I've got about twelve more minutes (before I need to head to a big band gig), so I'll make this quick. However, I have bunch of enclosure designs for my drivers that should be on my site. Here is a quick overview. I'll try to fill in pics and specs later on.
Betsy: The OB options are fairly straight forward, by herself or with a woofer. You can use her in a sealed box, but I'm not sure why you'd choose to do so. One unique option that came up in discussion is a small aperiodic box. It might be the smallest way to get a Burro speaker into your room, and with it, more sensitivity, dynamics and image size than you normally get in a bookshelf.
BetsyK: Sealed and vented options abound, but here are some more interesting things:
GM posted a 10:1 TQWT that looks great. If you can tolerate a wide cabinet with a decent sized footprint, it promises great performance and a very simple build. Specs to come.
Skinny quasi TQWT/TL: I designed a box for my brother in law after seeing the Zu Essence and liking the size. Mine is about 12x13x44". It is a very easy build with some advantages over a regular BR. I'm listening to a pair right now. I think this cabinet should be very, very popular. My in-laws are thrilled.
MooseBVR: ScottMoose was kind enough to simulate one of his double mouth BVR's for the BetsyK. I'll send you the dims if you want. I plan to build a pair. I meant to this fall, but the Skinny TQWT project got in the way.
BIB: My cabinets stayed in MN when I moved west. However, I can give you the specs I used (skinnier than the calculator produces). They are great fun.
I do plan to do a better, and more complete list than this thread. But, I wanted to get something fun up before folks get home from work!
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
Betsy: The OB options are fairly straight forward, by herself or with a woofer. You can use her in a sealed box, but I'm not sure why you'd choose to do so. One unique option that came up in discussion is a small aperiodic box. It might be the smallest way to get a Burro speaker into your room, and with it, more sensitivity, dynamics and image size than you normally get in a bookshelf.
BetsyK: Sealed and vented options abound, but here are some more interesting things:
GM posted a 10:1 TQWT that looks great. If you can tolerate a wide cabinet with a decent sized footprint, it promises great performance and a very simple build. Specs to come.
Skinny quasi TQWT/TL: I designed a box for my brother in law after seeing the Zu Essence and liking the size. Mine is about 12x13x44". It is a very easy build with some advantages over a regular BR. I'm listening to a pair right now. I think this cabinet should be very, very popular. My in-laws are thrilled.
MooseBVR: ScottMoose was kind enough to simulate one of his double mouth BVR's for the BetsyK. I'll send you the dims if you want. I plan to build a pair. I meant to this fall, but the Skinny TQWT project got in the way.
BIB: My cabinets stayed in MN when I moved west. However, I can give you the specs I used (skinnier than the calculator produces). They are great fun.
I do plan to do a better, and more complete list than this thread. But, I wanted to get something fun up before folks get home from work!
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
Last edited:
Here is 'Zilla's Betsy + Boomer kit for Betsy. The BetsyK can also be used in helper woofer applications for a little more sensitivity, but a little less flexibility.
Here is a link to GM's TQWT for the BetsyK.
I followed the top set of specs here for the BIB's I had the BetsyK's in. Maybe not ideal, but they worked well for me!
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
Here is a link to GM's TQWT for the BetsyK.
I followed the top set of specs here for the BIB's I had the BetsyK's in. Maybe not ideal, but they worked well for me!
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
Last edited:
Hi Paul, I spent three hours listening to music thru the Betsy/Boomers last night. Thought i'd watch some tv around 11pm before bed but when i came upstairs i saw it was 12:58am!!!
Open Baffle Speaker - Betsy and Boomer Open Baffle Speaker Kit
I put up some new pictures if anyone is interested in the Boomer idea to enhance their Betsy's.
The Betsy also sounds very good in a sealed or aperiodic cabinet sitting atop a pair of H-frames.
If anyone is interested in the Betsy/Boomer speaker kit let me know.
Godzilla
Open Baffle Speaker - Betsy and Boomer Open Baffle Speaker Kit
I put up some new pictures if anyone is interested in the Boomer idea to enhance their Betsy's.
The Betsy also sounds very good in a sealed or aperiodic cabinet sitting atop a pair of H-frames.
If anyone is interested in the Betsy/Boomer speaker kit let me know.
Godzilla
Congrats on the vendor forum! It's great to have things gathered in one place.
Just out of curiosity, were the Betsy BiB's skinnier because of an MJK sim, or for some other reason? I'm interested because I'm comparing the BiB calc to MJK's BiB worksheet, and I'm just finishing up a set of BiB's this very weekend (for a listening party next weekend).
Regarding the (very excellent) Betsy OB design, as you know I built it with my wife, but what's new is that I swapped out my two little tube amps for an SS (Cambridge Audio Azur 340A, $350) and the bass is so much tighter.
So that design only gets better with SS (at least that's my experience!)
Just out of curiosity, were the Betsy BiB's skinnier because of an MJK sim, or for some other reason? I'm interested because I'm comparing the BiB calc to MJK's BiB worksheet, and I'm just finishing up a set of BiB's this very weekend (for a listening party next weekend).
Regarding the (very excellent) Betsy OB design, as you know I built it with my wife, but what's new is that I swapped out my two little tube amps for an SS (Cambridge Audio Azur 340A, $350) and the bass is so much tighter.
So that design only gets better with SS (at least that's my experience!)
Godzilla: maybe a Betsy +Boomer thread is in order? I have the power to split threads here, but feel free to start one with a pretty pic!
RJbond: I built my BIB's cabs early on for another pair of drivers. ScottMoose spec'd those before GM came up with the formula from which all the "modern" BIB designs (and the calculator/spreadsheet) are derived. It may have been in the first hundred posts of the BIB thread! It was designed to be a smaller than ideal, so lower tuning (notice how long it is) helps avoid a hump in the midbass. The thing I liked least about those cabinets was the driver height. I frequently contemplated turning them upside down. Since I had gain to spare, I also thought about a K-slot, which would have made them the largest iBIBK (I think). But alas, I never got it done.
My wife is very tolerant, but one pair of giant BIB's was enough. The BetsyK specs pretty close to the drivers the cabs were originally built for. I tossed the BetsyK's in, and that pair lives in those cabinets to this day.
In retrospect, I may have had them overdamped for many peoples taste. I really did enjoy the LF extension. These TL's go deeper than I thought they would, but it is tough to compete with 12 cu. ft. When I built the BIB's, I was really looking for a pair of cabinets this size (for the drivers I had at the time). But, I didn't have the ability to simulate them, and I didn't want to build a basic bass reflex. The BIB thread exploded, and I didn't look back until we moved West.
I'm really enjoying these cabinets. I think nearly anyone could incorporate them into their room. As I mentioned I delivered a pair to my brother and sister in law. She is a picky decorator, and is tolerating them well despite my sub-par woodworking skills. I (nor they) are running any BSC, and with the boxes close to the boundaries, I'm pretty happy. They are probably a little shelved down in the bass, but I like a slightly forward midrange. Brings the girls closer. If folks drag them out into the room, a few DB of BSC wouldn't hurt, but keep in mind that they do have a couple db more bass gain than a comparably sized bass reflex or ML-TL.
I do have visions of giant cabinets. The MooseBVR was a big reason I parted with the BIB's. The design for the BetsyK's is only about 2/3 the volume of the BIB's I had. I knew I probably wouldn't build a pair as long as the BIB's were in the house. But, I'm also contemplating a OB/helper woofer setup. 'Zilla's kit looks great, but I already have too many amps. I'll be curious to see the Pass B4 PCB's. . .
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
RJbond: I built my BIB's cabs early on for another pair of drivers. ScottMoose spec'd those before GM came up with the formula from which all the "modern" BIB designs (and the calculator/spreadsheet) are derived. It may have been in the first hundred posts of the BIB thread! It was designed to be a smaller than ideal, so lower tuning (notice how long it is) helps avoid a hump in the midbass. The thing I liked least about those cabinets was the driver height. I frequently contemplated turning them upside down. Since I had gain to spare, I also thought about a K-slot, which would have made them the largest iBIBK (I think). But alas, I never got it done.
My wife is very tolerant, but one pair of giant BIB's was enough. The BetsyK specs pretty close to the drivers the cabs were originally built for. I tossed the BetsyK's in, and that pair lives in those cabinets to this day.
In retrospect, I may have had them overdamped for many peoples taste. I really did enjoy the LF extension. These TL's go deeper than I thought they would, but it is tough to compete with 12 cu. ft. When I built the BIB's, I was really looking for a pair of cabinets this size (for the drivers I had at the time). But, I didn't have the ability to simulate them, and I didn't want to build a basic bass reflex. The BIB thread exploded, and I didn't look back until we moved West.
I'm really enjoying these cabinets. I think nearly anyone could incorporate them into their room. As I mentioned I delivered a pair to my brother and sister in law. She is a picky decorator, and is tolerating them well despite my sub-par woodworking skills. I (nor they) are running any BSC, and with the boxes close to the boundaries, I'm pretty happy. They are probably a little shelved down in the bass, but I like a slightly forward midrange. Brings the girls closer. If folks drag them out into the room, a few DB of BSC wouldn't hurt, but keep in mind that they do have a couple db more bass gain than a comparably sized bass reflex or ML-TL.
I do have visions of giant cabinets. The MooseBVR was a big reason I parted with the BIB's. The design for the BetsyK's is only about 2/3 the volume of the BIB's I had. I knew I probably wouldn't build a pair as long as the BIB's were in the house. But, I'm also contemplating a OB/helper woofer setup. 'Zilla's kit looks great, but I already have too many amps. I'll be curious to see the Pass B4 PCB's. . .
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
RJ bond, I got distracted thinking about the BIB's. Does your tube amp have 4 ohm taps? If you find the SS amp tighter with the OB's, you probably prefer a little more damping. I sure don't find my tube amp sloppy down low, but then neither my tube amp or my SS are typical! My tube amp has tighter bass than the chip amp, unless I switch the small amount of feedback off. I do suspect that these OPT's are more substantial than is typical of "little" Chinese amps.
As regards info consolidation on this forum: it certainly can be a plus. On the other hand, I hope that you folks don't restrict discussion of my speakers to my little area! There will always be fewer potential customers lurking in these parts than on the main fullrange board.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
As regards info consolidation on this forum: it certainly can be a plus. On the other hand, I hope that you folks don't restrict discussion of my speakers to my little area! There will always be fewer potential customers lurking in these parts than on the main fullrange board.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
I received an email asking me to turn GM's TQWT specs into actual dimensions. Basically, the box needs to be (internally) 248 sq. inches at the top, and 24.8 sq. inches at the bottom and 44" high. The top is closed, the bottom is open, the driver is as close to the top as you can stand. GM recommends 30" wide (external, at the top), so assuming .75" material, that means the cabinet would be 10.25" deep (again, external). And of course, that means the cabinet will be 3" wide at the bottom. When you add the top in, the cabinet becomes 44.75" high externally, and you'd want some sort of stand to get the terminus off the ground. Stuff to .25 lb/ft per cubic foot: i.e. tease about 12 oz out to fill the cabinet.
That is a very wide an shallow interpretation. You could, of course, work those dimensions out any way you like. But, as you get narrower and deeper you may find you want a little BSC. And if that taper is a little too strange or creates too large a footprint for you, keep bugging me to draw out my TQWT.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
That is a very wide an shallow interpretation. You could, of course, work those dimensions out any way you like. But, as you get narrower and deeper you may find you want a little BSC. And if that taper is a little too strange or creates too large a footprint for you, keep bugging me to draw out my TQWT.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
Pardon my ignorance, but this tapers in two dimensions like a Metronome? Or am I mis-reading? Would this look like an inverted pyramid with the "tip" cut off?
Perhaps it could be folded like Bob Brines? FTA-2000
Might help to lower the driver height. Wow, 30" wide sounds big even by GM's standards
But it's the sound that matters. Big speakers are fine by me if the bass is crystal clear.
Perhaps it could be folded like Bob Brines? FTA-2000
Might help to lower the driver height. Wow, 30" wide sounds big even by GM's standards
But it's the sound that matters. Big speakers are fine by me if the bass is crystal clear.
It only tapers in one dimension, the depth stays constant. It is a basic TL, or in GM's terms, (which I like) a TQWT. So, an inverted triangle with the tip cut off, if you look at it in two dimensions.
It isn't really practical to fold a 10:1. If you did, it would be very short. You could make a very unusual bookshelf though!
A more traditional 1.4:1 works much better. The lesser taper makes for a longer length and a smaller footprint. This is the whole idea behind my little TL/TQWT! I need to get some specs up.
30" is wide, probably too wide for many people. But it will obviate the need for BSC. I'd be tempted to to a little narrower (24" wide?), toss it against a wall and take my chances.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
It isn't really practical to fold a 10:1. If you did, it would be very short. You could make a very unusual bookshelf though!
A more traditional 1.4:1 works much better. The lesser taper makes for a longer length and a smaller footprint. This is the whole idea behind my little TL/TQWT! I need to get some specs up.
30" is wide, probably too wide for many people. But it will obviate the need for BSC. I'd be tempted to to a little narrower (24" wide?), toss it against a wall and take my chances.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
I'm thinking a Betsy would work great in the new Zen Open Baffle design.....Great bass with no sub or bass speakers needed... driven by a flea amp... and it looks much smaller than the folding wing design.
I don't have the link but it's on the Decware site. How bout a DIY Wild Burro clone kit with precut flats for us poor folks with no woodworking skills?
I don't have the link but it's on the Decware site. How bout a DIY Wild Burro clone kit with precut flats for us poor folks with no woodworking skills?
That certainly is an interesting cabinet design. I am a bit skeptical, and I'd love to hear one. It is simple enough, that for most folks it would probably be much less expensive to have the wood cut locally. Shipping would be an absolute bear. I'm sure you've got a local cabinet shop that would do an excellent job for less than I'd have to charge.
In general, I think space is more the issue than skill. The folding baffle is neat because you can have the panel's precut easily (even on a home depot panel saw), and then one can screw it together in the living room. If, however, you've got the space, all you need are some cheap tools. A lack of skill doesn't stop me!
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
In general, I think space is more the issue than skill. The folding baffle is neat because you can have the panel's precut easily (even on a home depot panel saw), and then one can screw it together in the living room. If, however, you've got the space, all you need are some cheap tools. A lack of skill doesn't stop me!
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
Kreg Cabinet Building System
Last weekend I attended a woodworking class on building kitchen cabinets with the Kreg Pocket Hole Joinery System. It's got to be the easiest method on earth to contruct a strong box from plywood. This system has to have great application in speaker cabinet building. After cutting your plywood you can literally put a cab together in five minutes. Is anyone using this to make speaker cabs? I was so pumped I ordered my Kreg kit off ebay as soon as I got home from the class.
Last weekend I attended a woodworking class on building kitchen cabinets with the Kreg Pocket Hole Joinery System. It's got to be the easiest method on earth to contruct a strong box from plywood. This system has to have great application in speaker cabinet building. After cutting your plywood you can literally put a cab together in five minutes. Is anyone using this to make speaker cabs? I was so pumped I ordered my Kreg kit off ebay as soon as I got home from the class.
She kicked like a mule - then......
hey pjanda - a few minutes ago I fired up the fresh BetsyK mounted into the first Karlson 12 (introduced October 1954) - she kicked like a mule and rocked better than my Klipschorn on old 60's spy-rock - I probably didn't have enough power with my Monarchy SM70 and cds coming out though a Promitheus TVC - cone excursion at a very loud level was not even 1/8" peak to peak - but by the second cut I lost a tinsel joint to the cone - Misco imo needs to get a tougher solder connection - the cone movement was very small and I very happy for a few faint moments. The impedance curve looked good too with nearly equal amplitude for the 1st and 2nd peaks - I took a screen shot and the enclosure has a damping strip which allows some juggling of input Z.
if I can pull BetsyK (cramped space and I lack appropriate screwdrivers) then I'll see if she'll resolder like the first one I popped (that one was under high motion - this one was under a high load)
I'm impressed!
Karlsonette drawing by Greg B. from my horrid sketch
http://img228.imageshack.us/img228/8316/karlsonetteib7.png
hey pjanda - a few minutes ago I fired up the fresh BetsyK mounted into the first Karlson 12 (introduced October 1954) - she kicked like a mule and rocked better than my Klipschorn on old 60's spy-rock - I probably didn't have enough power with my Monarchy SM70 and cds coming out though a Promitheus TVC - cone excursion at a very loud level was not even 1/8" peak to peak - but by the second cut I lost a tinsel joint to the cone - Misco imo needs to get a tougher solder connection - the cone movement was very small and I very happy for a few faint moments. The impedance curve looked good too with nearly equal amplitude for the 1st and 2nd peaks - I took a screen shot and the enclosure has a damping strip which allows some juggling of input Z.
if I can pull BetsyK (cramped space and I lack appropriate screwdrivers) then I'll see if she'll resolder like the first one I popped (that one was under high motion - this one was under a high load)
I'm impressed!
Karlsonette drawing by Greg B. from my horrid sketch
http://img228.imageshack.us/img228/8316/karlsonetteib7.png
Wow! I've run them (my personal pairs, not those I sell) at double or triple Xmax for hours on end and I haven't broken one (often 20-30hz sine waves for break-in). This does open up an interesting opportunity though. Your pair is one of those early crippled ones where some current passes from tinsel to tinsel through the cone, which is why you measured those high Qes numbers. If you try and fix it, use a little nylon washer where it passes through the cone and that should correct the problem. Of course, you'd have to do it to the other one too to have a pair. FWIW, all the new production units have washers around the leads, so I suspect they are also more immune to snapping. It's funny that you should have tinsel lead problems. I'm planning to run some sweeps of my 15" OB woofers tomorrow, and those leads (basically the same as your BetsyK's) don't inspire great confidence at OB excursion levels.
BTW, if you can't fix them easily let me know. I'll see if I can work out a recone.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
BTW, if you can't fix them easily let me know. I'll see if I can work out a recone.
Paul
Wild Burro Audio Labs - DIY Full Range Speakers
I think (hope) the voice coil's good - but my vision doesn't converge well anymore for soldering so it'll be hit or miss if I can get it back into the cone's eyelet - BetsyK made a lot of noise - not just movement - Karlson will hold that cone motion down so power can be applied - it may (?) have helped if I'd had used a more powerful amp - say 60w -- it sounded like a band in a club !
re:washers - I've ~zero mobility to get stuff - how do they work to help the leads at the cone junction? - wonder if there's some sorta goop which would retain the lead and not cause response problems?
re:washers - I've ~zero mobility to get stuff - how do they work to help the leads at the cone junction? - wonder if there's some sorta goop which would retain the lead and not cause response problems?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
I doubt if the rear chamber has more than 1.5 cubic feet - if that - Front chamber on Karlson couplers in general are around 1/2 the rear chamber volume. 12" in K12 generally rolloff subjectively higher than what I heard from BetsyK - if one were building a K12, then it might be good to retain the 12" cutout and make an adapter plate for smaller drivers.
This was the first k12 from late 1954 - later K12 canted the front panel forwards and used a 6-slit distributed vent. I like the early one as it sounds
more like K15 .
give me a minute and I'll pull Julian Hirsch's old (1955) Audio League graph of two twelves and one 8 in Karlsonette -
here we go:
This was the first k12 from late 1954 - later K12 canted the front panel forwards and used a 6-slit distributed vent. I like the early one as it sounds
more like K15 .
give me a minute and I'll pull Julian Hirsch's old (1955) Audio League graph of two twelves and one 8 in Karlsonette -
here we go:
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
Betsy k compound horn
Here's a nice compound horn design I worked up. They're pretty big but the sound would be big too. I have included the hornresp model so you can see the performance you could expect. As you can see they are pretty flat down to 50Hz and have useful response down to 40Hz. They exceed 115db at Xmax and if like you said the do okay at over 2X Xmax then they should hit 123db down to 45Hz if you put them in the corners(that figure is for one speaker!) If anyone is interested in plans let me know. Or I could build them if anyone is interested as well.
Here's a nice compound horn design I worked up. They're pretty big but the sound would be big too. I have included the hornresp model so you can see the performance you could expect. As you can see they are pretty flat down to 50Hz and have useful response down to 40Hz. They exceed 115db at Xmax and if like you said the do okay at over 2X Xmax then they should hit 123db down to 45Hz if you put them in the corners(that figure is for one speaker!) If anyone is interested in plans let me know. Or I could build them if anyone is interested as well.
Attachments
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.