It's my pleasure when someone also has same interest with me about OB. Your first action is only need to cut your baffle, let say 24"x40" that will hold your drivers and get side wings support and then you are settled. No need fancy plywood on your first try, but if one day you think it is done then get Ikea bamboo to get nice baffle.
Then get any decent 6.5" - 8" Fullrange like Fostex, Dayton, Lowther etc and listen to it without any filter. you can proceed to add extra super tweeter: ribbon, amt, or bullet which can match FR sensitivity. Avoid any dome tweeter, they have low sensitivity. finally you can add your 18" with starting xo 200Hz 12db or 24db and increase or decrease xo point within 20Hz or 40Hz incremental.
you can also look at this guy journey
Trans-Fi Audio - OB Speakers
Then get any decent 6.5" - 8" Fullrange like Fostex, Dayton, Lowther etc and listen to it without any filter. you can proceed to add extra super tweeter: ribbon, amt, or bullet which can match FR sensitivity. Avoid any dome tweeter, they have low sensitivity. finally you can add your 18" with starting xo 200Hz 12db or 24db and increase or decrease xo point within 20Hz or 40Hz incremental.
you can also look at this guy journey
Trans-Fi Audio - OB Speakers
Hi Gadut,
Are you using Active Xover in your system ? Without an active crossover, I don't know how you can split up and adjust the the xo freq of sub, mid range and tweeter into 3 bands in b/w preamp and 3 different stereo amps or 6 mono amps into the speakers
After some readings and research, i think active crossover is the heart and soul of open baffle design in order to tweak and blend the XO freq between sub, mid and tweeter, right ? There're quite a bit of Math involved to get this XO freq right depending on different brand of Sub, mid, or tweeter that I will be using for the OB project. That's why I'm curious to know how you adjust the Xover and cutoff frequency for each in your project.
Is this the PureAudio Project you were referring to ? Why are they using 2 Sub and 1 midrange ? Is it because they want to achieve more of the lower frequency from 40 hz - 20hz with -6dB slope at the end ?
https://i.pinimg.com/originals/18/6a/ea/186aea964d668ed7f44143f203588c2a.jpg
Are you using Active Xover in your system ? Without an active crossover, I don't know how you can split up and adjust the the xo freq of sub, mid range and tweeter into 3 bands in b/w preamp and 3 different stereo amps or 6 mono amps into the speakers
After some readings and research, i think active crossover is the heart and soul of open baffle design in order to tweak and blend the XO freq between sub, mid and tweeter, right ? There're quite a bit of Math involved to get this XO freq right depending on different brand of Sub, mid, or tweeter that I will be using for the OB project. That's why I'm curious to know how you adjust the Xover and cutoff frequency for each in your project.
Is this the PureAudio Project you were referring to ? Why are they using 2 Sub and 1 midrange ? Is it because they want to achieve more of the lower frequency from 40 hz - 20hz with -6dB slope at the end ?
https://i.pinimg.com/originals/18/6a/ea/186aea964d668ed7f44143f203588c2a.jpg
Hi Tom,
I consider my system as FAST ~ 8" Fullrange ASsisTed by subwoofer and supertweeter.
currently i'm using active xo only for subwoofer, while for 8" fullrange is unfiltered then followed by additional supertweeter which only use simple 1st order filter with 0.47uF caps.
As i mentioned previously, I have tried 3way approach but using passive xo and it was a headache for me. All those theories and calculation drove me crazy, especially when I dont hear good result from the xo that i tried.
I also tried to build B5 active xo but extend to 24dB, i read you are also interested on this, however I did not finish it yet. I might revisit it someday after i complete my 5th variation which will require 15" & 8" xo, i will try it first with passive xo.
Yes indeed having active xo is a good choice, you can look at Behringer or minidsp product or other DIY solution but it is easier to build FAST as a starter.
What i mean to look at PAP is that just copy their baffle design concept, not totally follow their design. there are many other interesting design but again as a starter choose the easiest one you can build.
I consider my system as FAST ~ 8" Fullrange ASsisTed by subwoofer and supertweeter.
currently i'm using active xo only for subwoofer, while for 8" fullrange is unfiltered then followed by additional supertweeter which only use simple 1st order filter with 0.47uF caps.
As i mentioned previously, I have tried 3way approach but using passive xo and it was a headache for me. All those theories and calculation drove me crazy, especially when I dont hear good result from the xo that i tried.
I also tried to build B5 active xo but extend to 24dB, i read you are also interested on this, however I did not finish it yet. I might revisit it someday after i complete my 5th variation which will require 15" & 8" xo, i will try it first with passive xo.
Yes indeed having active xo is a good choice, you can look at Behringer or minidsp product or other DIY solution but it is easier to build FAST as a starter.
What i mean to look at PAP is that just copy their baffle design concept, not totally follow their design. there are many other interesting design but again as a starter choose the easiest one you can build.
Attachments
gadut, thank you for telling about your projects and experiences!
I started to think about wall reflections when I looked at your pictures. Obviously walls are concrete/tile and because of the room being relatively small the speakers must sit close to front and side walls. Dipoles are very sensitive to front wall reflection/interference and they need lots of free space to breathe.
Your measurements are obviously mostly at listening spot, then we see also back wall reflection and room modes... I have found that it is very difficult to get reliable and consistent measurements of bass indoors, because nearfield of a dipole doesn't tell much. Often reflected sound has more energy than direct, at listening spot!
My guess is that these problems are major factors making the challenges that you have had.
Here is John Kreskowsky's explanation of how different radiators speak with front wall. Please study all his other pages too! Boundary effects
I started to think about wall reflections when I looked at your pictures. Obviously walls are concrete/tile and because of the room being relatively small the speakers must sit close to front and side walls. Dipoles are very sensitive to front wall reflection/interference and they need lots of free space to breathe.
Your measurements are obviously mostly at listening spot, then we see also back wall reflection and room modes... I have found that it is very difficult to get reliable and consistent measurements of bass indoors, because nearfield of a dipole doesn't tell much. Often reflected sound has more energy than direct, at listening spot!
My guess is that these problems are major factors making the challenges that you have had.
Here is John Kreskowsky's explanation of how different radiators speak with front wall. Please study all his other pages too! Boundary effects
Thanks Juhazi, your building history inspired me, had a thought on baffleless build but maybe not in short time 
I agree that OB need extra room behind to breath, some say 80cm is minimum. But i dont have that luxury in my room now, i have 5x6m space on my backyard which i have to build one day (half right side on below picture) 1st floor as family room & 2nd as my children bedroom but this will be in the next 6yr after my saving is adequate. I might need around $25k to build that.
on previous month i had brought my setup to this backyard and put it on 6m side with 1m backside. Indeed i got better imaging and focus, with this experience I have to stop my greed to apply any extra mortgage for my renovation, I'd rather save money instead of paying extra interest.
The improvement that I got on moving from boxy speaker to OB is greater than what i experience from moving my system from 3x5m to 5x6m room. my point is that do not let room restriction to stop you step into OB, indeed it will give more eargasm to any room that you have instead of keeping on boxy speaker.
meanwhile for next 6yr, I will make some room treatment with diy absorber panel which also will look nice (ignore the bed, i just want to copy the idea)
I agree that OB need extra room behind to breath, some say 80cm is minimum. But i dont have that luxury in my room now, i have 5x6m space on my backyard which i have to build one day (half right side on below picture) 1st floor as family room & 2nd as my children bedroom but this will be in the next 6yr after my saving is adequate. I might need around $25k to build that.
on previous month i had brought my setup to this backyard and put it on 6m side with 1m backside. Indeed i got better imaging and focus, with this experience I have to stop my greed to apply any extra mortgage for my renovation, I'd rather save money instead of paying extra interest.
The improvement that I got on moving from boxy speaker to OB is greater than what i experience from moving my system from 3x5m to 5x6m room. my point is that do not let room restriction to stop you step into OB, indeed it will give more eargasm to any room that you have instead of keeping on boxy speaker.
meanwhile for next 6yr, I will make some room treatment with diy absorber panel which also will look nice (ignore the bed, i just want to copy the idea)
Attachments
Gadut,
Thank you for the explanation and the prompt reply. Really appreciate the input. As a starter, would you be able to share with me the good Passive XOver circuit that you are using and having good result on your OB ?
Also, you mentioned that you also built B5, do you have a full B5 schematic that you can share with me ? I'd like to give it a try and experiment with it and see how lucky I got with both active and passive Xover.
Your OB work inspired me, Gadut!
Thanks,
Tom
Thank you for the explanation and the prompt reply. Really appreciate the input. As a starter, would you be able to share with me the good Passive XOver circuit that you are using and having good result on your OB ?
Also, you mentioned that you also built B5, do you have a full B5 schematic that you can share with me ? I'd like to give it a try and experiment with it and see how lucky I got with both active and passive Xover.
Your OB work inspired me, Gadut!
Thanks,
Tom
Hi Tom,
I consider my system as FAST ~ 8" Fullrange ASsisTed by subwoofer and supertweeter.
currently i'm using active xo only for subwoofer, while for 8" fullrange is unfiltered then followed by additional supertweeter which only use simple 1st order filter with 0.47uF caps.
As i mentioned previously, I have tried 3way approach but using passive xo and it was a headache for me. All those theories and calculation drove me crazy, especially when I dont hear good result from the xo that i tried.
I also tried to build B5 active xo but extend to 24dB, i read you are also interested on this, however I did not finish it yet. I might revisit it someday after i complete my 5th variation which will require 15" & 8" xo, i will try it first with passive xo.
Yes indeed having active xo is a good choice, you can look at Behringer or minidsp product or other DIY solution but it is easier to build FAST as a starter.
What i mean to look at PAP is that just copy their baffle design concept, not totally follow their design. there are many other interesting design but again as a starter choose the easiest one you can build.
Hi Tom,
1st thing 1st, have you decided which grand design that are you going to build? with yours 18", what is your midrange & tweeter choice, will it be real 3way or fullrange? because passive xo is solely related to drivers choice.
if you choose 3way, i cant suggest you anything, it's like hunting in the wild for me. you better create a new thread and many experts will help you. midrange option can vary from 6.5" up to 12" with so many brands, plus tweeter can be a hard choice too.
btw how will you power 18"? passive xo is not an option for the beast.
If you choose simple fullrange, there are many suggestion available like my #18 post or below sample
Endorphine from Kingston Kitchen
http://www.diyaudio.com/forums/mult...lnico-baffle-lowther-america.html#post5273211
above is just general xo guideline. I suggest that you buy Audio nirvana 8" which I think it does not need any additional tweeter. Have you read best xo is no xo? so with this AN 8" you dont have to worry about any xo for midrange.
look at WalterW comment, he arrived with the same conclusion with me to use Fullrange + super tweeter with 0.47uf caps. He is also FW freak like you too with many FW clones.
http://www.diyaudio.com/forums/full-range/309794-sal-range-drivers-18.html#post5233947
related to B5, i have no schematic at all, everything is flying on my head when i build it, like always. but i use information from here
B1 Active Crossover
what i understand is that B5 basic is using dcb1 buffer, plus additional bass boost and bsc circuit where it's limited to 12dB filter. When I read B4 manual, i find it has more interesting option 24dB filter but using J74 will be very expensive
so what i build was B4 dna but using K170 only
1st thing 1st, have you decided which grand design that are you going to build? with yours 18", what is your midrange & tweeter choice, will it be real 3way or fullrange? because passive xo is solely related to drivers choice.
if you choose 3way, i cant suggest you anything, it's like hunting in the wild for me. you better create a new thread and many experts will help you. midrange option can vary from 6.5" up to 12" with so many brands, plus tweeter can be a hard choice too.
btw how will you power 18"? passive xo is not an option for the beast.
If you choose simple fullrange, there are many suggestion available like my #18 post or below sample
Endorphine from Kingston Kitchen
http://www.diyaudio.com/forums/mult...lnico-baffle-lowther-america.html#post5273211
above is just general xo guideline. I suggest that you buy Audio nirvana 8" which I think it does not need any additional tweeter. Have you read best xo is no xo? so with this AN 8" you dont have to worry about any xo for midrange.
look at WalterW comment, he arrived with the same conclusion with me to use Fullrange + super tweeter with 0.47uf caps. He is also FW freak like you too with many FW clones.
http://www.diyaudio.com/forums/full-range/309794-sal-range-drivers-18.html#post5233947
related to B5, i have no schematic at all, everything is flying on my head when i build it, like always. but i use information from here
B1 Active Crossover
what i understand is that B5 basic is using dcb1 buffer, plus additional bass boost and bsc circuit where it's limited to 12dB filter. When I read B4 manual, i find it has more interesting option 24dB filter but using J74 will be very expensive
so what i build was B4 dna but using K170 only
Attachments
Gadut,
Thank you for the reply and the links.
I will go with the full range as a starter experience with OB speaker build.
I will go with SAL driver from DIY store and pair it with 15 inch Subwoofer(I just tested out the 18in Altec sub that I inherited from someone in my family and find out that they are no longer working as I expected
I like the SAL thread http://www.diyaudio.com/forums/full-...ml#post5233947
This is what I have in mind for my 1st OB project
- Sub 15in: Altec 416-8A, Hawthorne Augie 15”, Beta, Delta, Definimax, TAD 1601's. (I like Altec 416 but not sure if I can find them these days, if not I have to go with other options that I see people are using in SAL thread) Do you have any recommendation ?
- Fullrange: Audio Nirvana 8in or SAL full range from DIY store
- Super tweeter: Fostex T90A Super Tweeter
Gadut, in your FAST system, if you use only active Xover for sub and non-filter for full range, and a 0.47uf cap for super tweeter, how would you connect your music source to the speaker ? I would assume music source go to Active Xover, then you have 2 or 3 outputs from the Active Xover to go to amplifiers to either LF, HF of speakers. Did you just only use 1 LF output from Active cross ? how would you connect your music source in this case to passive cross for full range for super tweeter ? Sorry for alot of questions. Hope you don't mind
Thanks and regards,
Tom
Thank you for the reply and the links.
I will go with the full range as a starter experience with OB speaker build.
I will go with SAL driver from DIY store and pair it with 15 inch Subwoofer(I just tested out the 18in Altec sub that I inherited from someone in my family and find out that they are no longer working as I expected
I like the SAL thread http://www.diyaudio.com/forums/full-...ml#post5233947
This is what I have in mind for my 1st OB project
- Sub 15in: Altec 416-8A, Hawthorne Augie 15”, Beta, Delta, Definimax, TAD 1601's. (I like Altec 416 but not sure if I can find them these days, if not I have to go with other options that I see people are using in SAL thread) Do you have any recommendation ?
- Fullrange: Audio Nirvana 8in or SAL full range from DIY store
- Super tweeter: Fostex T90A Super Tweeter
Gadut, in your FAST system, if you use only active Xover for sub and non-filter for full range, and a 0.47uf cap for super tweeter, how would you connect your music source to the speaker ? I would assume music source go to Active Xover, then you have 2 or 3 outputs from the Active Xover to go to amplifiers to either LF, HF of speakers. Did you just only use 1 LF output from Active cross ? how would you connect your music source in this case to passive cross for full range for super tweeter ? Sorry for alot of questions. Hope you don't mind
Thanks and regards,
Tom
Hi Tom,
i suggest you pick 15" woofer that is designed for OB, Augie should be good but maybe AE dipole will be better.
I find that MJK is happy with AE dipole and there are many other happy post about it.
8" Fullrange for OB is more common size that is used, i suggest you pick this size hence later you can swap different driver on the same hole. You have 8" option for AudioNirvana, Lowther, TangBand, etc. SAL driver is pricey and 6.5", better you start with AudioNirvana or TangBand, because spending more than $1k will be a real challenge. I will have an audition first before buying it, you can find someone near location that you can contact.
I'm using DCB1 which i add extra rca output, 1 goes to behringer that power my sub and another goes to FW clone which power 8" & T90a, easy and simple connection.
On fullrange side, you can look at T90a datashet that shows connection sample. While i'm using 0.47uf without attenuator or you can follow it.
i suggest you pick 15" woofer that is designed for OB, Augie should be good but maybe AE dipole will be better.
I find that MJK is happy with AE dipole and there are many other happy post about it.
8" Fullrange for OB is more common size that is used, i suggest you pick this size hence later you can swap different driver on the same hole. You have 8" option for AudioNirvana, Lowther, TangBand, etc. SAL driver is pricey and 6.5", better you start with AudioNirvana or TangBand, because spending more than $1k will be a real challenge. I will have an audition first before buying it, you can find someone near location that you can contact.
I'm using DCB1 which i add extra rca output, 1 goes to behringer that power my sub and another goes to FW clone which power 8" & T90a, easy and simple connection.
On fullrange side, you can look at T90a datashet that shows connection sample. While i'm using 0.47uf without attenuator or you can follow it.
Attachments
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Gadut,
Thank you so much for the valuable inputs. It is a great starting point for me. I will follow your advices to look for 8" full range and 15" sub for my OB design.
One last piece of info, when you said "I'm using DCB1 which i add extra rca output, 1 goes to behringer that power my sub and another goes to FW clone which power 8" & T90a, easy and simple connection. "
--> I would assume, you are building an active 2 way Xover using DCB1, output LP of Xover goes to behringer which power sub and output HP of Xover goes to FW clone that power 8" and T90a, right ?
Thanks,
Tom
Thank you so much for the valuable inputs. It is a great starting point for me. I will follow your advices to look for 8" full range and 15" sub for my OB design.
One last piece of info, when you said "I'm using DCB1 which i add extra rca output, 1 goes to behringer that power my sub and another goes to FW clone which power 8" & T90a, easy and simple connection. "
--> I would assume, you are building an active 2 way Xover using DCB1, output LP of Xover goes to behringer which power sub and output HP of Xover goes to FW clone that power 8" and T90a, right ?
Thanks,
Tom
hi Gadut,
It is indeed a great start! Just a bit more info that I needed before my build, all this time, I thought we *have to* use some sort of Passive or Active Xover to split the signal to LF and HP. If you use the full signal coming straight from DCB1 for both Sub and fullrange + supertweeter, do you have any kind of sound cross talk, interference b/w sub and full range ? what I mean is do we also hear vocal and high frequency coming out of Sub and bass, low freq coming out of full range ? I understand that adding sub and super tweeter is an enhancement to full range drive but I thought we need some soft of LP and UHP frequency split for sub and super tweeter ?
Thanks,
Tom
It is indeed a great start! Just a bit more info that I needed before my build
, all this time, I thought we *have to* use some sort of Passive or Active Xover to split the signal to LF and HP. If you use the full signal coming straight from DCB1 for both Sub and fullrange + supertweeter, do you have any kind of sound cross talk, interference b/w sub and full range ? what I mean is do we also hear vocal and high frequency coming out of Sub and bass, low freq coming out of full range ? I understand that adding sub and super tweeter is an enhancement to full range drive but I thought we need some soft of LP and UHP frequency split for sub and super tweeter ? Thanks,
Tom
Hi Tom,
i think it is a good time to start your build during holiday
it is just a regular dcb1, no additional filter at all. what goes to behringer and FW clone is full signal.
Hi Tom,
if you cross sub too high or T90a too low will have crosstalk effect, for me i want Fullrange to do most of the job. I had tested my sub amplifier which has internal active xo with 12dB filter between 80 & 120 Hz, i found the midbass is too dominant, hence 24dB is the best for me right now. While T90a was also tested with 1uF and was too dominant, so 0.47u the best for me.
Your ears and drivers option that are different with me will lead to different configuration, but you can start with what I had tested as starting point then adjust it later.
you might read this as your reference
Project 10 : Lowther Open Baffle / Acoustic Elegance H Frame System
if you cross sub too high or T90a too low will have crosstalk effect, for me i want Fullrange to do most of the job. I had tested my sub amplifier which has internal active xo with 12dB filter between 80 & 120 Hz, i found the midbass is too dominant, hence 24dB is the best for me right now. While T90a was also tested with 1uF and was too dominant, so 0.47u the best for me.
Your ears and drivers option that are different with me will lead to different configuration, but you can start with what I had tested as starting point then adjust it later.
you might read this as your reference
Project 10 : Lowther Open Baffle / Acoustic Elegance H Frame System
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