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Old 18th May 2011, 08:23 PM   #401
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Here's the couple of pics I took of John's speakers at LSAF. The orginal Manzanita and the HE version.

Click the image to open in full size.

Click the image to open in full size.
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Old 31st May 2011, 06:25 PM   #402
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Talking Updating the Manzanita to look like the LSAF picture!

OK, Now that we are post Lone Star Audio Fest, as promised, here is the first installment on the revised, and dare I say UPGRADED Manzanita layout. I will refer to this current version as the Manzania A.

The major changes include a new Mid-tweeter and the resulting crossover configuration upgrade.

The Manzanita Open Baffle project now has two tracks, the DIY "A" version and a couple of Commercial Versions. Manzanita CV's, if you will. The physical dimensions of the newer versions are nearly identical to the original, as is, of course, the core concept.

The Commercial Version offers upgraded cosmetic value relative to the DIY version, and a more refined (and much higher cost) crossover. A second Commercial Version (currently under development) uses a very high end full range up top, and with all that added cost, it no longer qualifies as a low cost concept.

Getting back to the new and improved DIY "A", low cost concept. After auditioning many small 2" - 4" wide range drivers, I decided on a particular Vifa 3-1/2" full range. I say particular, as there are several versions in this Vifa Series.

This particular configuration, IMHO, offers the best combination of low cost, low distortion, build quality, crossover simplification, durability and availability. Over all, the Vifa easily out performs both the original Seas TDFC tweeter and Scan Speak D3800 mid-tweeter in the mid range. The Vifa's high end extension is close to the D3800, but not quite as good as the TDFC. On the very low end, the Vifa is MUCH better than either of the previous. The best news is the Vifa is typically available for $8-15 each, a true bargain. Like the TDFC and the D3800, the Vifa is, for the money, a state of the art driver. This driver is available at Madisound and is current Vifa production, so it should be available world wide. The Madisound link is here. https://www.madisound.com/store/prod...oducts_id=8403

The Vifa allows a simple 5 element crossover, that can be easily adjusted with a common value resistor and or cap change. By adjusting, I am speaking of setting the high end level to suit room and owner preferences. So for less than $300 per pair, you can build a compact, high performance near full range, stand mounted Open Baffle design.

Next installment I will include the revised base crossover values and current baffle - wing layout.

John
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Old 1st June 2011, 01:01 AM   #403
vaughn is offline vaughn  United States
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Well you have my full attention!

I've been enjoying the originals very much. I am using them near field driven by a Yamaha CA-2010 in Class A mode and it is very sweet indeed...
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Old 4th June 2011, 10:33 PM   #404
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Default More Manzanita A tech stuff

Now some of the important stuff. Baffle dimensions, wing depth and baffle layout.

FYI, I am still "picture posting" challenged on the DIY site, so Pano, again, is bailing my *** out and will post a couple of pictures on the site. I can email them to him but just can NOT get them to post! The Pics will help the following make a bit more sense.

After many hours of True-RTA, ARTA & Holm Impulse measurements as well as a LOT of listening, I tweaked the baffle plate to 28" H X 15" W. The wings are now a bit simpler and symmetrical at 28" H X 4.25" D and 0.70" thick. (0.7" is the net thickness of standard 3/4" pine or oak boards found at Home Depot or Loews) You end up with a final assembled width of 17.4". The baffle is 3/4" birch ply as is the base plate which is full baffle width (15") and 8" deep. As with the original, the crossover is mounted on the base plate. For those who do not have a pick up truck or similar, you can buy 2' X 4' X 3/4" birch ply sheets from Home Depot that will fit in most cars. I think it is Chinese origin and the surface veneer is quite thin. More on that later.

BTW, the baffle H & W dimensions are not critical. Stay with in an inch on the width or 2 inches on the height you will be OK.

As shown in the pictures (Thanks again Pano), the baffle, wings and base plate are mounted together with simple pine 2" X 2" rear sub frame. (1.5" X 1.5" dimensional net) Sheet rock screws and or wood glue can be used to insure a rattle free structure. Once you are satisfied with your baffle assembly, the screw and glue combo is highly recommended. The Peerless cone movement is considerable and anything not held tightly in position will rattle. This includes all of the crossover components too.

Another change is integrating the rear radiation of the Vifa. The previous HF drivers were chambered and rear radiation was not an issue. The Vifa's rear radiation overall is beneficial, but not as simple to integrate. The Vifa's construction and relatively large magnet limits the rear open area. If you mount it on a full 3/4" thick baffle, there is near zero open area, the rear is radiating into a shallow tight tunnel which has several bad effects. So, to minimize the tunnel, I route a 4.5" diameter round counter sink on the rear side of the baffle with a sink depth of 7/16". This opens up the back radiation considerably, is simple to do (If you have a router) and there is still enough baffle thickness remaining to secure the Vifa with small screws. For those who do not have access to a router, there is a simple alternative that I will provide in a separate post.

The woofer is centered left to right with the woofer center height 12" from the bottom of the baffle. The Vifa center is 21" from the baffle bottom and 5.25" from the (Left or right) baffle plate edge. (This distance does NOT include the wing edge thickness) One needs to observe left and right positioning with the Vifa. The offset is very important and provides a great deal of baffle diffraction smoothing. The Vifa's off center (offset) position also sets F equal and F peak frequencies and the crossover is designed around these values. If you center the Vifa, be prepared to do a LOT of crossover work!

The crossover concept is a carry over of the original, but with some additional attention to the rising response of the Vifa TC9DF and the Vifa's rear radiation. Crossover details come next.
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Old 4th June 2011, 10:59 PM   #405
Pano is offline Pano  United States
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Here are 4 photos. Note the good views of the crossover.
Attached Images
File Type: jpg manzie_back1.JPG (64.7 KB, 2536 views)
File Type: jpg manzie_back2.JPG (53.4 KB, 2433 views)
File Type: jpg manzie_side.JPG (54.9 KB, 2390 views)
File Type: jpg manzie-front.jpg (53.1 KB, 1042 views)
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Old 12th June 2011, 08:08 PM   #406
brookbh is offline brookbh  United States
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Has an in-production suitable replacement woofer for the HE design been revealed yet? I am hoping you will say the Sigma Pro will work nicely. I wanted to thank you guys for posting your designs as I have been looking for ideas for a first speaker project based on a FR design.
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Old 13th June 2011, 02:35 AM   #407
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The Sigma pro is the leading horse at the moment.
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Old 13th June 2011, 03:10 AM   #408
ra7 is offline ra7  United States
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Quote:
Originally Posted by John Bsuch View Post
A second Commercial Version (currently under development) uses a very high end full range up top, and with all that added cost, it no longer qualifies as a low cost concept.
Thanks for the design, John. May I ask which high end full range up top?
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Old 14th June 2011, 12:34 AM   #409
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The cross over values would be greatly appreciated at this point. I've built a sealed 2 way and the Coniston full range so an OB project is in the cards...............
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Old 21st June 2011, 07:59 PM   #410
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Default RE: Manzanita Build Versions

Hi,
I'm new here and to DIY in general. After a long search for plans of an OB that I could complete, this looks to be a great place to start. First, thank you John for your commitment to simplicity and budget. Thanks too, Pano for being a part of this. My big question is this: What is the amplifier Ohm load? Right now, I can only manage 8 with my amp.
Thanks again,
Steve
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