Hi all,
Below is a hybrid ESL design I’m drawing up for a friend. I’m posting it here, seeking feedback and advice before proceeding. The big concerns are the woofer choice and the cavity resonance of the H-baffle.
A constraint is that the speakers must fit into my friend’s car for transporting. Hence; the modified H-baffle design with removable sides.
A single 12” woofer on an OB would not supply the lowest octaves but in this case the woofer only has to play from 250Hz down to 80Hz where separate subs will cross in. The setup would be tri-amp’d with a DSP crossover feeding some big Sunfire amps.
The H-baffle isn’t typical—being like a box with trapezoidal sides and the upper end missing. I have no idea how to calculate its cavity resonance, which I suspect will fall below the 250Hz crossover where it can do harm. Perhaps the open end and trapezoidal sides will mitigate the peak but I can’t say. I really need to know whether the cavity resonance is a show-stopper before proceeding.
I’m also conflicted about the woofer choice. OB dictates a high Qts but a clean blend with the ESL dictates a much lower Qts. So we are contemplating a compromise, using a lower Qts woofer and applying EQ to reach the 80Hz cutoff. I’m thinking Qts around .4, inductance <.8 mH and >8mm Xmax. I haven’t found a woofer that exactly fits.
My friend is looking at some AE woofers (IB type) but I’m leaning towards one of the two Eminence woofers below, (the BL of the Kappa-Lite 3012LF should make it a real thumper):
Kappalite 3012LF
Deltalite II 2512
Opinions and advice are appreciated… and if anyone thinks I’m nuts, I would need to hear that too.
Chaz
Below is a hybrid ESL design I’m drawing up for a friend. I’m posting it here, seeking feedback and advice before proceeding. The big concerns are the woofer choice and the cavity resonance of the H-baffle.
A constraint is that the speakers must fit into my friend’s car for transporting. Hence; the modified H-baffle design with removable sides.
A single 12” woofer on an OB would not supply the lowest octaves but in this case the woofer only has to play from 250Hz down to 80Hz where separate subs will cross in. The setup would be tri-amp’d with a DSP crossover feeding some big Sunfire amps.
The H-baffle isn’t typical—being like a box with trapezoidal sides and the upper end missing. I have no idea how to calculate its cavity resonance, which I suspect will fall below the 250Hz crossover where it can do harm. Perhaps the open end and trapezoidal sides will mitigate the peak but I can’t say. I really need to know whether the cavity resonance is a show-stopper before proceeding.
I’m also conflicted about the woofer choice. OB dictates a high Qts but a clean blend with the ESL dictates a much lower Qts. So we are contemplating a compromise, using a lower Qts woofer and applying EQ to reach the 80Hz cutoff. I’m thinking Qts around .4, inductance <.8 mH and >8mm Xmax. I haven’t found a woofer that exactly fits.
My friend is looking at some AE woofers (IB type) but I’m leaning towards one of the two Eminence woofers below, (the BL of the Kappa-Lite 3012LF should make it a real thumper):
Kappalite 3012LF
Deltalite II 2512
Opinions and advice are appreciated… and if anyone thinks I’m nuts, I would need to hear that too.
Chaz
Attachments
Hi,
250Hz upper bandwidth limit under useage of a H-baffle seems a bit ambitious to me.
I´d rather opt for a more classic-box appearance or trapezoidal shape .... woofer mounted to the front and an open backside (U-shape, or A-shape).
I´d guess that the ´free´ radiating front membrane is better suited for high bandwidth limitapplication .... and it also looks better
For a woofer You might look for a beefy PA-driver.
Above 60Hz the requirements for extra long excursion capability reduce considerably and many PA- drivers nowadays offer quite substantial excursions anyways.
A Fs of 40Hz or more accompanied by a Qts of >0.35 should hint to appropriate candidates.
As always with open baffle driver, a progressive suspension adds safety margin and takes heavy driving easier.
This Beyma caught my eye at a very quick search ;-) ...Beyma 12LX60V2 or this B&C 12PLB100
jauu
Calvin
250Hz upper bandwidth limit under useage of a H-baffle seems a bit ambitious to me.
I´d rather opt for a more classic-box appearance or trapezoidal shape .... woofer mounted to the front and an open backside (U-shape, or A-shape).
I´d guess that the ´free´ radiating front membrane is better suited for high bandwidth limitapplication .... and it also looks better
For a woofer You might look for a beefy PA-driver.
Above 60Hz the requirements for extra long excursion capability reduce considerably and many PA- drivers nowadays offer quite substantial excursions anyways.
A Fs of 40Hz or more accompanied by a Qts of >0.35 should hint to appropriate candidates.
As always with open baffle driver, a progressive suspension adds safety margin and takes heavy driving easier.
This Beyma caught my eye at a very quick search ;-) ...Beyma 12LX60V2 or this B&C 12PLB100
jauu
Calvin
I think if he well be using a Behringer type...digital crossover ...you well get great sound an output....
I say this only becase working on my ML Ascents an SL3...an having the back of the lower bass bin opened..an playing sound...WOw...
ezey to see why All ML 2 way esls are using two..woofer setup with one in the back an one in the front....really expands output an the sweet spot.
Others well tell what would best.. to use driver wise...but this is on my list of thing to try with my ML...
good luck
I say this only becase working on my ML Ascents an SL3...an having the back of the lower bass bin opened..an playing sound...WOw...
ezey to see why All ML 2 way esls are using two..woofer setup with one in the back an one in the front....really expands output an the sweet spot.
Others well tell what would best.. to use driver wise...but this is on my list of thing to try with my ML...
good luck
Funny, I've been pondering the 62-inch limit of my Impreza recently. Maybe the right solution is to stop focussing on a one-piece tower-shaped speaker. Modules? Separable pieces? Roof rack? Truck rental?
For a 250 Hz x-over, even a fairly shape slope, not desirable having driver sitting at floor level.
B.
For a 250 Hz x-over, even a fairly shape slope, not desirable having driver sitting at floor level.
B.
Last edited:
Hi,
250Hz upper bandwidth limit under useage of a H-baffle seems a bit ambitious to me.
I´d rather opt for a more classic-box appearance or trapezoidal shape .... woofer mounted to the front and an open backside (U-shape, or A-shape).
I´d guess that the ´free´ radiating front membrane is better suited for high bandwidth limitapplication .... and it also looks better
For a woofer You might look for a beefy PA-driver.
Above 60Hz the requirements for extra long excursion capability reduce considerably and many PA- drivers nowadays offer quite substantial excursions anyways.
A Fs of 40Hz or more accompanied by a Qts of >0.35 should hint to appropriate candidates.
As always with open baffle driver, a progressive suspension adds safety margin and takes heavy driving easier.
This Beyma caught my eye at a very quick search ;-) ...Beyma 12LX60V2 or this B&C 12PLB100
jauu
Calvin
Thanks Calvin... LOVE that Beyma woofer!
My friend has a car where the rear seats fold down allowing the speakers to occupy the trunk and extend into the passenger cabin. Every year in September he and I load up our cars with audio gear and head to the annual CarverFest retreat in NC for ten days. Two years ago I rented a van and took my big beam splitter ESL's, which was rather expensive-- so my friend mandated that these speakers must fit into his car.
You're thinking that having the mid bass woofer at floor level will pull the vocals down to the floor? That'a a valid concern. It doesn't seem to be a problem with my big beam splitter ESLs which likewise have the woofer at floor level-- however, my speakers angle the woofer 8 degrees upward and cross in a bit lower at 228Hz. That may be an option with my friends speaker design.
Hi,
if You'd consider a bass tower alongside the panel as I have done, You could build the tower from segments ... see the 'blue Klaus' on my website.
By using 6.5" drivers I could keep the dimensions of the bass so small, that a xover of 250Hz became possible.
The thin high bass strip integrates smoothly with the panel, better than a single dipole.
The tower was divided into four segments with two drivers each.
Two neighbouring segments were hold together by just one one single threaded bolt and nut and two small pins used for alignment.
Each segment had its own cable terminal mounted to tge sidewall ... hadn't found a optically more pleasing solution on the quick then ... but You may consider a plugging connector system in the top and bottom of each segment.
The tower was simply placed near the panel/electronics tower.
In the later prototype I used a common base on to which both the tower part and the panel/electronics were mounted.
The bass tower and the electronics cabint were simply bolted on to the base.
Two long metal rails were then screwed on to the sides of the electronic cabinet.
To these rails a aluminum profile was glued that held the panel and a curved metal sheet (the latter of the height of the electronic cabinet, just for optics)
Today I' omit with the rather high electronic cabinet below the panel as the overall height of the whole system becomes too much (194cm)
Like in the later esl model I'd reduce the height to panel plus base thickness only.
The smaller number of bass drivers fitting into that height (6 instead of 8) has proven to be fully sufficient down to ~50Hz (probabely even down to 35Hz when combined to a less efficient pabel).
The reduced height (~130cm) and the tiny footprint of the bass tower would even allow for transportation if the bass tower were a single piece and not segmented into smaller subassemblies.
The electronics may be fitted into the base or be mounted in a external standalone casing.
For transportation I designed a box system of 3 boxes/containers ... one for the two panels and the two bases and one each for the two bass towers from that brownblack coated plywood I forgot the name of ... very convenient and safe.
jauu
Calvin
if You'd consider a bass tower alongside the panel as I have done, You could build the tower from segments ... see the 'blue Klaus' on my website.
By using 6.5" drivers I could keep the dimensions of the bass so small, that a xover of 250Hz became possible.
The thin high bass strip integrates smoothly with the panel, better than a single dipole.
The tower was divided into four segments with two drivers each.
Two neighbouring segments were hold together by just one one single threaded bolt and nut and two small pins used for alignment.
Each segment had its own cable terminal mounted to tge sidewall ... hadn't found a optically more pleasing solution on the quick then ... but You may consider a plugging connector system in the top and bottom of each segment.
The tower was simply placed near the panel/electronics tower.
In the later prototype I used a common base on to which both the tower part and the panel/electronics were mounted.
The bass tower and the electronics cabint were simply bolted on to the base.
Two long metal rails were then screwed on to the sides of the electronic cabinet.
To these rails a aluminum profile was glued that held the panel and a curved metal sheet (the latter of the height of the electronic cabinet, just for optics)
Today I' omit with the rather high electronic cabinet below the panel as the overall height of the whole system becomes too much (194cm)
Like in the later esl model I'd reduce the height to panel plus base thickness only.
The smaller number of bass drivers fitting into that height (6 instead of 8) has proven to be fully sufficient down to ~50Hz (probabely even down to 35Hz when combined to a less efficient pabel).
The reduced height (~130cm) and the tiny footprint of the bass tower would even allow for transportation if the bass tower were a single piece and not segmented into smaller subassemblies.
The electronics may be fitted into the base or be mounted in a external standalone casing.
For transportation I designed a box system of 3 boxes/containers ... one for the two panels and the two bases and one each for the two bass towers from that brownblack coated plywood I forgot the name of
... very convenient and safe.jauu
Calvin
Hi,
if You'd consider a bass tower alongside the panel as I have done, You could build the tower from segments ... see the 'blue Klaus' on my website.
By using 6.5" drivers I could keep the dimensions of the bass so small, that a xover of 250Hz became possible.
The thin high bass strip integrates smoothly with the panel, better than a single dipole.
The tower was divided into four segments with two drivers each.
Two neighbouring segments were hold together by just one one single threaded bolt and nut and two small pins used for alignment.
Each segment had its own cable terminal mounted to tge sidewall ... hadn't found a optically more pleasing solution on the quick then ... but You may consider a plugging connector system in the top and bottom of each segment.
The tower was simply placed near the panel/electronics tower.
In the later prototype I used a common base on to which both the tower part and the panel/electronics were mounted.
The bass tower and the electronics cabint were simply bolted on to the base.
Two long metal rails were then screwed on to the sides of the electronic cabinet.
To these rails a aluminum profile was glued that held the panel and a curved metal sheet (the latter of the height of the electronic cabinet, just for optics)
Today I' omit with the rather high electronic cabinet below the panel as the overall height of the whole system becomes too much (194cm)
Like in the later esl model I'd reduce the height to panel plus base thickness only.
The smaller number of bass drivers fitting into that height (6 instead of 8) has proven to be fully sufficient down to ~50Hz (probabely even down to 35Hz when combined to a less efficient pabel).
The reduced height (~130cm) and the tiny footprint of the bass tower would even allow for transportation if the bass tower were a single piece and not segmented into smaller subassemblies.
The electronics may be fitted into the base or be mounted in a external standalone casing.
For transportation I designed a box system of 3 boxes/containers ... one for the two panels and the two bases and one each for the two bass towers from that brownblack coated plywood I forgot the name of
jauu
Calvin
Thanks Calvin,
I think I got the gist of what you suggest-- I will draw up a sketch and present that option to my friend, Martin.
I envision Calvin's "Blue Klaus" as the ultimate hybrid ESL... fully balanced bass/panel for matched dipole radiation, with ESL panel and woofer array on separate baffles to mitigate acoustic coupling between them.
The plan for Martin's speaker was to use the same 12x48 segmented wire panel used in my speaker, since it's proven and I already have the wire stretching jig. In order to approximate Calvin's Blue Klaus I would mod my jig to extend the panel height to 60 inches (since there would be no woofer under the panel). And then add the A-baffle multi-woofer array. Not sure it could all fit into Martin's car-- let's see....
The plan for Martin's speaker was to use the same 12x48 segmented wire panel used in my speaker, since it's proven and I already have the wire stretching jig. In order to approximate Calvin's Blue Klaus I would mod my jig to extend the panel height to 60 inches (since there would be no woofer under the panel). And then add the A-baffle multi-woofer array. Not sure it could all fit into Martin's car-- let's see....
Hi,
48"x12" resp. 120x30cm is fine sizewise.
It fits well into a six bass driver concept utilizing 6.5" to 7" drivers.
Depending on the size of the car, the parts may even fit in transverse direction.
A third non-acoustic reason to remain below 50" is optics.
Below that limit objects are rather 'overlooked', appear small, rather not noticed ... above the limit, they appear as obstacles in Your way, big ... even more so from a sitting position.
jauu
Calvin
48"x12" resp. 120x30cm is fine sizewise.
It fits well into a six bass driver concept utilizing 6.5" to 7" drivers.
Depending on the size of the car, the parts may even fit in transverse direction.
A third non-acoustic reason to remain below 50" is optics.
Below that limit objects are rather 'overlooked', appear small, rather not noticed ... above the limit, they appear as obstacles in Your way, big ... even more so from a sitting position.
jauu
Calvin
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