I'm building another pair of Ripole subs and sharing the build pics here. These are a bit more compact than my earlier builds.
The woofer cabs are 3/4 red oak plywood with oak edge members inserted and rounded over. This arrangement looks better than exposed plywood edges but it's a LOT more work. The "C" center section is solid brown oak indexed to the cabs with oak dowel pins. The cabs and center section are held together with all-thread rods and button head cap nuts.
The light-colored cabs will be oil stained with a mixture of 1 part golden oak, 3 parts natural, and then a bit of powdered turmeric root is added for a yellowish tint. The brown oak center section will have a darker red oak stain for a nice contrast. The finish will be two or three sprayed-on coats of clear satin polyurethane with a #320 sanding step between coats.
More to come as I complete them, but for now-- enjoy the build pics.
Below - Rabbited cab panels bank together for gluing:
Below - Cab glued and clamped:
Below- Cab edges notched on the table saw to accept edge inserts:
Below- Red oak edge inserts held in place with stretched painter’s tape while the glue sets:
Below- Cab with mitered edge inserts glued in and sanded flush:
Below - Woodwork completed on cabs and center C-section:
Below - Rear view of assembly with edges rounded to 3/8” radius on a router table:
Below - Front view, ready for stain & satin clear coat.
Below - Details stained and first coat of satin poly clear sprayed on:
More to come…
The woofer cabs are 3/4 red oak plywood with oak edge members inserted and rounded over. This arrangement looks better than exposed plywood edges but it's a LOT more work. The "C" center section is solid brown oak indexed to the cabs with oak dowel pins. The cabs and center section are held together with all-thread rods and button head cap nuts.
The light-colored cabs will be oil stained with a mixture of 1 part golden oak, 3 parts natural, and then a bit of powdered turmeric root is added for a yellowish tint. The brown oak center section will have a darker red oak stain for a nice contrast. The finish will be two or three sprayed-on coats of clear satin polyurethane with a #320 sanding step between coats.
More to come as I complete them, but for now-- enjoy the build pics.
Below - Rabbited cab panels bank together for gluing:
Below - Cab glued and clamped:
Below- Cab edges notched on the table saw to accept edge inserts:
Below- Red oak edge inserts held in place with stretched painter’s tape while the glue sets:
Below- Cab with mitered edge inserts glued in and sanded flush:
Below - Woodwork completed on cabs and center C-section:
Below - Rear view of assembly with edges rounded to 3/8” radius on a router table:
Below - Front view, ready for stain & satin clear coat.
Below - Details stained and first coat of satin poly clear sprayed on:
More to come…
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Very beautiful. I have been following your work for many years.
Made for electrostats, PPD subwoofer, inventor Alvipet.
The size is like 1/3 of the ripoles.
These are my subwoofers - layout.
Made for electrostats, PPD subwoofer, inventor Alvipet.
The size is like 1/3 of the ripoles.
These are my subwoofers - layout.
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Subwoofer from the inventors Petrenko and Petrushevsky (Alvipet).
Hole area calculation. We follow Axel's recommendations - the area of the front hole is 1/4 Sd, the area of the rear hole is 1/2 Sd.
The volume of the anterior and posterior chambers is minimal.
Unlike Ripol, there is practically no parasitic radiation at a frequency of 200-300 Hz.
The efficiency is higher than that of Ripol.
Hole area calculation. We follow Axel's recommendations - the area of the front hole is 1/4 Sd, the area of the rear hole is 1/2 Sd.
The volume of the anterior and posterior chambers is minimal.
Unlike Ripol, there is practically no parasitic radiation at a frequency of 200-300 Hz.
The efficiency is higher than that of Ripol.
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Update Wednesday 12/14/22
Waiting for the woofers to arrive--- I think the new/smaller Ripoles will look very nice 😎
Waiting for the woofers to arrive--- I think the new/smaller Ripoles will look very nice 😎
congrats it looks classssss. what drivers you planning to use and what crossover will it work till. I have visaton petite orgue and dual 10" per side i find its prssure is low need 8 drivers i think
I will be using them with my homebuilt Jazzman MkIII hybrid electrostatic main speakers . And I will use the 8-Ohm version of the Peerless SLS 12 woofers wired in parallel push/push configuration, for 4-Ohms.
I plan to cross them in at around 80Hz using a 24db or 48db slope LR filter with a DBX Driverack Venu 360 DSP/Crossover.
I plan to cross them in at around 80Hz using a 24db or 48db slope LR filter with a DBX Driverack Venu 360 DSP/Crossover.
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If your miniDSP can do a 12db slope minimum (24 is better) and you crossover below 100Hz, then I think that would be OK. sufficient. Note Ripole sized for 12" woofers will have a rather loud cavity resonance that peaks somewhere around 250Hz. So-- you need to avoid exciting the resonance by crossing over at least one octave below the resonance with a 24db filter slope (minimum)-- and if you must crossover higher, you can apply a parametric EQ to notch out the resonance peak. It's simpler to crossover low and avoid the cavity resonance.
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This is quite amazing... I've never seen a sub like this one before!
The finish on the cabinet is very nice too 🙂
Thank you!
I never use a gloss finish on red oak because the open grain wood is almost impossibly difficult to fill and would take many steps to do so and any remaining imprecations would show up like a sore thumb on a gloss finish. I just spray on a coat or two of satin poly, sand it with #320 grit the next day an spray on a final thin coat of satin. BTW, the yellow tint is from the powdered turmeric root I mixed in.
Nice do you have a build of this subs would like to build a set but what are to parameters needed in choosing the woofer to be use in this build and how much space in the front and back chamber also how high can they play to is it 200 to 300hz or can you go up to 500 Hz and would the magnet size make a difference if it's larger and coming out the other side would it matter and how low can it play in this build if the fs is 30hz would play down to 20 hz please let me know thanks in advance
Update Thursday 12/15/22:
My new Ripole subs are finally finished and I've been playing some very demanding bass tracks this evening...from Malia & Boris' album Convergence to Bela Fleck's Flight of the Cosmic Hippo-- and they sound ridiculously good.
It's astounding that subs this small (especially dipoles) can play this low, and their tonal quality is tight and clean and beautiful !
Very happy !
BTW; I can provide a freebie dimensioned CAD drawing and parts list if anyone wants it-- just PM an email address.
The perfect match for my hybrid electrostats:
My new Ripole subs are finally finished and I've been playing some very demanding bass tracks this evening...from Malia & Boris' album Convergence to Bela Fleck's Flight of the Cosmic Hippo-- and they sound ridiculously good.
It's astounding that subs this small (especially dipoles) can play this low, and their tonal quality is tight and clean and beautiful !
Very happy !
BTW; I can provide a freebie dimensioned CAD drawing and parts list if anyone wants it-- just PM an email address.
The perfect match for my hybrid electrostats:
1. The size of the speakers - from 12", better than 15". I have two 12" (Beima 12br70).
The parameters of the heads in the design is the ratio of Bl to Mms - the higher, the better. Fs preferably not higher than 35-40 Hz. A hypothetically acceptable Qts value is 0.7, but the inventor used 0.35 to 1 - also acceptable. Xmax, the more the better. SPL from 88-89 dB.
2. Front hole area 1/4 Sd, rear hole area 1/2 Sd. The volume of the anterior and posterior chambers is minimal.
3. The back hole area is 1/2 Sd, not including the magnet area.
Example: Sd = 540 cm2, D magnet = 13.4 cm, S magnet = 140 cm2, S = 0.5 * 540 + 140 = 410 cm2, D holes = 22.8 cm
The size of my subwoofers is 386x386x140 mm. Front opening 128 mm. Rear opening 224 mm.
4. My subwoofers have a magnet protruding 3 cm.
5. I have a cutoff frequency of 85-100 Hz
Shelf plays from 30 to 100 Hz.
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Link to the new PPD subwoofer topic from the inventor https://www.diyaaudio.com/community/threads/ppd-subwoofer.393371/#post-7204699
The enclosure looks like a BP6P. You guys need to post some raw REW measurements in both threads. I bet they have bandpass type curves.
Hope CharlieM does not mind me tagging on to this thread with a Ripole variation I have in mind, having been inspired by Charlie's impressive builds.
Quick background to explain why I'm thinking about a drum style 10" ripole: I originally bought an LXmini kit from Frank Brenner's Linkwitz store and later added a pair of LXsub2 kits. I like the cylindrical shape of the subs as they fit in well with the LXmini. Here's a picture of my build before I changed the basket and FR tube for a neater solution:
New top assembly now looks like this:
Hence I would like to keep the circular theme rather than square boxes.
I already have a length of the same 12" pressure pipe as I had planned to maybe just build an additional pair to see if this would help with a bit better bass capacity before I came across this Ripole idea (and similar including SL's dipole woofer 1 design). I do not want more bass as such, just the ability to handle an unexpected heavy low end from movie effects when broadcasters mess up! This happened recently when the BBC put out The English in 2-channel in what I can only assume was a downmix from surround, adding at least 10dB to the LFE channel and then adding it into the broadcast L & R channels. There is a point where there is a very low frequency effect which I measured around 30dB higher than most of the rest of the movie. Probably ok if had been in the LFE channel, it would have been sent to my four corner boxed subs but in this case it drove my LXsubs into terrible overdrive, I though the cones would part company with the rest of the driver!
Anyway, a cylinder design is my target and 10" drivers my preferred choice, only because I have a pair of them and could just buy two more, although two more of the Seas L26RO4Y D1004 drivers would cost about the same as four Peerless SLS 12" drivers, but then they would fit my pipe.....
Here's my idea for the design, any helpful comments (for or against the design) will be most appreciated. Firstly with the Seas 10" drivers:
With Peerless SLS 10" drivers:
The front cutout is 1/3 * SD * 2, the rears are each 0.67 * SD.
Assembly will be an interesting challenge, but I have some ideas for that.
Finally, a question regarding the radiation pattern of ripoles in the vertical direction? I guess still some sort of cardoid? What would happen if the sub was flipped on it's side/end?
Quick background to explain why I'm thinking about a drum style 10" ripole: I originally bought an LXmini kit from Frank Brenner's Linkwitz store and later added a pair of LXsub2 kits. I like the cylindrical shape of the subs as they fit in well with the LXmini. Here's a picture of my build before I changed the basket and FR tube for a neater solution:
New top assembly now looks like this:
Hence I would like to keep the circular theme rather than square boxes.
I already have a length of the same 12" pressure pipe as I had planned to maybe just build an additional pair to see if this would help with a bit better bass capacity before I came across this Ripole idea (and similar including SL's dipole woofer 1 design). I do not want more bass as such, just the ability to handle an unexpected heavy low end from movie effects when broadcasters mess up! This happened recently when the BBC put out The English in 2-channel in what I can only assume was a downmix from surround, adding at least 10dB to the LFE channel and then adding it into the broadcast L & R channels. There is a point where there is a very low frequency effect which I measured around 30dB higher than most of the rest of the movie. Probably ok if had been in the LFE channel, it would have been sent to my four corner boxed subs but in this case it drove my LXsubs into terrible overdrive, I though the cones would part company with the rest of the driver!
Anyway, a cylinder design is my target and 10" drivers my preferred choice, only because I have a pair of them and could just buy two more, although two more of the Seas L26RO4Y D1004 drivers would cost about the same as four Peerless SLS 12" drivers, but then they would fit my pipe.....
Here's my idea for the design, any helpful comments (for or against the design) will be most appreciated. Firstly with the Seas 10" drivers:
With Peerless SLS 10" drivers:
The front cutout is 1/3 * SD * 2, the rears are each 0.67 * SD.
Assembly will be an interesting challenge, but I have some ideas for that.
Finally, a question regarding the radiation pattern of ripoles in the vertical direction? I guess still some sort of cardoid? What would happen if the sub was flipped on it's side/end?
Further thought to be able to use the 12" Peerless SLS with my existing pipe. The driver out diameter matches the pipe outer diameter, so two pieces like this:
and a C shaped spacer between the two drivers for the front port, joined by long threaded bolts through come of the driver mounting holes. Basically a similar concept to Charlie's above but round boxes. Should have the advantage of smaller cavities for higher cabinet resonance, although in my case I'll be crossing over around 60Hz for the LXmini.
and a C shaped spacer between the two drivers for the front port, joined by long threaded bolts through come of the driver mounting holes. Basically a similar concept to Charlie's above but round boxes. Should have the advantage of smaller cavities for higher cabinet resonance, although in my case I'll be crossing over around 60Hz for the LXmini.