So I'm doing my every-so-often review of closeout drivers for a super cheap line array, weighing the appeal of the killer visual impact with the ubiquitous advice of "it might just sound like a big bunch of cheap drivers".
One thing I've never quite understood: what's the point with these half-array or mini-array designs, where there are many drivers used, but still way short of extending between floor to ceiling. What niche do they fit in?
One thing I've never quite understood: what's the point with these half-array or mini-array designs, where there are many drivers used, but still way short of extending between floor to ceiling. What niche do they fit in?
leadbelly said:
A smaller array will cut down on the ceiling/floor reflections, not as much as a ceiling to floor array but more than conventional designs.
The near-field/far-field issues will depend on the specifics of the small array. With the Nonsuch 4s, the frequency response is normal, provided that the listener is seated and is at a distance of at least 4 or 5 feet from the speakers, in other words, normal listening conditions for most people. If you stand up you will lose some of the high frequencies. I have added a link connection across the terminals so you can cut out the outer two drivers when you need to stand or walk about while listening.
It's not for me to say whether 'mini array' speakers can still make for great speakers. If you use mediocre drive-units you can expect a reduced distortion as, for a given SPL, each unit is working a lot less. You still won't make a great speaker, you need top quality drivers for that.
I'm looking forward to a neutral forum member listening to my particular example of the genre (are there any other examples out there?) and reporting back to the forum.
Does anyone live near South London?
Steve
Also are you reffereing to something with like 12 3" drivers per side, or just something simple like 4 3" tang bands?
I will probably do something like the latter soon for my TV/Gameing system, so that I can have something that has alot of impact, and doesn't need a lot power. It's a big room and my little B&W DM302's just sound plain terrible by themselves. However at the same time I'm not concerend about utmost sound quality, because I have another dedicated system and frankly I'd like to keep the precious notion that my MMG's are the best speakers ever!
I will probably do something like the latter soon for my TV/Gameing system, so that I can have something that has alot of impact, and doesn't need a lot power. It's a big room and my little B&W DM302's just sound plain terrible by themselves. However at the same time I'm not concerend about utmost sound quality, because I have another dedicated system and frankly I'd like to keep the precious notion that my MMG's are the best speakers ever!
Actually, I'm not really planning anything now. I did see a sale, reread the Linus White Paper, and then asked myself for the upteenth time "how come so many people have designs for mini-arrays that fly in the face of the science of it, at least as I understand it". You know, you see these designs with large spaces in between the drivers and such and all kinds of weird stuff like that. I just wanted to know what was the cr*p and what was for real.
One of my projects this summer will be a line array of 16 Tangbands. It will be configured as a MMMMMMMMTMMMMMMMMW system and tri-amplified. To avoid comb effects and time smearing the array will be curved, with the focal point at my seated listening position.
The bass system will be 4 - 12" per channel is sealed enclosures, Q=.5. Low to mid crossover will be about 120Hz.
Multiple mids in series parallel will allow for high SPL and high power handling.
I have recently heard a line array of 3" drivers, 24 per channel, operating full range. I left with the impression that all the time delays had destroyed the "you are there" potential in the system. I believe the curved array and the added tweeter is the solution.
The bass system will be 4 - 12" per channel is sealed enclosures, Q=.5. Low to mid crossover will be about 120Hz.
Multiple mids in series parallel will allow for high SPL and high power handling.
I have recently heard a line array of 3" drivers, 24 per channel, operating full range. I left with the impression that all the time delays had destroyed the "you are there" potential in the system. I believe the curved array and the added tweeter is the solution.
Mini-line Arrays
Bill,
I could resist logging in to direct you to my 16 Tang Band W3-871S and single Esg3 ribbon tweeter line array that avoids the LA shortcomings you mentioned. I call it the Needles. It is a straight baffle but with a driver spacing and a crossover that avoids comb lines. A slight power taper is used to anchor the blend between the TBs and the Esg3. It works very well most anywhere within a listening room but without your head in a vise location issue of a curved array. More information on this design can be had at:
www.creativesound.ca
or from me.
Jim Griffin
Bill,
I could resist logging in to direct you to my 16 Tang Band W3-871S and single Esg3 ribbon tweeter line array that avoids the LA shortcomings you mentioned. I call it the Needles. It is a straight baffle but with a driver spacing and a crossover that avoids comb lines. A slight power taper is used to anchor the blend between the TBs and the Esg3. It works very well most anywhere within a listening room but without your head in a vise location issue of a curved array. More information on this design can be had at:
www.creativesound.ca
or from me.
Jim Griffin
Yep, but you have a narrow 'sweet spot', as little as cocking your head narrow depending on the curvature/listening distance, not to mention the front/back limitation. Still, in the 'sweet spot' they can sound quite good and a great way to get plenty of dynamics/low distortion without the need for XOs or bulky horns.
GM
GM
hmm, i was just thinking, and BTW i am usually wrong, but what if you made an array ceiling down to floor with fewer speakers, placing the speakers at unequal distances, all of which would be non-harmonic, and possibly non-monotonic (so you may have a foot between driver 1 and 2, an inch from 2-3 and 4.5 inches from 5-6.) monotonics just a word you don't hear everyday. in any case there should be a reason it would or would not work.
One time I think I remember reading that having varied xo points for the drivers would help too. For example using full range driver; the center drivers would run full range, but the outer drivers might have a gentle XO up top, so that they are not all playing the same freqs. Maybe it was the other way around not sure....does this make sense?
Theoretically, you should get a horizontal line (although not a straight line) as the stereo focus of the two curved arrays.Jim Griffin said:
Here is a thread that discusses arrays and has some of the background on Bill Fitz’s project.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=5851&highlight=array+bill+project
Mini-line Array Comments
In a parallel thread to this one I posted some comments that might be of interest regarding the original topic of this discussion--mini-line arrays. See this posting at:
http://www.diyaudio.com/forums/showthread.php?postid=195455#post195455
Look at Post #24.
Jim
In a parallel thread to this one I posted some comments that might be of interest regarding the original topic of this discussion--mini-line arrays. See this posting at:
http://www.diyaudio.com/forums/showthread.php?postid=195455#post195455
Look at Post #24.
Jim
Well, the topic certainly has jumped around in this thread. So, let me ask another of the questions I have mulled over for a while.
In a 2-way LA, let's say with a line of 5" mids and a line of tweeters, our crossover point winds up being in the 2500-3000 Hz area, right smack in the middle of voice or lead instrument or such.
Are there any special issues with an LA that make this crossover point even worse impacting than single driver designs?
In a 2-way LA, let's say with a line of 5" mids and a line of tweeters, our crossover point winds up being in the 2500-3000 Hz area, right smack in the middle of voice or lead instrument or such.
Are there any special issues with an LA that make this crossover point even worse impacting than single driver designs?
Line Array Crossover Impact
Leadbelly,
Sounds like you don't much of a choice. With 5" drivers (likely up to 5.87" diameter counting the frames and with metal touching) you have to crossover no higher than the one wavelength center to center spacing to prevent comb lining at twice the WL value (first cancellation point). Hence, you are looking at a range between 2300 to 2700 Hz just from the WL consideration.
What I would do is to crossover in the 2300-2700 Hz (or even lower) as appropriate and try to use an acoustical slope that assures that the attenuation is on the order of 20 dB or greater by 5000 Hz. Likely, you are talking about a fourth order acoustical slope Linkwitz-Riley filter. All this assumes that you have a relatively well behaved midrange woofer without nasty peaks in the proposed stop band.
Jim
Leadbelly,
Sounds like you don't much of a choice. With 5" drivers (likely up to 5.87" diameter counting the frames and with metal touching) you have to crossover no higher than the one wavelength center to center spacing to prevent comb lining at twice the WL value (first cancellation point). Hence, you are looking at a range between 2300 to 2700 Hz just from the WL consideration.
What I would do is to crossover in the 2300-2700 Hz (or even lower) as appropriate and try to use an acoustical slope that assures that the attenuation is on the order of 20 dB or greater by 5000 Hz. Likely, you are talking about a fourth order acoustical slope Linkwitz-Riley filter. All this assumes that you have a relatively well behaved midrange woofer without nasty peaks in the proposed stop band.
Jim
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