The wait is over: Genelec 8381A point source main monitor has arrived

[Fredygump]

Please elaborate

I'd call it an "artists rendition", but I'm not an artist. Top woofer is actually a coaxial driver in reality, but I didn't try to draw the wave guide... Both front facing drivers are 12", and the rear sub is 10". (I've done some detailing of the internals since this screen capture was taken, but this is the essence of the design.)

I'm expecting to take this to the Parts Express speaker competition this summer. But the MDF and particle board cabinets I have right now aren't gonna cut it! So I gotta get cracking on building the fancy version.

 

[Axo1989]

But why not? There is enough deep bass capability. It’s the midbass and higher that was the limitation. That’s why that was what was really worked on.

"Why not?" is my question.

I'm not discounting the work done on the triple coaxial (compression tweeter/upper-mid/4x lower-mid) at all (fwiw I don't think the 4x are doing any active steering).

But I had assumed it would be like the W371 with a couple of bass driver modes: one for max SPL and one for less SPL but greater control of bass directivity. Maybe that's there, but it isn't elaborated (we could do with a KEF style white paper, I'm guessing Genelec don't have the comms skills/staff for that). Basically, why not?

I appreciate your perspective that you didn't find the W371 modes so useful. I guess I've been interested in recent cardiod bass speakers from the usual suspects, along with some RiPol subs.

Edit: autocorrect decided 'bass driver' should be 'bus driver' ... sigh.

 

[thewas]

But I had assumed it would be like the W371 with a couple of bass driver modes: one for max SPL and one for less SPL but greater control of bass directivity. Maybe that's there, but it isn't elaborated (we could do with a KEF style white paper, I'm guessing Genelec don't have the comms skills/staff for that).

Genelec has published even several journal papers https://www.genelec.com/publications and I agree with you, would love to read more about their bass "steering", also in interaction with the GLM identification of room anomalies, guess they don't do it as they are afraid of being copied.

 

[Axo1989]

Genelec has published even several journal papers https://www.genelec.com/publications and I agree with you, would love to read more about their bass "steering", also in interaction with the GLM identification of room anomalies, guess they don't do it as they are afraid of being copied.

I'll check out the publications, thanks. Yes of course, keeping trade secrets is another reason not to present too much detail.

 

[tomtoo]

View attachment 285848

5926 W of power? Even if gifted I can’t afford that.

6kW? But only in mono.

You need a crane and a nuclear power station near you.

 

[fineMen]

Genelec has published even several journal papers ..., would love to read more about their bass "steering", also in interaction with the GLM identification of room anomalies, guess they don't do it as they are afraid of being copied.

Yeah, aren't we amateurs--at best? The science loving audiophiles we are!

I said it with my very first, and confirmed with my second post on this topic that the new, then still secret magic was about interference. Different drivers with dedicated phase to, you name it, 'steer' the radiation.

My contribution was dismissed as always as unqualified, superficial at best, at least without any merit. You opted to discuss instead the looks of your (wishful thinking) new little black thingy as to please your significant other. Impressive results were achieved.

C'mon, the bass steering is ages old. It is trivial once budgetary and size restrains are lifted. What we have here.

Bear with me, what you are missing utterly in its entirety is an analysis what you as an instance of the targeted end consumer of audio recordings would need to appreciate the information contained in recorded audio. The intellectual meaning of the sound that is transmitted to your homes. By how much the intelligence of that meaning is suppressed by imperfections of the transmission. Yes, the *meaning* of a reording, what it is supposed to tell to a human mind, the message. Too abstract of a a concept, bad English? Sure.

 

[thewas]

I said it with my very first, and confirmed with my second post on this topic that the new, then still secret magic was about interference. Different drivers with dedicated phase to, you name it, 'steer' the radiation.

I am afraid you are mixing here things up, the bass steering of the three 8381 woofers like of the W371 is something different to the four mid drivers which are used to increase SPL and keep the directivity high up to its lower frequency range as I also simulated in the thread.

My contribution was dismissed as always as unqualified, superficial at best, at least without any merit. You opted to discuss instead the looks of your (wishful thinking) new little black thingy as to please your significant other. Impressive results were achieved.

Who is "you", I didn't discuss about looks?

C'mon, the bass steering is ages old. It is trivial once budgetary and size restrains are lifted. What we have here.

Of course it is, any decent festival uses it since years.

 

[fpitas]

View attachment 285848

5926 W of power? Even if gifted I can’t afford that.

On the bright side, if you have those in your home drawing that much power, most likely you'll go deaf before the breaker trips. So there's a silver lining

 

[fineMen]

I am afraid you are mixing here things up, the bass steering of the three 8381 woofers like ...

Bass 'steering' is first of all a general concept understood best and finally since ages. And again you "quoted" "scientific literature" without explicating on the clue, let alone with any specifics. I'm not picking on you, but please do't use quotations as a blanket statement in a competition for expert-ship.

It is so bothersome to look out and interpret all the documents ony to find nothing related to your quite interesting claims.

 

[thewas]

And again you "quoted" "scientific literature" without explicating on the clue, let alone with any specifics. I'm not picking on you, but please do't use quotations as a blanket statement in a competition for expert-ship.

?? I just linked to the Genelec site of their published papers as an answer to a erroneous post that they don't have such, no specific topics nor qualitative analysis from my side there, although I have read quite few of them and found them helpful.

It is so bothersome to look out and interpret all the documents ony to find nothing related to your quite interesting claims.

As above it seems you are mixing up different posts and topics, I never claimed there is a paper there about their bass steering or their new 4 mid driver configuration.

 

[fineMen]

?? I just linked to the Genelec site of their published papers as an answer to a erroneous post that they don't have such, no specific topics nor qualitative analysis from my side there, although I have read quite few of them and found them helpful.


As above it seems you are mixing up different posts and topics, I never claimed there is a paper there about their bass steering or their new 4 mid driver configuration.

Exactly.

 

[Elitzur–Vaidman]

I'm not discounting the work done on the triple coaxial (compression tweeter/upper-mid/4x lower-mid) at all (fwiw I don't think the 4x are doing any active steering).

".... when we place these four drivers at the critical distance from each other and around this physical coaxial unit, then we can actually create directivity in the lower midrange, and this is something that we exploit here."

 

[thewas]

".... when we place these four drivers at the critical distance from each other and around this physical coaxial unit, then we can actually create directivity in the lower midrange, and this is something that we exploit here."

Yes, those mids are as said used to extend the directivity lower, guess the term "active steering" has here not a unique definition, the Genelec bass steering can change the direction and shape of directivity actively according to the individual needs, which these four probably don't as there is no need.

 

[Elitzur–Vaidman]

I think I've been interpreting "active steering" as using phase manipulation to shape directivity.

Under a generous interpretation, what the four drivers appear to be doing could be called active steering, but they probably don't satisfy a stricter interpretation unless the directivity can be shaped to preference.

 

[fineMen]

.... using phase manipulation to shape directivity.

... they probably don't satisfy a stricter interpretation unless the directivity can be shaped to preference.

The term "manipulating" insinuates a regular, naturally given response. Such a take would appear quite naive to an engineer who has done at least half a speaker design. Really, what are you talking about?

 

[Elitzur–Vaidman]

The term "manipulating" insinuates a regular, naturally given response. Such a take would appear quite naive to an engineer who has done at least half a speaker design. Really, what are you talking about?

One can influence the directivity by shifting the phase of 4 equidistant drivers, thereby controlling the cancelations/reinforcements. Without manipulating the phase of multiple spaced out drivers you'd get intense comb filtering (arguably the "naturally given response" you're asking for).

 

[fineMen]

One can influence the directivity by shifting the phase of 4 equidistant drivers, thereby controlling the cancelations/reinforcements. Without manipulating the phase of multiple spaced out drivers you'd get intense comb filtering (arguably the "naturally given response" you're asking for).

Alas, that's not possible.

 

[Elitzur–Vaidman]

Alas, that's not possible.

What's not possible? Controlling constructive and destructive interreference is certainly possible by using phase shift.

 

[Axo1989]

I think I've been interpreting "active steering" as using phase manipulation to shape directivity.

Under a generous interpretation, what the four drivers appear to be doing could be called active steering, but they probably don't satisfy a stricter interpretation unless the directivity can be shaped to preference.

Yes, I didn't intend to start a disagreement on semantics. I should probably have said active/variable steering.

I was thinking of previous discussion on how many amplification channels were employed in the design, and concluded (speculatively) that the four lower-mid drivers run on a single channel. I may be wrong of course, but I think we probably don't have variable dispersion for different rooms, or variable focus that might (say) shift that focus between one of a number of listening positions (closer/further or offset left/right like the B&O 90 does—employing multiple drivers on different facets of the speaker body in that case).

I don't think it's incorrect to call what you have described as active, fwiw.

 

[bungle]

Yngvie Malmsteen's early review of 8381A: