I have been Sitting on Purchased Speaker Driver Units to start a Three Way
Open Baffle Build for a while, and this is now looking to be my Winter Project.
I have selected Two Way box speakers to use while the Quads are out of use and the OB's take up their position.
I would like to try out a Home Built Ripole with the Quads before I dismantle the Stacked 57's, and then try out the Ripole as the first OB Sub Woofer to work with the rest of the OB Array .
I have an itch to Scratch and would like to produce a
Ripole Sub using 4 x (very used) Eminence Beta 15's, where there will be
2 x Beta's mounted in a Framing, and have a 2 x Driver Ripole produced for each Channel, to have the experience of the Ripole as a Sub Woofer Design.
I have been extracting various information supplied on here to produce a Ripole using 15 Inch Drivers.
To attempt to get the Framing Dimensions as accurate as possible to match my drivers.
I have used an information shown in a Post where the Beta's Xmax is less than 10mm at 4mm,
the Front Chamber Opening is to be calculated at 0.25 x 823.7 Sd .
The Rear Opening is to be calculated at 0.5-1 x 823.7 Sd.
I have never built a Speaker before of any type, and my Maths are not quite working out, as I don't seem to be creating any Width to a Chamber, that is close to some of the Build Plans I have reviewed ? .
I can forget this and use a Plan for a 15" Driver I have downloaded from this Forum, that has a Side Panel Dimension of 412.74mm (H) and 419.1mm (W).
The Font Chamber Opening is a 152.4mm (W),
the Rear Chamber Opening is a 76.2mm (W).
If there is a benefit from using the Driver Specification to produce the dimensions ?, then this is how I would like to proceed, and would be greatful if I can be given a Pointer to Side Panel Dimension and the Chambers Width Spacing.
The Beta's are 384.8mm in Overall Diameter and has a Depth of 153.7mm, my Side Panel dimension on Paper to accommodate this Drivers dimension is 435mm x 435mm, which was simply produced by adding an extra 25mm to the Perimeter on each plane.
Thanks in advance for any advice offered.
Open Baffle Build for a while, and this is now looking to be my Winter Project.
I have selected Two Way box speakers to use while the Quads are out of use and the OB's take up their position.
I would like to try out a Home Built Ripole with the Quads before I dismantle the Stacked 57's, and then try out the Ripole as the first OB Sub Woofer to work with the rest of the OB Array .
I have an itch to Scratch and would like to produce a
Ripole Sub using 4 x (very used) Eminence Beta 15's, where there will be
2 x Beta's mounted in a Framing, and have a 2 x Driver Ripole produced for each Channel, to have the experience of the Ripole as a Sub Woofer Design.
I have been extracting various information supplied on here to produce a Ripole using 15 Inch Drivers.
To attempt to get the Framing Dimensions as accurate as possible to match my drivers.
I have used an information shown in a Post where the Beta's Xmax is less than 10mm at 4mm,
the Front Chamber Opening is to be calculated at 0.25 x 823.7 Sd .
The Rear Opening is to be calculated at 0.5-1 x 823.7 Sd.
I have never built a Speaker before of any type, and my Maths are not quite working out, as I don't seem to be creating any Width to a Chamber, that is close to some of the Build Plans I have reviewed ? .
I can forget this and use a Plan for a 15" Driver I have downloaded from this Forum, that has a Side Panel Dimension of 412.74mm (H) and 419.1mm (W).
The Font Chamber Opening is a 152.4mm (W),
the Rear Chamber Opening is a 76.2mm (W).
If there is a benefit from using the Driver Specification to produce the dimensions ?, then this is how I would like to proceed, and would be greatful if I can be given a Pointer to Side Panel Dimension and the Chambers Width Spacing.
The Beta's are 384.8mm in Overall Diameter and has a Depth of 153.7mm, my Side Panel dimension on Paper to accommodate this Drivers dimension is 435mm x 435mm, which was simply produced by adding an extra 25mm to the Perimeter on each plane.
Thanks in advance for any advice offered.
I have just picked up on a error in my Calc's.
The Dimension of 435mm, needs to to be converted to 43.5Cm to create the Front and Rear Chamber Widths that relate to the Sd that is shown in Cm's.
As said this is a first build attempt for me.
If the Calc's below could be looked at, it would again be appreciated.
The combined Driver Sd is 823.7Cm
I am now showing a Front Chamber Width of 4.735 Cm.
I am showing the Rear Chamber Widths can be 4.67 Cm, 7.1 Cm or 9.45 Cm
when calculating the Chamber to be produced x 0.5, x 0.75, or x 1 when calculating for a single driver with a Sd 411.85 Cm.
The Dimension of 435mm, needs to to be converted to 43.5Cm to create the Front and Rear Chamber Widths that relate to the Sd that is shown in Cm's.
As said this is a first build attempt for me.
If the Calc's below could be looked at, it would again be appreciated.
The combined Driver Sd is 823.7Cm
I am now showing a Front Chamber Width of 4.735 Cm.
I am showing the Rear Chamber Widths can be 4.67 Cm, 7.1 Cm or 9.45 Cm
when calculating the Chamber to be produced x 0.5, x 0.75, or x 1 when calculating for a single driver with a Sd 411.85 Cm.
Thank You for your reply and offered advice.
I own the Tools and Materials to create the Framing, which will not be a great loss if a Mistake is made with the Driver size used.
I would prefer to get the Ripole as accurate as possible and if this means considering a alternative driver then I would be happy to be informed of my options.
The Driver Selection I have in my possession, were a very affordable purchase and are intended to be used as a Learning Experience.
If there is a Better Driver Type to used than a 15" in a Ripole,
can this be suggested, as my most recent investigations into many posts did not seem to show any negative's expressed towards Builds that had used the 15" size or any of the other Driver Sizes seen in use.
There were suggestions seen for Driver Brands and their Specifications.
I own the Tools and Materials to create the Framing, which will not be a great loss if a Mistake is made with the Driver size used.
I would prefer to get the Ripole as accurate as possible and if this means considering a alternative driver then I would be happy to be informed of my options.
The Driver Selection I have in my possession, were a very affordable purchase and are intended to be used as a Learning Experience.
If there is a Better Driver Type to used than a 15" in a Ripole,
can this be suggested, as my most recent investigations into many posts did not seem to show any negative's expressed towards Builds that had used the 15" size or any of the other Driver Sizes seen in use.
There were suggestions seen for Driver Brands and their Specifications.
The classic Ripole uses the Peerless 830669 12" woofer. See here for one of the original and widely copied designs for it:
Jazzman's DIY Electrostatic Loudspeaker Page: Ripole Subwoofers:
Also here:
RiPole Subwoofer
This thread has some info on Ripoles:
Considering ripole, but are these drivers suitable?
The self-resonance I mentioned is the peak in the black curve in this plot. The larger the driver you use, the lower in frequency that peak will appear. But with a 12" driver it works out OK.
Another question I could ask is, as the intention is to produce a Open Baffle Sub Woofer as a Trial Experience and I have the Materials available with no 'Costs Involved'
to build any OB Baffle Design I have investigated, from a Large 2mtr x 1mtr Planar Baffle down to a H or W Frame.
Where would I best use the Beta 15's and produce a Bass that is not too over bearing, as a first build.
What I do not know is if the Beta 15's are not suitable as drivers for all the Design Options I can choose to Trial.
In the Past It had been suggested that I looked into the 2mtr x 1mtr Baffle.
When investigating this, I was working with the initial placement,
and was going to Try to couple the OB Baffle Frame to the ESL 57 Stacked Framing as a first method of placement and then work with placements from this point on.
I also recall there was a suggestion to make a Bookshelf from the OB Baffle and use Corner Placement in the Room.
I would need to revisit this investigation to get back on track with all suggestions offered.
to build any OB Baffle Design I have investigated, from a Large 2mtr x 1mtr Planar Baffle down to a H or W Frame.
Where would I best use the Beta 15's and produce a Bass that is not too over bearing, as a first build.
What I do not know is if the Beta 15's are not suitable as drivers for all the Design Options I can choose to Trial.
In the Past It had been suggested that I looked into the 2mtr x 1mtr Baffle.
When investigating this, I was working with the initial placement,
and was going to Try to couple the OB Baffle Frame to the ESL 57 Stacked Framing as a first method of placement and then work with placements from this point on.
I also recall there was a suggestion to make a Bookshelf from the OB Baffle and use Corner Placement in the Room.
I would need to revisit this investigation to get back on track with all suggestions offered.
If you use a large, wide baffle keep in mind that still must be at least 1m from walls. Do you have a large enough listening room to do that?
Making a large planar baffle is certainly easy. Just get some plywood and cut a hole for the driver. Done. In a planar baffle there will not be any appreciable extra loading of the driver by the baffle, so the response you will get is just about the free air (e.g. MFG data sheet) values for Fs and Qts. With the Beta-15A you will get extension to the low 40s before rolloff begins in earnest. But it would still be a good idea to compensate for the 6dB/oct dipole rolloff or the bass may sound a bit lean.
After that, you might try to copy one of Martin King's U-frame or H-frame designs from his paper (do you have that reference). Because the Beta-15A has much lower Qts than the Alpha-15A you will again have to compensate for the extra bass rolloff you will get.
If you do some listening for each build, that will keep you busy for awhile!
Making a large planar baffle is certainly easy. Just get some plywood and cut a hole for the driver. Done. In a planar baffle there will not be any appreciable extra loading of the driver by the baffle, so the response you will get is just about the free air (e.g. MFG data sheet) values for Fs and Qts. With the Beta-15A you will get extension to the low 40s before rolloff begins in earnest. But it would still be a good idea to compensate for the 6dB/oct dipole rolloff or the bass may sound a bit lean.
After that, you might try to copy one of Martin King's U-frame or H-frame designs from his paper (do you have that reference). Because the Beta-15A has much lower Qts than the Alpha-15A you will again have to compensate for the extra bass rolloff you will get.
If you do some listening for each build, that will keep you busy for awhile!
JohnnoG,
I am considering building a Ripole too, I had built not tested thoroughly yet a 15" pair of woofers, I am going back to test jig again sometimes in the future.
One way I think is best to 'optimise the ripole freq. response for given pair of 12 or 15" woofer is build a wooden test jig(not so difficult to build) similar to this:
Views MusikBass black - ModalAkustik
notice the panel is laminated, you can increase or decrease the size(width) of the mouth/opening by introducing or removing the laminated panel(s).
I am still getting my measuring instruments for testing ready and won't be testing for a while.
I am considering building a Ripole too, I had built not tested thoroughly yet a 15" pair of woofers, I am going back to test jig again sometimes in the future.
One way I think is best to 'optimise the ripole freq. response for given pair of 12 or 15" woofer is build a wooden test jig(not so difficult to build) similar to this:
Views MusikBass black - ModalAkustik
notice the panel is laminated, you can increase or decrease the size(width) of the mouth/opening by introducing or removing the laminated panel(s).
I am still getting my measuring instruments for testing ready and won't be testing for a while.
Thank you for the further replies.
As for the Physical Side of the Build I do believe I have no concerns,
I have access to a Variety of Materials for immediate use from Plywood Boards up to 18mm x 2400mm x 1200mm (3/4 Inch x 8ft x 4ft) ,
the Plywood will be my Trial Build Material.
Then a little of the Beaten Track with material options,
Phonotherm Board 'Densified Foam' 30mm x 1800mm x 700mm
(1 1/4 Inch x 6ft x 28 Inch).
This has structural capabilities and is workable like a Wood.
Composite Sheets in 40mm (1 1/2 Inch) x 900mm x 3000mm (3ft x 10ft)
This is a Foam Sandwiched between two metal sheets 1mm (1/16 Inch)
This will work as a flat baffle of can be Shaped and Joined using Metal Angle at the connections on the framing
Aluminium Sheet 600mm x 400mm ( 24 Inch x 18 Inch)
Drivers can be mounted into this and this could be inserted into another Baffle Material
Steel Sheet 12mm x 1100mm x 700mm (1/2Inch x 3ft7Inch x 28Inch)
These are ridiculously heavy to handle, I know I one used in the HiFi Set Up at present.
It could be used as a Flat Baffle, and have a attenuated material applied to it if need be, to control any unwanted sound emission.
Where I will fall short in great measure is with the Electronics Side of things, but to help with this side of things, a Friend is happy to help me with using their measuring equipment.
ttan98
Thank you for the Link, I am keen to see reports on your Ripole Project.
As for the Physical Side of the Build I do believe I have no concerns,
I have access to a Variety of Materials for immediate use from Plywood Boards up to 18mm x 2400mm x 1200mm (3/4 Inch x 8ft x 4ft) ,
the Plywood will be my Trial Build Material.
Then a little of the Beaten Track with material options,
Phonotherm Board 'Densified Foam' 30mm x 1800mm x 700mm
(1 1/4 Inch x 6ft x 28 Inch).
This has structural capabilities and is workable like a Wood.
Composite Sheets in 40mm (1 1/2 Inch) x 900mm x 3000mm (3ft x 10ft)
This is a Foam Sandwiched between two metal sheets 1mm (1/16 Inch)
This will work as a flat baffle of can be Shaped and Joined using Metal Angle at the connections on the framing
Aluminium Sheet 600mm x 400mm ( 24 Inch x 18 Inch)
Drivers can be mounted into this and this could be inserted into another Baffle Material
Steel Sheet 12mm x 1100mm x 700mm (1/2Inch x 3ft7Inch x 28Inch)
These are ridiculously heavy to handle, I know I one used in the HiFi Set Up at present.
It could be used as a Flat Baffle, and have a attenuated material applied to it if need be, to control any unwanted sound emission.
Where I will fall short in great measure is with the Electronics Side of things, but to help with this side of things, a Friend is happy to help me with using their measuring equipment.
ttan98
Thank you for the Link, I am keen to see reports on your Ripole Project.
Beta 15 don't have enough xmax. Any open baffle sub needs drivers with decent xmax , otherwise you run the risk of over excursing.
I played with ripoles 10 years ago .... Not for me .
They don't go loud enough, they reach their limits easily, no punch .
They do sound clean though .. but everytime I used them, I was underwhelmed.
To have any chance with ripoles, you need multiple moderate qts, high xmax drivers .. and some eq/ high pass
I played with ripoles 10 years ago .... Not for me .
They don't go loud enough, they reach their limits easily, no punch .
They do sound clean though .. but everytime I used them, I was underwhelmed.
To have any chance with ripoles, you need multiple moderate qts, high xmax drivers .. and some eq/ high pass
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All OB Baffle Design Types will be considered.
I will need to learn a bit more about the framing dimensions to suit 2 x Drivers per channel.
As the Beta 15" are already owned it will probably be these used as a first experience.
I have never been a seeker of Deep Bass Notes, this is a first venture to achieve a Bass that is extended.
I will need to learn a bit more about the framing dimensions to suit 2 x Drivers per channel.
As the Beta 15" are already owned it will probably be these used as a first experience.
I have never been a seeker of Deep Bass Notes, this is a first venture to achieve a Bass that is extended.
For an H and U frame, I haven't seen it suggested for ripole but I don't see why not? In a small room it's quite effective since it's unlikely you'd be able to get them far enough away from the side wall to take much advantage of the off axis null anyway, and we are talking about low frequencies with long wavelengths
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I am doing a little reading on H Frame Dimensions, and I don't seem to be able to discover the Dimensions for a H Frame to Suit a Faming with
2 x Eminence Beta 15's per channel, even though I am discovering the
Beta 15 use as a Driver in some H Frame Projects.
I have 5 x Beta 15's available.
Could there be a method to use the Fifth Beta 15 Driver in this Subwoofer Design, to get a little extra from the Performance ?
Is there any Dimensions that can be supplied to help me get my Framing Materials cutting list produced ?
As for the Subwoofer, the First Experience will be to try them out with Stacked 57's, and then when delivering a Bass that is satisfying,
use them as part of a OB Build I am to undertake.
The advise I am working with at present, is to use the Subwoofer with Dedicated Bass Amps to help keep Xover costings down when integrating them into the Passive OB Design.
2 x Eminence Beta 15's per channel, even though I am discovering the
Beta 15 use as a Driver in some H Frame Projects.
I have 5 x Beta 15's available.
Could there be a method to use the Fifth Beta 15 Driver in this Subwoofer Design, to get a little extra from the Performance ?
Is there any Dimensions that can be supplied to help me get my Framing Materials cutting list produced ?
As for the Subwoofer, the First Experience will be to try them out with Stacked 57's, and then when delivering a Bass that is satisfying,
use them as part of a OB Build I am to undertake.
The advise I am working with at present, is to use the Subwoofer with Dedicated Bass Amps to help keep Xover costings down when integrating them into the Passive OB Design.
JohnnoG,
I thought you want to know this.
I have some experience with U frame and H frame would be similar. Both of these topologies have something in common:
1. You can cross over with the midbass at around 200-300Hz
2. You cannnot get lower Bass than the fs of the Driver.
If you have the budget buy a better quality bass driver(usually more expensive), they will give you satisfactory results.
Whereas the Ripole has these characteristics:
1. You seldom be able to cross above 150Hz more like 120Hz due mainly to rising resonance at around 150-200Hz.
2. Difficult to tame the resonance unless you DSP to do it. You can use active analog filters.
3. You can get a lower frequency response lower than the fs of the driver.
4. Easier to locate the bass module anywhere in the room.
I thought you want to know this.
I have some experience with U frame and H frame would be similar. Both of these topologies have something in common:
1. You can cross over with the midbass at around 200-300Hz
2. You cannnot get lower Bass than the fs of the Driver.
If you have the budget buy a better quality bass driver(usually more expensive), they will give you satisfactory results.
Whereas the Ripole has these characteristics:
1. You seldom be able to cross above 150Hz more like 120Hz due mainly to rising resonance at around 150-200Hz.
2. Difficult to tame the resonance unless you DSP to do it. You can use active analog filters.
3. You can get a lower frequency response lower than the fs of the driver.
4. Easier to locate the bass module anywhere in the room.
I have been through the initial thoughts of using a improved Driver,
the Fane 18XB Colossus has had my attention, but not knowing enough about Drivers Design Requirements I baulked, as that will be a another expense incurred at a very early stage of a opportunity to learn about building a OB Subwoofer.
As said I am in a Position to dedicate time to produce the Framing and have Five Beta 15's to be used 'if required', with a design in mind for 2 x Beta's per channel.
I have a Dimension on Paper for the Ripole Framing, but can't seem to find a clear defined dimension for a H Frame with 2 x 15" Driver mounted into it.
The New information offered for the Xover Points will be useful, as I can discuss these with the individual who will be helping me with the in room measurements.
I have a Listening Room, with a range of Absorption and Deflection Panels in place, so further arrangements to this room can be put in place to accommodate the positioning of the Subwoofer, without causing any concerns for their appearance.
the Fane 18XB Colossus has had my attention, but not knowing enough about Drivers Design Requirements I baulked, as that will be a another expense incurred at a very early stage of a opportunity to learn about building a OB Subwoofer.
As said I am in a Position to dedicate time to produce the Framing and have Five Beta 15's to be used 'if required', with a design in mind for 2 x Beta's per channel.
I have a Dimension on Paper for the Ripole Framing, but can't seem to find a clear defined dimension for a H Frame with 2 x 15" Driver mounted into it.
The New information offered for the Xover Points will be useful, as I can discuss these with the individual who will be helping me with the in room measurements.
I have a Listening Room, with a range of Absorption and Deflection Panels in place, so further arrangements to this room can be put in place to accommodate the positioning of the Subwoofer, without causing any concerns for their appearance.
Thank You Scott
I will produce a Frame for each channel of:
W 800mm (31 1/2 Inch) x H 450mm (18 Inch) x D 1000mm (39Inch).
I can attach if seen as useful, a Trombone Type Extension to enable a variance to the Length when working with the Setting Up of the Subwoofer.
Will being able to have a set up where a different position for the Driver Baffle within the Frame help with the setting up of the Subwoofer ?
i.e, Start with a ratio that is a 50/50 (500mm/500mm) Split and then change the Front and Rear Ratios.
I will produce a Frame for each channel of:
W 800mm (31 1/2 Inch) x H 450mm (18 Inch) x D 1000mm (39Inch).
I can attach if seen as useful, a Trombone Type Extension to enable a variance to the Length when working with the Setting Up of the Subwoofer.
Will being able to have a set up where a different position for the Driver Baffle within the Frame help with the setting up of the Subwoofer ?
i.e, Start with a ratio that is a 50/50 (500mm/500mm) Split and then change the Front and Rear Ratios.
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