Fast, fun, Inexpensive OB project

Another note on components. For a long time I used a 18 mH coil with a dcR of around 0.9 ohms, but thought a lower dcR was worth a try so I got hold of a 20mH/ 0.5 ohmd - and (a little surprisingly?) it added clarity to the lower register. Not much, but it was audible.

Difficult when changing more than one parameter at a time (L and RDC), but the added clarity could be because the increased woofer level relative to the Vifa?

Alternative you could verify this by lowering the Vifa level a bit, with the old inductor in place?
 
I'm building a pair of Manzanita Ultra's as my first speaker building project. This will be my first crossover to build. It looks pretty straightforward but I was wondering if someone can take a clear close up picture of their crossover so I can take a look and make sure I understand it correctly. Thanks
 
I'm also thinking Ultras. I've got like four tabs open in my browser, from following links, just in THIS thread! :D

I currently run a pair of 2-way OB, Audio Nirvana Super 8" over MJK spec'd Goldwood GW-1858 H-Frames, biamped and actively crossed. I have friends who are interested (I think they can be pushed over the edge!) in DIY speakers, especially OB, but the idea of multiple amps, active XO, etc. is understandably intimidating for some. So I've been looking for:

1) an easy build for the first timer
2) inexpensive, from readily sourced components
3) passive XO for single amp use, likely some major brand AV receiver (80+ wpc if specs can be believed)

I'm trying to start a tiny circle of locals on the DIY/OB path and I think a Manzanita variant might be just the ticket. I'll have to build them first, of course...

So the Ultra is the "tower" version? If I understand correctly this has some advantages over the original stand mounted version? This is what I'm most interested in. Before I go trying to fill a PE shopping cart from posts made a few years ago I just want to make sure I have the latest version nailed down, with a few extra components for tuning...

Post 851 seems to have the most recent BOM and XO schematic for the "Ultra"?

And then I see a "woofer trap" detailed on 1059?

Still correct?

I too would love a photo or two of what a proper XO for these should look like. I've never built a passive XO before. One last request... these shouldn't be too difficult to figure out but has anyone done a cutsheet for the Ultras based on 4'x8' sheet? My table saw is sketchy and I'd like to have the lumber yard do most of the big cuts.

Perhaps the first post could be updated to reflect the current versions of the various builds? :)

Thanks in advance!
 
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Hello to everybody, I'm planning to build a Manzanita OB, but unfortunately I can't find GRS speakers in my country, and Peerless are not cheap enough for my first DIY loudspeaker. Surfing the net I found the Monacor sp302pa woofer, that is cheap, and with these characteristics :
8 Ohm, Fs 45 Hz, Spl 90 db, Mms 57 g, Qts 0,89; Vas 51 l, Xmax +- 2.5 mm. Pretty linear response. Do you think it may fit the project?
Thanks
Marco
 
Thinking about building a set of the Ultra's and want to verify the dimensions. The baffle is 24" X 48" with 6" wings Correct? The standard crossover is L1-20mh, C1-6.0uf, L2-2.75mh (air core), R1- 15ohm, and R2-8ohm. John and others have also recommended a filter of a 15uf and 0.4mh filter on the woofer and a 0.1uf parallel cap on the C1 tweeter cap. I am a some what competent wood worker and am curious of any physical tweaks to the enclosure. Is a tapered wing on the sides beneficial or just a time consuming aesthetic? I plan to use some type of damping on the back of the baffle and thought of using Dynamat or a similar type of car sound deadener. This would be my first OB speaker so is there anything else I should know? Thanks in advance for your input.
 
This is a popular thread so is there anyone who might be able to fill in the blanks for me? I have ordered all my parts and will hopefully start my build in the next few weeks. I have seen 4" and 6" wings noted, so which one is it? Do they attach to the sides of the baffle or on the back edge. I ordered all my crossover components, if I use the woofer trap are any of the original crossover components not needed? I also bought a couple of .1uf caps that I will run in parallel with the 6.0uf tweeter cap. I will post pictures once I complete them. Thanks for any assistance you can provide.
 
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The project is ever evolving, but the info on the Ultra is up to date.
  • Wings. Tapered on one side is better. The straight wings are for ease of build and WAF. The normally attach to the sides of the baffle.
  • Crossover. The woofer trap is not a must have item, just a nice tweak. Good for the GRS
  • Baffle. Thick is good. I've seen John build out of 2" OSB, which is hard to find outside of California. Truck bed liner in a spray can from NAPA auto parts works well on the back of the baffle. I have made versions with nothing on the front, or felt, burlap and even faux fur. It's up to you. :)
 
The MiniDSP and 4 channels of tpa3116d will be extremely handy for any project. And you won't be stuck with redundant xover parts and loss of money as you make changes.

Having said that, it will take more money and time to setup initially and you will need a umik to really get the most out of it in the long term.

There is a certain satisfaction to passive xo but if you know you are going to tweak and make changes then dsp is great value.
 
Does this crossover look right?

Please excuse my crude drawing, but does this crossover look correct? I have ordered the parts and want to make sure before any soldering starts. I put the value of the parts I am going to use on the drawing. After reading through the thread I decided to use a 7.5ohm resister on R2 so I have a little less attenuation on the high end. I hope to post a drawing of my planned speaker build later so it can be looked over prior to cutting any wood. Thanks everyone for your input.
 

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That looks correct. I ended up with 8 ohm at R2
Real important to chamfer away back side of vifa mounting hole
To give it room to breathe.



Please excuse my crude drawing, but does this crossover look correct? I have ordered the parts and want to make sure before any soldering starts. I put the value of the parts I am going to use on the drawing. After reading through the thread I decided to use a 7.5ohm resister on R2 so I have a little less attenuation on the high end. I hope to post a drawing of my planned speaker build later so it can be looked over prior to cutting any wood. Thanks everyone for your input.
 
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I think someone tried it, but don't remember the results. It's going to cause a sort of horn loading.
Better to make a thin sub-baffle to mount it on, say 6" diameter, and mount it from the back.

MiniDSP. I would say no. I tried and tired and tried active crossovers on these (and other OB speakers). Never was happy with them. The big inductor on the woofer is what makes it all work, for some strange reason.