all it takes is that he buys 4 ribbon tweeters, and that's probably most of his $1000 budget gone already.
And I'm not quite sure what you mean by near-field and far-field? The way I think I understand it, if you walk towards a "point source" speaker, it gets exponentially louder compared to ambient reflections and whatnot. Whereas the relatively flat wave-front of a line array makes it seem like the sound source is far away.
Re: my earlier comment about people going crazy with an "all or nothing" approach, I wasn't implying any actual "madness" as such... It's just that all it takes is that he buys 4 ribbon tweeters, and that's probably most of his $1000 budget gone already.
And I'm not quite sure what you mean by near-field and far-field? The way I think I understand it, if you walk towards a "point source" speaker, it gets exponentially louder compared to ambient reflections and whatnot. Whereas the relatively flat wave-front of a line array makes it seem like the sound source is far away.
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