Lovely setup Garytr. I love the OB sound, tubes and full range drivers so i believe i'd find your system excellent. I want to setup my powered sub amp just like yours in a slim self standing case with a handle so i can build any kind of sub i want and connect the amp easily. I wonder how your bass compares to the H-frames i have? I bet it's different shades of wonderful.
LCAO vs 208Sigma vs TB-1808
If the treble with L CAO driver is not fully flat to 20K, how does this driver compare to the Fostex 208Sigma, which too is whizzer-less but needs tweeter(ribbon) support.
Or, if it has rising treble response how would the LCAO fare againt the TB W8-1808....of course the presumtion is usage on an OB with H-frame woofer support upto ~200Hz.
If the treble with L CAO driver is not fully flat to 20K, how does this driver compare to the Fostex 208Sigma, which too is whizzer-less but needs tweeter(ribbon) support.
Or, if it has rising treble response how would the LCAO fare againt the TB W8-1808....of course the presumtion is usage on an OB with H-frame woofer support upto ~200Hz.
Hi all, kind of new to responding, more of a reader, so pls. take this into consideration with my response.
Norman: the push pull is not entirely an acoustic design choice, but rather consideration of balance in the context of the weight of the drivers/magnets. If not push pull, then the speaker would be back heavy. But as a result you now have a more focused upper bass with one driver. The bass cabinets are modular, So I can switch out the FR with one wing nut and the speaker cables of course.
Godzilla:The "H" frame is made of 1.125" birch butcher block and 1/4" aluminum plate on the sides with two types of viscoelastic damping, one inside another outside. This keeps the width of the cabinet as narrow as possible. The whole thing is pretty dead.
Soundaatma: The treble is full.The L.Cao rises from 7500hz - 12000hz and rolls off about -3db at 20khz. I believe the highest fundamentals are violin at 4500hz or so and then overtones take over. The two combined are called partials, which we can hear. The higher you go the more subtle they get. The sound at those frequences are like a heavy hiss. I think of it like fog, a heaviness in the air.I played with this thru my stereo with a tone generator a couple of years ago. Depending on your hearing it is audible but hard to define. Turn it off and you know something is missing. Most of us can't hear 20k.
Von.ah : Yes 1" threaded rod, machined on the bottom to points and 1.25" Birch butcher block shelves ( Ikea) and it is a solid.
bww: I use 12" 16 ohm GR Research servo subs and matching Rythmik 370PEQ Plate amps. Not cheap, but really good. That's why I made the cabinets modular, they are really detailed, flat to 25hz and I have never bottomed out xmax. Supposed to be good to 300hz, so really with 4th order 200hz would be the highest I would venture. I run them about 125hz as they do have a rising response. Having said that, they do upper bass very well, clear and defined.
I am leaving for vacation on Sat. and I don't believe internet will be available so I hope I was of some help?
Gary
Norman: the push pull is not entirely an acoustic design choice, but rather consideration of balance in the context of the weight of the drivers/magnets. If not push pull, then the speaker would be back heavy. But as a result you now have a more focused upper bass with one driver. The bass cabinets are modular, So I can switch out the FR with one wing nut and the speaker cables of course.
Godzilla:The "H" frame is made of 1.125" birch butcher block and 1/4" aluminum plate on the sides with two types of viscoelastic damping, one inside another outside. This keeps the width of the cabinet as narrow as possible. The whole thing is pretty dead.
Soundaatma: The treble is full.The L.Cao rises from 7500hz - 12000hz and rolls off about -3db at 20khz. I believe the highest fundamentals are violin at 4500hz or so and then overtones take over. The two combined are called partials, which we can hear. The higher you go the more subtle they get. The sound at those frequences are like a heavy hiss. I think of it like fog, a heaviness in the air.I played with this thru my stereo with a tone generator a couple of years ago. Depending on your hearing it is audible but hard to define. Turn it off and you know something is missing. Most of us can't hear 20k.
Von.ah : Yes 1" threaded rod, machined on the bottom to points and 1.25" Birch butcher block shelves ( Ikea) and it is a solid.
bww: I use 12" 16 ohm GR Research servo subs and matching Rythmik 370PEQ Plate amps. Not cheap, but really good. That's why I made the cabinets modular, they are really detailed, flat to 25hz and I have never bottomed out xmax. Supposed to be good to 300hz, so really with 4th order 200hz would be the highest I would venture. I run them about 125hz as they do have a rising response. Having said that, they do upper bass very well, clear and defined.
I am leaving for vacation on Sat. and I don't believe internet will be available so I hope I was of some help?
Gary
Nuuk see these:
New Adventures In High Efficiency My Lowther Journey With a rant or two sprinkled in for good measure. Article By Scott Faller
Open Baffle Lowthers
I went with the modular bass bins which keeps phase and coherency of the FR and bass units a little tighter than putting the bass behind a separate FR baffle. The measurements from Scott Faller don't have to be exact but I kept them as close as my bass baffle allows.
Polycarbonate or Acrylic is quite appealing with less domination of the room. I am going to source some 3/4" Polycarbonate hopefully.
New Adventures In High Efficiency My Lowther Journey With a rant or two sprinkled in for good measure. Article By Scott Faller
Open Baffle Lowthers
I went with the modular bass bins which keeps phase and coherency of the FR and bass units a little tighter than putting the bass behind a separate FR baffle. The measurements from Scott Faller don't have to be exact but I kept them as close as my bass baffle allows.
Polycarbonate or Acrylic is quite appealing with less domination of the room. I am going to source some 3/4" Polycarbonate hopefully.
Thanks Gary - some interesting reading! I asked because the baffle for the FR driver goes way above the driver. My drivers are placed near the top of a shorter baffle so I will experiment by extending the height of mine to see if it there is an improvement.
I agree about the placement of the bass bins and would always have mine immediately below the FR driver. In one of my previous designs, I built the woofers into a separate frame such that the FR baffle was decoupled from the woofers. I'm not sure how much improvement that makes but it can't be a bad thing to isolate the FR unit from the woofers and their vibrations.
I still have the 12 inch woofers and if time and energy allow will build something like your H-frame to go with some other FR units that I have lying around.
I agree about the placement of the bass bins and would always have mine immediately below the FR driver. In one of my previous designs, I built the woofers into a separate frame such that the FR baffle was decoupled from the woofers. I'm not sure how much improvement that makes but it can't be a bad thing to isolate the FR unit from the woofers and their vibrations.
An externally hosted image should be here but it was not working when we last tested it.
I still have the 12 inch woofers and if time and energy allow will build something like your H-frame to go with some other FR units that I have lying around.
I've been thinking of replacing my Jordan JX125 drivers with the L.Cao 8", plus isobaric bass ('cos I like it) and active xover. Your project has made me more confident to try. I use Valab often, and find Kevin helpful too. I just need to sell the Jordans first!
Is there any need to add an HF driver, or is the treble good enough from the L. Cao?
Hello Nuuk,
Nice build with 2 GR drivers in a compact dipole. Did you use a simulation program for this kind of a woofer configuration. Martin's MathCAD sheets can do only H and U frames. What are benefits and tradeoffs of your folding scheme. Did you try a W-frame...though I have no idea how to simulate that either.
Thanks.
Nice build with 2 GR drivers in a compact dipole. Did you use a simulation program for this kind of a woofer configuration. Martin's MathCAD sheets can do only H and U frames. What are benefits and tradeoffs of your folding scheme. Did you try a W-frame...though I have no idea how to simulate that either.
Thanks.
I made those speakers some years ago, and shamefully pulled them to pieces when I ran out of room in my hi-fi over-run home. It was before I was aware of Martin's MathCad so I just built the woofer enclosure to be as compact as I could so that it fitted in between the 'legs' (side panels) of the main baffle.
I haven't tried a W-baffle. I only use the woofers up to around 90 hz and I wonder if one design will have that much audible difference to another. Not saying that it won't but these days I don't have the energy or money to try them all. Currently I am very satisfied with 15 inch Hawthorne Augies on a flat baffle under my Goodmans 201's. Anyway, I don't want to take Gary's thread on the L Cao's too far off track.
Nuuk nice cabinets.
Awkwardbydesign this is a subjective question, but will try to respond with some objective reasoning:
The Alnico has a different spider, phenolic, than the ceramic and claims better transient response and better FR at both extremes due to the Alnico magnet and resulting parameters. Nelson Pass already noted the ceramic had quite a bit of treble output, and his response graph looks decent, a liitle shy above 18khz.
My previous speakers were a mini line array of 4 Fostex FF85K's per channel (=94db efficiency, same as L.Cao)which had a peak of 6db at 19k and response to 32khz I don't notice anything missing on the L.Cao, but have no balance control on my pre to A/B the two.
Just my two coppers.
Awkwardbydesign this is a subjective question, but will try to respond with some objective reasoning:
The Alnico has a different spider, phenolic, than the ceramic and claims better transient response and better FR at both extremes due to the Alnico magnet and resulting parameters. Nelson Pass already noted the ceramic had quite a bit of treble output, and his response graph looks decent, a liitle shy above 18khz.
My previous speakers were a mini line array of 4 Fostex FF85K's per channel (=94db efficiency, same as L.Cao)which had a peak of 6db at 19k and response to 32khz I don't notice anything missing on the L.Cao, but have no balance control on my pre to A/B the two.
Just my two coppers.
Recently I got around to trying the L Cao with the Alnico magnets. I was
surprised to find that the response curve was quite a bit different, and the
drivers were accompanied by an LRC designed to notch the midrange
response. Listening to them without the network gave a rather dull
presentation, and with the network I still found the top end pretty soft.
It's a mystery as to why they should be so different, but at this point if you
are considering them you might want to think about a tweeter above 5 KHz.
surprised to find that the response curve was quite a bit different, and the
drivers were accompanied by an LRC designed to notch the midrange
response. Listening to them without the network gave a rather dull
presentation, and with the network I still found the top end pretty soft.
It's a mystery as to why they should be so different, but at this point if you
are considering them you might want to think about a tweeter above 5 KHz.
Garytr and Nelson; thanks for the replies.
At the moment I use Jordan JX125s for midrange, 150Hz up to about 4kHz, active xover to the bass, but temporarily passive to the Jordan JX6RHD treble. My active xover is 4 way, if I wish, so the idea is to set the MF/HF xover point to suit whichever drivers I settle on.
The Jordan 125s have a big resonant peak at about 6kHz, so I want to move away from them, and saw the original thread about the L.Cao 8" drivers.
I could use the JX6s down to 150Hz, or even lower, but power handling would be compromised. In fact, I did that with two JX6s per side, but then bought the 125s hoping for more power without compromising the sound. Unfortunately they don't sound as good as I had hoped.
I would like to stay with wide range drivers, as that moves xover points away from the midrange region, but the 125's peak makes that difficult. If the L.Cao 8" drivers are transparent enough from 150Hz to say, 6kHz, then they might suit.
I still have a pair of Shackman electrostatic panels from the 70s, so I could try them for HF, and if the MF drivers are used in OB, that might suit the Shackmans. Or stick with the Jordan JX6s, as I already have them. If that doesn't work, then a leaf or ribbon, whatever seems to match without great expense.
I have 4 KEF B139 (racetrack style) drivers to play with for isobaric bass, and a Parasound HCA-1205A 5 channel power amp, so I can use 4 channels, one for each driver. The rest is valve.
Unfortunately, I have to sell before I buy new stuff, so it's hard to just try things!
Recently I have been acoustically tailoring my living room, as it was echoey and boomy; much better now, so I'm ready to start playing with speakers again.
BTW Gary, looking at your pics reminded me, I used to run Jordan JX92s above my bass cabs, with a square metal cage fixed to the bass cabs to support a "sock" of grill fabric. The Jordan's cabs were sat on top of the bass cabs with spikes between. When I tried hanging the MF cabs with cotton shoelaces (I don't know if it has to be cotton!) from the grill frame, so they could swing back and forth, the way the bass cleaned up was astonishing. I hadn't expected the bass to improve. I thought it would be the midrange! My MF cabs had enough mass, I think, to make them stable. The new speakers will definitely start out that way, and I will then spike them to the bass cabs for comparison. At the moment my current speakers rest on Max Townshend style inner tube stands, as that seems to minimise interaction with the room. That didn't work so well with the electronics, though, maybe I didn't do it well enough.
At the moment I use Jordan JX125s for midrange, 150Hz up to about 4kHz, active xover to the bass, but temporarily passive to the Jordan JX6RHD treble. My active xover is 4 way, if I wish, so the idea is to set the MF/HF xover point to suit whichever drivers I settle on.
The Jordan 125s have a big resonant peak at about 6kHz, so I want to move away from them, and saw the original thread about the L.Cao 8" drivers.
I could use the JX6s down to 150Hz, or even lower, but power handling would be compromised. In fact, I did that with two JX6s per side, but then bought the 125s hoping for more power without compromising the sound. Unfortunately they don't sound as good as I had hoped.
I would like to stay with wide range drivers, as that moves xover points away from the midrange region, but the 125's peak makes that difficult. If the L.Cao 8" drivers are transparent enough from 150Hz to say, 6kHz, then they might suit.
I still have a pair of Shackman electrostatic panels from the 70s, so I could try them for HF, and if the MF drivers are used in OB, that might suit the Shackmans. Or stick with the Jordan JX6s, as I already have them. If that doesn't work, then a leaf or ribbon, whatever seems to match without great expense.
I have 4 KEF B139 (racetrack style) drivers to play with for isobaric bass, and a Parasound HCA-1205A 5 channel power amp, so I can use 4 channels, one for each driver. The rest is valve.
Unfortunately, I have to sell before I buy new stuff, so it's hard to just try things!
Recently I have been acoustically tailoring my living room, as it was echoey and boomy; much better now, so I'm ready to start playing with speakers again.
BTW Gary, looking at your pics reminded me, I used to run Jordan JX92s above my bass cabs, with a square metal cage fixed to the bass cabs to support a "sock" of grill fabric. The Jordan's cabs were sat on top of the bass cabs with spikes between. When I tried hanging the MF cabs with cotton shoelaces (I don't know if it has to be cotton!) from the grill frame, so they could swing back and forth, the way the bass cleaned up was astonishing. I hadn't expected the bass to improve. I thought it would be the midrange! My MF cabs had enough mass, I think, to make them stable. The new speakers will definitely start out that way, and I will then spike them to the bass cabs for comparison. At the moment my current speakers rest on Max Townshend style inner tube stands, as that seems to minimise interaction with the room. That didn't work so well with the electronics, though, maybe I didn't do it well enough.
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