ASR Directiva Open Source Speaker Review

[McFly]

Yes, of course...

How about a few tube connectors and a side of copper caps to go with that too?

only if it uses sonicap platinum's, i need my electrons to know how much I spent on their circuit paths

 

[dukanvadet]

This deserve a video. Maybe with Rick and Ctrl as guests?

 

[Phorize]

It’s cheaper than maintaining an anechoic facility. Lol.

But inordinately more expensive than free field testing for those that have it available, hence the existence of well measuring speakers made by small companies without either anechoic facilities or an NFS

 

[xarkkon]

This deserve a video. Maybe with Rick and Ctrl as guests?

this is a fantastic idea! would be great to walk through the thinking behind the design process, choice of drivers, etc. i know it's all the the thread, but video's a fun medium too, and great to hear thoughts after the fact and next steps from here.

 

[PeteL]

Not sure what the problem is here…ok 1.5k for parts instead of 1k. And sure finishing. So 2k maybe? Who cares It performs outstandingly well at any comparable price point at its firm factor. That was the goal as I read it. So job well done. Period.

No need to figure out how to do it cheaper. That’s a different speaker project. And I suspect one that would be extremely hard to do and significantly be better than the best sub 1k speakers out there.

I didn't say it's a problem, I didn't say we need to figure out to do it cheaper. it's a budget unlimited project, in other words , what is the best 2 way bookshelf we can make if there are no budget limits. There is nothing wrong with that, there is room for the uber expensive stuff, they make the SOTA advance.
Do you already own all the tools to do it? Do you have 4 channels of DSP And 4 channels of good amplification dedicated to it? ) I don't compute how you can evaluate the cost of an active speaker system without at least calculating that, and it's an extra 2K right there. You can, OK not think your time is worth any money, I can accept that, it's a great project and we can have hobby and learning activities.
What I'm saying is. If you don't have all that, The workshop, the time, the tools, the talent, the amps and the DSP, Nobody would deliver that to you under 5K, and that's if he is really nice. I am not talking "If it was to be a commercial project" Then it would be more, much more, just count the manufacturer, distributor, and dealers margin on top of that 5K. But Again I don't have anything against that.

 

[Tangband]

DXT is known to have such break-up:

www.audioexcite.com » SEAS H1499 27TBCD/GB-DXT

I wonder if it woudn't be bad to cutoff above 21-22kHz.

Yes , this is a good tweeter to play 44,1 or 48 kHz sampling material. Not for 88 or 96 kHz . The resonance at 27 kHz will have distortion peaks at multiples of that frequency. That will cause a rise in the distortion profile at 13.5kHz for the second-order, 9kHz for the third-order and 5.4kHz for the fifth-order.
Something that can be seen at 96 dB distortion measurements at 13,5 kHz .
Here is a comparison with Genelec 8330 .

 

[digitalfrost]

Couldn't this be fixed with a RCL parallel to the tweeter?

 

[Tangband]

Couldn't this be fixed with a RCL parallel to the tweeter?

With material sampled up to 48 kHz there should be no problem. The highest level of information should then be at 24 kHz, not exiting the resonance at 27 kHz.
The measurements of this tweeter is really good, Ím just pointing at the small faults the tweeter has.
It seems that the SB 26adc for about the same price is maybe a bit better, has lower distortion , but no waveguide and lower sensitivity.

 

[gab]

@ctrl @Rick Sykora could you make a passive version as an MTM with another woofer in a bigger cabinet with a different tweeter for less than the cost of a Genelec? And could you change it from a PR to an MLTL?

Seas Bragi MTM Speaker Kit

Seas Bragi MTM Speaker Kit

www.madisoundspeakerstore.com

Passive
MTM
Different woofer
Bigger cabinet
Same excellent tweeter
2.6KHz crossover
10% discount on parts

 

[musicforcities]

I didn't say it's a problem, I didn't say we need to figure out to do it cheaper. it's a budget unlimited project, in other words , what is the best 2 way bookshelf we can make if there are no budget limits. There is nothing wrong with that, there is room for the uber expensive stuff, they make the SOTA advance.
Do you already own all the tools to do it? Do you have 4 channels of DSP And 4 channels of good amplification dedicated to it? ) I don't compute how you can evaluate the cost of an active speaker system without at least calculating that, and it's an extra 2K right there. You can, OK not think your time is worth any money, I can accept that, it's a great project and we can have hobby and learning activities.
What I'm saying is. If you don't have all that, The workshop, the time, the tools, the talent, the amps and the DSP, Nobody would deliver that to you under 5K, and that's if he is really nice. I am not talking "If it was to be a commercial project" Then it would be more, much more, just count the manufacturer, distributor, and dealers margin on top of that 5K. But Again I don't have anything against that.

Open source implies that once the design is finalized the design and specs will be available to anyone to reproduce. You don’t need all the measuring equipment to build the exact same speaker.

DIY implies one enjoys making them. A hobby, fun in which one trades time for price perhaps but that is only one aspect.

A passive version would make sense to offer. But beginning with it as active makes sense to me; especially as the dsp etc allows one to test different crossovers, filters etc. and trouble shoot bugs (even crowdsourcing those things on this forum) far easier than building a static crossover. it helps with the open part of the source in regards to the design process.

Eventually a specs for passive one could be offered Or even a few different options for a hardwired crossover.

 

[PeteL]

Open source implies that once the design is finalized the design and specs will be available to anyone to reproduce. You don’t need all the measuring equipment to build the exact same speaker.

DIY implies one enjoys making them. A hobby, fun in which one trades time for price perhaps but that is only one aspect.

A passive version would make sense to offer. But beginning with it as active makes sense to me; especially as the dsp etc allows one to test different crossovers, filters etc. and trouble shoot bugs (even crowdsourcing those things on this forum) far easier than building a static crossover. it helps with the open part of the source in regards to the design process.

Eventually a specs for passive one could be offered Or even a few different options for a hardwired crossover.

Sure, but I didn't even mention measuring equipment. Someone still have to cut the MDF. It takes tools and it takes know how (and time that can be waived if it's for yourself) All the cost drivers are not development, they are mandatory to make the thing a complete working active system. Yes passive will be cheaper. But again, if we accept the premisse that it's a cost no object design, those crossover shouldn't be cheap to match this level of performance.

 

[Spocko]

... One imagines what the DIY designers of the world could do with low-cost drivers *and* the services of a Klippel....

And don't forget the DSP active crossover - this is a real game changer IMO

 

[musicforcities]

Sure, but I didn't even mention measuring equipment. Someone still have to cut the MDF. It takes tools and it takes know how (and time that can be waived if it's for yourself) All the cost drivers are not development, they are mandatory to make the thing a complete working active system. Yes passive will be cheaper. But again, if we accept the premisse that it's a cost no object design, those crossover shouldn't be cheap to match this level of performance.

I don’t understand…it’s either diy and open source or not. One either wants to and has the skills and equipment needed or not. I guess I am misunderstanding what you are trying to say. My apologies if so.

 

[Rick Sykora]

Sure, but I didn't even mention measuring equipment. Someone still have to cut the MDF. It takes tools and it takes know how (and time that can be waived if it's for yourself) All the cost drivers are not development, they are mandatory to make the thing a complete working active system. Yes passive will be cheaper. But again, if we accept the premisse that it's a cost no object design, those crossover shouldn't be cheap to match this level of performance.

A few quick points....

1. Am already working with potential suppliers of pre-cut cabinets. So expect no major power tools will be needed.
2. Directiva r1 was NOT cost-no-object. As stated earlier, the cost target was $1000. I missed a bit.
3. Passive may be cheaper, but cannot attain the same level of bass extension without eq.

 

[Rick Sykora]

BOM has been posted to the first post of the build thread.

Already busted the budget again as the price of the tweeter rose (a little) since I did the estimate for Amir.

Bear in mind, the prices are retail and you may be able to do better. Ofc, prices are subject to change.

 

[BrokenEnglishGuy]

Imho the current bang for the buck its R3 + DUAL Rythmik L12 + mini DSP + UMIK1 + PURIFI EVAL1
Thats something like 4800 USD ~

 

[madbrayniak]

Great looking speaker!

I was looking at trying to accomplish something similar(though I lack many of the skills to design one).

I was looking at the DIY Sound Group SEOS-8 dome tweeter waveguide( https://www.diysoundgroup.com/speaker-parts/seos-8-tweeter.html) mated to the SB acoustics ring radiating tweeter( https://www.madisoundspeakerstore.c...sb29rdcn-c000-4-neo-magnet-ring-dome-tweeter/).

I’m curious if something like that would help with that dip around 3khz?

Also, would changing the woofer to the 8ohm version to drive easier be a drop in replacement or would the crossover need to be reworked?

 

[Rick Sykora]

For the record, Directiva r1 cost constraints (or lack thereof) were entirely imposed by me!

The budget was mostly done to prevent creeping elegance for the initial parts selection. A fancier tweeter or better dsp could have easily more than doubled the cost. In the end, am quite pleased with how it worked out. I have considered a number of larger (mainly passive) speakers over time and could not justify the cost of gutting them to make them active. @amirm made this experiment possible on a smaller scale and really appreciate his support. Am really anxious to try a larger speaker and am looking forward to the next iteration. I hope many of you are as well!

 

[ctrl]

DXT is known to have such break-up:
www.audioexcite.com » SEAS H1499 27TBCD/GB-DXT I wonder if it woudn't be bad to cutoff above 21-22kHz.

There is no reason to do so, since with normal music material the 27kHz frequency range is not addressed and even if it were, you will not be able to hear it.

The slightly increased harmonic distortions with HD3@9kHz and HD2@13,5kHz could not be reduced by a lowpass filter, because they are excited at 9kHz and 13.5kHz, where the filter would not work.

In simpler terms, when a 9kHz tone is excited, another tone (HD3) is simultaneously excited at 27kHz (no electronic filter or passive notch filter can prevent this), which has about -31dB less sound pressure level than the main tone. Same for a 13.5kHz tone.

Here is a comparison with Genelec 8330 .

You have chosen a somewhat unfortunate example. The Genelec 8330A also has a metal tweeter, which shows less HD2 at 96dB due to the breakup resonance (could be around 27kHz too, like the SeasDXT), but slightly higher HD3 compared to the SeasDXT.

A good silk dome tweeter might have been a better example to show the difference.

 

[PeteL]

A few quick points....

1. Am already working with potential suppliers of pre-cut cabinets. So expect no major power tools will be needed.
2. Directiva r1 was NOT cost-no-object. As stated earlier, the cost target was $1000. I missed a bit.
3. Passive may be cheaper, but cannot attain the same level of bass extension without eq.

Just out of curiosity, if it is not cost no object, do you do you know any known designs of a 2 way bookshelf speaker pair, DIY or commercial, that would have a larger than 1.4K BOM cost before any active or passive electronics, before any woodworking? If this is not cost no objects, It would be pretty close no? I fail to see how you can get more expensive than that?

BTW my DIY similar size 2 Way passive main speakers costed me close to 2 K, that's with an available online simple common design, and I a m not even in these league of component cost. I did have to pay for woodwork tough. Pre cut don't mean free especially, at this level, no finishing would be a bit sad considering the value of the object.