Can professional CD solutions be used in a home space?
It would seem that if you look at Keele's design, but why did no one build a similar design here at DiyAudio?
Don Keele's CBT (Constant Beamwidth Transducer) Page
Constant Directivity: A New Approach | PreSonus
Constant directivity loudspeaker designs
It would seem that if you look at Keele's design, but why did no one build a similar design here at DiyAudio?
Don Keele's CBT (Constant Beamwidth Transducer) Page
Constant Directivity: A New Approach | PreSonus
Constant directivity loudspeaker designs
Attachments
" These patents must be taken into account in any home-construction DIY project. "
Could this be the reason ?
(see the end of the link)
Don Keele's CBT (Constant Beamwidth Transducer) Page
Could this be the reason ?
(see the end of the link)
Don Keele's CBT (Constant Beamwidth Transducer) Page
I see there are no answers, perhaps the question was not understood:
There are several threads here at DiyAudio on the benefit of DC - constant directivity - that is, keeping the same SPL over the entire audible frequency range over a wide spectrum, off-axis. That's what professional Line Array systems do, making a viewer hear the same SQ regardless of their location in the venue.
It is supposed to be a goal very pursued by audiophiles, that of staying in the "sweet space" of the equilateral triangle gets tired, and even gives stiff neck in very prolonged listening .....😀
So if we use one of these solutions / configurations - which seem to be very effective - in our room, what would be the problem? Why does no one undertake such a project? Is it for a purely aesthetic reason? The archi-named WAF factor ? 😡
There are several threads here at DiyAudio on the benefit of DC - constant directivity - that is, keeping the same SPL over the entire audible frequency range over a wide spectrum, off-axis. That's what professional Line Array systems do, making a viewer hear the same SQ regardless of their location in the venue.
It is supposed to be a goal very pursued by audiophiles, that of staying in the "sweet space" of the equilateral triangle gets tired, and even gives stiff neck in very prolonged listening .....😀
So if we use one of these solutions / configurations - which seem to be very effective - in our room, what would be the problem? Why does no one undertake such a project? Is it for a purely aesthetic reason? The archi-named WAF factor ? 😡
Lots of people use horns at home, perhaps mostly in the DIY community but also traditional consumers with products like from Klipsch. Actually I believe close to 50% of the threads in this forum is dedicated to horn designs. In many cases it outperforms traditional hifi but typically gets too big for the normal consumer (
due to waf or just ignorance or availability. Most people have no idea what they buy but trust the magazines, you don’t see much horns in the mags.
due to waf or just ignorance or availability. Most people have no idea what they buy but trust the magazines, you don’t see much horns in the mags.
Right, us 'hornies' 'beat this drum' every chance we get, though how far down in frequency we need it is a personal and/or room limitation with Dr. Geddes at one time stating 1 kHz was sufficient while me and some other DIYers were down to as much as ~500 Hz, though side wall room treatment, toe-in, floor 'accent' rugs, etc., makes it a flexible way to achieve it.
Mainly, ideally no 1st reflections till behind our ears with a diffuse sound-field behind us.
Mainly, ideally no 1st reflections till behind our ears with a diffuse sound-field behind us.
To answer your question of course they can.
CBT 36 Circular Arc Line Array Loudspeaker | Parts Express Project Gallery
CBT 36 Circular Arc Line Array Loudspeaker | Parts Express Project Gallery
I work out of corners to increase the early reflection delay times and to avoid a 'baffle step' region.
Is constant directivity and line arrays really just the same? I don’t think I’ve seen people hanging speakers from the ceiling in their homes since the 70s.
The question should be: what purpose does constant directivity serve in a domestic hifi system for reproducing recorded sound?
Listening environments are not anechoic and the human ear/brain auditory perception system integrates the energy of early reflections into the perception of loudness. This has serious implications in domestic sized listening rooms where it is necessary for the power response of a loudspeaker to slope downwards as frequency rises.
A constant directivity system will have far too much high frequency energy in any room with reflections in the first 35mS or so to sound natural.
Listening environments are not anechoic and the human ear/brain auditory perception system integrates the energy of early reflections into the perception of loudness. This has serious implications in domestic sized listening rooms where it is necessary for the power response of a loudspeaker to slope downwards as frequency rises.
A constant directivity system will have far too much high frequency energy in any room with reflections in the first 35mS or so to sound natural.
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Wayne at Pi Speakers has been selling finished and kit CD corner home speakers (five- through eight-pi models) at least since the early 80's. There's a pile of info at his site and he's a patient teacher on his forum.
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I see that there are several answers that deserve to be thought about a bit before answering, because I am not an expert but neither a neophyte in the field of audio ...
So for today, I'll answer the easiest thing. (It's not too late here, but I don't want to miss my favorite show in an hour ..)
So for today, I'll answer the easiest thing. (It's not too late here, but I don't want to miss my favorite show in an hour ..)
Robh3606 has provided a link of Keele's project with Dayton Audio speakers, I see that the link does not work, perhaps it is no longer for sale because of the low demand...?
I knew it, the WAF factor spoils the best intentions!
I can not complain, I say it in general ...
I knew it, the WAF factor spoils the best intentions!
I can not complain, I say it in general ...
The concept is the same, it is in the links that I attached.
In the photo you can see that Mr. Keele's Line Array development has a base, I deduce that it would be unnecessary if the cabinet were to be hung from the ceiling.
All I can say after struggling for the past 8 months with getting my DSP equalized 3 way active horn based system to sound tolerable in a modest sized room 12' x 17' is that it has been unexpectedly challenging. A lot of things broke during the past year due to very high use, and as I made the necessary repairs I became less and less happy with what I was hearing.
The in room power response is fundamental as John points out below, some additional EQ maybe necessary. My EQ is built on top of the HK target curve but includes some rather significant LF and mid-band modifications. Be prepared to do a lot of measurements and experimentation - you will not get there without good tools. I have substantial boost below 100Hz and a 1dB scallop in the 1kHz region currently, and this is the best I have done so far. It actually sounds good at the moment.
The original goals were tight imaging and the dynamics of horns. I have those and a whole lot of headaches that I am slowly resolving. As GM probably remembers this has been a very long journey for me. In the end I would probably do it again.
The in room power response is fundamental as John points out below, some additional EQ maybe necessary. My EQ is built on top of the HK target curve but includes some rather significant LF and mid-band modifications. Be prepared to do a lot of measurements and experimentation - you will not get there without good tools. I have substantial boost below 100Hz and a 1dB scallop in the 1kHz region currently, and this is the best I have done so far. It actually sounds good at the moment.
The original goals were tight imaging and the dynamics of horns. I have those and a whole lot of headaches that I am slowly resolving. As GM probably remembers this has been a very long journey for me. In the end I would probably do it again.
Commercial (PA) speakers for the DIY-averse
I admire the DIY efforts, but speaking for myself, I'm not skilled enough to build a complex speaker.
Many people use PA speakers such as waveguides at home. Many of these are constant directivity. I'm a fan of the Danley Unity (now Synergy) designs. For about six years, I've been quite happy with a pair of Yorkville Unity U15 (no longer sold, but were about $2000/pair new), bought used, slightly modified and run active. With various tweaks (the towel cowl and/or Geddes style foam plug) they are easily the best speakers I've ever owned.
I'm sure you could do as well, or better, with similar commercial PA speakers that offer CD.
KevinKR reports a challenging set-up. If I may blow Mr. Danley's horn, so to speak 🙂 his designs are a virtual point source that reduces or eliminates lobing issues that afflict nearly all other multi-driver designs. The overall room response is much more uniform, providing various benefits in EQ as well as sound quality. I am very lucky to have the system I do, cost me perhaps $700 for the speakers alone (used). If I had to replace them, I would look for another pair of U15's, or perhaps the Danley SM60F. SH50 if I hit the lottery 🙂 .
I admire the DIY efforts, but speaking for myself, I'm not skilled enough to build a complex speaker.
Many people use PA speakers such as waveguides at home. Many of these are constant directivity. I'm a fan of the Danley Unity (now Synergy) designs. For about six years, I've been quite happy with a pair of Yorkville Unity U15 (no longer sold, but were about $2000/pair new), bought used, slightly modified and run active. With various tweaks (the towel cowl and/or Geddes style foam plug) they are easily the best speakers I've ever owned.
I'm sure you could do as well, or better, with similar commercial PA speakers that offer CD.
KevinKR reports a challenging set-up. If I may blow Mr. Danley's horn, so to speak 🙂 his designs are a virtual point source that reduces or eliminates lobing issues that afflict nearly all other multi-driver designs. The overall room response is much more uniform, providing various benefits in EQ as well as sound quality. I am very lucky to have the system I do, cost me perhaps $700 for the speakers alone (used). If I had to replace them, I would look for another pair of U15's, or perhaps the Danley SM60F. SH50 if I hit the lottery 🙂 .
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I started this journey in 2006 and am still on the road, there have been some fortunate and not so fortunate twists and turns along the way. At that time I think the Unity horn was just on the horizon and so exotic I didn't know to consider it. Today I recommend it would be one of the first options to look at.
Going active really opened a can of worms, particularly since I designed and built most of the electronics to do it. (Only the DSP processor is not my design: I will put in a plug for the MiniDSP SHD, despite it's comparatively modest price it's the real deal.) It took me a long time to understand that the electronics were for the most part not broken, what was broken was my understanding of the physics involved. (Still pretty broken, but now I know it. And there was some broken electronics along the way.)
Going active really opened a can of worms, particularly since I designed and built most of the electronics to do it. (Only the DSP processor is not my design: I will put in a plug for the MiniDSP SHD, despite it's comparatively modest price it's the real deal.) It took me a long time to understand that the electronics were for the most part not broken, what was broken was my understanding of the physics involved. (Still pretty broken, but now I know it. And there was some broken electronics along the way.)
+1 😀 I started back when corner mono ruled, so saw no good reason to change with stereo, Quadraphonic or THX. 😉
Sorry to say only that we had some discourse and the small room that ideally requires higher directivity than any Altec horns have except the much too large long throw 203. That, or create a near-field area, which defeats the purpose of compression horns and just use pure WGs up high, i.e. studio monitors.
They are not super popular but they are there Jim Griffin built a nice one and there has even been a dipole attempt. There is a difference between Constant Directivity design and Constant Beamwidth Transducers. Many more CD designs than CBT.
Jim's new CBT Arrays -
Techtalk Speaker Building, Audio, Video Discussion Forum
CBT Dipole with SB65WBAC25-4
Building some CBT clones ...
DIY CBT Thread | HiFiCircuit
Live sound the arrays are popular, can provide loud sound to the back seats without deafening the people on front. Same can be done with one loudspeaker instead of array as well like Danley soundlabs is doing. At home this front to back loudnes problem doesnt exist but still constant direcrivity allows smooth sound and waveguides are simplest way to get constant directivity at home (at least ~1kHz and up). Mind you constant directivity can be omni (low directivity index) or something narrower (high DI) or some kind of mix of the two low DI at bass and higher on the treble with (hopefully) smooth transition somewhere in between.
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