ASR Directiva Open Source Speaker Review

[ROOSKIE]

You’d need to add amps and DSP on top of that, that’s how read it anyway.

Yes, however that can be affordable.

For most of my DIY active stuff I have used either 2, 30 watt x 2, FX audio chip amps I purchased for $30USD each on clearance or I have a 3 Monoprice 605030 amps (100-150watts x 2)that I have been using for active 3-ways. ($100 each when on sale so I spent about $300 for 6, 100-150-watt RMS channels.
For farfield/midfield usages these have all sounded superb. I see no reason to upgrade for SQ, and yes I know these are not low distortions amps yet I am not experiencing any adverse effects. (though I might buy a 6 or 8 channel amp to help simplify the situation) They all have some hiss if fully active so bear that in mind for near field. You could mitigate or even get rid of the hiss by doing some passive components on the tweeter.

A miniDSP 2x4HD $200-230USD (really, pay the extra over the regular 2x4) is totally worth it's cost and I use the 8 output version ($500-550) for my 3 ways.

 

[RickS]

Then it would be Ricks decision.
But I don't expect Rick to suddenly want to put a 2dB bump in the axis frequency response at an arbitrary point when fine tuning.

In the end, however, the listening impression should always be decisive.

As long as it is only about the active version of the Directiva, the interaction of measurements and listening impression does not play such a decisive role, since the crossover can be changed and adjusted by anyone.



No, not at all. @kimmosto, the developer of VCAD, has enabled direct import of exported NFS measurement files.

Would also like to thank @kimmosto here for giving us helpful tips regarding the use of VCAD.

By the way, there is also a crossover proposal from him in the "Introducing Directiva" thread (still needs to be adapted from miniDSP 48k to 96k, but no problem to do so), which shows the great advantage of an active Directiva version - you can compare virtually any number of configurations directly in a listening test and decide for yourself which crossover is best for you.

Good catch! I will second the shout out to @kimmosto and add @JohnPM

Directiva would not have been possible without the outstanding software from these guys!

 

[Hemi-Demon]

SEAS Prestige 27TBCD/GB-DXT (H1499) Tweeter



Purifi Audio PTT6.5X04-NFA-01 6.5" Woofer - 4 ohm



Box is from Part Express and front baffle cutouts are on the build thread.

Specifications: • Panel thickness: 3/4" • Panel material: Medium Density Fiberboard (MDF) • Finished cabinet volume: 0.56 cubic feet • External dimensions: 16" H x 8.5" W x 11" D • Internal dimensions: 14.5" H x 7" W x 9.5" D • Made in the U.S.A. • Sold individually.

Product Details
Brand Denovo Audio Inc
Part Number 300-7064



SB Acoustics SB15SFCR-00 5x8 Passive Radiator


It is posted in this thread multiple times and is on DIY forum thread for Directiva r1 Active Crossovers



Thanks!

Thank you for writing all of that, I guess my use of the search function sucks. I appreciate all that you have done to get this all setup.

 

[Newman]

I have been meaning to ask: regarding the legend of these Early Reflections graphs:-

What convention is being used for “Front Wall” and “Rear Wall”?

I look at the steeply tapered “Rear Wall” graph and I assume that is the wall behind the speakers — and in front of the listener?

I just want this confirmed because, to me intuitively, that is the wall I call the front wall. I sit in my listening chair and the wall in front of me is what I call the front wall of my room. The wall behind my head — I have trouble calling that the Front Wall!!

Cheers

 

[NTK]

From ANSI/CTA-2034-A, it seems the "front wall bounce" is the sound radiated toward the listening position and then bounced backed by the wall behind it (as 0° is the reference axis).

 

[Newman]

OK that does confirm what I am saying, as long as Amir is sticking to that. Can anyone confirm he is doing so?

(P.S. very very strange decision about the rear wall bounces including 90 degree sideways…? Where is the logic in that?)

 

[richard12511]

Yes , the violent 27 KHz resonance in the tweeter is a real issue - especially if you play high resolution material . With 44,1 or 48 KHz sampling material theres no problem.

Can you explain this more?

My understanding is that this only show up because the sine sweep plays up that high at equal volume and ignites that harmonic resonance. With real music(even hi-res), I would guess that the spl at 27kHz is going to be way down(-30dB?) from the spl in the upper bass and mids.

 

[richard12511]

I that comparison I would love to see though also multitone IMD measurements like from Sound & Recording which unfortunately get often ignored, although they can be more audible and there a 3-way design like the KH310 has usually inherent advantages.

I too would love to see IMD measurements. I would expect the Neumann to win that battle, being 3 way.

It really surprised me just how close this speaker is to the KH310 in terms of measured performance. When Amir first mentioned the $4-5k "retail price", I thought that would be way too high to actually work, but now I'm not so sure, especially for those who want something small.

 

[mdsimon2]

Yes, however that can be affordable.

For most of my DIY active stuff I have used either 2, 30 watt x 2, FX audio chip amps I purchased for $30USD each on clearance or I have a 3 Monoprice 605030 amps (100-150watts x 2)that I have been using for active 3-ways. ($100 each when on sale so I spent about $300 for 6, 100-150-watt RMS channels.
For farfield/midfield usages these have all sounded superb. I see no reason to upgrade for SQ, and yes I know these are not low distortions amps yet I am not experiencing any adverse effects. (though I might buy a 6 or 8 channel amp to help simplify the situation) They all have some hiss if fully active so bear that in mind for near field. You could mitigate or even get rid of the hiss by doing some passive components on the tweeter.

A miniDSP 2x4HD $200-230USD (really, pay the extra over the regular 2x4) is totally worth it's cost and I use the 8 output version ($500-550) for my 3 ways.

100% agree.

I hate to use the term "investment" when it comes to audio equipment but if there were ever items that qualified as an investment it is a multichannel DAC / DSP and amplifiers for use in a DIY active system. Very easy to repurpose if you decide to move to move to a new design.

Michael

 

[miofu]

Can you explain this more?

My understanding is that this only show up because the sine sweep plays up that high at equal volume and ignites that harmonic resonance. With real music(even hi-res), I would guess that the spl at 27kHz is going to be way down(-30dB?) from the spl in the upper bass and mids.

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.

 

[Newman]

For me, though, the question is would it matter?

 

[617]

@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?

 

[richard12511]

Then it would be Ricks decision.
But I don't expect Rick to suddenly want to put a 2dB bump in the axis frequency response at an arbitrary point when fine tuning.

In the end, however, the listening impression should always be decisive.

As long as it is only about the active version of the Directiva, the interaction of measurements and listening impression does not play such a decisive role, since the crossover can be changed and adjusted by anyone.



No, not at all. @kimmosto, the developer of VCAD, has enabled direct import of exported NFS measurement files.

Would also like to thank @kimmosto here for giving us helpful tips regarding the use of VCAD.

By the way, there is also a crossover proposal from him in the "Introducing Directiva" thread (still needs to be adapted from miniDSP 48k to 96k, but no problem to do so), which shows the great advantage of an active Directiva version - you can compare virtually any number of configurations directly in a listening test and decide for yourself which crossover is best for you.

Cool to see how close some of those sims look to the actual NFS measurement.

 

[richard12511]

While Klippel works great for bookshelf size speakers it has considerable limitations when measuring larger floor standing models, as shown with the Revel F328Be. Even if Klippel became a standard speaker manufacturer tool there would need to be recognized alternate setups for capturing data on larger floor standing speakers. When Klippel measurements show bass rolloff starting at 70Hz and the F328Be offers strong response down to 29Hz with REW measurements you know there's a glitch in the data capture.

I wouldn't really consider in room response to mean much. It can be very different depending on the room. 29Hz is about what I would expect, given that Harman lists the -3dB point as 35Hz. It's just so hard to predict and correlate, though. For example, my woofers have a -3dB of 16Hz, but in room they dig 10-11Hz lower than that.

The NFS measured the F328Be's -6dB point at 29Hz. That seems mostly in line with Harman's figure and your in room measurement.

 

[RickS]

@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?

Yes, of course...

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

 

[musicforcities]

It might surprise you to know, the drivers are only a tiny percent of the overall cost. The box, labor to construct it and so on, PROFIT and advertising Shipping and so on, are most of the cost really. The drivers are most likely well under $100.00 I would guess.

It might surprise you to know, the drivers are only a tiny percent of the overall cost. The box, labor to construct it and so on, PROFIT and advertising Shipping and so on, are most of the cost really. The drivers are most likely well under $100.00 I would guess.

Not surprising at all. One also needs to include whatever retail markup there is well.
R&D can’t be nothing either. At least for certain companies.

Of course that also applies to the price paid for drivers bought retail for DIY projects…which might have a relatively high markup due to volume.

 

[musicforcities]

.

But the Directiva is far from 1k... 1400$ in parts and does not include the DSP and amplification. Not include tooling, not include R&D, engineering, fabrication, nice finish, marketing (OK as DIY you can scratch Marketing, but none of the other stuff... ). Amir's evaluation of the real cost at 4-5k for a full finished speaker is in my opinion under evaluated, we are maybe looking at a considerably more expensive than 5k pair of bookshelf powered speakers.

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.

 

[musicforcities]

I don't believe a Klippel is reagrded as "peanuts" for any company, letalone a medium sized speaker manufacturer, or, for that matter, an individual.

Sure, in comparison to board machinery (CNCs, vacuum presses, laminating lines, paint lines) where a million dollars is par for the course, but consider these guys have already invested and have most likely amortised all their factory machinery decades ago. A Klippel would be a tough sell IMO. After all, the board will simply want a straight up ROI. What is the answer?

Ever run a cnc machine? Running costs are not insignificant for those things.

And it would be unusual for a company to be using the same production equipment it was decades ago. If it has not outsourced fabrication, significant investment would need to be made to compete. A lot has changed. Things are not made the same way.

Even if some equip is decades old, it’s not like you buy production machines once and have zero costs. They need to be maintained, overhauled, replaced, retooled, etc.

It’s like a building: maintenance costs will exceed construction costs if it’s lifespan is long enough.

Second law of thermodynamics is expensive.

Computers are turned over every 3-4 years at most companies.

So 100k -200k or so for a klippel system ain’t peanuts it’s not unreasonable. It’s cheaper than maintaining an anechoic facility. Lol.

 

[musicforcities]

Yes, of course...

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

+500 per speaker. Copper tubing is expensive! Lol

 

[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