These speakers were inspired by MJK's open baffle article at Quarter Wavelength Loudspeaker Design. The wide-range drivers are Radio Shack RS 40-1297. The woofers are vintage Magnavox. I used first ordered high-pass and low-pass filters tuned to 1kHz and 250Hz respectively. This is meant to equalize the predicted 500 Hz peak due to the baffle width. They could probably use a sub-woofer and super-tweeters, but I like the sound pretty well.
Attachments
Very nice NaO Note implementation with a hint of 'CS2' flavour by SAC 
www.diyaudio.com/forums/multi-way/221948-nao-note-ii-rs-44.html#post3899279
www.diyaudio.com/forums/multi-way/221948-nao-note-ii-rs-44.html#post3899279
I am humbled by some of the amazing works of art that are on display here. I'm an active AudioKarma member and just rediscovered this site after a long hiatus. Pleased to see that OB experiments are at the top of the heap!
I was inspired by a similar AK thread and used a pair of these unique Morel Integra-300 coaxial drivers on a piece of leftover OBX. I was amazed at how much I liked what I heard!
I've decided to take the OB concept further and build some baffles out of hardwood plywood. I'm still very confused about how to manipulate the bass frequency response for the best effect. If anyone can explain that in "street language" that would be great!
First question, should I center-mount the drivers on the baffle about 32" A.F.F. O/C from the floor? Or should I "mirror" the drivers to one side or the other?
THANKS!
For a crossover, I am using a very rudimentary "filter and choke". All drivers are left unattenuated for now. Once I get the baffle figured out, it will be time to tweak the crossover.
I was inspired by a similar AK thread and used a pair of these unique Morel Integra-300 coaxial drivers on a piece of leftover OBX. I was amazed at how much I liked what I heard!
I've decided to take the OB concept further and build some baffles out of hardwood plywood. I'm still very confused about how to manipulate the bass frequency response for the best effect. If anyone can explain that in "street language" that would be great!
First question, should I center-mount the drivers on the baffle about 32" A.F.F. O/C from the floor? Or should I "mirror" the drivers to one side or the other?
THANKS!
For a crossover, I am using a very rudimentary "filter and choke". All drivers are left unattenuated for now. Once I get the baffle figured out, it will be time to tweak the crossover.
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Did you use countertop from IKEA? I thought of that too for mine, but figured I'd try with plywood first. NICE!
Open Baffle HW KITS form a robust platform for almost any desired OB DIY project. Assembly is tool-less, breeze simple and fun
Plan your OB project, cut and finish your desired baffles and simply mount them (and the drivers) on your HW Kit.
Two models:
- Tower15 HW KIT is designed for drivers up to 15"
- Tower10 HW KIT is designed for drivers up to 10"
Wood feet come in standard length (92cm and 114cm) or cut and drilled to match any custom baffles configuration !
info@pureaudioproject.com
Open Baffle Hardware Kits - PureAudioProject
Plan your OB project, cut and finish your desired baffles and simply mount them (and the drivers) on your HW Kit.
Two models:
- Tower15 HW KIT is designed for drivers up to 15"
- Tower10 HW KIT is designed for drivers up to 10"
Wood feet come in standard length (92cm and 114cm) or cut and drilled to match any custom baffles configuration !
info@pureaudioproject.com
Open Baffle Hardware Kits - PureAudioProject
Attachments
"Wharfedale SFB"
Nice Briggs clones:
6moons industry features: X-Fi 2012 with Marja & Henk
Quote and image from above link.
.
Nice Briggs clones:
6moons industry features: X-Fi 2012 with Marja & Henk
Quote and image from above link.
.
Hi all,
New speakers, H frame with 2 Alpha15A, OB with Supravox 165GMF and Fountek Neo CD3.5H, and adding Fostex FT17..
Look is not impressive, but it's sounding well ( at my taste).
Phil.
New speakers, H frame with 2 Alpha15A, OB with Supravox 165GMF and Fountek Neo CD3.5H, and adding Fostex FT17..
Look is not impressive, but it's sounding well ( at my taste).
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Phil.
Crossover : 155 hz 12 db (Q 0,5) for H frame, 210 hz 12 db for Supravox 165 GMF (used in fullrange), 5800 hz 12 db for ribbon tweeter and 6 db at 35000 hz for FT17.
Response curve at listening point (3,5 m) :
No EQ, except a little like "loudness" with very low level..
Complete system : Window 8, Foobar playing on Ramdisk, Vdac 2, passive preamp, bi amping (vintage mosfet for bass and LM3886 diy for mid and hight)..
Phil.
Response curve at listening point (3,5 m) :
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
No EQ, except a little like "loudness" with very low level..
Complete system : Window 8, Foobar playing on Ramdisk, Vdac 2, passive preamp, bi amping (vintage mosfet for bass and LM3886 diy for mid and hight)..
Phil.
Hi Phil,
Can't understand few things : on the graph the crossover seems to be 350 hz ?
How do you do with a 16 cm with low qts and and small baffle to have a flat curve below 600 hz without EQ ? Why not move back the FT17 for time alignement ?
Think you will have maybe better result with a lower Qts with the bass driver with e.g. the one Troels use in him OBL 11 ! Qts is near 0.9 (more than the number given by the brand) if it is good in theory, th elack of transcient stay a bader trade off than a lower Qts and a stronger magnet : go for the little Neodyn (if it's not for the customers ...because the price of the alpha15 stays a good bargain for a 15".
At least... very near from the front wall for an OB, no ?
Anyway, hope you have good weather in the pretty Baie de Somme ! Used to have good time myself at Le Crotoy .
regards
Can't understand few things : on the graph the crossover seems to be 350 hz ?
How do you do with a 16 cm with low qts and and small baffle to have a flat curve below 600 hz without EQ ? Why not move back the FT17 for time alignement ?
Think you will have maybe better result with a lower Qts with the bass driver with e.g. the one Troels use in him OBL 11 ! Qts is near 0.9 (more than the number given by the brand) if it is good in theory, th elack of transcient stay a bader trade off than a lower Qts and a stronger magnet : go for the little Neodyn (if it's not for the customers
...because the price of the alpha15 stays a good bargain for a 15".At least... very near from the front wall for an OB, no ?
Anyway, hope you have good weather in the pretty Baie de Somme ! Used to have good time myself at Le Crotoy
.regards
Hi eldam,
Yes the crossover seems to be 350 hz, because the difference in height relative to the floor causes a hole near 380 hz. Height mid is 1,25 m and Alpha15A is 0,5 m, so at listening position (3,5m) that create a little hole.
Distance to rear wall is 0,7 m, for waf reason I must live this that !!
This causes a slight bump near 200 hz, at listening it's not a problem, just more pleasant low mid for my taste. Maybe with other Q crossover (or nice EQ) I can reduce that.
Qts of Supravox 165GMF is near 0,5, and I did not observe some big difference above 200 hz with several Qts. Below, hight Qts (1 and more) occurs more flat response.
I predict H frame with MJ King software, and this predict are very close to reality :
In this graph, crossover Q is not the same, it's LR type.
You can not see at photograph, but all cones are time alignement by impulse mesurement. Note that I don't ear the FT17 (just a little at 20 cm), but sound quality of bass are better with it.
Phil.
Next time you go to the Baie de Somme, maybe you can stop at home..
Yes the crossover seems to be 350 hz, because the difference in height relative to the floor causes a hole near 380 hz. Height mid is 1,25 m and Alpha15A is 0,5 m, so at listening position (3,5m) that create a little hole.
Distance to rear wall is 0,7 m, for waf reason I must live this that !!
This causes a slight bump near 200 hz, at listening it's not a problem, just more pleasant low mid for my taste. Maybe with other Q crossover (or nice EQ) I can reduce that.
Qts of Supravox 165GMF is near 0,5, and I did not observe some big difference above 200 hz with several Qts. Below, hight Qts (1 and more) occurs more flat response.
I predict H frame with MJ King software, and this predict are very close to reality :
An externally hosted image should be here but it was not working when we last tested it.
In this graph, crossover Q is not the same, it's LR type.
You can not see at photograph, but all cones are time alignement by impulse mesurement. Note that I don't ear the FT17 (just a little at 20 cm), but sound quality of bass are better with it.
Phil.
Next time you go to the Baie de Somme, maybe you can stop at home..
More pictures of these beautiful dipoles from here
http://www.musicalaffairs.com/home-fieldcoil/
"Mini Baffle"
Notice the speciality of ceiling firing small midrange, the essential part of the original Briggs SFB.
http://www.musicalaffairs.com/home-fieldcoil/
"Mini Baffle"
Notice the speciality of ceiling firing small midrange, the essential part of the original Briggs SFB.
Nice Briggs clones:
6moons industry features: X-Fi 2012 with Marja & Henk
Quote and image from above link.
.
