This is really getting to have nothing to do with the Hyperion but leaving information that could confuse others later seems like a bad idea so..
CBT's are good but not the only option either.
Of course a true infinite array cannot exist but inside a room with a floor and ceiling a line array that covers most of the floor to ceiling height can get a useful benefit from the acoustic mirror images. Of course without making your floor and ceiling totally reflective the mirrors will not be perfect but they still add something. Beaming and a line source cannot be viewed the same way as with a conventional speaker. The vertical directivity is high which looks on a polar plot like beaming. But with a line source as you move up and down that beam moves with you to a much greater extent due to there still being sources at that point. You can listen from the floor through sitting and standing and the sound does not change nearly as much as it does with a cone and dome type setup.
CBT's are good but not the only option either.
It is important to distinguish the difference between a PA style line array being used in a stadium or outdoors vs the sort of line that may be used in a home environment in a room. Inside a room with a floor to ceiling array the 3dB per doubling of distance holds to be true over a fairly wide range of frequencies at typical listening distances.
Very true. If a floor to ceiling array can indeed deliver the reflections to make it as appear as if infinite in length, 3dB would surely hold...well, for at least a significant range of frequencies.
My take though, is that we are still stretching reality in hoping the floor and ceiling gives the reflections required.
Maybe it would be closer to reality if the floors and ceiling were mirrors laminated on concrete slabs....plain dunno what it would truly take.
Hi Mark100,
My first DIY was a CBT array. But I built it from scratch not based on any previous design. Consequently, I read through all of Don Keele's papers. That's why I knew sound field narrowing reduced SPL drop-off over distance. An exception would be narrowing via destructive interference/active cancellation.
You can see Linkwitz explain it here if you scroll down to Keele's CBT. If you look at the graphs you'll see measurements to two meters but it work much further than that. The far field would be really far, much larger than a residential room.
Similarly, the Danley horn SPL will drop off at a slower rate for frequencies in the horn control - way beyond near field. Which will be good for home theater. When Danley markets their speaker for home theater they're telling the truth.
My first DIY was a CBT array. But I built it from scratch not based on any previous design. Consequently, I read through all of Don Keele's papers. That's why I knew sound field narrowing reduced SPL drop-off over distance. An exception would be narrowing via destructive interference/active cancellation.
You can see Linkwitz explain it here if you scroll down to Keele's CBT. If you look at the graphs you'll see measurements to two meters but it work much further than that. The far field would be really far, much larger than a residential room.
Similarly, the Danley horn SPL will drop off at a slower rate for frequencies in the horn control - way beyond near field. Which will be good for home theater. When Danley markets their speaker for home theater they're telling the truth.
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I just said this but might as well highlight the relevance to the Hyperion. It's marketed as a home theater speaker. Why? At least partly because a lower drop-off rate over distance is good in home theater.
The CBT is one alternative to the Hyperion because it behaves similarly in this regard, however, it is narrow vertical with wide horizontal.
Here's a link to measurements made of a standard meter high array. You can see it works over a long distance. Alternatively, a ground plane CBT array "doubles" the length of the array, over both carpet and hard floors.
Line Array Attenuation - Ideal vs Actual
No matter what, you don't need a floor to ceiling array in a residential room. Of course, the floor to ceiling array would be better than a meter tall array because it would control a larger bandwidth. Granted, that doesn't do you a great deal of benefit under 800-1,000Hz. But an array that is around average human height is enough to give you a good sound field for standing or sitting.
Line Array Attenuation - Ideal vs Actual
No matter what, you don't need a floor to ceiling array in a residential room. Of course, the floor to ceiling array would be better than a meter tall array because it would control a larger bandwidth. Granted, that doesn't do you a great deal of benefit under 800-1,000Hz. But an array that is around average human height is enough to give you a good sound field for standing or sitting.
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You have an uncanny knack of dragging threads away from their starting point, as your posts contain incorrect information this is my last try to help you understand
It is not narrowing but the change in wavefront shape that causes it over distance away from the device. A true line and a CBT are very similar a horn is not.
That is stating that a CBT drops off at 3dB with distance which is correct, it does not mean that it is a universal truth to all narrowed directivity.
It will not and Tom will not market it as such because he actually understands how this works.
Again not right, it would make a good Home Theatre speaker because of the controlled directivity, and high output.
You managed to choose the same link that I posted in #36 and yet still misunderstand the point of it.
The longer the array the better it approximates an infinite line source and the less issues it will have. It is worth doing and it will give a much better response than any truncated array across the full bandwidth.
First, big thumbs up on using SynAudCon as a reference.
Best no BS audio science out there, imo.
But I think you're missing what the link you gave is saying, ...that in their example -3dB line array vs distance, only works for high frequencies, where WL is short relative to line length..
And sigh again, i think you have it backwards, floor to ceiling is completely important....unless you think all audio is about HF/VHF.
Floor to ceiling lengthens the line to lower it's effective control, for instance the SynAudCon example shows the 1m line craps out at around 2kHz.
and where oh where, did you get a CBT "doubles" the length of the array...????
maybe slow the melon down some
Best no BS audio science out there, imo.
But I think you're missing what the link you gave is saying, ...that in their example -3dB line array vs distance, only works for high frequencies, where WL is short relative to line length..
And sigh again, i think you have it backwards, floor to ceiling is completely important....unless you think all audio is about HF/VHF.
Floor to ceiling lengthens the line to lower it's effective control, for instance the SynAudCon example shows the 1m line craps out at around 2kHz.
and where oh where, did you get a CBT "doubles" the length of the array...????
maybe slow the melon down some
Haha, what's to talk about directly pertaining, other than a marketing blurb?
The CBT uses the floor to double the effective length through an acoustic mirror in the same way a straight array would do, so that part is actually the most factually correct
There isn't much to talk about with the Hyperion yet but I hope the array stuff can be left behind as it has no relevance here.
Given the aspirational marketing material I suspect the price will be suitable for target buyers to brag to their friends about how much it cost
Anywho...the reason drop-off over distance matters is because the Hyperion is a home theater speaker.
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Yes, that's why I've been referring to the horn's control range. It looks like the Danley Hyperion synergy horn is 18 inches which controls down to around 800Hz.
Arrays control frequencies at a fraction of their length. Which is why the one meter array started controlling around 2kHz.
We know a lower attenuation rate is good for home theater. But you don't need to control the entire frequency spectrum in a small room. You definitely don't need to control as low as the modal region. So you control somewhere above that where you get the most benefit. It looks like Danley is following Geddes in this regard.
At present, I don't know if it's better to go with an array or a horn in a home theater.
I don't think it matters a great deal in the size of room that most people would have access to but again the Hyperion will follow inverse square attenuation -6dB with doubling of distance.
Not spraying the sound all over the walls, floor and ceiling is controlling the directivity that is entirely separate to inverse or inverse square attenuation over distance.
Both Toole and Linkwitz think lower attenuation/distance is better for home theater. You don't think it matters as much, which is fine. I think their arguments are compelling.
I don't understand why you think a horn is different from an array in terms of drop-off/distance. Does the surface area of expansion suddenly explode?
I don't understand why you think a horn is different from an array in terms of drop-off/distance. Does the surface area of expansion suddenly explode?
The CBT uses the floor to double the effective length through an acoustic mirror in the same way a straight array would do, so that part is actually the most factually correct
Yeah, my bad. Not sure how i forgot that, especially since i built a pair.
Oh well, i have "Mark" written on my bathroom mirror to remind me who i am
But for making a factual point i busted on, pls accept my apology bradleypnw
Bradley I'm not sure what isn't clicking in your brain about understanding the difference between a cylindrical and a spherical wavefront and how that affects the level over distance, but if you know anyone who works in pro audio they can empirically explain that the effect is quite profound.
I designed a system for a dance company that utilized a 50 foot tall stack of Bohlender Graebener Pro-1.9(High power version of the RD75) per side. That system went into theaters that had everything from EV and JBL point and shoot systems with big horns to Meyer CQ and various line arrays. That system was designed to keep most of the audience in the near field to 300 hz and below depending on the room. When we A/B'd our system with the house systems there was no question. You could be up in a balcony at the very top of the array 100' away sitting in a seat and stand up and the level would drop like 20 db.
Now in a living room I don't really know that it matters one way or another, other than that I can tell you that in my reverberant listening room you can definitely hear the room/reverberation less with Magnepan Tympani IIIb, which is of course a dipole, at 20 feet away than even the largest horn (in my case Peavey MB1/2" Selenium D405-18" Mystery WG/B&C DE250-Wayne Parham H290C). Both systems do certain things better, which is why I switch them out.