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Open Baffle Epiphany!

SixCats! said:
Hi z-ad,

Might you have any suggestions as to the proper (size/configuration) Baffle for use with (one of my many) vintage 12" Coaxial Drivers ? I'm interested in having a Baffle made for a MONO (near field) vintage Coaxial Speaker system. I have 12" University 6201, UTAH 12" Coaxial and a lovely vintage 12" Phillips/Norelco/Duotone (so called) Full Range Driver. Tube Amps would be Mono 2A3 SET, Pilot AA-903B (el-84) Mono, FISHER 500 Mono Receiver.

View attachment 2760089
UTAH G12 P5
View attachment 2760094

I have a SINGLE "Duotone 12" Driver:
View attachment 2760102

Thanks for any suggestion you may offer z.

Regards,
SixCats! aka Tom in Maine
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This isn’t something you are likely to nail perfectly the first time, so my advice is to start simple, see how it goes and add complexity to it as you go. My approach to OB is to begin with a simple flat baffle, braced and with good structural support. Then add to that until the desired result is achieved. For example, you can start with just a flat baffle then add 1 wing, then another which gives you a U-Frame. Try different sized wings too. See what works best by adding one thing at a time and do mock set-ups before making anything “permanent.” No way to predict what will work best because the room plays a big part, but I would personally go as big as comfortably possible with the initial flat baffle and keep the driver off centered. See how it goes then experiment with foldable wings.
 
z-adamson said:
This isn’t something you are likely to nail perfectly the first time, so my advice is to start simple, see how it goes and add complexity to it as you go. My approach to OB is to begin with a simple flat baffle, braced and with good structural support. Then add to that until the desired result is achieved. For example, you can start with just a flat baffle then add 1 wing, then another which gives you a U-Frame. Try different sized wings too. See what works best by adding one thing at a time and do mock set-ups before making anything “permanent.” No way to predict what will work best because the room plays a big part, but I would personally go as big as comfortably possible with the initial flat baffle and keep the driver off centered. See how it goes then experiment with foldable wings.
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Ah! OK z-ad, will do. Simple approach would be a very good approach as I just want to sort of experiment and not (at this point) invest much money as I just have soooo much other gear. I'm thinking something not too big (like the Betsy) size Baffle as things are getting rather crowded in my room.
I'm just having fun exploring/playing with different Drivers/Speaker(s). I am truly stunned how good this little nOrh 4.0 (gifted single) Speakers sounds as a small (near field) Mono (tube Amp) System so, I'm itching to give O.B. (even Mono) a try.

321805487_1856546808012018_9073386987740144965_n.jpg


Thanks z-ad.

Regards,
SixCats! aka Tom in Maine
 
SixCats! said:
Hi dfoulk, pray tell, does not the "Betsy" use the Lii drivers ? I'm confused regarding Lii, Betsy, Wild Burro Audio's offerings.

SixCats!
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When Decware upscaled Caintuck Randy’s barrel shaped baffles, using the Lii drivers, Steve mistakenly called them “Betsy’s”, because Randy had been selling the smaller baffles, with Wild Burros Betsy drivers, he called “Betsy Baffles”. Steve thought that that’s what the baffle itself was called, not realizing that it was actually the driver itself.

Steve Deckert actually had correspondence with Wild Burro about the mixup (Wild Burro was not happy that Decware was selling what they were calling “Betsy Baffles”). Steve agreed to stop using the term, but the damage had already been done, and now, everybody is calling any barrel shaped baffle, Betsy :rolleyes:
 
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Genov said:
When Decware upscaled Caintuck Randy’s barrel shaped baffles, using the Lii drivers, Steve mistakenly called them “Betsy’s”, because Randy had been selling the smaller baffles with Wild Burros Betsy drivers, he called “Betsy Baffles”. Steve thought that that’s what the baffle itself was called, not realizing that it was actually the driver itself.

Steve Deckert actually had correspondence with Wild Burro about the mixup (Wild Burro was not happy that Decware was selling what they were calling “Betsy Baffles”). Steve agreed to stop using the term, but the damage had already been done, and now, everybody is calling any barrel shaped baffle, Betsy :rolleyes:
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Ahhhh! Thank you for this explanation Genov.

Regards,
SixCats!
 
SixCats! said:
Hi dfoulk, pray tell, does not the "Betsy" use the Lii drivers ? I'm confused regarding Lii, Betsy, Wild Burro Audio's offerings.

SixCats!
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Apologizes for slow response, but was out of town, but thanks to others, it looks like your confusion has been handled:)
To me, the Betsy was the Wild Burro Lab's speaker, and not the baffle, though I can see how the confusion could get started. I have never heard the Betsy speaker in a baffle,
though I have come close on a few occassions of purchasing a pair of them. I ended up going off in a Zenith Alnico direction at the time, though I am currently listening to some
modded Rectilinear Lowboys, a totally different can of worms!
 
dfoulk said:
Apologizes for slow response, but was out of town, but thanks to others, it looks like your confusion has been handled:)
To me, the Betsy was the Wild Burro Lab's speaker, and not the baffle, though I can see how the confusion could get started. I have never heard the Betsy speaker in a baffle,
though I have come close on a few occassions of purchasing a pair of them. I ended up going off in a Zenith Alnico direction at the time, though I am currently listening to some
modded Rectilinear Lowboys, a totally different can of worms!
Click to expand...

Hi dfoulk, Thank you for your response and helping to fix my confusion. Wow, Zenith Alnico and (modded) Lowboys eh. Yes indeed, an entirely different direction. Enjoy!

Regards,

SixCats! aka Tom in Maine.
 
cptnCanada said:
So its -25 Celcius and the car wont start so of course I started messing around with my gear and came up with what I can only call an epiphany!

I took a pair of Foster (Fostex) FE103 alnicos with Planet-10-HIFI phase plugs that I had lying around and decided to cut up a left over cardboard box from xmas and create some crude open baffle speakers to see what the fuss is about...

WOW!:music:

Of course I have a sub hooked up for the bass.

Ive never heard anything like this in my life! I can hear the echo from the snare drum coming from BEHIND the speakers! Its like the whole front of me is the sound stage! Total open compared to my JBL decade 36, or any other speaker I've heard for that matter.

I like where this is going :D

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If you connect enough full range drivers you may find you won't need sub woofers. There is something about all frequencies coming out of all the full range drivers your running.
 
Wall of sound.

As i finally have my OBs all finished and have the crossovers and tweeters installed. I had a couple hours to seriously evaluate the SQ. The gate I like best is that there is no identifiable "source" to point to. From 15' away It's a wall of sound. The bigness of it is unmistakable. It's a little loose compared to many conventional speakers, but i find the looseness to be relaxing, effortless listening. There's a little bloom in the bass, but with the kind is music i like it sounds warm and relaxed. Vocals are the big standout! All i can say is WOW! I thought my Magnepans did good vocals, but these 12" EVs cream the Maggies. This effect is especially true with older recordings where the techniques involved less vocal processing. My Julie London CD just puts my right in the front row of a small jazz club. Lush!

My setup is:
Alpha 15" woofers in an open back box 18" deep up to 100Hz
DSP crossover set to 18dB octave at 100Hz
12" EV SP12A from 100Hz to 12kHz
12dB physical crossover at 12kHz
3/4" Tweeter from 12kHz up to whatever it goes to

So, now I'm thinking of going really big. Replacing the 12" full range with (2) x 15" drivers. If big is good, maybe bigger is better?

I'm now wondering about the acoustic effects of two drivers mounted close to each other vertically.
 
I could resist adding some OB to my office system. I picked up these 10" Zenith drivers IMG_0567.JPG for about $30 bucks. I am replacing my Andrew Jones Pioneer Bookshelf speakers.
 
Hope to be joining this chorus soon. After many years sitting in the back of my workshop I finally pulled two Zenith 49CZ924's from a console. My goal is to give building a set of OBs a try. I have some ideas as to what I want to do and started booking marking a few places with information. Looks like this is s good place to start.
Cheers
IMG_6183.JPEG IMG_6186.JPEG

EDIT: Edited to correct spelling and change OP to OB.
 
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Greetings,

IIRC there is posted somewhere on AK the specifications for the Zenith 49CZ924 but I can't seem to locate where.
If anyone has the spec's or a link I would be grateful.
Cheers,
Rick
 
bingow said:
Thanks all, for those enlightening tutorials; it's easy to be paralized by the possibilities. However, in my low-tech garage setup, I have tons of space: all overhead and none on the floor, so simple OBs seem my best solution. Update: my system is now complete except for making a solid sealed subwoofer box of the recommended size, vs the too small box out of foam. A proper sub box is in work.
For the Betsy's OBs, I replaced the hanging hooks (post 4928) with a 7' long cleat on the beam. That eliminated the gap while allowing the OBs to be slid horizontally for experimenting. In the photo below, they're butted, and sound better than with, say, a foot space between. Does that make sense?
View attachment 2615569
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  • I'm about to go down a similar route. i.e. open baffles suspended from a workshop ceiling
  • I'm going to use a pair of ciare CH250 I've had for ages (and a sub woofer) - they sounded great last summer in the garden but totally failed the WAF
  • the idea of suspending them sideways never occurred to me until I saw your picture - thanks!

I'd like to hear more about:
  • any successful improvements you made to the sound
  • what if anything you used as speaker cloth to minimise dust - I certainly can create a lot of sawdust
  • any issues with vibration and the cleat
 
OK, I've wanted to play on this thread for quite some time. A flea watt amp is soon to be in my life, so set out looking for efficient speakers (I didnt own any). No sooner had I won a Goodwill auction for some Klipsch RF35s, my long time search for some Zenith drivers popped up the very next day. Someone had already pulled them from a console and made baffles along with the 5" mids that were in the console as well. So ended up with the Zenith 49CZ873 twelve inchers and 49U856 5 inchers already mounted in smallish board. For $75 it was a no brainer. Once of the 12" drivers had a split in the cone which I finally patched and let everything cure, so today was first time I got to crank them. Definitely left me with some observations and questions. They are hooked up to a HK430 now as its the lowest powered thing I have:

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Anyway, after a time to let my ears adjust, they have great mids but I wasnt blown away like I expected to be. Weird change in sound but got used to it. The HF and LF were totally lacking though. Hooked up the 5" mids in series and was a definite improvement in the HF. The previous owner and the guy before who made them apparently didnt like the 5"s hooked up so was surprised I found them critical. Anyway- should these be hooked up in series or in parallel with the 12" drivers? Also Im stumped on what the value of the in line filter cap for these originally was. My transistor tester has some other functions I dont trust, but gives a clue. Anyway the caps tested- 6039nF/6192nF, Vloss 5.6%/6.3%, ESR .87R/1.2R. Id like to replace them with something modern, in spec, and inexpensive. Were these 3uF 30V originally? Would that be the right substitute?

zenithmids.jpg

Also would bigger baffles help the LF? Its not rolled off- its non existent.
 
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