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Old 10th October 2011, 02:34 AM   #451
Pano is offline Pano  United States
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Getting an open baffle speaker away from the wall is good. I ran my Manzanitas about 3 feet from the wall and was happy with that. 2 feet is not optimal. Not optimal for most speakers, in fact.

Let's see what John has to say, I know he has mentioned it before.
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Old 10th October 2011, 11:17 PM   #452
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Thanks for the reply!
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Old 10th October 2011, 11:56 PM   #453
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Default Manzanita wall separation distances

Like all open baffles, distance from any large reflective surface is good.

You can run the Manzanita from about 24" or more from rear and side walls and obtain good results. As the distance to the rear wall diminishes, so does the low end extention and tonal balance.

One can spread the distance between the left and right speakers a bit and increase the angle of the baffle face relative to the rear wall and some what offset the loss of bass extention. You can go up to around a 45 degree angle and adjust your seating distance - position to make up the difference.

You can also increase the inductor a bit more to make up for the mid bass gain a close rear wall proximaty will provide.

Bottom line, using some trial positions you can usually find a reasonable compromise of bass extension, tonal balance and seating position.

Hope this helps.

John
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Old 11th October 2011, 12:18 AM   #454
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Thanks! I am considering making some of these for fun...
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Old 20th October 2011, 03:47 PM   #455
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Default More updated info on the current Manzanita project

There have been some changes and refinements in the Manzanita since it first appeared 4 years ago in this thread. Let's look at those changes and improvements and give you an updated map to a Fast, Fun Affordable OB speaker.
Some of the following information has been previously posted here, but thought it appropriate to consolidate all the latest information into a single comprehensive post.

First, the Drivers.
The excellent Peerless SLS 830669 - 12" Woofer has been retained and is the heart of the Manzanita speaker. The original tweeter has been dropped from the design and replaced with the very good Vifa TC9FD18-08, 3.5" Full Range doing upper mid/tweeter duties. Many drivers were tried; the Vifa 3.5" is a winner for sound quality, cost and integration with the design.

Second, the Baffle.
I've tweaked the baffle plate to 28" H X 15" W. The wings are now simpler and symmetrical at 28" H X 4.25" D and 0.70" thick mounted on the sides. You end up with a final assembled width of 16.4". The baffle is 3/4" birch ply as is the base plate. The base plate (foot) is full baffle width 15"W x 8"D. As with the original, the crossover is mounted on the base plate. For those who do not have a pickup truck or similar, you can buy 24" X 48" X 3/4" birch ply sheets from Home Depot, Lowes, etc. that will fit in most cars. BTW, the baffle H & W dimensions are not critical. Stay within an inch on the width & height you will be OK.

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) Once you are satisfied with your baffle assembly, a sheet rock 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. Both drivers are mounted on the baffle front.
We need to integrate the rear radiation of the Vifa. The previous HF drivers were chambered and rear radiation was not an issue. When the Vifa TC9FD18-08 is mounted on a full 3/4" thick baffle, there is near zero rear open area. To correct for this and let the back of the Vifa breath, route a 4.5" diameter round counter sink on the REAR side of the baffle with a sink depth of 7/16". You now have a stepped hole for the Vifa, larger in back than in front. 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. You can visit the June 4th posts and see pictures of the front and rear of the prototype for reference. Fast, fun, Inexpensive OB project

The Peerless 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 (for the Vifa) and the crossover is designed around these values. If you center the Vifa, the crossover will not be right!

And Third:
What many have been waiting for, the new crossover. The Woofer is very simple as it uses a single inductor of 20mH. I recommend an Iron Core 15 or 16 gauge inductor. This inductor is connected in series with the Positive terminal of the Peerless woofer. That's all the woofer needs. The Vifa TC9FD18-08 (available from Madisound in the USA) requires 4 components to do its thing. A good quality 6 MFD high pass capacitor (Solen or better), a high quality 4.5 ohm, 5 watt pad resistor follow by a 2 element trap are used in series.

What really makes the Vifa behave is the trap. The trap controls the rising response the Vifa exhibits. Use a good air core 2.0 Mh (14-18 ga.) with a 8-10 ohm bypass resistor. Like the resistor and cap, the Inductor-resistor trap is placed in series with the positive terminal of the Vifa. Place the trap between the high pass cap and the positive terminal of the Vifa. You can vary the value of the pad and/or bypass resistor to tune the speaker to your room and your ears.

It will be interesting to get feedback from those who try the above solution In a later post I'll talk about tweaking the crossover to suite your room, your ears and your taste. But these values will get you started and 90% of the way there. After that, it's just fine tuning.

Pano will be posting updated dimensional drawings and crossover schematic reflecting the above later today. Thanks for the continuing interest in the Manzanita OB project!!
Attached Images
File Type: png new_crossover-revised.png (6.2 KB, 6747 views)
File Type: png new-baffle.png (19.2 KB, 5413 views)
File Type: png new-wing.png (7.5 KB, 4996 views)

Last edited by Pano; 20th October 2011 at 05:32 PM. Reason: Added images
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Old 20th October 2011, 04:05 PM   #456
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JB,
Thanks so much for this!
I have to go to work, but can't wait for the Pano plans. Can I source most of this from PE? Keeping the parts 'in house' would be great for shipping costs.

Can't wait to do this project!
Lyndon
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Old 20th October 2011, 05:30 PM   #457
Pano is offline Pano  United States
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Most of this can come from P.E. Only the Vifa 3.5" is not there (I think).
I'm adding the crossover schematic and new baffle dims to John's post above.
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Old 20th October 2011, 05:42 PM   #458
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Thanks, Pano
Source the Vifa at Maddy sound? I guess.
I wish I had my printer hooked up for this info.
Thanks again so much, fellas!
Lyndon
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Old 20th October 2011, 05:44 PM   #459
Pano is offline Pano  United States
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yeah, Madisound has the Vifa, for sure.
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Old 20th October 2011, 06:42 PM   #460
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Thanks John and Pano for the updates. Now I just need to sell off my ART arrays so I have room for a pair of these!!!!!
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