Perfect Q....
Hi Scott,
Some people do prefer the over-damped Q and technically you can argue its advantage.
Personally I agree with Linkwitz and the majority and go with 0.707 as the perfect Q ....It certainly sounds better!
Technically I like the balance of a 0.707 Q ie the F3 = the box resonance.
For example the box might be 50Hz and the -3dB Fs is also 50Hz.
All the best
Derek.
Hi Scott,
Some people do prefer the over-damped Q and technically you can argue its advantage.
Personally I agree with Linkwitz and the majority and go with 0.707 as the perfect Q ....It certainly sounds better!
Technically I like the balance of a 0.707 Q ie the F3 = the box resonance.
For example the box might be 50Hz and the -3dB Fs is also 50Hz.
All the best
Derek.
Hi Derek, no argument whatsoever re individual preferences for xyz box Q -I was just slightly confused by the 'transient perfect' reference you applied to Butterworth since critically damped (transient perfect) Q is 0.5, not 0.707. Technically speaking overdamped = anything less than 0.5 since it's no longer accurately tracking the signal, while anything above that is under-damped since the overshoot / settling / ringing is progressively longer.
Yes, Linkwitz et al do make some interesting points re using higher box Qs (up to 1.0 IIRC) providing system resonance is low enough to keep the response balanced within the desired passband. Worth exploring, especially if digital filtering is available. Personally I prefer a 0.5 Qtc for woofers when possible (& again, assuming F0 is low enough to meet the design requirements); with smaller units I tend to vary depending on what they're being used for, particularly if EQ is being brought into play.
Yes, Linkwitz et al do make some interesting points re using higher box Qs (up to 1.0 IIRC) providing system resonance is low enough to keep the response balanced within the desired passband. Worth exploring, especially if digital filtering is available. Personally I prefer a 0.5 Qtc for woofers when possible (& again, assuming F0 is low enough to meet the design requirements); with smaller units I tend to vary depending on what they're being used for, particularly if EQ is being brought into play.
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Q=0.707 is max flat FR not best transient response. For that a lower Q is needed. I usually target 0.58.
dave
Q-fusion
Actually, I always thought "perfect" was Q 0.707. Needless to say, I have been misinformed all this time. Not terribly surprised, as there is a lot of factual confusion in Audio. Thanks for the clarification, Scott.
Considering I will more then likely be using the array below the FS of the drivers, I will be needing to take this into consideration.
So if I was to shoot for a transient perfect sealed enclosure of Q 0.5 for this array project, the only driver I see on my current list with a Qts lower then 0.5 is the 3" Tectonic at Qts 0.46. (Assuming the data is correct). All the rest would have to be in open baffles! Not sure if I like that.
The other option is to cross the driver above the driver's FS. If I am reading into what Scott is saying, I am assuming the Q alignment of say 1.01 has minimum effect on the higher band pass above FS?
I would actually like to hear a given driver in the two different cabinets, one aligned for 0.5 and another for 0.707. When I choose a driver, I may experiment with this assuming it is even possible with the given Qts.
I can not see EQ making a high Q alignment more "transient perfect", just tame the Q peak, yes?
Actually, I always thought "perfect" was Q 0.707. Needless to say, I have been misinformed all this time. Not terribly surprised, as there is a lot of factual confusion in Audio. Thanks for the clarification, Scott.
Considering I will more then likely be using the array below the FS of the drivers, I will be needing to take this into consideration.
So if I was to shoot for a transient perfect sealed enclosure of Q 0.5 for this array project, the only driver I see on my current list with a Qts lower then 0.5 is the 3" Tectonic at Qts 0.46. (Assuming the data is correct). All the rest would have to be in open baffles! Not sure if I like that.
The other option is to cross the driver above the driver's FS. If I am reading into what Scott is saying, I am assuming the Q alignment of say 1.01 has minimum effect on the higher band pass above FS?
I would actually like to hear a given driver in the two different cabinets, one aligned for 0.5 and another for 0.707. When I choose a driver, I may experiment with this assuming it is even possible with the given Qts.
I can not see EQ making a high Q alignment more "transient perfect", just tame the Q peak, yes?
Driver choices update...
I looked over some of the newer options. These are the ones that seem to be better designed for line array applications.
Still no information on the Celestion AN3510, anybody? I am drawn to the well thought out design of this unit for this application.
Not much on the Aura NS2 outside of the Linkwitz Pluto crowd, but I am still some what curious about it, as I like the array-able design.
The Aura Dave was referring to, the NS3, I am thinking would be an option for my surround arrays.
I am still liking the Fostex FF85wk, and out of the conventional drivers on this post, it is holding the #1 spot.
And the Peerless TG9 is holding the spot for a more cost effective build...
Now on to the BMR's...
I looked over some of the newer options. These are the ones that seem to be better designed for line array applications.
Still no information on the Celestion AN3510, anybody? I am drawn to the well thought out design of this unit for this application.
Not much on the Aura NS2 outside of the Linkwitz Pluto crowd, but I am still some what curious about it, as I like the array-able design.
The Aura Dave was referring to, the NS3, I am thinking would be an option for my surround arrays.
I am still liking the Fostex FF85wk, and out of the conventional drivers on this post, it is holding the #1 spot.
And the Peerless TG9 is holding the spot for a more cost effective build...
Now on to the BMR's...
Proprietary BMRs
Derek, I read through the BMR thread and learned a lot about the BMR technology and your audio adventure in applying them to your products. I enjoyed seeing your designs progress from the 8 driver "bowls" array to the trapezoidal wall arrays with the silk surround BMRs. I think You have some strong valid points on using EQ. I can relate to having issues with using EQ, because my drivers do beam at higher frequencies. I also agree that surface area is very important, not only for distortion, but to also project a more "true to life" scale to music. I believe surface area is essential for an engaging sound stage. Like I have mentioned before, I went through a lot of point source systems to come to the conclusion that there is a lot more then tonality and time alignment. Point sources always sound far away to me. I think your music producing friend said it best "your system sounds like what I hear when changing a mic on stage" A point source can not move a large enough area of air to do that. All and all, I think You have something going for You with your products. And many consumers want an all inclusive system like yours that they can build upon as funds permit. It will be exciting watching your concept take off in today's market.
I am disappointed about one thing, and it is just one thing, and You already know what that is: Here I am all excited, getting fired up to try out some first rate BMR's with square bezels, to fit as much SD as I can between ceiling and floor, silk double surrounds and the such, only to find that I have to buy a complete "kit" with cabinets, and the such... You have done what Audience, B & G, and the Audio Artistry CBT36 have done, and You have closed off the DIY market. I really hope I am not jumping to conclusions here, and if I am, please correct me! I am sorry I am calling You out like this. I know You are concerned about people doing it wrong, and that is going to happen, but that should not affect the reputation of the workmanship of your completed products. At first, You did offer drivers, did You see the joy Jason had building his own cabinets (even though they were your design)? What I am asking here is why can't I be granted the opportunity to fail forward to success like You did when creating your products? Is that not the true essence and innovation of DIY?
I have been a professional Artist all my life (between all my other jobs), and I really enjoy woodworking and furniture design. Part of the excitement of this project is designing my own cabinets in the shape that I like and creating a hardwood mosaic patterns to inlay in the cabinets. Your wall hanging cabinets will work for my surround arrays, (although they are not the shape I want). If I have my arrays against the wall in the front of my room, I will get early reflections from the side walls. My room is more narrow then wide, but I have two large openings on each side of the room. So I place my speakers 4 feet in front of my front wall, so the outermost radiation pattern shoots into these adjacent areas to avoid early reflections. My 10 X 14 ft room sounds a lot bigger then it is.
I would like to try the BMR's, at least have a driver blow-out between them and the Fostex.
I feel like I just got the most awesome toy for Christmas, but it does not work, because I do not have the batteries!
I am truly sorry I had to bring this up, but I think someone had to say it.
On the commercial end, You have it happening
Allen
Derek, I read through the BMR thread and learned a lot about the BMR technology and your audio adventure in applying them to your products. I enjoyed seeing your designs progress from the 8 driver "bowls" array to the trapezoidal wall arrays with the silk surround BMRs. I think You have some strong valid points on using EQ. I can relate to having issues with using EQ, because my drivers do beam at higher frequencies. I also agree that surface area is very important, not only for distortion, but to also project a more "true to life" scale to music. I believe surface area is essential for an engaging sound stage. Like I have mentioned before, I went through a lot of point source systems to come to the conclusion that there is a lot more then tonality and time alignment. Point sources always sound far away to me. I think your music producing friend said it best "your system sounds like what I hear when changing a mic on stage" A point source can not move a large enough area of air to do that. All and all, I think You have something going for You with your products. And many consumers want an all inclusive system like yours that they can build upon as funds permit. It will be exciting watching your concept take off in today's market.
I am disappointed about one thing, and it is just one thing, and You already know what that is: Here I am all excited, getting fired up to try out some first rate BMR's with square bezels, to fit as much SD as I can between ceiling and floor, silk double surrounds and the such, only to find that I have to buy a complete "kit" with cabinets, and the such... You have done what Audience, B & G, and the Audio Artistry CBT36 have done, and You have closed off the DIY market. I really hope I am not jumping to conclusions here, and if I am, please correct me! I am sorry I am calling You out like this. I know You are concerned about people doing it wrong, and that is going to happen, but that should not affect the reputation of the workmanship of your completed products. At first, You did offer drivers, did You see the joy Jason had building his own cabinets (even though they were your design)? What I am asking here is why can't I be granted the opportunity to fail forward to success like You did when creating your products? Is that not the true essence and innovation of DIY?
I have been a professional Artist all my life (between all my other jobs), and I really enjoy woodworking and furniture design. Part of the excitement of this project is designing my own cabinets in the shape that I like and creating a hardwood mosaic patterns to inlay in the cabinets. Your wall hanging cabinets will work for my surround arrays, (although they are not the shape I want). If I have my arrays against the wall in the front of my room, I will get early reflections from the side walls. My room is more narrow then wide, but I have two large openings on each side of the room. So I place my speakers 4 feet in front of my front wall, so the outermost radiation pattern shoots into these adjacent areas to avoid early reflections. My 10 X 14 ft room sounds a lot bigger then it is.
I would like to try the BMR's, at least have a driver blow-out between them and the Fostex.
I feel like I just got the most awesome toy for Christmas, but it does not work, because I do not have the batteries!
I am truly sorry I had to bring this up, but I think someone had to say it.
On the commercial end, You have it happening
Allen
Available BMRs
As far as I know, I have two choices:
The 3 1/2" Tectonic seems more finished then the 3", but that dip at 1900 Hz makes me nervous as I am not sure if this is something EQ can fix. Also, this has a ferrite magnet and a non-truncated bezel.
The 3" Tectonic seems like a better spec-ed driver with a Neo magnet, but the bezel has a lip sticking out all the way around. My NSB's had that poor design aspect. I think Derek called that "CD" - lowest Common Demoninator!
So needless to say, neither of those options are a go. Are there any other BMR options?
As far as I know, I have two choices:
The 3 1/2" Tectonic seems more finished then the 3", but that dip at 1900 Hz makes me nervous as I am not sure if this is something EQ can fix. Also, this has a ferrite magnet and a non-truncated bezel.
The 3" Tectonic seems like a better spec-ed driver with a Neo magnet, but the bezel has a lip sticking out all the way around. My NSB's had that poor design aspect.
I think Derek called that "CD" - lowest Common Demoninator!So needless to say, neither of those options are a go. Are there any other BMR options?
Periphery HF emission
Any examples?
Do any of the drivers I have considered have this characteristic? (I am thinking the BMR's might)
Thanks in advance...
Any examples?
Do any of the drivers I have considered have this characteristic? (I am thinking the BMR's might)
Thanks in advance...
My Room
Here is the current layout of the room in a 4.2 set-up, with the Aveburys in the front and the arrays in the back. The back speaker locations are not ideal, but it does work better then You would expect. Side wall mounted THX di-poles would work good in this room. As You can see, 7 main channels would be over kill, but for movies, I do prefer 4 channel compared to a 2 channel mix down. For music, I definitely prefer 2 channel. I move the arrays from front to back quite a bit.
As some of You already know, I swap The Avebury and arrays all the time. Avebury has the tonality and DDR, and the Arrays have the encompassing, engaging sound field. My goal is to have the best of both systems for this project.
Also, I will be figuring something to do with the back wall, as it is so close to the main listening area. Right now, I have a heavy fir rug hanging up there, which does help, but more needs to be done...
Here is the current layout of the room in a 4.2 set-up, with the Aveburys in the front and the arrays in the back. The back speaker locations are not ideal, but it does work better then You would expect. Side wall mounted THX di-poles would work good in this room. As You can see, 7 main channels would be over kill, but for movies, I do prefer 4 channel compared to a 2 channel mix down. For music, I definitely prefer 2 channel. I move the arrays from front to back quite a bit.
As some of You already know, I swap The Avebury and arrays all the time. Avebury has the tonality and DDR, and the Arrays have the encompassing, engaging sound field. My goal is to have the best of both systems for this project.Also, I will be figuring something to do with the back wall, as it is so close to the main listening area. Right now, I have a heavy fir rug hanging up there, which does help, but more needs to be done...
Attachments
Commercial products beta tested in DIY market?
Hiya Allen,
Phew.....So much for quiet Sunday lunchtime DIY forum chat....!
Hopefully I will be able to explain why we have to focus on the commercial stuff first & why we cant release the drivers / DSP directly to the DIY market.
After all ATC (and many others) dont release their best drivers to the DIY market for commercial reasons and everyone loves them....
Other members may get a bit bored with my OT ramblings here so happy to PM more ideas on some beta test type deals if thats something you want to try?
I will just bullet point a few answers here:
(1) Its taken longer than expected to develop the new BMR's (over 4 years) with costs higher than expected (well over £100K) if we include the DSP / Manchester University joint venture funding, so repaying the investors and generating a profit this has to our first priority, morally and legally!
(2) We can not launch with DIY kits / drivers / DSP / electronics as the DIY market is so small we would take 10 years or more to break even! You would be surprised just how few DIY guys are interested in spending £300 to £3,000 on drivers......Lots of talk but not many Pay Pay transfers!!
(3) The Professional mixing / mastering studios (music, movies & now gaming) are the ultimate "proof of concept" as the top guys in that industry demand the very best performance and build quality (reliability) and have no hang ups about branding or nostalgic technology (valves are not required!!) so a new brand with new ideas and products is given a level playing field to win market share.....This is where we must focus.
(4) We are already getting "OMG / WTF have you done!" type responses from the few studio guys and musicians we have demo'd to....The final versions are still being developed but we are getting close to signing off the studio monitor design.
(5) Once this is done, we might be able to sell some driver / DSP / amp packages as part of a beta test program. The format would not be to important ie Line Arrays or studio monitors, as long as the drivers / DSP amps get used correctly and the customer agrees to fill in a monthly system check list for a 6 month period.
These deals would be very limited in numbers and have to be agreed on an individual basis.
All the best
Derek.
Derek, I read through the BMR thread and learned a lot about the BMR technology and your audio adventure in applying them to your products. I enjoyed seeing your designs progress from the 8 driver "bowls" array to the trapezoidal wall arrays with the silk surround BMRs. I think You have some strong valid points on using EQ. I can relate to having issues with using EQ, because my drivers do beam at higher frequencies. I also agree that surface area is very important, not only for distortion, but to also project a more "true to life" scale to music. I believe surface area is essential for an engaging sound stage. Like I have mentioned before, I went through a lot of point source systems to come to the conclusion that there is a lot more then tonality and time alignment. Point sources always sound far away to me. I think your music producing friend said it best "your system sounds like what I hear when changing a mic on stage" A point source can not move a large enough area of air to do that. All and all, I think You have something going for You with your products. And many consumers want an all inclusive system like yours that they can build upon as funds permit. It will be exciting watching your concept take off in today's market.
I am disappointed about one thing, and it is just one thing, and You already know what that is: Here I am all excited, getting fired up to try out some first rate BMR's with square bezels, to fit as much SD as I can between ceiling and floor, silk double surrounds and the such, only to find that I have to buy a complete "kit" with cabinets, and the such... You have done what Audience, B & G, and the Audio Artistry CBT36 have done, and You have closed off the DIY market. I really hope I am not jumping to conclusions here, and if I am, please correct me! I am sorry I am calling You out like this. I know You are concerned about people doing it wrong, and that is going to happen, but that should not affect the reputation of the workmanship of your completed products. At first, You did offer drivers, did You see the joy Jason had building his own cabinets (even though they were your design)? What I am asking here is why can't I be granted the opportunity to fail forward to success like You did when creating your products? Is that not the true essence and innovation of DIY?
I have been a professional Artist all my life (between all my other jobs), and I really enjoy woodworking and furniture design. Part of the excitement of this project is designing my own cabinets in the shape that I like and creating a hardwood mosaic patterns to inlay in the cabinets. Your wall hanging cabinets will work for my surround arrays, (although they are not the shape I want). If I have my arrays against the wall in the front of my room, I will get early reflections from the side walls. My room is more narrow then wide, but I have two large openings on each side of the room. So I place my speakers 4 feet in front of my front wall, so the outermost radiation pattern shoots into these adjacent areas to avoid early reflections. My 10 X 14 ft room sounds a lot bigger then it is.
I would like to try the BMR's, at least have a driver blow-out between them and the Fostex.
I feel like I just got the most awesome toy for Christmas, but it does not work, because I do not have the batteries!
I am truly sorry I had to bring this up, but I think someone had to say it.
On the commercial end, You have it happening
Allen
Hiya Allen,
Phew.....So much for quiet Sunday lunchtime DIY forum chat....!
Hopefully I will be able to explain why we have to focus on the commercial stuff first & why we cant release the drivers / DSP directly to the DIY market.
After all ATC (and many others) dont release their best drivers to the DIY market for commercial reasons and everyone loves them....
Other members may get a bit bored with my OT ramblings here so happy to PM more ideas on some beta test type deals if thats something you want to try?
I will just bullet point a few answers here:
(1) Its taken longer than expected to develop the new BMR's (over 4 years) with costs higher than expected (well over £100K) if we include the DSP / Manchester University joint venture funding, so repaying the investors and generating a profit this has to our first priority, morally and legally!
(2) We can not launch with DIY kits / drivers / DSP / electronics as the DIY market is so small we would take 10 years or more to break even! You would be surprised just how few DIY guys are interested in spending £300 to £3,000 on drivers......Lots of talk but not many Pay Pay transfers!!
(3) The Professional mixing / mastering studios (music, movies & now gaming) are the ultimate "proof of concept" as the top guys in that industry demand the very best performance and build quality (reliability) and have no hang ups about branding or nostalgic technology (valves are not required!!) so a new brand with new ideas and products is given a level playing field to win market share.....This is where we must focus.
(4) We are already getting "OMG / WTF have you done!" type responses from the few studio guys and musicians we have demo'd to....The final versions are still being developed but we are getting close to signing off the studio monitor design.
(5) Once this is done, we might be able to sell some driver / DSP / amp packages as part of a beta test program. The format would not be to important ie Line Arrays or studio monitors, as long as the drivers / DSP amps get used correctly and the customer agrees to fill in a monthly system check list for a 6 month period.
These deals would be very limited in numbers and have to be agreed on an individual basis.
All the best
Derek.
To such tests under controlled SPL wouldn't Linkwitz transform inside JRiver's DSP engine be a perfect tool.
Attachments
If you like the sound of an A7.3 but want a tighter square bezel and lower cost - the Peerless P830986 should be on your list to look at. It has an aluminum cone with a very large breakup peak around 12k that gives it that enhanced ring induced audibility of low level detail.
http://www.parts-express.com/pedocs/specs/264-1056-peerless-830986-specifications.pdf
http://www.parts-express.com/pedocs/specs/264-1056-peerless-830986-specifications.pdf
Do You have your dream house drawn up yet?
Thanks Derek,
I both admire and appreciate that You took the time to respond.
As I am considering BMR drivers for my arrays, and it is apparent that You have put a lot of passion into developing the BMR technology farther, other DIY readers of this thread who are curious about BMR's may also be wondering why they can not acquire your drivers.
In response to your points:
(1) First off, congratulations that You got investment support for your concept. That is an honor very few of us have the luxury to partake in.
(2) Sad but true. Yet there are some of us (very, very, very few) that are seeking passionately designed components to match our passionately labored DIY efforts. Considering the work it takes to build a pair of floor to ceiling arrays that are going to be jazzed up with solid wood mosaic inlays, I may as well spend the money and get some good drivers. If I go with the Fostex FF85wk, 32/cabinet, I am looking at spending $2560 plus shipping. But I will include a confession here: I will be buying the drivers in groups of 10 as funds become available, no hurry as the cabinets are going to take a while to build
(3) & (4) You are seeing it BIG, which means You are crazy enough to succeed! (That is a compliment - by the way!)
(5) So I can design my own cabinets (to your "proven" volume and other parameters) using your "proven" synergy of DSP, DAC and Amps; and design a customized system for my room; and report results from personal discoveries and "required" experiments on your behalf? Depending on where this current project leads me, that may be something I am interested in.
Now back to the possibilities now: (and I am still addressing Derek)
I am still interested in the BMR concept, esp if I can find a decent driver to experiment with. Initially, when You were using the CSS 4.5 unit, you mentioned that being a good size, as it provided enough driving surface area and a reasonable compromise in the highs. The two Tectonic drivers are smaller, meaning less low, but maybe better highs? Would it be worth considering these if I was to run them at 300 Hz and higher, and build a bass line for the lows? I would like to find some 6" or 8" drivers for the bass line, (this would be floor to ceiling also), but I am not sure if any are available that meet the specs You mentioned earlier. (low Q, non-rubber surround, large voice coil, in small sealed enclosures, EQed for the felt bass). If course all of this rests on if the Tectonic drivers are even worth playing with quality wise.
Also, You mentioned about running the woofer and main lines as separate cabinets or as one cabinet. What has been your experience using either of these design approaches, bearing in mind using DSP for time alignment.
Thanks again for your honest and straight forward approach... You inspired me so much that I had a creative crash when I realized I could not buy your drivers... yet! (And I do not think I am the only one
Allen
Phew.....So much for quiet Sunday lunchtime DIY forum chat....!
Thanks Derek,
I both admire and appreciate that You took the time to respond.
As I am considering BMR drivers for my arrays, and it is apparent that You have put a lot of passion into developing the BMR technology farther, other DIY readers of this thread who are curious about BMR's may also be wondering why they can not acquire your drivers.
In response to your points:
(1) First off, congratulations that You got investment support for your concept. That is an honor very few of us have the luxury to partake in.
(2) Sad but true. Yet there are some of us (very, very, very few) that are seeking passionately designed components to match our passionately labored DIY efforts. Considering the work it takes to build a pair of floor to ceiling arrays that are going to be jazzed up with solid wood mosaic inlays, I may as well spend the money and get some good drivers.
If I go with the Fostex FF85wk, 32/cabinet, I am looking at spending $2560 plus shipping. But I will include a confession here: I will be buying the drivers in groups of 10 as funds become available, no hurry as the cabinets are going to take a while to build (3) & (4) You are seeing it BIG, which means You are crazy enough to succeed! (That is a compliment - by the way!)
(5) So I can design my own cabinets (to your "proven" volume and other parameters) using your "proven" synergy of DSP, DAC and Amps; and design a customized system for my room; and report results from personal discoveries and "required" experiments on your behalf? Depending on where this current project leads me, that may be something I am interested in.
Now back to the possibilities now: (and I am still addressing Derek)
I am still interested in the BMR concept, esp if I can find a decent driver to experiment with. Initially, when You were using the CSS 4.5 unit, you mentioned that being a good size, as it provided enough driving surface area and a reasonable compromise in the highs. The two Tectonic drivers are smaller, meaning less low, but maybe better highs? Would it be worth considering these if I was to run them at 300 Hz and higher, and build a bass line for the lows? I would like to find some 6" or 8" drivers for the bass line, (this would be floor to ceiling also), but I am not sure if any are available that meet the specs You mentioned earlier. (low Q, non-rubber surround, large voice coil, in small sealed enclosures, EQed for the felt bass). If course all of this rests on if the Tectonic drivers are even worth playing with quality wise.
Also, You mentioned about running the woofer and main lines as separate cabinets or as one cabinet. What has been your experience using either of these design approaches, bearing in mind using DSP for time alignment.
Thanks again for your honest and straight forward approach... You inspired me so much that I had a creative crash when I realized I could not buy your drivers... yet! (And I do not think I am the only one
Allen
Thanks X, I will see if I can find a CSD. This driver is in the same price range as the TG9, a blow-out between these two would be quite interesting.
I will need to revisit the Linkwitz site, to remember what this is all about, it has been awhile...
Input for invetigation phase
If add a bass line too is no problem as with the BMRs then what about 2½” SB65WBAC25-4 it could yield a nice tight spacing and has HF extension as a tweeter.
Link to shared distortion plots by 5th element http://www.diyaudio.com/forums/full...in-5in-full-range-drivers-43.html#post4257521, and general recommendation http://www.diyaudio.com/forums/full-range/268626-vifa-tc9fd18-08-best-bang-buck-21.html#post4247643.
xrk971 have a pair mayby he could make comment his experience their sound quality http://www.diyaudio.com/forums/full-range/273211-sb-acoustics-sb65wbac25-4-what-do.html.
Picture two show its propotional size compared a A7.3.
If add a bass line too is no problem as with the BMRs then what about 2½” SB65WBAC25-4 it could yield a nice tight spacing and has HF extension as a tweeter.
Link to shared distortion plots by 5th element http://www.diyaudio.com/forums/full...in-5in-full-range-drivers-43.html#post4257521, and general recommendation http://www.diyaudio.com/forums/full-range/268626-vifa-tc9fd18-08-best-bang-buck-21.html#post4247643.
xrk971 have a pair mayby he could make comment his experience their sound quality http://www.diyaudio.com/forums/full-range/273211-sb-acoustics-sb65wbac25-4-what-do.html.
Picture two show its propotional size compared a A7.3.
Attachments
Last edited:
Hi Allen,
Thank you for your kind words and enthusiasm for my designs....I am genuinely flattered.....Que the Australian bar maid joke...." Well I do now ya smooth talking bas****"!!....Now I feel obligated to releasing some DIY drivers!!
It sounds like you are very serious about researching and developing a SOTA line array and whilst I am very wary of my drivers being used incorrectly and DIY nightmares causing commercial customers to doubt the commercial products, there might be a way to help each other achieve our goals.....
You want the very best system you can afford with minimum of risk and headaches.
I would be delighted to see a killer BMR line array used as a North American demo reference for the DIY community.
Especially if the process involves comparisons with a range of other top drivers / DIY kits.....I have already satisfied myself how they compare with the latest Jordan Eikonas / Lowther, various Pro drivers and Manger, but it would be great to get independent comparisons as well.
Ok, there must be some way to work together on this....
I will have a think and get back to you later in the week on this.
Re your technical questions, I will answer them later tonight.
Must dash
Cheers
Derek.
That is a sharp looking driver. I could fit 40 -42 of these per channel, bringing the price to $1340/channel. This is in the same price bracket as the Fostex, so they would be compared in that light.
When I do the driver blow-outs, I can set these up as a FAST system, using my Avebury cabinets for the Lows, as that would allow me a cross-over point between 150 - 300 Hz and really good integration due to the Alpair 12. Once I found the full-ranger I like for the mids and highs, I would then find a suitable mid-bass for the bass arrays. Who knows, maybe a line of Alpair 12s.
I have not heard the Alpair 7, but I would be interested in your impressions between the Alpair and the SB Acoustics. Better yet would be impressions between the FF85wk and the SB65W. I really like the off-axis response of the SB, considering it is not a BMR.
The part I really want right with this system is the 1 kHz - 6 kHz range. I want this area clean of any "nasties" what so ever. I also want the best off axis dispersion behavior possible in this area. I do not mind EQing the response if it is solely a response issue, verses a break-up, resonance, or wacko phasing issue (which can not be fixed with EQ. Reasonable phasing issues might be able to be fixed with convolution). At the very least, I want the selected driver to play down to at least 300 Hz with a reasonable cross-over. I will play with cross-over slopes more during the driver blow-outs.
It looks like the SB acoustics fits this criteria well. Will need to check out a CSD on this also. This unit has a tough running mate: the FF85wk.
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