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ASR Directiva Open Source Speaker Review

Hidde

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That tweeter's dispersion performance is so nice, but the other parameters are purely mediocre compared to that purifi woofer. Something like the Bliesma T34B has much better performance regarding THD and control of resonances (though also in a different price category).
Source:

I wonder why SEAS doesn't release a higher end version of this very popular tweeter. They manufacture the Beryllium dome for the Grimm speakers (and thus should be possible). Brief measurements of that driver can be found here: https://vcllabs.com/transducers/#tweeters (under the name DXT-Be).

Developping a waveguide with similar waveguide is fairly complex.
 

Holmz

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The woofer is superb, but the tweeter simply isn't.
Directivity is not that good, and one of my least favoured tweeters because of the way it sounds, I genuinely hate that thing if I'm honest.

So, choosing "as a product" by the measurements and my personal impression of the tweeter, I still will choose one of Neumann over Directiva.
They sound neutral at least, and there is a clear difference between the loudspeaker which is designed by professionals who can design the directivity properly or not.
If I spend on that woofer in my DIY project, I will choose (subjectively) a far preferable tweeter and design a better waveguide for it.

Do you a few examples you could recommend?
 

Tangband

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The woofer is superb, but the tweeter simply isn't.
Directivity is not that good, and one of my least favoured tweeters because of the way it sounds, I genuinely hate that thing if I'm honest.

So, choosing "as a product" by the measurements and my personal impression of the tweeter, I still will choose one of Neumann over Directiva.
They sound neutral at least, and there is a clear difference between the loudspeaker which is designed by professionals who can design the directivity properly or not.
If I spend on that woofer in my DIY project, I will choose (subjectively) a far preferable tweeter and design a better waveguide for it.
Theres always a tradeoff of everything. The seas dxt tweeter has a very small waveguide, making it good for crossing higher in frequency than 2,3 kHz.
The purifi midbass starts beaming at a lower frequency, depending on the size of the midbass.
A bigger waveguide like monacor wg300 allows for a slightly lower crossover frequency, depending also on the tweeter used.
Then a crossover at about 1,8 KHz might result in a better listening result, and even better measurements. Maybe.
But, you get better dispersion at high frequencies with a smaller, more shallow waveguide. As I said, Its all about compromises….

Read more about beaming here :
 
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Arc Acoustics

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Do you a few examples you could recommend?
I personally tend to love textile dome tweeters.

Theres always a tradeoff of everything. The seas dxt tweeter has a very small waveguide, making it good for crossing higher in frequency than 2,3 kHz.
The purifi midbass starts beaming at a lower frequency, depending on the size of the midbass.
A bigger waveguide like monacor wg300 allows for a slightly lower crossover frequency, depending also on the tweeter used.
Then a crossover at about 1,8 KHz maight result in a better listening result, and even better measurements. Maybe.
But, you get better dispersion at high frequencies with a smaller, more shallow waveguide. As I said, Its all about compromises….
That is what I say "clear difference between the loudspeaker which is designed by professionals who can design the directivity properly or not."
And DXT does not have that clean directivity in the higher region either, it's no more than "decent directivity".

I really like DXT tweeter very much - especially in Kii with low pass filter applied.
That's interesting because what I actually heard was Kii Three with CD sources.
Perception depends on individuals, obviously.
If you hate DXT, use this:
Nah, TW29BNWG's directivity is way too messy so, as I said, I will design waveguide.
 

mtg90

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I think there are some misconception on how harmonic distortions work and are shown in graphs.

The harmonic products are plotted at the fundamental frequency but the actual tones generated by those harmonics are multiples of it.

So with this tweeter it has a breakup peak at 27kHz, this means a fundamental of 13.5kHz will cause any 2nd harmonics generated to land on the 27kHz breakup and get elevated. Same goes for for 3rd harmonics of a 9kHz fundamental and so on. While the spikes in distortion seem to be at the fundamental where they are plotted the actual output from those harmonics are all at 27kHz which is well out of the range of audibility.
 

beagleman

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The woofer is superb, but the tweeter simply isn't.
Directivity is not that good, and one of my least favoured tweeters because of the way it sounds, I genuinely hate that thing if I'm honest.

So, choosing "as a product" by the measurements and my personal impression of the tweeter, I still will choose one of Neumann over Directiva.
They sound neutral at least, and there is a clear difference between the loudspeaker which is designed by professionals who can design the directivity properly or not.
If I spend on that woofer in my DIY project, I will choose (subjectively) a far preferable tweeter and design a better waveguide for it.


It is not as simple, as just getting a "Better" tweeter. All aspects of tweeters to not move in unison as you go higher in price.

Some aspects will be better, but there will be trade offs in other areas.

Like asking what is the best tweeter.....You will get a dozen answers, but based on what aspects you WANT to be better. There is not one tweeter that does everything better than all the rest.
 

Godataloss

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Excellent design exercise, but it kills me a bit to see that driver is capable of 33hz in a slightly larger (.8 ft3) box. The cost of a larger box would likely be offset by using a port tube instead of a PR. Losing the PR also brings in the possibility of the use of plate amps with dsp. 33hz with the same BOM and similar footprint seems like a nobrainer.
 

PeteL

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Excellent design exercise, but it kills me a bit to see that driver is capable of 33hz in a slightly larger (.8 ft3) box. The cost of a larger box would likely be offset by using a port tube instead of a PR. Losing the PR also brings in the possibility of the use of plate amps with dsp. 33hz with the same BOM and similar footprint seems like a nobrainer.
I tend to agree that the possibility of a plate amp would be great on a design like that, but I believe there are technical reasons for the Passive radiator too. I'm no expert but I don't think the designer added it just for fun. I think an other prototype with a port and the same woofer was measured here and the performance was not as great. Not sure why.
 

beagleman

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I tend to agree that the possibility of a plate amp would be great on a design like that, but I believe there are technical reasons for the Passive radiator too. I'm no expert but I don't think the designer added it just for fun. I think an other prototype with a port and the same woofer was measured here and the performance was not as great. Not sure why.
Advantage of Passive, is no radiation of upper frequencies as how a port does.

Passive loses a "Bit" of deep bass compared to port, but cleaner midrange is probably a better trade off
 

Godataloss

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Advantage of Passive, is no radiation of upper frequencies as how a port does.

Passive loses a "Bit" of deep bass compared to port, but cleaner midrange is probably a better trade off
7 hz is huge in the bottom octave extension. Slightly less midrange perfection is a good trade if it means not having to run a sub. A port also makes room placement easier than a PR.
 
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Chromatischism

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7 hz is huge in the bottom octave extension. Slightly less midrange perfection is a good trade if it means not having to run a sub. A port also makes room placement easier than a PR.
I definitely don't agree with that last sentence, at least not if the port is in the rear.

The Purifi and the SB Acoustics drivers that Bruno designed before it just work better with the passive radiator. I couldn't tell you how, but I'm sure the info is out there.
 

Tangband

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Excellent design exercise, but it kills me a bit to see that driver is capable of 33hz in a slightly larger (.8 ft3) box. The cost of a larger box would likely be offset by using a port tube instead of a PR. Losing the PR also brings in the possibility of the use of plate amps with dsp. 33hz with the same BOM and similar footprint seems like a nobrainer.
One can actually design this speaker to go down to 20 Hz with a closed box at 15 liters and Linkwitz transformer Dsp crossover. 20 Hz is ofcourse overkill and the spl will be very limited, but 30 Hz is low enough.
If you live in a flat with concrete walls you gonna have big room-gain so the spl might be high enough without subwoofers. In that way you can make the best of this low distortion driver.
Passive radiators always sound worse with somewhat bad articulation than a good slot-port or closed box construction - my opinion.
 
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mjvbl

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First time I see posts about not liking the Seas DXT and I don't quite get it. It always seemed great in every metric really, pretty smooth FR/CSD (looks smoother to me than some others mentioned above), low distortion (overall, but higher 3rd than some others mentioned above, but is that even significant below a certain threshold) and I thought probably better directivity characteristics than just about anything if you're not going to star an experimentation project with custom waveguides. The computer generated score is 8.0 w/ sub, which part of the polar map should I look at to see the not that good off-axis performance?
 

Godataloss

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I definitely don't agree with that last sentence, at least not if the port is in the rear.

The Purifi and the SB Acoustics drivers that Bruno designed before it just work better with the passive radiator. I couldn't tell you how, but I'm sure the info is out there.
Far easier than with the PR in the rear. Port needs less room to breath. But hell, put it in the bottom of the enclosure and damp with a stand- maybe that would hide it from the Kipple too, lol?
 

Tangband

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First time I see posts about not liking the Seas DXT and I don't quite get it. It always seemed great in every metric really, pretty smooth FR/CSD (looks smoother to me than some others mentioned above), low distortion (overall, but higher 3rd than some others mentioned above, but is that even significant below a certain threshold) and I thought probably better directivity characteristics than just about anything if you're not going to star an experimentation project with custom waveguides. The computer generated score is 8.0 w/ sub, which part of the polar map should I look at to see the not that good off-axis performance?
Its a good tweeter but maybe its not perfect, as this thread shows split opinions of liking the sound from that driver. And we are comparing with the best . There are other options for the same price ( scanspeak D2608 or SB 26adc ) but you may have to construct a special waveguide to get the directivity right.
 

Godataloss

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Its a good tweeter but maybe its not perfect, as this thread shows split opinions of liking the sound from that driver. And we are comparing with the best . There are other options for the same price ( scanspeak D2608 or SB 26adc ) but you may have to construct a special waveguide to get the directivity right.
No reason the tweeter even has to be in the box. Top mount and time-align. Use whatever tweeter you fancy.
 

PeteL

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I don't say it in a cynical way, honest question, are all who goes about, do this instead of that, are speaker designers? To whom feels adressed, Don't take it personally and I don't want to offend anyone, but it seem to me that a decent amount of R&D was made to come up with this design, and doesn't feel like the same amount of studying on the task at hand was performed by going with general statements like this. But I may be wrong really, no offense.
 
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