Introducing Denotiva DIY speakers!

[RickS]

Well was planning to wait until a later date to announce this, but the budget Directiva project required that I exchange the Seas DXT tweeter and so it seemed the time had arrived. To date all Directiva speakers have used the DXT tweeter but as I worked on a budget version I realized that the cutout would also fit a Dayton ND25FW tweeter. I happen to have one leftover from my C-Note build and could readily matched with the Dayton SIG180 midwoofer. As calling it D-Note seemed presumptuous but it does have Directiva genes, I decided I would call the new speaker(s) Denotiva.

Denotiva is not an open source project like Directiva. Some Denotiva designs will share the cabinet and front baffle design from Directiva r1. As a D-Note implies, expect it can be built for $500 (or less). Various cabinet types (sealed, vented, passive radiator) will be supported, but the primary target is a vented box with a passive crossover. Parts Express recently changed cabinet suppliers and so one reason to wait was its availability. PE customer service tells me that the cabinet should be available in March though. If you prefer a small tower, expect that Denotiva will support the Parts Express one. Am expecting it a bit sooner. Total cost will depend on the new cabinets and final crossover designs.

As I anticipate it will be requested, expect an active crossover design will be done for each Denotiva speaker. Along with the budget Directiva, expect the first full Denotiva design will be done within the next 2 months. Amir has agreed to review and, based in his findings, will refine the design if needed before finalizing.

As usual, I welcome any questions.

Kind regards,

Rick


Note: Denotiva designs are not for commercial use without my express written consent.

 

[restorer-john]

As usual, I welcome any questions.

I'm confused. It's DIY, but not "open source" (whatever that means in this case). What does that mean?

Are you selling anything, or deriving any benefit, because if so, the thread should surely be in the desperate dealers section?

 

[McFly]

Yeah is this going to be a Kit for sale? I guess it qualifies as DIY, but yeah, dealers section. Looks good though! What kind of bass extension does that woofer get in that cabinet? What's system sensitivity?

 

[RickS]

I'm confused. It's DIY, but not "open source" (whatever that means in this case). What does that mean?

Are you selling anything, or deriving any benefit, because if so, the thread should surely be in the desperate dealers section,,,

I plan to publish the designs but am controlling the use of them for commercial purposes.

 

[RickS]

Yeah is this going to be a Kit for sale?

TBD

I guess it qualifies as DIY, but yeah, dealers section. Looks good though! What kind of bass extension does that woofer get in that cabinet? What's system sensitivity?

Am working on the crossover rn. Expect sensitivity in the mid-upper 80s, f3 in the mid 40s.

 

[im_gumby]

I plan to publish the designs but am controlling the use of them for commercial purposes.

Looking at this from the Software Community perspective...

There are multiple Open Source licenses (Gnu being the first or one of the first) thru to Apache and then modifications and versions.
Each has different levels of control.

All are open source.

If you've got a friend who's a lawyer... talk to them, or maybe pay a lawyer up front if you're going to do multiple iterations. Once you get your licensing squared away... rinse and repeat.

 

[somebodyelse]

I plan to publish the designs but am controlling the use of them for commercial purposes.

You could pick one of the Creative Commons options - there are a few non-commercial variations with differing terms for derivative works.

 

[RickS]

Thanks folks but as IP stuff goes, I spent 2 years as a corporate licensing engineer working with our attorneys and my son is an attorney. Was not sure I really liked the name, but has really grown on me and so I now own the domain.

If the day comes when I need to worry more about licensing, will spend more time on it. For now, let’s stick to the fun parts! I have spent a good part of last week on crossover design but am not ready to share. I thought I was close and had minidsp crash on me and lose the configuration. Never had that happen before so am saving the configuration more often now. First crossover design will be active with an eye on ready conversion to passive.

 

[John Limbach]

Just confirming at some point cabinet designs will be available? I enjoy that process so just wondering. Thanks so much!

 

[RickS]

Just confirming at some point cabinet designs will be available? I enjoy that process so just wondering. Thanks so much!

Yes. it is a couple of minor tweaks to the Directiva design. The tweeter recess is shallower and the woofer one is slightly wider.

A member is working on the precut baffle and his CNC is more accurate than my routing skills. Can share when he is done.

p.s. Basing it on Directiva cabinet design also allows Denotiva to be upgraded to a Directiva r1. It would need the aluminum cone Purifi midwoofer, deeper recesses for the tweeter and (obviously) a different crossover.

 

[John Limbach]

Thank you so much. As a side note I and a fine woodworking professor at our local art college are finishing a complicated pair of SB Acoustic Ara Txtremes soon and she has loaded all into CAD to confirm the 17 pages of cab drawings lol so we could now, even being just about done CNC Ara cabinets lol. This has been a no joke build. Thanks Rick!

 

[RickS]

Here is a first pass at a potential passive crossover design. It crosses around 2.6 kHz and only uses a couple of filters and a pad for the tweeter. Did not realize how much I crutch on active filters, so it took a bit longer for me to do using minidsp without using any added gain...

It droops above 10 kHz and still has some directivity challenges but was done by experimenting rather than simulation. Expect it may need some baffle step comp before it is final but for now, its progress.

 

[Joe BKNY]

Here is a first pass at a potential passive crossover design. It crosses around 2.6 kHz and only uses a couple of filters and a pad for the tweeter. Did not realize how much I crutch on active filters, so it took a bit longer for me to do using minidsp without using any added gain...


View attachment 354814


It droops above 10 kHz and still has some directivity challenges but was done by experimenting rather than simulation. Expect it may need some baffle step comp before it is final but for now, its progress.

Exciting to see progress being made. I know you have to juggle multiple responsibilities, and so appreciate your ongoing commitment to this!

 

[RickS]

Another pass with comparable directivity but flatter overall....

Gave it a listen with my favorite tunes and sounds pretty good too!

Meanwhile a friend prototyped one with closer driver distances. Ofc, it involves trimming the tweeter waveguide. See what you think...

 

[carbidetooth]

I like it...

 

[RickS]

I like it...

Thanks friend!

 

[Bryguy]

How are these coming along? I might be interested in building a sealed pair

 

[RickS]

Admittedly slowly as too many home projects and audio ones are causing me to thrash. I did the initial work with my UMIK-1 but now need to switch to my speaker design rig to do properly. I hoped I might get away with a quick turn, but the drivers are not integrating as readily as I expected. One issue is the SIG180 not quite living up its spec as the fS is much higher than claimed. Was hoping some break-in would improve but has not helped much. This seems to mainly seems to be a stiff spider and hopefully will improve with later units. If you want to use sealed cabinet, the f3 will likely be higher than expected. Given the price, they are usable still.

I should be able to post a crossover before the end of the month. If you are not picky or using an active crossover, PM me and can share what the current crossover.

 

[TonyJZX]

my read of this is that you are free to build your own set for private home use

but if you use the plans and sell them to the reds or tekton and they stamp out 1,000s then that's not on.. which is fair

why should a big conglom profit off this? BUT i'm free to make a single set for my own use

 

[Bryguy]

Admittedly slowly as too many home projects and audio ones are causing me to thrash. I did the initial work with my UMIK-1 but now need to switch to my speaker design rig to do properly. I hoped I might get away with a quick turn, but the drivers are not integrating as readily as I expected. One issue is the SIG180 not quite living up its spec as the fS is much higher than claimed. Was hoping some break-in would improve but has not helped as much. This seems to mainly seems to be a stiff spider and hopefully will improve with later units. If you want to use sealed cabinet, the f3 will likely be higher than expected. Given the price, they are usable still.

I should be able to post a crossover before the end of the month. If you are not picky or using an active crossover, PM me and can share what the current crossover.

I know how it goes no hurry

Very interesting project though. Thanks for sharing!