Hi,
I'm pleased to announce the new CSS EL70 extended full range loudspeaker designed and built by Mark Fenlon of Mark Audio in Hong Kong. Over the past year or so, Mark and I spent time talking about the need for a smaller "classic" paper cone driver with extended frequency range. Both of us recognized the need for a moderately priced driver capable of providing audiophile grade output and that's easy to use in a wide variety of applications. The EL70's frequency range is ultra-wide (Fs=64Hz, Fr to 25-kHz @+80dB). It’s very capable of delivering extended low bass response and with a Qts of 0.55 is usable in many box designs. Applications range from close field desk top, small BR for power handling, larger BR for extended range, MLTL, horn etc.
The first batch is on its way from China and should arrive in Vancouver around August 17th. Prototypes and the first production units are scattered around the globe as a number of DIY people are co-operating on a variety of cabinet designs. These will be released over the next few weeks and the plan is to compile them all into one place for easy distribution.
For now there will be 3 SKUs set up on the CSS website, although others may also be developed. All drivers include mounting screws and gaskets. Here are the initial prices for the first month.
EL70 single driver US $45, C$ 50
EL70KITP1 2 drivers, 2 ports, 2 sets of binding posts, 16 gauge wire, connectors US $90, C$ 100
EL70KITP2 4 drivers, 2 ports, 2 sets of binding posts, 16 gauge wire, connectors US $170, C$ 185.
Dr Jim Griffin showed his design with 2 EL70s per cabinet at the Dayton DIY event on July 11th. He will also show these at the Atlanta DIY event August 8th. A pair of EL70s as well as a pair of Mark Audio Alpair 10s will be given away at that event.
Stay tuned, more to follow.
Bob
I'm pleased to announce the new CSS EL70 extended full range loudspeaker designed and built by Mark Fenlon of Mark Audio in Hong Kong. Over the past year or so, Mark and I spent time talking about the need for a smaller "classic" paper cone driver with extended frequency range. Both of us recognized the need for a moderately priced driver capable of providing audiophile grade output and that's easy to use in a wide variety of applications. The EL70's frequency range is ultra-wide (Fs=64Hz, Fr to 25-kHz @+80dB). It’s very capable of delivering extended low bass response and with a Qts of 0.55 is usable in many box designs. Applications range from close field desk top, small BR for power handling, larger BR for extended range, MLTL, horn etc.
The first batch is on its way from China and should arrive in Vancouver around August 17th. Prototypes and the first production units are scattered around the globe as a number of DIY people are co-operating on a variety of cabinet designs. These will be released over the next few weeks and the plan is to compile them all into one place for easy distribution.
For now there will be 3 SKUs set up on the CSS website, although others may also be developed. All drivers include mounting screws and gaskets. Here are the initial prices for the first month.
EL70 single driver US $45, C$ 50
EL70KITP1 2 drivers, 2 ports, 2 sets of binding posts, 16 gauge wire, connectors US $90, C$ 100
EL70KITP2 4 drivers, 2 ports, 2 sets of binding posts, 16 gauge wire, connectors US $170, C$ 185.
Dr Jim Griffin showed his design with 2 EL70s per cabinet at the Dayton DIY event on July 11th. He will also show these at the Atlanta DIY event August 8th. A pair of EL70s as well as a pair of Mark Audio Alpair 10s will be given away at that event.
Stay tuned, more to follow.
Bob
I will also mention that in cooperation with Bob & Mark, a limited number of these will be treated, matched, and sold as Planet10-HiFi EL70eN.
As well, some consideration is being given to an upgrade programme for those who wish to upgrade stock drivers at a later date.
Contact me about pre-order pricing. (i'm expecting mine will start dribbling out early September)
dave
As well, some consideration is being given to an upgrade programme for those who wish to upgrade stock drivers at a later date.
Contact me about pre-order pricing. (i'm expecting mine will start dribbling out early September)
dave
Hi Guys,
I think forum members may like a little background from me on the EL70.
For some time I felt the lower cost end of the full range driver market needed drivers that could deliver greater performance. The CHR-70 was the first driver I made to meet the need for increasing performance demands of custom builders on a budget. Its giving an extended lease of DIY life to many builders. The CHR70 will continue to be available with some minor revisions coming soon.
The EL70 takes the concept further. Bob and me spent time consulting many members of this forum to gain insight. Many guys said they wanted a driver that's easy to use in a variety of box designs, have a wide range and deliver audiophile grade detail. More bass delivery was also wanted.
So, I opted to produce a range of driver models based around my 70-mm cone design. Bob encouraged me to explore paper and produce a design, thus the EL70 was born.
The EL70 is designed with a low Fo while maintaining a useful Qts above 0.5. The damping at this level means the driver will be good at handling power in smaller boxes or extended range in larger boxes. This level of flexibility was high on the "wish list" of many home builders.
Many guys complained about the lack of high range in lower cost drivers. The EL70 is the first of the 70-mm cone model drivers that works towards meeting this challenge. This driver really does help to do away with the need for a tweeter. So full range single driver purists, have fun!
I've produced a batch of EL's that will go to Dave (Planet 10) for Enabling. This holds the prospect for the supply of an up-market version of the EL70.
This gives you a snapshot of the thinking that went into the EL70 concept.
Bob will publish more data soon.
Cheers,
Mark.
I think forum members may like a little background from me on the EL70.
For some time I felt the lower cost end of the full range driver market needed drivers that could deliver greater performance. The CHR-70 was the first driver I made to meet the need for increasing performance demands of custom builders on a budget. Its giving an extended lease of DIY life to many builders. The CHR70 will continue to be available with some minor revisions coming soon.
The EL70 takes the concept further. Bob and me spent time consulting many members of this forum to gain insight. Many guys said they wanted a driver that's easy to use in a variety of box designs, have a wide range and deliver audiophile grade detail. More bass delivery was also wanted.
So, I opted to produce a range of driver models based around my 70-mm cone design. Bob encouraged me to explore paper and produce a design, thus the EL70 was born.
The EL70 is designed with a low Fo while maintaining a useful Qts above 0.5. The damping at this level means the driver will be good at handling power in smaller boxes or extended range in larger boxes. This level of flexibility was high on the "wish list" of many home builders.
Many guys complained about the lack of high range in lower cost drivers. The EL70 is the first of the 70-mm cone model drivers that works towards meeting this challenge. This driver really does help to do away with the need for a tweeter. So full range single driver purists, have fun!
I've produced a batch of EL's that will go to Dave (Planet 10) for Enabling. This holds the prospect for the supply of an up-market version of the EL70.
This gives you a snapshot of the thinking that went into the EL70 concept.
Bob will publish more data soon.
Cheers,
Mark.
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I have always loved the Vifa "classic" paper cone drivers. And I love my CHR-70's in their dual-chamber reflex box which replace my PL11-based MT. I believe these could be the "b*st*rd love child" that I've been wanting to build my first set of "epic" speakers. Now that I'm working again, I think I'll be ordering the quad-set package from CCS.
Gentlemen, fine work and I'm looking forward to published measurements and all the future impressions.
Gentlemen, fine work and I'm looking forward to published measurements and all the future impressions.
Hi Lemarchand,
The EL70 is a different driver from the FR125. The cone employed on the EL70 uses a new forming process to create its profile. The cap on the EL is directly bonded to the coil former while the FR has a fixed phase plug. The FR uses XBL while the EL70 has a twin ferrite magnet arrangement with shielding.
Hi Speakrsfun,
The EL''s wont break the bank so don't worry. Enjoy the full range fun!
Hope this helps,
Mark.
The EL70 is a different driver from the FR125. The cone employed on the EL70 uses a new forming process to create its profile. The cap on the EL is directly bonded to the coil former while the FR has a fixed phase plug. The FR uses XBL while the EL70 has a twin ferrite magnet arrangement with shielding.
Hi Speakrsfun,
The EL''s wont break the bank so don't worry. Enjoy the full range fun!
Hope this helps,
Mark.
Hi,
The EL70 does not use XBL though Mark and I have talked about using it on future product. The main differences with the FR125SR is the higher sensitivity of the EL which was a very specific goal. Since both use paper cones there will be similarities in the overall sound. The technology employed in forming the EL70 cone is new and bodes well for further cone development. With a slightly higher Xmax and larger voice coil the FR will handle a little more power but that is so often enclosure loading dependent.
Given the large number of enclosure designs that will be released in the next weeks it is clear that the EL parameters support a very wide range of designs. The manufacturing track record evident in all Mark Audio productions also means the driver to driver consistancy will be higher with the EL70.
We expect to be doing some extensive listening comparisons in a couple of weeks at the Vancouver Island DIY event at Dave's so look forward to those results and impressions.
Bob
The EL70 does not use XBL though Mark and I have talked about using it on future product. The main differences with the FR125SR is the higher sensitivity of the EL which was a very specific goal. Since both use paper cones there will be similarities in the overall sound. The technology employed in forming the EL70 cone is new and bodes well for further cone development. With a slightly higher Xmax and larger voice coil the FR will handle a little more power but that is so often enclosure loading dependent.
Given the large number of enclosure designs that will be released in the next weeks it is clear that the EL parameters support a very wide range of designs. The manufacturing track record evident in all Mark Audio productions also means the driver to driver consistancy will be higher with the EL70.
We expect to be doing some extensive listening comparisons in a couple of weeks at the Vancouver Island DIY event at Dave's so look forward to those results and impressions.
Bob
CSS/XBL said:
yes, Bob - too many designs for us to possibly build all of them - but I think it's fair to say there's probably something for just about everyone, and I do love what I've been able to hear so far
edit:
Have you or Mark had a chance to measure these yet? At the very least, I think the @80dB figure for sensitivity is low.
Henkjan EL70 Desktop TL
Here is the 1st one:
Plans
dave
Here is the 1st one:
An externally hosted image should be here but it was not working when we last tested it.
Plans
dave
Hi Guys,
Bob has asked me to point out some features on the EL70. Much of the following info also applies to my other designs.
Please take a look at the picture as I've numbered the features.
1 - Surround: there's various grades of material available. Cheaper drivers will use single or dual mix butyl. The EL70 uses a tri-mix Ei grade, a type mostly found on more expensive units. We test each cone/surround sub-assembly to be within +/- 3(Fo-Hz) of its design rating. This is very close tolerance for a lower cost driver.
2 - Bonds: single bond glues cost less. On the EL70, an A/B mixed bond is used to get the solid connection needed to make the cap acoustically efficient.
3 - Cones: there's a lot of talk about paper cones. The EL70's cone paper is sourced from Japan, the source for most of the best papers. The material is important but also must be accurately moulded. Our new Multiform process give us micro-control over the complete surface of the cone, making all production cones precise at the micro level.
4 - Frame: is a mixed polymer. it's rigid, strong and acts as a resonance damping component. I make no apologies to those who love metal frames, many ring like a bell sending stray resonance's into the cabinet. We could have cut costs by using an "off the shelf" frame, instead the EL70 uses the same Markaudio custom frame found on the CHR-70.
5 - Connector: this humble part is custom sized. So many drivers come with this component straight from the parts bin, not the case for the EL70. Most cheap drivers have this part riveted to the frame. On the EL70, its glued and screwed.
6 - Coil to cone: the fit tolerance on many cheaper drivers is up to 0/+0.5mm. On the EL70, its 0/+0.1mm. We use less glue because the fit is more accurate. Less glue means less mass and less variation in the moving mass of the power-train.
7 - Spiders: cheaper drivers (and many expensive units) use Conex and similar grade materials. These grades of material are mostly fine depending on the weave selection for a given load. The factory standard tolerance is +/-0.15 on the specified stiffness rating. Typically, a spider can vary by as much as 35% of the mean stiffness within a batch. This can result in a wide range of variance in the resonance frequencies within a batch of drivers. This is not the case with the EL70. Each spider is individually checked to a working tolerance of +/-0.1, much tighter than most other driver production.
8 - Power-train layout: This section of a driver design is critical. I design the layout to make sure there is no spider damage during the soldering process. One small undetected nick in the spider will reduce the life of the driver and results in an un-even distribution of the stiffness compliance. The flying leads are accurately positioned with enough room to remain clear of other driver parts while under LF loads.
These are some of the features, there's much more but I'll leave them for another time.
Some of you know my approach to building drivers. For those who are new to these drivers, I "engineer" these units in order to gain consistent high performance and reliable service life.
Cheers,
Mark.
Bob has asked me to point out some features on the EL70. Much of the following info also applies to my other designs.
Please take a look at the picture as I've numbered the features.
1 - Surround: there's various grades of material available. Cheaper drivers will use single or dual mix butyl. The EL70 uses a tri-mix Ei grade, a type mostly found on more expensive units. We test each cone/surround sub-assembly to be within +/- 3(Fo-Hz) of its design rating. This is very close tolerance for a lower cost driver.
2 - Bonds: single bond glues cost less. On the EL70, an A/B mixed bond is used to get the solid connection needed to make the cap acoustically efficient.
3 - Cones: there's a lot of talk about paper cones. The EL70's cone paper is sourced from Japan, the source for most of the best papers. The material is important but also must be accurately moulded. Our new Multiform process give us micro-control over the complete surface of the cone, making all production cones precise at the micro level.
4 - Frame: is a mixed polymer. it's rigid, strong and acts as a resonance damping component. I make no apologies to those who love metal frames, many ring like a bell sending stray resonance's into the cabinet. We could have cut costs by using an "off the shelf" frame, instead the EL70 uses the same Markaudio custom frame found on the CHR-70.
5 - Connector: this humble part is custom sized. So many drivers come with this component straight from the parts bin, not the case for the EL70. Most cheap drivers have this part riveted to the frame. On the EL70, its glued and screwed.
6 - Coil to cone: the fit tolerance on many cheaper drivers is up to 0/+0.5mm. On the EL70, its 0/+0.1mm. We use less glue because the fit is more accurate. Less glue means less mass and less variation in the moving mass of the power-train.
7 - Spiders: cheaper drivers (and many expensive units) use Conex and similar grade materials. These grades of material are mostly fine depending on the weave selection for a given load. The factory standard tolerance is +/-0.15 on the specified stiffness rating. Typically, a spider can vary by as much as 35% of the mean stiffness within a batch. This can result in a wide range of variance in the resonance frequencies within a batch of drivers. This is not the case with the EL70. Each spider is individually checked to a working tolerance of +/-0.1, much tighter than most other driver production.
8 - Power-train layout: This section of a driver design is critical. I design the layout to make sure there is no spider damage during the soldering process. One small undetected nick in the spider will reduce the life of the driver and results in an un-even distribution of the stiffness compliance. The flying leads are accurately positioned with enough room to remain clear of other driver parts while under LF loads.
These are some of the features, there's much more but I'll leave them for another time.
Some of you know my approach to building drivers. For those who are new to these drivers, I "engineer" these units in order to gain consistent high performance and reliable service life.
Cheers,
Mark.
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