Fast, fun, Inexpensive OB project

Great to see so much continued interest in this design...

Thanks again to Michael and all contributors....
.

The pleasure is all mine – your trick with the inductor on SLS simply is genious !
Whats actually your naiming "Manzanita" from?


So Michael, how are you liking the Manzanita with your dipole ribbon/horn?
What do you think are its strong and weak points?


Not being able to compare to the original Manzanita and given the tough competition of my many times more complex system with AMT on PC XO I’m used to – well - how does it actually sound???

Certainly my crazy Manzanita OB / dipole-horn in its passive XO variant can’t compete in that its as minute detailed and throughout balanced, like possible with advanced active systems – and it can not compete in freedom of coloration which is partly from the drivers but even more true for the sonic pattern of the horn when we go down low - where group delay rises significantly and adds a sonic pattern not possible to compensate by simple (passive) FR EQing (Jean-Michel thanks for pointing me there ! :) ).

So, the sweet part regarding the NEO3-W on dipole horn had to be moved up higher as mere horn loading (SPL capability) would allow from looking at the measured response that extends pretty way down – finally resulting in a usable passive crossover point somewhere in the range of the original Manzanita.

What I liked so far is the high resolution of the NEO3-W which makes amateur recordings, ambience or occasionally mixed in “natural sounds” – sounding “to be the real thing”.
Anything with strings, especially percussively plucked ones, are very pretty rendered.
Female voices are sometimes “to die for” (well, I have a soft spot for female singers anyway - be it good old Ella, hyper modern Laurie or Sofia Madrigal or or or ...).
To my surprise the low and very low department can sound astonishing too.
The overall sonic “fresh appearance” I count as a pro too.

Where I see room for improvement is with male voices, where I (sometimes) would like to have better tonal “throughout balance” and with more complex music where we get lots of enjoyable sound but loose in detail – though, choral music still can be an "experience".
Possibly my biggest complain is that the NEO3-W on dipole horn is “different” with respect to the SLS – meaning you have to listen at a certain level to enjoy full harmonic richness.
At usual and forced levels merging is ok for me for most types of music, though by no means seamless, but at late night listening levels its really not as good IMO.
Speaking of levels – this combination certainly could do well for your next party.

There is a verve affinity to percussive instruments (like vibraphone, marimba, triangle ..) and of course to all horn and brass instruments too – making them sound enjoyable as kind of “extra natural” – which sometimes turns out to be a double sided sword. ;)

All above is also highly a matter of break-in to a degree I have not heard before (or better put - the disjointed impression at the beginning was stellar compared to even now - seems as if the two drivers had a travel from opposite sides of cosmos for their appointment here).


But - how will it sound *for you* ???
Frankly - I have no idea, but I guarantee for a looooot of *fun*...

If I sounded a little bit euphoric in my description – yes I've to confess, never worked with such cheap drivers getting such a reward - I really love that babies!


Michael
 
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Bearberry.....

Thank you for your interest in the Manzanita.... and BTW.... while I remember...I owe Mige0 an answer about the name Manzanita... it is a red bark shrub found on in the CA and OR foot hills... except here in the central Sierra foot hills there is a tree sized variant that can reach 40' in height.

Back to the main issue... the Dayton ND90 looks like a nice driver... however it is a couple of DB short efficiency wise.... down low it barely gets to it's advertized 82 db/watt (assuming the PE data is correct) and from the upper mid range on up it's more like 80 db... so it just does not play load enough... and because it also does not roll off until below 100 HZ it would take considerable cross over work to mate well with the SLS and it's simple single inductor. I would recommend something with at least 86 dbw true efficiency in the 800-17,000 band pass as a minimum. And if you can find a driver that has a natural rolloff similar to the SS D3800 it makes for a much simpler crossover and better integration.

Hope this helps....


John
 
Good news !

The NEO3-W (*without* DPR extension) performs even better in dipole horn

Parts-Express.com:*Bohlender Graebener Neo3W Planar Tweeter w/Back Cup | neo3 planar tweeter ribbon tweeter planar transducer

NEO3-W_non-DPR.jpg

NEO3-W_non-DPR2.jpg


Got the second set of speakers today. Here is a comparison:


DPRW_non-DPRW.png



we see that efficiency is ~ 4-5dB up (compared to the NEO3 *with* DPRW extension) I have shown earlier in
http://www.diyaudio.com/forums/multi-way/110583-fast-fun-inexpensive-ob-project-3.html#post1996193
- and also overall FR smoothness and polar smoothness in the horn is way better:

non_DPRW_polar_0_10_20_30deg_smooth_text.png


I bought the second pair as I wasn't really satisfied with my first measurements of the NEO3 * DPRW* but didn't know if its from my quasi min phase horn or from the NEO3.

There still is some polar wiggle in the 2.5kHz region but even that one is slightly smoother now.
So - room for improvement and tweaking of that NEO3-W.

Michael

I bolted a "true" ribbon tweeter from creativesound.ca to a tractrix horn, and also found that it measured quite nice. Here's some things you might try:

  • Be careful doing distortion measurements. Ribbons are fragile - I blew mine up in a day.
  • I believe that the reason that ribbons work nicely in a waveguide is because the diaphragm is flat. I have also measured the flat-coned tangband drivers on a shallow waveguide, and their off-axis performance was much better than you'd normally see at very high frequency. Basically the response shape barely changed at all as you moved off-axis, even at 20khz!
  • A great "trick" to improve horns and waveguides is modeling clay. Press some into the throat so that there's a very VERY smooth transition from diaphragm to throat.

Looks like a cool project!

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Thanks, and questions for Manzanita owners

Bearberry.....

the Dayton ND90 looks like a nice driver... however .... if you can find a driver that has a natural rolloff similar to the SS D3800 it makes for a much simpler crossover and better integration.

Hope this helps....


John

Thanks for the gently delivered explanation, John. :eek:
Keeping my eyes open for a more suitable alternative than the Dayton, but will likely go with the NEO3-W (Thanks for the variant, mige0).

John and other Manzanita owners: Have you been able to compare with anything based on Martin King's open baffle designs (OB Theory), or of greater interest, has anyone modeled the Manzanita with MJK's worksheets? Many people think the Manzanita sounds good, so I'm curious about how well MJK's software predicts the success of this design.

bb
 
This manzanita project is a success, well done as well as MJK projects. Better than any software, my measurements and my ears say it is a success :D

I think it is useless to compare design, you make a loudspeaker because you need it ?
You cannot compare a floor stander and a stand mount, non sense to do this.
You cannot compare a 15" and a 12" ... A bigger speaker works better than a smaller one.
All these design have strength and weakness : A 1" dome doesn't work well below 2kHz, a 4" cannot make treble like a 1" tweeter etc.

The Manzanita project is a good project, an unusual design with great result for it price. It's a very versatile loudspeaker.

:)

Thanks for the gently delivered explanation, John. :eek:
Keeping my eyes open for a more suitable alternative than the Dayton, but will likely go with the NEO3-W (Thanks for the variant, mige0).

John and other Manzanita owners: Have you been able to compare with anything based on Martin King's open baffle designs (OB Theory), or of greater interest, has anyone modeled the Manzanita with MJK's worksheets? Many people think the Manzanita sounds good, so I'm curious about how well MJK's software predicts the success of this design.

bb
 
Open baffle design approaches

Found another thread where John Bsuch and MJK are in the process of comparing their OB design principles:
http://www.diyaudio.com/forums/multi-way/155803-eminance-15-beta-vs-dayton-dc380-8-ob.html
That may answer one of my questions above.

As to my other inquiry about listening comparisons between MJK's published OB projects and the Manzanita:
... I think it is useless to compare design, you make a loudspeaker because you need it ?... The Manzanita project is a good project, an unusual design with great result for it price. It's a very versatile loudspeaker.
:)

I'm not going to build speakers because I need them, I already have a number of good commercial speakers, purchased before I found this site and others like it. I want to build speakers because I greatly enjoy building things and listening to music, and because I am curious about the differences between the sound of different types of speakers. I'm drawn to the opportunity to explore those differences by building speakers instead of buying, and to learn from the experiences of others who are interested in DIY speakers due to curiosity, rather than need.

Jerome, maybe I'm not properly understanding your comment, given that you compared alternative tweeters for your mini-Manzanita variant. I asked about a comparison between two speakers knowing that they are unlikely to sound the same, but not having heard a multi-way OB, being curious about how they differ (or don't), and whether any differences might be due to the design philosophy as opposed to the physical variation. I presume curiosity was also behind your tweeter tests, not the need for 3 different sets of mini-Mazanitas.;)

At any rate, I appreciate the contributions you've made to this thread, especially the mini variant. :nod: I might build it, but for now mige0's design takes me farther into unheard territory.

CLS, beats me how I managed to get the thumbs down icon in my previous post. Not intentional!

bb
 
Yes DIY is a fantastic experience ;) You will enjoy a lot :) OB is "an other world" but the rules of multi-way are the same than loudspeakers in box.

I understand what you want to say but ... I never compare any loudspeaker. It's a very difficult task because you quickly compare the coupling with the amplifier instead loudspeakers. And the criteria are not simple because you will always found a difference for physical reasons.
3 variants of mini-manzanita with 3 different tweeters because I own these tweeters and can be useful for people who have one of these tweeters ;). No comparison between them but comparisons with real music, which seem to me the more realistic to my ears, it is my preference.

I agree, the mige0's setup is very interested ;)

Have Fun :)
 
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I'm new to speaker building but this build seems like the perfect one to start out with although I do have the Hawthorne OB drivers now that I'm listening to.

I ordered the drivers from Madisound but can anyone suggest where to get the caps and inductors. Madisound also I would think but since I'm new part number would be nice or at least what wire gauge/model for the inductors and type of capacitors.

I have decided on the Pano version to start with the following

12R Resistor
5uF film cap
3mH Inductor (aircore or sledgehammer)??
12mH Inductor (aircore or sledgehammer)??

Thanks

PS, I forgot to ask what's the best type of bolts/nuts for mounting the drivers?
 
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Hi. Which tweeter did you order?

For inductors you want Sledgehammer (iron core) for the 12mH and air core for the 3mH.
Hang on a bit before ordering, I think John as some new refinements that he likes.

For mounting I just used black wood screws that I got from Parts Express (I think)
 
Hi Panomaniac
I ordered the D3806 tweeter.

Regarding John's updates, are they different than that schematic of his you posted right after yours? I was thinking of just getting the schematic with the fewest number of parts but if it's an audible upgrade, I am eager to wait and see yours/his suggestions!