AudioCircle
Audio/Video Gear and Systems => Planar Circle => Topic started by: Jazzman53 on 14 Apr 2018, 05:25 pm
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This speaker project is for a friend who likes OB's. And the speakers must fit into his Audi for transporting (rear seats folded forward, speakers occupying trunk & rear passenger compartment). Thus; some compromises are required.
We settled on a modified H-baffle design with an electrically segmented wire-stator ESL panel, 66"H x 14.5"W x 15" base. The triangular base forms the H-baffle and is removable.
The drawing below shows the speaker with a Peerless SLS 12 woofer, front-mounted on the baffle, which was the initial plan. However, we have changed to a different woofer and mounting it on the rear of the baffle.
This will not be a stand-alone speaker-- a single 12 woofer on a baffle this narrow will not give thundering low bass. With that in mind, we opted to break the rules for OB and go with a low-Q woofer for optimal blending to the stat panel (Eminence Kappalite 3012LF). The woofer will only provide mid bass here. The lows will be handled by separate OB subs (each with two 15" AE's).
The panel is tried and true. The rest we won't know until we hear it play.
(http://www.audiocircle.com/image.php?id=178815)
(http://www.audiocircle.com/image.php?id=178816)
(http://www.audiocircle.com/image.php?id=178832)
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I'm at that stage of the project (this happens with every project) where I'm burned out and wishing I had never started it. My air compressor motor burning up today didn't help-- so now we're at an impasse for sanding and painting the frames. At least I finally finished cutting the stator details today-- two hard days on that. Can't finish without the air compressor to spray the stain and satin clear coat.
Below is my friend Martin hand sanding and pre-fitting the oak lattice stator supports. I think Martin is starting to grasp how no sane person would go thru all this to build a speaker... definitely a psychosis
(http://www.audiocircle.com/image.php?id=178858)
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Update: Got the air compressor back up and running yesterday and sprayed stain on the stator lattices last night. After work today will spray the lattices with satin poly clear coat and tomorrow we can start stringing wires in the stretching jig. The stator lattices are 96 interlocking oak details... each piece hand sanded and fitted.
(http://www.audiocircle.com/image.php?id=178929)
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Looks sweet. Keep the updates coming.
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You have a LOT of patience ! Nice work. Would be curious on the total hours spent when finished.
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Nice work, Charlie! Thanks for posting the build.
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Stretching the wires and assembling the first stator tonight. Stretching the wires to 1.5% elongation renders them perfectly straight
(http://www.audiocircle.com/image.php?id=178991)
(http://www.audiocircle.com/image.php?id=179031)
(http://www.audiocircle.com/image.php?id=178990)
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Update 4/20:
As of last night, one stator is finished and another is in the stretching jig awaiting the glue to set. Probably won't be able to work on it much this weekend (honey-do list -- overruled by higher authority) but will be back at it Sunday evening or Monday.
(http://www.audiocircle.com/image.php?id=179109)
(http://www.audiocircle.com/image.php?id=179110)
(http://www.audiocircle.com/image.php?id=179111)
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I am very impressed. Wow.
Rocket Ronny
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Very nice. Can't wait for the sound report.
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Beautiful.
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Your friend really doesn't need to drive them all the way to Pennsylvania in his Audi for me.
FedEx is fine.
P.S.
These are coming along nicely, impressive work as always.
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Your friend really doesn't need to drive them all the way to Pennsylvania in his Audi for me.
FedEx is fine.
P.S.
These are coming along nicely, impressive work as always.
OK Steve, I just verified the 66" tall speakers will fit into Martin's Audi. So if they don't meet Martin's expectations, we'll be needing your address.
(http://www.audiocircle.com/image.php?id=179190) :lol:
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I should be so lucky.
Like everyone else I really enjoy your build threads.
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The project is on hold at the moment, until Martin decides about speaker feet, some of the electronics components, and ordering the Licron Crystal to coat the diaphragms.
In the meantime, I heat bent some polycarbonate covers for the electronics (step up transformers, high-voltage biasing supply, speaker cable binding posts, etc...) to be located on the rear shelf, as shown in the photo below:
(https://www.audiocircle.com/image.php?id=179477)
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Update 6/12/2018:
I finished my H-baffle hybrid ESL project late yesterday evening. It was a LOT more WORK than I imagined but it turned out really nice. I like having the segmentation resistor networks and transformers & bias supplies under clear plastic covers.
I did play them a little last night-- initially there was significant booming centered around 160Hz (probably the H-baffle’s cavity resonance) but they were sounding pretty good after tamping down the resonance with a parametric EQ. I will get them tuned in over the coming week and post a video later.
I didn’t start out building these speakers for myself but it ended up that way (for reasons I won’t go into here). And since I don’t have enough equipment to run both my old beam-splitter speakers and the new H-baffles, I suppose I will have to listen to them a while and then choose which ones to keep—it will be a difficult decision (rather like selecting one of your children to sell).
BTW; breaking the rules by using a low-Q Pro woofer in an OB might not be such a bad idea--- it was immediately apparent that these Kappa-Lite LF woofers have serious PUNCH and they seem to blend well with the stat panels.
Here’s some eye candy for the planar pervs:
(https://www.audiocircle.com/image.php?id=181254)
(https://www.audiocircle.com/image.php?id=181255)
(https://www.audiocircle.com/image.php?id=181256)
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Update 6/12/2018: …
Those are absolutely gorgeous, Jazzman. :o :bowdown:
Very, very nice.
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If they sound half as good as they look you've got it made.
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These are indeed very nice looking. At what frequency do you cut over the woofer? Sorry if I missed this detail from earlier.
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Fantastique handy work Jazzman congratulations :thumb:
There is any way you can adjust the planar decay resonance time?
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These are indeed very nice looking. At what frequency do you cut over the woofer? Sorry if I missed this detail from earlier.
I had intended to cross the panel to the woofer around 220Hz but since I apparently over-tensioned the diaphragm (the 160Hz peak is the diaphragm's drum-head resonance)--so I had to raise the X-over frequency to 260Hz using a 48db filter slope, so as to minimize exciting the resonance. On the bottom end, the woofer crosses into the subs at 60Hz with a 24db filter slope.
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Fantastique handy work Jazzman congratulations :thumb:
There is any way you can adjust the planar decay resonance time?
The diaphragm's drum-head resonance can be dampened to a degree by adding a cloth covering or felt pad strip (acoustic impedance) on the rear stator. I'm not aware of any other technique to manipulate the resonance. A rule of thumb for hybrid ESL's is to avoid exciting the resonance by setting the crossover frequency at least one octave above the resonance with a 48/octave filter, or 2 octaves above resonance with a 24db filter.
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Beautiful as always, thanks for sharing Charlie....... :thumb:
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You are a true craftsman, Jazzman. Quite the amazing accomplishment.
<SNIP>
it will be a difficult decision (rather like selecting one of your children to sell).
Sorry, I couldn't resist.
https://www.youtube.com/watch?v=AsWxkU0g9Z4 (https://www.youtube.com/watch?v=AsWxkU0g9Z4)
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How much SPL it will have?
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How much SPL it will have?
The ESL Calculator shows max SPL of 102 decibels at 3 meters (that's for the panel-- it doesn't calculate the woofer's output )
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This is amazing, my Carver Amazing have only 89dB, requiring a 300W monster amp.
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This is amazing, my Carver Amazing have only 89dB, requiring a 300W monster amp.
I've heard the Carver ribbons at Carverfest... the sound great but they do need a stout amp. Most people cant believe how loud my speakers can play. As a general rule, hybrid ESL's with close diaphragm to stator spacing (like mine) can play much louder than [let's say] a Quad 57 or 63. And mine are very efficient (even for a hybrid) because the wire size and spacing yield high field density and optimum open area (42%). I haven't measured the SPL myself but they can play to painful volume. The 102 decibels I quoted was derived with Steve Bolser's ESL Calculator Excel spreadsheet (see screen shot below), which I used to determine the segmentation resistor values. The green lines are panel frequency response and SPL with @ 1 watt input power at 3 meters. The red line is max potential output at 3 meters. Of course, the mechanical portions of the speaker won't produce sound out to 100kHz but the driving electrical output feeding the wire groups can extend that high.
(https://www.audiocircle.com/image.php?id=181370)
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What is your membrane diafragm?
Any idea why the Amazing Kapton/alu Carver used sound so good?
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What is your membrane diafragm?
Any idea why the Amazing Kapton/alu Carver used sound so good?
The diaphragm is 6-micron (0.00025" thick) Mylar C, with 10.5" x 46.5" radiating area and weighing just under a gram (absent the coating). The Licron Crystal conductive coating adds about 1.5 -2.0 microns and a bit more weight-- still lightening fast.
My friend Ed rebuilds those Carver ribbons at a reasonable price. Unfortunately, Ed says the original 1 mil Kapton material is no longer available but he found a company willing to make up a batch of 2-mil Kapton with bonded aluminum conductors. Ed made up a little hand powered rotary thingy that corrugates the film, like the originals. It's a bit heavier ribbon than the originals but it sounds really good--- extends to about 15kHz, I think.
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The original 60'' respond to 40kHz according the factory specs.
The Amazing weak point was detail were not great by current standards, it needs a new ligther material.
(https://www.stereophile.com/images/archivesart/Amazfig4.jpg)
There is a service manual here:
https://www.turntableneedles.com/Carver_Amazing_Dynamic_Loudspeaker_Instant_PDF_Download_English_Service_Manual
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Nice job.
Excellent construction.
Thanks for posting this.
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I figured it’s about time to update this thread:
As previously mentioned, this speaker was built for a friend who imposed a requirement that the speaker pair had to fit into his 2008 Audi for transport. Hence; the OB bass section.
I had so many reservations about the design that I was hesitant to post anything more about it until I had confirmed that it works. The low-qts woofer on an OB was a risky choice; giving priority to blending well with the ESL at the expense of requiring separate subs for the bottom two octaves—but my friend has DSP and awesome subs, so it’s not a problem.
In the end the speakers turned out esthetically gorgeous, and thanks to some really smart people on the DIY Audio Forum who helped me along the way, they sound really nice too. The video link below shows the speakers playing this past week at the 2018 Carverfest retreat in NC. They made a big hit and the Bobfather (Bob Carver) raved about them.
https://youtu.be/67Flmub-dYo