As I build this Christmas what i had long ago planned to be the bass module of Directiva R2, one might wonder if something is cooking under the hood with the team?
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Introducing Directiva - An ASR open source platform speaker project
- Thread starter Rick Sykora
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Originally, the r2 bass module was supposed to be very modular and not be concerned with directivity. A recently posted subwoofer article made me reconsider as I discovered how easy it is to do a cardioid. I have a couple of vented RS225 bass modules from an earlier design. Trying to design the cardioid indoors may be problematic with room modes involved though.
My woodshop turned into storage area with a recent visit from relatives. Am looking to prototype a couple of bass modules after the new year. @abdo123 have something in mind?
My woodshop turned into storage area with a recent visit from relatives. Am looking to prototype a couple of bass modules after the new year. @abdo123 have something in mind?
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Colonel7
Addicted to Fun and Learning
Do you have a link to the article Rick?
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My bass module so far is consisting of a subwoofer pretty enough to sit under my L and R channels. Nothing really special.
This is a very incredible video, I wonder if someone made something similar but not for ports but for different drivers (the tweeter acting as a passive radiator for woofer or vice versa). those harmonics were insane.
I was wondering the opposite, would stacked woofers in a large enclosure "correct" errors through resonance of their twin or should they all be enclosed/vented separately?
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In the spirit of staying on-topic and reduced clutter, ask that the discussion about the subwoofer video be done on that thread please!
Biblob
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I was just thinking about this, and then to read you're already thinking about it! How awesome!
Recent discussions, make me think chasing cardioid bass might be a wortwhile exercise. At least untill around 80-100hz or so before crossing to subs.
DualTriode
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Hello All,
I just took a look/search through this thread, I see the term bass module mentioned many times.
While trying out drivers and enclosure for my "big speakers" I tried several mid-range drivers in separate stand alone enclosures. I tried out tweeters in separate baffles. I also tried woofers in in separate enclosures. Finally I put 18 inch subs into different enclosures.
Then I stacked the final woofer, mid and tweeter contestants one on top of the other. Each driver/enclosure was modular.
Is this the concept of modular you all are speaking of when you say Bass Module?
Thanks DT
I just took a look/search through this thread, I see the term bass module mentioned many times.
While trying out drivers and enclosure for my "big speakers" I tried several mid-range drivers in separate stand alone enclosures. I tried out tweeters in separate baffles. I also tried woofers in in separate enclosures. Finally I put 18 inch subs into different enclosures.
Then I stacked the final woofer, mid and tweeter contestants one on top of the other. Each driver/enclosure was modular.
Is this the concept of modular you all are speaking of when you say Bass Module?
Thanks DT
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- #1,211
Expect I will turn my efforts back to the monitor speaker next week. I will do a bit more testing with other woofers on the bass module, but then I need to complete the larger cabinet to evaluate. This transition will occur right after a ceiling paint job in our family room. Since I will move the home theater speakers out before painting ensues, once paint is dry, plan to sideline them and dedicate the space to measuring the r2 monitor.
After this, will do an integration pass with the smaller bass module. If all goes well, should be able to call r2 done.
After this, will do an integration pass with the smaller bass module. If all goes well, should be able to call r2 done.
A couple years ago I started a very similar build with the 0.56 cu ft flat pack, Purifi 6.5X04 and Bliesma T34B, ported. I've resumed working on them again recently, but my question is, should I be dropping the Bliesma in favor of the Seas DXT? Off axis measurements of the Bliesma look pretty smooth to me but there may be something I'm not seeing.
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Directiva r1 uses the Seas DXT as it is a solid performer, is readily available globally and very reasonably priced. While availability may have improved, the T34B is currently about 6 times more expensive than the DXT in North America. We were already stretching the r1 budget with the Purifi woofer. Even is avaiability was not an issue, price would have kept the T34B out if consideration.
I recall the hificompass folks already have designs using the T25B with the Purifi woofer. They should be be able to tell you how they compare to the T34B. Without actually having the tweeters to compare, it is difficult to say whether the T34B is much better than the Seas. Notably, along with the flange, the cabinet, crossover and other parts play a major role In determining how the speaker performs.
Ok I understand. My main question is, am I throwing away any semblance of controlled directivity by not using a waveguide tweeter?
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It is a factor but so is the cabinet and the crossover. How much is hard to say without actually measuring and modeling the overall design.
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So sorry folks I just realized it is almost 2 months since I said I would get back to working on r2. The good news is I can finally say I am making progress.
Am currently doing baseline measurements with the drivers in the sealed cabinet. Am working on the crossover and like what I see so far but struggling with getting the low end to work even with significant eq. Should be about to post some results later this week. The real test for r2 is the resistive cabinet design and that is next in line.
Am currently doing baseline measurements with the drivers in the sealed cabinet. Am working on the crossover and like what I see so far but struggling with getting the low end to work even with significant eq. Should be about to post some results later this week. The real test for r2 is the resistive cabinet design and that is next in line.
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Digital_Thor
Senior Member
I've heard the T34B in a few designs. It's a great driver.... when used in a waveguide - IMO. As a direct radiator.... it just throws sound in all direction.... and you lose the stereo image. I played with the DXT for some years - great driver if used in a narrow baffle or with very wide smoothly cruved baffle, but I did find the SB26ADC in an Augerpro waveguide to be more smooth and a bit more "resolved" - in a narrow baffle or with deep slanted cuts.
Thanks for the update.
Tis life. Keep us posted!
If you use the flat pack cabinet the response of the T34B will not be so smooth, cabinet diffraction will affect it. You can almost eliminate this by faceting the baffle.
Here is an example of a project designed to use a few different strategies to control directivity without a waveguide.
https://www.diyaudio.com/community/threads/new-project-tower-3-way-with-twin-8s.378223/post-7103088
The DXT is a better match for a smaller driver, for the 6.5 Purifi, Augerpro's waveguides for various tweeters, Hificompass's for the T25 and Pida's for the T34B will work better if you want a ready made waveguide.
https://www.somasonus.net/waveguides
https://pkaudio.webnode.cz/ellips-a/
