Thx Mark I think I will go then for the original volume (105 liter) for the two, this sounds already very satisfying 😍😍.
I think it will be my next project.
I have the perfect donors here in my house.
Meanwhile I listen to the Super 10 Alnico with great pleasure.
I think it will be my next project.
I have the perfect donors here in my house.
Meanwhile I listen to the Super 10 Alnico with great pleasure.
Attachments
Autism Starter Pack:
1) speakers
2) bicycles
3) choo choo trains
Hi,
these are very good chassis, even compared to today's. I agree with you that the old cabinet did not really match their quality. It seems to be on the small side of the optimum. This often is a marketing decision, as smaller box may seem more attractive for the majority. I like your new design. To make your conversion a success, there are a few points you may consider.
The original speaker is W-M-T-SW-SW. The x-over was probably designed for this setup.
Your construction is W-T-M-SW-SW. This will not go well with the old x-over, as the distance M-W changes too much.
You may go for T-M-S-SW-SW without change of the x-over.
The W-SW distance is not critical, as well below beaming of the chassis.
Tweeter at listeners ear level is usually best.
Some constructions are simply made a special way, because the buyer can not differentiate how much this "special, innovative construction" does for the sound in the end. So it is simply marketing. Like the brace with damping on top. Different, but not better.
The volume of the lower cabinet is too large for my taste. If you want to get the optimum out of these woofers, place one left and the other one on the right hand side. Make the cabinet maybe 150l and tune it accordingly. Simulation will show you what makes sense with these woofers. The area of the vent has to match the area of the woofers, 1/4 minimum. This will result in longer vents. No problem, as you x-over very low.
Brace it really careful, not these small "alibi" braces in your construction. This will do more for a "dry" base than having one woofer run in a closed volume.
Think about doing the sub section aktice. Sound of the top section will in most cases improve drastically from activation. This will not not be much more expensive than a well made sub x-over with low resistance air core inductors.
A smaller Hypex should do. Do not get yourself more amp power than you ever need with class D. They play clean even at high output. 4x vented 25cm woofer have a very good efficiency. One module for both sides is OK, if really too small, you may double up later.
Have a look at the rest of the x-over. There may be room for improvements, I see (old) electrolytic's. Better replace them with new ones and match in 10% of the capacitance with film foil caps. Capacitors in parallel simply add up.
these are very good chassis, even compared to today's. I agree with you that the old cabinet did not really match their quality. It seems to be on the small side of the optimum. This often is a marketing decision, as smaller box may seem more attractive for the majority. I like your new design. To make your conversion a success, there are a few points you may consider.
The original speaker is W-M-T-SW-SW. The x-over was probably designed for this setup.
Your construction is W-T-M-SW-SW. This will not go well with the old x-over, as the distance M-W changes too much.
You may go for T-M-S-SW-SW without change of the x-over.
The W-SW distance is not critical, as well below beaming of the chassis.
Tweeter at listeners ear level is usually best.
Some constructions are simply made a special way, because the buyer can not differentiate how much this "special, innovative construction" does for the sound in the end. So it is simply marketing. Like the brace with damping on top. Different, but not better.
The volume of the lower cabinet is too large for my taste. If you want to get the optimum out of these woofers, place one left and the other one on the right hand side. Make the cabinet maybe 150l and tune it accordingly. Simulation will show you what makes sense with these woofers. The area of the vent has to match the area of the woofers, 1/4 minimum. This will result in longer vents. No problem, as you x-over very low.
Brace it really careful, not these small "alibi" braces in your construction. This will do more for a "dry" base than having one woofer run in a closed volume.
Think about doing the sub section aktice. Sound of the top section will in most cases improve drastically from activation. This will not not be much more expensive than a well made sub x-over with low resistance air core inductors.
A smaller Hypex should do. Do not get yourself more amp power than you ever need with class D. They play clean even at high output. 4x vented 25cm woofer have a very good efficiency. One module for both sides is OK, if really too small, you may double up later.
Have a look at the rest of the x-over. There may be room for improvements, I see (old) electrolytic's. Better replace them with new ones and match in 10% of the capacitance with film foil caps. Capacitors in parallel simply add up.
Thank you Tubowatch2 for your good advice and comments. I will use it in the next revised concept design.
New Concept.
Volume bracing total: 10 liter
Volume gross bas cabinet: 132 liter.
Volume net bas cabinet: 122 liter.
2 ports each 70mm x 103mm.
Tuning @ 35 Hz
37 Hz @ -3 dB
Volume bracing total: 10 liter
Volume gross bas cabinet: 132 liter.
Volume net bas cabinet: 122 liter.
2 ports each 70mm x 103mm.
Tuning @ 35 Hz
37 Hz @ -3 dB
Attachments
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Assembly Vifa Basis 95 - 2023 - 2.jpg -
Assembly Vifa Basis 95 - 2023 - 3.jpg -
Bracing 1.jpg -
Opstelling Vifa Basis 95 - 2023 - 1.jpg -
Opstelling Vifa Basis 95 - 2023 - 2.jpg -
Opstelling Vifa Basis 95 - 2023 - 3.jpg -
Opstelling Vifa Basis 95 - 2023 - 4.jpg -
Opstelling Vifa Basis 95 - 2023 - 5.jpg -
Assembly Vifa Basis 95 - 2023 - 1.jpg -
Assembly Vifa Basis 95 - 2023 - 0.jpg -
122 liter netto.JPG -
Assembly bass cabinet 1.jpg -
Assembly bass cabinet 2.jpg -
Assembly bass cabinet 3.jpg -
Assembly bass cabinet 4.jpg -
Assembly bass cabinet 5.jpg -
Assembly bass cabinet 6.jpg -
Assembly bass cabinet 7.jpg
The horizontal braces, i know you have some already, but i think the horizonyal ones don’t do much as they are.
Are teh woofer magnets coupled to the rest of the box? The horizonal right behinf the seicwea might help in that respect.
dave
Are teh woofer magnets coupled to the rest of the box? The horizonal right behinf the seicwea might help in that respect.
dave
Yes the woofers magnets coupled with the bracing.
I think I can leave this vertical bracing below.
This because the solid wood panels that I want to use again for this project are extremely stiff in that direction.
With the low frequency of the woofers it will not resonance.
I think I can leave this vertical bracing below.
This because the solid wood panels that I want to use again for this project are extremely stiff in that direction.
With the low frequency of the woofers it will not resonance.
Attachments
Last edited:
Installing the big boys this afternoon.
That sounds familiair 🙂.
Very nice 😎.
Drivers are in excellent condition 👌.
That sounds familiair 🙂.
Very nice 😎.
Drivers are in excellent condition 👌.
Attachments
Very very very Fat 😍😍😍.
Cool 😎.
Not that heigh.
Total height 1154mm 🙂😊 (original Basis '95 -> 1310mm 😕).
Tweeter at 1080mm, mmmm okay...?
Base cabinet 130 liters gross, 120 liters net.
Ports in the baffle 😛😛.
Proportion of bass cabinet and top cabinet is very nice.
Cool 😎.
Not that heigh.
Total height 1154mm 🙂😊 (original Basis '95 -> 1310mm 😕).
Tweeter at 1080mm, mmmm okay...?
Base cabinet 130 liters gross, 120 liters net.
Ports in the baffle 😛😛.
Proportion of bass cabinet and top cabinet is very nice.
Attachments
Here some small modifications.
Nice to start building them 😍 😍 .
Nice to start building them 😍 😍 .
Attachments
From my experience, the ports are a little small. Maybe make them 10cm instead of 7cm. Placing them as in the modified construction picture will load the drivers more symetrical. You don't see them from behind that often, so try to ignore your desire to make them "look in the right position" and better please the acoustics.
Second, tune a little deeper, like 30Hz or 28Hz, like 40cm long. The room will not leave even a trace of your simulated, linear response. If later, you do not like it, just shorten them, this is no big deal. In the lowest register, any dB is desired. Group delay improves, too.
Second, tune a little deeper, like 30Hz or 28Hz, like 40cm long. The room will not leave even a trace of your simulated, linear response. If later, you do not like it, just shorten them, this is no big deal. In the lowest register, any dB is desired. Group delay improves, too.
Attachments
One problem with ports is the air velocity. The higher it gets, the more losses. When the air gets turbulent, "port noise" will be audible.
So the port diameter should be in a reasonable relationship to the cone area and maximum excursion of the driver.
As your drivers are quite conservative in excursion, you should get away with ports on the smaller side.
Have a look at WinISD: The rear port air velocity. At 17m/sec we start to get uncomfortable.
Too small ports make funny, chuffing noises.
If you need very long ports, this may get problematic, but your setup will be just fine with two 40cm long 10cm diameter ports.
So no need for expensive, fancy trumpet style port constructions. Just cheap DN100 plasic pipe from your lockal "ijzerhandel".
The larger port area couples the low frequency better to the room than a small one. Remember, the port delivers the energy around the tuning frequency, while the cone movement is extremely reduced. So you can see the larger port like a larger woofer. If we replace the port with a passive radiator, we even make it larger than the driving cone.
Maybe think of including a brace for the port, about half way, like 25cm from the rear wall.
So the port diameter should be in a reasonable relationship to the cone area and maximum excursion of the driver.
As your drivers are quite conservative in excursion, you should get away with ports on the smaller side.
Have a look at WinISD: The rear port air velocity. At 17m/sec we start to get uncomfortable.
Too small ports make funny, chuffing noises.
If you need very long ports, this may get problematic, but your setup will be just fine with two 40cm long 10cm diameter ports.
So no need for expensive, fancy trumpet style port constructions. Just cheap DN100 plasic pipe from your lockal "ijzerhandel".
The larger port area couples the low frequency better to the room than a small one. Remember, the port delivers the energy around the tuning frequency, while the cone movement is extremely reduced. So you can see the larger port like a larger woofer. If we replace the port with a passive radiator, we even make it larger than the driving cone.
Maybe think of including a brace for the port, about half way, like 25cm from the rear wall.
Okay Turbowatch2, very clear! Thanks for your good advice!
I will change the ports with the PVC 110mm x 3,2mm.
Bracing the ports inside a cabinet is no problem 😎 .
I will change the ports with the PVC 110mm x 3,2mm.
Bracing the ports inside a cabinet is no problem 😎 .
Attachments
If you have some one CNC'ing the braces for free, they are fine.
If you have to pay for wood and work consider simpler bracing, which will be equaly or even more effective.
Maybe not that over engineered, but gives a virtually "dead" cabinet and diffuses reflections. I cut long stripes on the table saw and then make them fit in situ.
See the picture just as an example. I use to keep the boxes around 10x10cm. Bracing material 16-19mm strong, the height about 4-5 times the wall strength.
You can connect opposing walls, not pictured here. Such a cabinet can stand the weight of a tank, a small one at last.
If you have to pay for wood and work consider simpler bracing, which will be equaly or even more effective.
Maybe not that over engineered, but gives a virtually "dead" cabinet and diffuses reflections. I cut long stripes on the table saw and then make them fit in situ.
See the picture just as an example. I use to keep the boxes around 10x10cm. Bracing material 16-19mm strong, the height about 4-5 times the wall strength.
You can connect opposing walls, not pictured here. Such a cabinet can stand the weight of a tank, a small one at last.
