Hi there,
Just saw yesterday that my wood distributor has baltic birch plywood in 24mm, 27mm or 30mm thickness. For my first speakers project, I used 18mm as suggested. The petite Onken were built with 24mm (25mm suggested).
I'm wondering for the 416 bass-reflex cab what should be the better option. I am tempted to go with 30mm as I saw few interesting project made with 30mm thickness and more (60mm!). But honestly, I don't have any knowledge to decide which thickness. Do you guys have any experience with 27mm or 30mm baltic birch speakers cab?
Sébastien
Just saw yesterday that my wood distributor has baltic birch plywood in 24mm, 27mm or 30mm thickness. For my first speakers project, I used 18mm as suggested. The petite Onken were built with 24mm (25mm suggested).
I'm wondering for the 416 bass-reflex cab what should be the better option. I am tempted to go with 30mm as I saw few interesting project made with 30mm thickness and more (60mm!). But honestly, I don't have any knowledge to decide which thickness. Do you guys have any experience with 27mm or 30mm baltic birch speakers cab?
Sébastien
Hi guys,
Thanks for your suggestion. I admit that the Petite Onken bracing in its own port is an excellent idea. Kaputt, did you place other bracing in yours beside the one on the original plan?
With this project, I want to keep the internal felt curtain (see picture,) which is excellent to deal with internal standing waves, and the front to back renforcement in 50mm x 50mm. This curtain in place won't leave much space for bracing. An option could be another 50mm x 50mm piece going across the cab from side to side in front of the curtain, behind or in both places.
To discuss,
Sébastien
Thanks for your suggestion. I admit that the Petite Onken bracing in its own port is an excellent idea. Kaputt, did you place other bracing in yours beside the one on the original plan?
With this project, I want to keep the internal felt curtain (see picture,) which is excellent to deal with internal standing waves, and the front to back renforcement in 50mm x 50mm. This curtain in place won't leave much space for bracing. An option could be another 50mm x 50mm piece going across the cab from side to side in front of the curtain, behind or in both places.
To discuss,
Sébastien
Attachments
Hi GM and everyone,
I've just found an enclosure resonances calculator on mh-audio website. Plus, it gives the ratio. Actually, the cab shows good quality with its projeted dimensions:
mh-audio.nl
Sébastien
I've just found an enclosure resonances calculator on mh-audio website. Plus, it gives the ratio. Actually, the cab shows good quality with its projeted dimensions:
mh-audio.nl
Sébastien
Hi there,
The work really progressed in the last month. I received in April my Great Plains Audio 416-8B. I also had the time in May to start the assembly. Picture don't show it, but I installed felt in the cabs. The port is actually not glued. I made a system which could allow to move it for adjustement. I started with a lenght that Ajmars help me calculate using a Francis Brooke's extremity correction for rectangular port.
Well, speakers are almost ready to be try! I need to sand the boxes, paint them and place the speakers and cables before a first try! I called them "416 French Connection" for inspiration and help Ajmars gave me in the project.
Here's a few pics:
The work really progressed in the last month. I received in April my Great Plains Audio 416-8B. I also had the time in May to start the assembly. Picture don't show it, but I installed felt in the cabs. The port is actually not glued. I made a system which could allow to move it for adjustement. I started with a lenght that Ajmars help me calculate using a Francis Brooke's extremity correction for rectangular port.
Well, speakers are almost ready to be try! I need to sand the boxes, paint them and place the speakers and cables before a first try! I called them "416 French Connection" for inspiration and help Ajmars gave me in the project.
Here's a few pics:
Attachments
The 416 French Connection are finish since a little bit more than one month. I joined some pictures of them painted. Comparing to the petite Onken, they offer deeper and more extented bass and a bit more dynamic impact, which place them more closer to the kind of impact of a bass-horn cab like a Voice of the Theatre but they are going deeper than the VOTT which the petite Onken already did.
I was wondering if there would be loss in the low-midrange comparing to the excellent GPA 414-8B, but I don't find any. GPA 416-8B has to my ears the same qualities as its little brother and a bit more. I actually cut it around 650 Hz with a second order filter.
I worked quite a bit to get a good cab tuning and had to play a bit also with internal treatment. I add to the felt 3 polyester pillows and ajust the lenght of the port to 125 mm that was it. You can see on the impedance measure the tuning around 30 Hz.
Sébastien
I was wondering if there would be loss in the low-midrange comparing to the excellent GPA 414-8B, but I don't find any. GPA 416-8B has to my ears the same qualities as its little brother and a bit more. I actually cut it around 650 Hz with a second order filter.
I worked quite a bit to get a good cab tuning and had to play a bit also with internal treatment. I add to the felt 3 polyester pillows and ajust the lenght of the port to 125 mm that was it. You can see on the impedance measure the tuning around 30 Hz.
Sébastien
Attachments
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Hi Sebastien,
looks awesome. how does it sound like? what compression drivers are you using for the mid/high frequency? what amplifier are you using to drive this speaker. ahhh. to much questions..
BTW i just want to share some photos of my previous project (June 24, 2016) 360L Onken,
Together with other Big Brother Speakers.
and my newly acquired all Hirata Tango Transformer 300B SET Amp for the 360L Onken
looks awesome. how does it sound like? what compression drivers are you using for the mid/high frequency? what amplifier are you using to drive this speaker. ahhh. to much questions..
BTW i just want to share some photos of my previous project (June 24, 2016) 360L Onken,
Together with other Big Brother Speakers.
and my newly acquired all Hirata Tango Transformer 300B SET Amp for the 360L Onken
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Hi Norelco,
You can read some comment above regarding the sound of them comparing to the petite Onken for example. Regarding the amplifier, I am actually using a 5687 WOT tubes preamp and a recent Kaneda design number 228+ power amplifier (29W in 8 Ohms).
Onken OS-500MT tooks care of the mid via an Onken 500Wood horn and an Onken 5000T tweeter tooks 8kHz and above.
Regarding your Onken 360L project. I tought this speaker was design to be use with Altec 416-8A. Isn't it?
Regards,
Sébastien
You can read some comment above regarding the sound of them comparing to the petite Onken for example. Regarding the amplifier, I am actually using a 5687 WOT tubes preamp and a recent Kaneda design number 228+ power amplifier (29W in 8 Ohms).
Onken OS-500MT tooks care of the mid via an Onken 500Wood horn and an Onken 5000T tweeter tooks 8kHz and above.
Regarding your Onken 360L project. I tought this speaker was design to be use with Altec 416-8A. Isn't it?
Regards,
Sébastien
The only place I found with the original felt is a company called Laoureux in France. And it is pretty expensive.
Fournisseur de feutre industriel - Laoureux.
On all my speaker's project, I used a 12 mm thick sub-floor felt which we can find easily. I has the same density as the original one.
Sébastien
Sebastien, you can find some good wool from bed company or take it from an old bed if yu ask a beds vendor... not an enthusiastic task but... it's the hobby that asks such "sacrifices"
Of course the under carpet felt is not costing much... if for any reason you want it from France, ask a french fellow fro Melaudia to buy some at "Saint Maclou" and send you, not too much expensive cause the low weight and the low price... though CE frontiers are closed (dunno fr goods though). You also may ask to a local company that "greens" the old clothes for insulating house with pannels or rolls made of it...
At the end qualofil from Dupont&Nemours seen in some pilows can be cheap (Ikea) : qualofil is basicly like hollofil fiber but wit 4 open tube in it.... surface in increased and mass-spring-mass behavior as well... theorically.
I really don't know but is it possible to tune the cabinet to make it deeper cause the Waf and putt one driver more like the Onken W but behind like do Logan Martin adding a 8 shape radiating pattern ? (although ML seems to uses one sealed volume per bass driver design for the high end line... it's not vented as an Onken)
hope that helps
Of course the under carpet felt is not costing much... if for any reason you want it from France, ask a french fellow fro Melaudia to buy some at "Saint Maclou" and send you, not too much expensive cause the low weight and the low price... though CE frontiers are closed (dunno fr goods though). You also may ask to a local company that "greens" the old clothes for insulating house with pannels or rolls made of it...
At the end qualofil from Dupont&Nemours seen in some pilows can be cheap (Ikea) : qualofil is basicly like hollofil fiber but wit 4 open tube in it.... surface in increased and mass-spring-mass behavior as well... theorically.
I really don't know but is it possible to tune the cabinet to make it deeper cause the Waf and putt one driver more like the Onken W but behind like do Logan Martin adding a 8 shape radiating pattern ? (although ML seems to uses one sealed volume per bass driver design for the high end line... it's not vented as an Onken)
hope that helps
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That's a very good idea!
The felt used in France was something Mr. Hiraga had found for bed toppers in hospitals to prevent bed sores. It was soft and came in a big roll.I just looked around the web and there are many wool felt bed toppers for sale, often inside a cover. That could work if getting some from a mattress company isn't an option.
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