Big E Speakers pt 3

[J.Wolf]

I'm sure the complete explanation is much more than my tiny walnut sized brain can understand, luckily I subscribe largely to the school of 'how does it work?', minus the word 'how'.

 

[spiritbass]

I'm sure the complete explanation is much more than my tiny walnut sized brain can understand, luckily I subscribe largely to the school of 'how does it work?', minus the word 'how'.

 

[Arjank]

the flex has not excited room nodes to any degree.

Ok, do the following test and then come back to this thread again.

Run sine-waves through this cab ranging from 30hz to 120hz in 1hz steps. With every "step" walk around the room and listen if the sound pressure is the same everywhere you walk. Of course there will be frequencies where the sound-pressure is pretty even throughout the room but not all of 'm. If none of these frequencies has un-even spots around the room then the MVW is a miracle.

 

[nomatic]

Ok, do the following test and then come back to this thread again.

Run sine-waves through this cab ranging from 30hz to 120hz in 1hz steps. With every "step" walk around the room and listen if the sound pressure is the same everywhere you walk. Of course there will be frequencies where the sound-pressure is pretty even throughout the room but not all of 'm. If none of these frequencies has un-even spots around the room then the MVW is a miracle.

Are you a working player?
What pro's require is function.....
I am a professional mastering engineer as my day job
and I gig at night and play on records. I could care less about
how the cab measures because I can hear myself better when
Playing really problematic rooms.

 

[Arjank]

I could care less about
how the cab measures

What I suggested isn't really measuring, it's just to show if room-nodes are exited by the cabinet. You can even do this to compare it to a "regular" cabinet and see if that regular one exites room-nodes more then the MVW. It's just a test to prove one of the anekdotes....

Btw. I'm playing bass for a hobby and I design and build loudspeakers for more then 25 years.

 

[Thomas Ewers]

Arjank,

I can honestly tell you they do still excite. However to a much lesser degree. We have had no trouble playing untreated gyms with the new alignment. Nothing is absolute here just the degree to which it does it.

BigE

 

[LowG]

This is what is so difficult to understand. I suppose maybe it is a patent application that keeps people from wanting to explain the "why"? I am simply quite curious about the physics of how a speaker could excite room modes "less" than another. Anyone should be able to see that it is a revolutionary concept that upends decades of traditional thought. If this is indeed true the creator certainly deserves the wealth and fame that is sure to come.

So how does it work? When can it be told?

 

[lelandcrooks]

As Tom says it is still there, but much mitigated. I have done as you suggest half a dozen times in high school gyms. You'll usually find a null in one of the corners where the bass really drops out, in a small area. The rest of the gym sounds dead even. Shows that way on an rta also.

 

[DukeLeJeune]

This is just an hypothesis: I think part of what's going on is related to de-correlation.

Basically when the bass energy in the room is well-correlated, we get peaks and dips where that energy neatly sums and cancels. If that in-room bass energy was all scrambled up, it would neither add in-phase-enough to generate major peaks, nor out-of-phase enough to generate major dips. That's the benefit of de-correlation, and subjectively it sounds "fast", even though the actual time-domain behavior isn't improved at all, and may even measure worse.

In the home audio world, I use four small subwoofers distributed around the room to de-correlate the in-room bass energy, and this works quite well. Credit to Earl Geddes; I'm using his idea with his permission. Full-range dipole speakers also introduce decorrelation relative to a monopole speaker, as the backwave is shifted in phase 180 degrees relative to the frontwave (which tends towards cancellation at long wavelengths, but is otherwise smoother in-room). I think that a good transmission line introduces decorrelation due to the internal path-length-induced time delay on the backwave energy, such that we have the phase relationship between the two bass sources - woofer and line terminus - rotating relative to one another (to my ears a good transmission line sounds better than it measures, and this is one possible explanation). The MVW cabinet theoretically does more scrambling-up of the backwave energy than either a transmission line or dipole, and therefore should be less room-sensitive than either.

(De-correlation also has benefits further up the spectrum, but that's sort of a different topic).

Anyway that's my best guess at this point. This is all imo, ime, and ymmv.

 

[kesslari]

Simple.

The ground up finger bones of Marie Laveau are mixed into the glue.
That and a bit of John the Conqueror root.

And this boy's gonna git him some!

 

[Mark Sacchetti]

The MAS 46 arrives tomorrow !

 

[seamonkey]

This is what is so difficult to understand. I suppose maybe it is a patent application that keeps people from wanting to explain the "why"? I am simply quite curious about the physics of how a speaker could excite room modes "less" than another. Anyone should be able to see that it is a revolutionary concept that upends decades of traditional thought. If this is indeed true the creator certainly deserves the wealth and fame that is sure to come.

So how does it work? When can it be told?

The whole vortex claim is these guys them not understanding the text book:
"Theory of Vortex Sound by M.S.Howe"

Look for the intro paragraph of this book and have a good laugh.

A patent doesn't mean it actually works. And they are selling and shipping these anyhow, the patent is no protection until it's granted.

Clearly there are many patents by those who failed basic physics that have revolutionized audio.

I've got to say I've changed my mind in one area. There's no equating what's going on here to Dr Bose. There's a lot more to Dr Bose. Professor at MIT for 45 year and he donated a majority of Bose stock to MIT. He had some credentials and proven smarts. He used science and physics. Science being the study of the natural world.

 

[seamonkey]

Ok, do the following test and then come back to this thread again.

Run sine-waves through this cab ranging from 30hz to 120hz in 1hz steps. With every "step" walk around the room and listen if the sound pressure is the same everywhere you walk. Of course there will be frequencies where the sound-pressure is pretty even throughout the room but not all of 'm. If none of these frequencies has un-even spots around the room then the MVW is a miracle.

That is such a simple thing to try. Wonder why it draws out a abrasive response and credential flinging. I'm going to have to give it a try

 

[mntngrown]

This thread is fun.

 

[kesslari]

That is such a simple thing to try. Wonder why it draws out a abrasive response and credential flinging. I'm going to have to give it a try

Speaking of abrasive responses...
Lots of sarcasm in yours, isn't there?

Here's a question.
Why would a small business have to jump to fulfill the request of some skeptic on the internet?
Instead of building product for interested customers?
As a potential customer who is satisfied with both the reviews these cabs are getting, and the insights from other speaker designers I respect, I prefer that the effort go into the latter.

 

[blowinblue]

There are those who try to build better bass cabinets and there are those who stand on the sidelines and heckle. You can probably guess who has my respect (and who doesn't).

M. M.

 

[Arjank]

There are those who try to build better bass cabinets and there are those who stand on the sidelines and heckle. You can probably guess who has my respect (and who doesn't).

M. M.

Don't know who you're talking about but I try to build better bass cabinets

 

[DukeLeJeune]

The whole vortex claim is these guys them not understanding the text book:
"Theory of Vortex Sound by M.S.Howe"

Look for the intro paragraph of this book and have a good laugh.

How about I save everyone the trouble of finding a copy of the book. Here's the first paragraph:

"Vortex sound is the sound produced as a by-product of unsteady fluid motions. It is part of the more general subject of aerodynamic sound. The modern theory of aerodynamic sound was pioneered by James Lighthill in the early 1950's. Lighthill (1952) wanted to understand the mechanisms of noise generation by the jet engines of new passenger jet aircraft that were then about to enter service. However, it is now widely recognized that any mechanism that produces sound can actually be formulated as a problem of aerodynamic sound. Thus, apart from the high speed turbulent jet - which may be regarded as a distribution of intense turbulence velocity fluctuations that generate sound by converting a tiny fraction of the jet rotational kinetic energy into the longitudinal waves that generate sound - colliding solid bodies, aeroengine rotor blades, vibrating surfaces, complex fluid-structure interactions in the larynx (responsible for speech), musical instruments, conventional loudspeakers, crackling paper, combustion and combustion instabilities in rockets, and so forth all fall within the theory of aerodynamic sound in its broadest sense."

This is not a book about loudspeaker design; rather, it is a graduate-level text on sound generation, coming from an angle that you're probably not used to. Let me distill that paragraph a bit:

"...any mechanism that produces sound can actually be formulated as a problem of aerodynamic sound. Thus... musical instruments, conventional loudspeakers... and so forth all fall within the theory of aerodynamic sound in its broadest sense." [emphasis in the original text]

Judging from your objection and its mocking tone, I assume you claim to have an understanding of this paragraph that precludes the possibility of the aerodynamic theory of sound, and in particular vortex theory, being applied to loudspeaker systems. Kindly share your insights with us, or withdraw your criticism.

And since you have embraced the role of critic (which by the way is a much easier role than that of creator or discoverer or inventor), would you also be so kind as to do so under your real name? Of course you have the right to use a moniker, but since you persist in your role as a critic, one would think you'd want to lend credibility to your position by having the courage to attach your real name.

And if you'd like to share any credentials that would reflect your technical or musical expertise (the latter so that we may understand why your criticism should be given greater weight than the actual experience of gigging musicians, some of whom possess a strong technical background), please consider this an open invitation to do so.

Duke LeJeune

 

[DukeLeJeune]

Ha!

Nice drawing, but you left off my beard.

 

[Mike Arnopol]

Seamonkey

I've tried to be civil. I've tried to take the high road. You are following back and forth to create a negative atmosphere. Since you have nothing positive to say and are casting an enjoyable discussion in a negative light. Everyone says to ignore the trolls. That's difficult for me to do as I feel it's not fair that every time you show up on a thread---it no longer makes me angry---it just saddens me.

I respectfully ask for you to not post on any of the threads involving my speakers. I know that there is no one on these threads that wants to hear from you. Your presence offers nothing positive.

I am going to strongly voice my opinions to the mods and have you unable to post in these threads.

Talkbass is nearly always a positive experience---even when opinions differ. I don't think it's fair that every time I open one of these threads I feel saddened by your presence.

Actually your petty rants have no influence on anyone's interest in my cabinets. I feel that when someone's presence only causes negativity (as the obvious goal)that it's not out of line to ask the mods to step in.