Wide dispersion removes the biggest advantage of using a unity type horn in a domestic environment. With a 90 degree horn in a rectangular room, you have no way of controlling where the sound goes. You are simply "lighting up" the walls. If I could control the beamwidth of my system full band, I would aim for a 30-40 degree pattern. That would fill the listening position without filling the room with sound. As it is my main system gradually broadens its pattern below 500Hz to 90 degrees in the horizontal plane. This is not such a problem because the imaging cues don't go down that low and the absorption of the walls is starting to increase too.
Look up Critical Distance and think about the ramifications of going for a wider pattern. A narrower pattern increases the critical distance in a reverberant room.
My workshop speakers are 90 degrees wide because there is no defined listening area. I needed to flood the whole area with high quality sound, not just one seat. In that environment they work great, but I would not use them in my main system.
Cheers
William Cowan
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Why would you prefer to go higher? The only reason I can think of is so a cheaper compression driver can be used. It causes many problems along the way.
Cheers
William Cowan
Hi William,
Can you tell us more about your 8" driver based Unity/Synergy horn?
Specifically:
1. Beam Width (i.e. 50x50 degree, 60x60 degree)
2. 8" Drivers Used
3. Horn Dimensions
It sounds like with the work that you, Paul and Mr Bateman have done it will be possible to reproduce a lot of the characteristics found in the Danley Synergy horns. Good work.
Cheers,
Mike
Can you tell us more about your 8" driver based Unity/Synergy horn?
Specifically:
1. Beam Width (i.e. 50x50 degree, 60x60 degree)
2. 8" Drivers Used
3. Horn Dimensions
It sounds like with the work that you, Paul and Mr Bateman have done it will be possible to reproduce a lot of the characteristics found in the Danley Synergy horns. Good work.
Cheers,
Mike
Here's a link
It's an old project (on an older webpage) that I haven't written up yet. I'll do some polars first. Similar dimensions to the SPL Runt. The 90 degree horizontal beamwidth makes it less applicable for most domestic indoor use. See the banter between Paul and myself above.
Cheers
William Cowan
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I don't know - if you take the 'build it into the corners' route, 90 degree dispersion seems to make sense. In fact, near the top of my 'projects I hope I get to someday' list is a Unity style setup designed to be an in-wall right in the upper corners of a room - i.e. a 3-sided "90x90" arrangement. The idea being that it would take up zero floor space but offer wonderfully uniform coverage and avoid near-wall reflections entirely. Not necessarily the ultimate placement for imaging/soundstaging, but great in some difficult circumstances.
The wider your dispersion, the lower your in room signal to noise ratio. Any sound that reaches your ears that is not a part of the initial wavefront from the loudspeaker is noise. Controlled dispersion does remove a large part of the rooms influence. Rather than using large amounts of absorption on my walls to achieve the sound quality I was after, I opted for accurate pattern control instead.
Cheers
William Cowan
While I don't want to see this thread get too far off topic, there are two basic schools of thought here. One is to avoid room reflections with narrow dispersion or room treatment, or to control them like you would in a studio control room. That will tend to minimise the influence of the room and result in a dry sound. The other is to consider room reflections as potentially an enhancement, especially in a system that has a well behaved on and off axis response. So you have guys like Geddes and Linkwitz tending to suggest fairly live untreated rooms combined with speakers aiming for controlled directivity. If this seems too broad brush or simplistic, I'm trying to be brief.
In my room, 60 degrees means some seats which are sometimes used are pushing the limits to the sides. My initial impression with my 60 degree S1 was that it was a bit "too dry" compared to my previous builds which generally had typically around 90 degrees dispersion with waveguide speakers, so they also had much wider dispersion lower down. With both my Synergy builds, the dispersion was controlled way down into the lower midrange. S2 was still controlling dispersion within the defined angle down to 300 Hz, the rest is cut off by the x axis limit so I don't know how low pattern control was held (can't read Arta files unless you have bought it!) It does take some time to get used to the different sound you can get with speakers like these. What at first appears to be "too dry" can soon become "much greater clarity." And let's not discount personal preference here.
Side wall reflections can add a sense of body to the sound and have an impact on imaging. According to Toole, most people find this prefereable, while other reflections add less desirable effects. So if we are to have a little more room sound than a very narrow dispersion option, then we are best to bias things towards side wall reflections more than anything. Or if you want to take the studio live end dead end concept and use it at home, you do the same thing but angle the side walls towards a diffuse treated rear wall behind the listening chair.
I would not try to build a 90 x 90 Synergy. I see no benefit to the increased vertical disperson and you lose bottom end extension. A two way horn no longer works and you are forced into making it a lot more expensive with woofers in the horn as well. Woofers in the horn will tend to work as direct radiators below about 200 Hz, once you get below that point you can't simply use small low cost drivers coasting along and offering ultra high sensitivity. If you look at Danley Synergy horns with woofers in the mouth, you can see in some of them the transition to the woofers now working as direct radiators. Some of them are in effect 6th order bandpass added to the horn to retain the point source nature, but only the upper part of their range loaded by the horn then below a certain point you get the sensitivity going down, unless loaded up with enough of them to match the sensitivity as direct radiators.
The widest I would attempt would be 90 x 60. You will notice that if you want to achieve low extension, high extension and a wide coverage angle, you need to use more drivers. If you read through all the Danley Synergy horn range, you can take note of the way in which drivers are chosen for different coverage angles, but also be sure to note that they tend to show voltage sensitivity, and some of them are 4 ohms, other 8. So for the 4 ohm versions you have to subtract 3 dB.
Some examples.
SH100 uses an 8" coax with a waveguide added to constrain it to 110 degrees. We get 95 db and 70 Hz extension, only slightly higher by about 2 db compared to a typical 8" pro midwoofer.
Now onto a monster - SH96. 90 x 60 101 db and 50 Hz extension. To get there we have a 1.4" CD, 6 x 4" mids and 4 x 15" woofers! Obviously the woofers on their own will get similar numbers as direct radiators, being 95 db or so each. Still we see some horn loading effect on their upper range.
Now a more moderate version is the SH69 - same angles but 96 db 1w1m. Still has 6 mids to handle the wider dispersion, but it's a more compact box with only a pair of 12" woofers and a 1" CD.
A real best is the SH25. Only 25 x 25 coverage, obviously for long throw applications. 107 db (converted to 1w1m) and 90 Hz extension. Interesting how it only needs a 1" CD and 4 x 4" mids - this is due to the narrow coverage which is helping them both out. 8 small woofers.
SH50 is apparently the one that Danley uses at home. 97 db and 50 Hz, 50 x 50 with 2 x 12" woofers in a 6th order bandpass, 4 x 5" mids and 1" CD. So this is very much like a redeveloped version of the Unity kit. In the response you can see the dual peaks related to the two tuning points of the bandpass enclosure. There is a dip from 80 - 200 Hz in the middle, suggesting the bandpass box is being asked to cover a range that puts the two tunings too far apart to get it flat in the middle. In the original Unity, the sensitivity was set by the CD, where passive filters are used and the mids probably need to come down a bit to match up with the top end of the CD. However, in this version it appears the sensitivity is set by the woofers.
SH64 is an interesting one. 103 db and 65 Hz extension. Like the large 60 x 90 it has 4 x 15" woofers and you will notice on their bottom end, they do about the same job, but the narrower dispersion means it can use 4 mids instead of 6.
SM60M has only one 5" coax yet achieves 60 x 60 and 100 db! Almost as high as the giant SH96 with just one coax driver. How? It has a fairly narrow coverage and extension to 270 Hz. In other words, it's range is confined to it's horn loaded output. If you wanted to add extension and maintain the sensitivity, you would have to load it up with enough woofers to match the sensitivity as a direct radiator. Of course, this isn't a DIY friendly option because the porting of the coax to the horn is tricky, probably the most difficult of all of them save the Jericho and Genesis horns. Personally I think for anyone buying these for an extreme home system, this is one of the most appealing ones.
SM60F is similar but adds a pair of 8" midwoofers. I have similar drivers for my surrounds, B&C 8PS21. They tend to get about 93 - 94 db sensitivity and an fs around 80 Hz. Placed on wall you can just manage around 80 - 100 Hz with a vented box so they can make a nice gutsy surround wall mounted, very much like a Geddes Harper.
You get 96 db and about 90 Hz extension. This one would be great for a HT system where it goes down low enough to cross to a sub. It has to give up 3 db sensitivity to let the woofers keep up. Seems they are 6th order bandpass where you can see the upper holes are for the front chamber and the bottom ports are for the rear and have been placed further forward due to their lower tuning and also so they sit on the second flare angle to interfere less with the HF. Notice how this one is not as smooth as the version without the woofers? This is probably due to the ports affecting the response especially above 1k.
Everywhere you look with this project, there is a compromise. One of the things I like about the Synergy is the ability to control the dispersion and make it whatever you want, within reason. In a big live room you might want dispersion a bit narrower. William has such a room, 60 x 60 is probably pretty good. My room is smaller and the seating area is wider relative to the room, so I need wider dispersion. A smaller room also becomes dead quicker, especially if you are using a lot of bass traps as I am, although I will be controlling that with membranes. As a general rule I tend to prefer 90 x 60, but perhaps in some rooms a 50 or 60 degree might mean working better without any room treatment at all. Your room and preferences do come into it.
For a DIY home system, I think something like my S2 is an ideal mix of compromises. You can get a 2 way horn to extend to around the Shroeder frequency of a domestic room and then issues like boundary interference and modal issues IMHO become more sigificant than phase coherence extending into the bass range. You also avoid having woofers in the horn, which adds a great deal to the cost and also inteferes with the smoothness of the response, although I'm sure this point could be debated! What isn't debatable is the cost added. The design I'm now looking at would probably work with a certain Celestion CD which is a lot cheaper than DE250 or the BMS often used. The mids are dirt cheap. Now if you put 4 woofers in the mouth, they benefit little from horn loading so I believe you want to start spending on some good motors. Now the cost goes through the roof. Easily it could go up by a factor of 4, depending on choices.
Now for many who already have active crossovers, measurement tools and compression drivers handy, this project can be dirt cheap. William's version is a nice example of simplicity - he basically uses 8 sub drivers well chosen to be able to extend up high, soffit mounts them and he has a 3 way that goes all the way down. Only 4 amp channels! My plan is a little different, with a 2 way horn installed flush in a big bass trap, 18" woofers also flush in the bass trap with a sealed box then crossing to future subs under the floor, still planning tapped horns.
I don't meant to open a debate here about room interaction, but I say this to give people contemplating a Synergy project something to think about. Think about your room and what it needs, as well as the camp in which you sit.
If you look at say 2 way waveguide projects, like say an Ewave or a Geddes speaker, they are quite different to a Synergy horn. I believe there are two main differences. The waveguide speakers will often have wider dispersion and control directivity only about 1 - 2k. Below that point the response widens to omni quickly and you have the sound characteristics of a direct radiator, the midrange driver is quite important. With a Synergy you can extend constant directivity all the way down to the Shroeder frequency and now the midrange is coupled to a horn so the design of the horn becomes dominant, perhaps even more so than the drivers used. Those who have heard Synergy horns all tend to talk about the detail and clarity, and I suspect that it relates to the reduced room interaction and the use of horn loading in the midrange.
In my room, 60 degrees means some seats which are sometimes used are pushing the limits to the sides. My initial impression with my 60 degree S1 was that it was a bit "too dry" compared to my previous builds which generally had typically around 90 degrees dispersion with waveguide speakers, so they also had much wider dispersion lower down. With both my Synergy builds, the dispersion was controlled way down into the lower midrange. S2 was still controlling dispersion within the defined angle down to 300 Hz, the rest is cut off by the x axis limit so I don't know how low pattern control was held (can't read Arta files unless you have bought it!) It does take some time to get used to the different sound you can get with speakers like these. What at first appears to be "too dry" can soon become "much greater clarity." And let's not discount personal preference here.
Side wall reflections can add a sense of body to the sound and have an impact on imaging. According to Toole, most people find this prefereable, while other reflections add less desirable effects. So if we are to have a little more room sound than a very narrow dispersion option, then we are best to bias things towards side wall reflections more than anything. Or if you want to take the studio live end dead end concept and use it at home, you do the same thing but angle the side walls towards a diffuse treated rear wall behind the listening chair.
I would not try to build a 90 x 90 Synergy. I see no benefit to the increased vertical disperson and you lose bottom end extension. A two way horn no longer works and you are forced into making it a lot more expensive with woofers in the horn as well. Woofers in the horn will tend to work as direct radiators below about 200 Hz, once you get below that point you can't simply use small low cost drivers coasting along and offering ultra high sensitivity. If you look at Danley Synergy horns with woofers in the mouth, you can see in some of them the transition to the woofers now working as direct radiators. Some of them are in effect 6th order bandpass added to the horn to retain the point source nature, but only the upper part of their range loaded by the horn then below a certain point you get the sensitivity going down, unless loaded up with enough of them to match the sensitivity as direct radiators.
The widest I would attempt would be 90 x 60. You will notice that if you want to achieve low extension, high extension and a wide coverage angle, you need to use more drivers. If you read through all the Danley Synergy horn range, you can take note of the way in which drivers are chosen for different coverage angles, but also be sure to note that they tend to show voltage sensitivity, and some of them are 4 ohms, other 8. So for the 4 ohm versions you have to subtract 3 dB.
Some examples.
SH100 uses an 8" coax with a waveguide added to constrain it to 110 degrees. We get 95 db and 70 Hz extension, only slightly higher by about 2 db compared to a typical 8" pro midwoofer.
Now onto a monster - SH96. 90 x 60 101 db and 50 Hz extension. To get there we have a 1.4" CD, 6 x 4" mids and 4 x 15" woofers! Obviously the woofers on their own will get similar numbers as direct radiators, being 95 db or so each. Still we see some horn loading effect on their upper range.
Now a more moderate version is the SH69 - same angles but 96 db 1w1m. Still has 6 mids to handle the wider dispersion, but it's a more compact box with only a pair of 12" woofers and a 1" CD.
A real best is the SH25. Only 25 x 25 coverage, obviously for long throw applications. 107 db (converted to 1w1m) and 90 Hz extension. Interesting how it only needs a 1" CD and 4 x 4" mids - this is due to the narrow coverage which is helping them both out. 8 small woofers.
SH50 is apparently the one that Danley uses at home. 97 db and 50 Hz, 50 x 50 with 2 x 12" woofers in a 6th order bandpass, 4 x 5" mids and 1" CD. So this is very much like a redeveloped version of the Unity kit. In the response you can see the dual peaks related to the two tuning points of the bandpass enclosure. There is a dip from 80 - 200 Hz in the middle, suggesting the bandpass box is being asked to cover a range that puts the two tunings too far apart to get it flat in the middle. In the original Unity, the sensitivity was set by the CD, where passive filters are used and the mids probably need to come down a bit to match up with the top end of the CD. However, in this version it appears the sensitivity is set by the woofers.
SH64 is an interesting one. 103 db and 65 Hz extension. Like the large 60 x 90 it has 4 x 15" woofers and you will notice on their bottom end, they do about the same job, but the narrower dispersion means it can use 4 mids instead of 6.
SM60M has only one 5" coax yet achieves 60 x 60 and 100 db! Almost as high as the giant SH96 with just one coax driver. How? It has a fairly narrow coverage and extension to 270 Hz. In other words, it's range is confined to it's horn loaded output. If you wanted to add extension and maintain the sensitivity, you would have to load it up with enough woofers to match the sensitivity as a direct radiator. Of course, this isn't a DIY friendly option because the porting of the coax to the horn is tricky, probably the most difficult of all of them save the Jericho and Genesis horns. Personally I think for anyone buying these for an extreme home system, this is one of the most appealing ones.
SM60F is similar but adds a pair of 8" midwoofers. I have similar drivers for my surrounds, B&C 8PS21. They tend to get about 93 - 94 db sensitivity and an fs around 80 Hz. Placed on wall you can just manage around 80 - 100 Hz with a vented box so they can make a nice gutsy surround wall mounted, very much like a Geddes Harper.
You get 96 db and about 90 Hz extension. This one would be great for a HT system where it goes down low enough to cross to a sub. It has to give up 3 db sensitivity to let the woofers keep up. Seems they are 6th order bandpass where you can see the upper holes are for the front chamber and the bottom ports are for the rear and have been placed further forward due to their lower tuning and also so they sit on the second flare angle to interfere less with the HF. Notice how this one is not as smooth as the version without the woofers? This is probably due to the ports affecting the response especially above 1k.
Everywhere you look with this project, there is a compromise. One of the things I like about the Synergy is the ability to control the dispersion and make it whatever you want, within reason. In a big live room you might want dispersion a bit narrower. William has such a room, 60 x 60 is probably pretty good. My room is smaller and the seating area is wider relative to the room, so I need wider dispersion. A smaller room also becomes dead quicker, especially if you are using a lot of bass traps as I am, although I will be controlling that with membranes. As a general rule I tend to prefer 90 x 60, but perhaps in some rooms a 50 or 60 degree might mean working better without any room treatment at all. Your room and preferences do come into it.
For a DIY home system, I think something like my S2 is an ideal mix of compromises. You can get a 2 way horn to extend to around the Shroeder frequency of a domestic room and then issues like boundary interference and modal issues IMHO become more sigificant than phase coherence extending into the bass range. You also avoid having woofers in the horn, which adds a great deal to the cost and also inteferes with the smoothness of the response, although I'm sure this point could be debated! What isn't debatable is the cost added. The design I'm now looking at would probably work with a certain Celestion CD which is a lot cheaper than DE250 or the BMS often used. The mids are dirt cheap. Now if you put 4 woofers in the mouth, they benefit little from horn loading so I believe you want to start spending on some good motors. Now the cost goes through the roof. Easily it could go up by a factor of 4, depending on choices.
Now for many who already have active crossovers, measurement tools and compression drivers handy, this project can be dirt cheap. William's version is a nice example of simplicity - he basically uses 8 sub drivers well chosen to be able to extend up high, soffit mounts them and he has a 3 way that goes all the way down. Only 4 amp channels! My plan is a little different, with a 2 way horn installed flush in a big bass trap, 18" woofers also flush in the bass trap with a sealed box then crossing to future subs under the floor, still planning tapped horns.
I don't meant to open a debate here about room interaction, but I say this to give people contemplating a Synergy project something to think about. Think about your room and what it needs, as well as the camp in which you sit.
If you look at say 2 way waveguide projects, like say an Ewave or a Geddes speaker, they are quite different to a Synergy horn. I believe there are two main differences. The waveguide speakers will often have wider dispersion and control directivity only about 1 - 2k. Below that point the response widens to omni quickly and you have the sound characteristics of a direct radiator, the midrange driver is quite important. With a Synergy you can extend constant directivity all the way down to the Shroeder frequency and now the midrange is coupled to a horn so the design of the horn becomes dominant, perhaps even more so than the drivers used. Those who have heard Synergy horns all tend to talk about the detail and clarity, and I suspect that it relates to the reduced room interaction and the use of horn loading in the midrange.
The great thing about this thread is how you can tell that the participants are learning a TON about audio as we pursue this goal. Today I spent a solid three hours learning how to calculate QMS and QES from examining an impedance curve, and I learned what reactance annulling is.
This thread is like a lab class in horn loudspeakers.
G'day Paul
That was an excellent discussion on some of the tradeoffs involved. Thank you for elaborating on some of the decisions that were made in the planning phase of your project. I've enjoyed following along and you are making some very real progress in your design. (I'm almost tempted to do another pair myself!)
I understand that personal preference plays a big part on the desired character of a sound system. Our games room uses a pair of floor to ceiling planar magnetic speakers that do light up the room. If I were to have a loud rocking party, that would be my system of choice, and not because of a lack of output in the main system. It has a very live and energetic sound though lacks some of the accuracy of the horns.
The narrow dispersion loudspeakers in my large room (~80M^2 all up) gives me an acoustic character that is about as close to my Beyerdynamic DT880 headphones as I could ever believe possible. Despite the same target frequency response in the planar system, it's not even close to the DT880s. I've really grown to love the dry presentation of the Unities. There's no question I'm resolving detail in my recordings that no other system I've heard has been able to. If I want to party I walk to the other end of the house. It really is the best of both worlds.
You obviously felt uncomfortable about combining a discussion on room interaction with one on loudspeaker design. In my mind these two subjects must be thought of together. The room with it's construction and furnishings is a part of the system and must be treated as such. To attempt to design a loudspeaker that can just be placed in any room and work well is just folly. Ideally every high end loudspeaker must be designed for the room it is to be used in, anything else is a compromise.
All the best
William Cowan
That was an excellent discussion on some of the tradeoffs involved. Thank you for elaborating on some of the decisions that were made in the planning phase of your project. I've enjoyed following along and you are making some very real progress in your design. (I'm almost tempted to do another pair myself!)
I understand that personal preference plays a big part on the desired character of a sound system. Our games room uses a pair of floor to ceiling planar magnetic speakers that do light up the room. If I were to have a loud rocking party, that would be my system of choice, and not because of a lack of output in the main system. It has a very live and energetic sound though lacks some of the accuracy of the horns.
The narrow dispersion loudspeakers in my large room (~80M^2 all up) gives me an acoustic character that is about as close to my Beyerdynamic DT880 headphones as I could ever believe possible. Despite the same target frequency response in the planar system, it's not even close to the DT880s. I've really grown to love the dry presentation of the Unities. There's no question I'm resolving detail in my recordings that no other system I've heard has been able to. If I want to party I walk to the other end of the house. It really is the best of both worlds.
You obviously felt uncomfortable about combining a discussion on room interaction with one on loudspeaker design. In my mind these two subjects must be thought of together. The room with it's construction and furnishings is a part of the system and must be treated as such. To attempt to design a loudspeaker that can just be placed in any room and work well is just folly. Ideally every high end loudspeaker must be designed for the room it is to be used in, anything else is a compromise.
All the best
William Cowan
Thanks William for your link to the 8" project and thanks Paul for that excellent summary of both the room interaction trade-offs and the design decisions made by Danley in his Synergy line.
I wish that Danley (or someone else) would release a flat-pack kit of the SH50 or SH60 so we could easily build a quasi-full range Synergy horn at home. Mr Danley: If you are reading this then I hope you can find the time to pursue a DIY kit as you have mentioned on other forums/threads. Please sign me up as a pre-order (crossover not necessary).
Before Paul's projects and this thread I was seriously considering the baby Danley - the SM60F as it gives a good compromise on directivity (60x60) is small enough for a living room and could be crossed directly to a sub (basically a full range 4 way system). Now it looks like I need to get busy with Excel, Sketchup and HornResp to see if a DIY reproduction of a SH50 can be produced using the 4" Celestions. As I have told Paul I have a DEQX for use as an active crossover so that will easily take care of the difficult job of not messing up phase/group delay.
Good to see so much interest in this thread (and so many aussie flags on the left).
Cheers,
Mike
I wish that Danley (or someone else) would release a flat-pack kit of the SH50 or SH60 so we could easily build a quasi-full range Synergy horn at home. Mr Danley: If you are reading this then I hope you can find the time to pursue a DIY kit as you have mentioned on other forums/threads. Please sign me up as a pre-order (crossover not necessary).
Before Paul's projects and this thread I was seriously considering the baby Danley - the SM60F as it gives a good compromise on directivity (60x60) is small enough for a living room and could be crossed directly to a sub (basically a full range 4 way system). Now it looks like I need to get busy with Excel, Sketchup and HornResp to see if a DIY reproduction of a SH50 can be produced using the 4" Celestions. As I have told Paul I have a DEQX for use as an active crossover so that will easily take care of the difficult job of not messing up phase/group delay.
Good to see so much interest in this thread (and so many aussie flags on the left).
Cheers,
Mike
William, I agree completely on thinking about both at the same time. However, I just didn't want to overwhelm the thread with a tangent that might take it over.
Lately I've been thinking about some very different projects, like having a nice passive stand mount in my room as well. Actually it's more just an excuse to have more audio projects going on ....
Lately I've been thinking about some very different projects, like having a nice passive stand mount in my room as well. Actually it's more just an excuse to have more audio projects going on ....
G'day Mike
A Unity/Synergy horn is worthless without the crossover or the individual driver transfer functions. Much of the "secret sauce" is tied up in the crossover. Only half of the design is in the drivers/horn. Don't think that going active will suddenly make it easy to obtain a flat phase response from your speakers. The design effort is similar to going passive.
BTW all the info to build a copy of the original Lamdba Unity is online. My webpage even has the "secret sauce" needed to pull it together.
Paul, you probably won't like the sound of a quality two way after hearing what a well designed Unity/Synergy can do.
Cheers
William Cowan
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Hi William,
I am not sure if you have seen what a DEQX can do. The guys that have built it (also Aussies) have done an amazing job with the device and the software. It will almost completely automate the process of measurement, equalisation, time alignment and active crossover FIR for a three way system. The amazing bit is how it will calculate linear phase crossovers which should be able to at least match the Danley passive ones.
The biggest problem is that it can only time align at one point in space which is why a design like the Synergy acting as a point source is ideal.
I have got out my Excel, HornResp and basic Trigonometry and having a play...
Cheers,
Mike
I am not sure if you have seen what a DEQX can do. The guys that have built it (also Aussies) have done an amazing job with the device and the software. It will almost completely automate the process of measurement, equalisation, time alignment and active crossover FIR for a three way system. The amazing bit is how it will calculate linear phase crossovers which should be able to at least match the Danley passive ones.
The biggest problem is that it can only time align at one point in space which is why a design like the Synergy acting as a point source is ideal.
I have got out my Excel, HornResp and basic Trigonometry and having a play...
Cheers,
Mike
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Hey Paul,
I like your description of "dry sound" and how you expanded on the various different camps of thought. I think you balanced your writing well without forcing any undue bias. The approach I've found that I like the best thus far is to aim for a more narrow dispersion and "dry sound". I then balance that with some harmonic richness from a single ended tube amp. This results in what I would describe as well detailed sound with a nice organic sweetness. I find the harmonious mixture of smooth warmness coupled with great articulation very addictive. Sorry to go all “Stereophile” on you with the terms and descriptions, but that’s the best I could describe it.
I like your description of "dry sound" and how you expanded on the various different camps of thought. I think you balanced your writing well without forcing any undue bias. The approach I've found that I like the best thus far is to aim for a more narrow dispersion and "dry sound". I then balance that with some harmonic richness from a single ended tube amp. This results in what I would describe as well detailed sound with a nice organic sweetness. I find the harmonious mixture of smooth warmness coupled with great articulation very addictive. Sorry to go all “Stereophile” on you with the terms and descriptions, but that’s the best I could describe it.
Paul, great discussion. I'm also in the 90 degree camp, as my listening area.is narrow, with seating that extends to nearly in front of each speaker. I'm particularly sensitive to being restricted horizontally and want the image stable no matter how I sit or move around near the seat. My previous waveguide I made had about 75deg coverage, and didn't work as well as did 90deg horns for the time/intensity trading for wide sweet spot. Now I'm back to 90deg (SEOS15) and that is working fine. Until I start reading about your 90/40 Synergies, that is!
One issue with assymetric horns like 90/40, though, is that the vertical pattern control doesn't extend as low as the horizontal. So while the narrow pattern helps with floor reflections up higher, it falls apart too quick to help much with the Allison Effect null.
But I'm going to be trying a wide Synergy, even if the wife makes me keep it in the basement.
One issue with assymetric horns like 90/40, though, is that the vertical pattern control doesn't extend as low as the horizontal. So while the narrow pattern helps with floor reflections up higher, it falls apart too quick to help much with the Allison Effect null.
But I'm going to be trying a wide Synergy, even if the wife makes me keep it in the basement.
Update on fitting an 8PE21 to a unity. A 50 degree design seems to converge well, and could be built as 60 x 40. As shown is about as much low end as I can seem to get from it without a big size compromise. The SPL shown in Akabak is with the port velocity as also shown. I may be able to squeeze a few more dB out of it, more if the ports measure better than they sim. I'm not worried about the dip around 1kHz, but I'd just as soon not use Akabak for the crossover.
