Steerable Array

"Before the advent of amplified music, this (meeting the needs of musicians and audiences) happened naturally. Musicians playing acoustically could hear the natural uncolored sounds that they and their fellow musicians were producing and because each sound came directly from its source it was mixed in a natural way so that the musicians and their audience enjoyed an automatic connection between the visual and the aural. The source of a particular instrumental sound could be instantly located and fully appreciated." (https://youtu.be/neIOP1uhjpE?t=23)

The abovementioned video makes reference to instruments generally. But my request for an L1SA (Steerable Array) is to have a speaker that will accurately guide the attention of each person in the largest possible audience to the source of the most amazing instrument of them all, the human voice.

@Uncle John posted:

"Before the advent of amplified music, this (meeting the needs of musicians and audiences) happened naturally. Musicians playing acoustically could hear the natural uncolored sounds that they and their fellow musicians were producing and because each sound came directly from its source it was mixed in a natural way so that the musicians and their audience enjoyed an automatic connection between the visual and the aural. The source of a particular instrumental sound could be instantly located and fully appreciated." (https://youtu.be/neIOP1uhjpE?t=23)

The abovementioned video makes reference to instruments generally. But my request for an L1SA (Steerable Array) is to have a speaker that will accurately guide the attention of each person in the largest possible audience to the source of the most amazing instrument of them all, the human voice.

Hi Uncle John,

Without doubt, Bose considers the voice of a singing performer or public speaker an instrument, and it is dispersed and localized in the same manner as a musical instrument is when using an L1 speaker system.

All line arrays are steerable to some extent. The L1 series of speakers vary in their coverage, but the general idea is wide horizontal coverage and lesser, controlled, vertical coverage. These dispersion patterns limit unwanted reflections which contributes greatly to the listeners ability to locate the source of sound.

An audience member listening to a singer performing in front of a L1 will have no difficulty locating the position of the singer.

O.. 

Concur, most of the audiences I’m in front of with an L1 behind me know it’s me singing...

This is a link to a thread I started many years ago that talks about localization, among other things, check it out.

O..

Hi, Uncle John.

@Uncle John posted:

Add a fourth system. Call it the Model 1SA. It would look similar to the Model 1S. The difference would be that the top array would be the Panaray MSA12X beam-steering loudspeaker ( https://pro.bose.com/en_us/pro...tml#ProductTabs_tab3 .

That's an interesting idea.

@Uncle John posted:

"Before the advent of amplified music, this (meeting the needs of musicians and audiences) happened naturally. Musicians playing acoustically could hear the natural uncolored sounds that they and their fellow musicians were producing and because each sound came directly from its source it was mixed in a natural way so that the musicians and their audience enjoyed an automatic connection between the visual and the aural. The source of a particular instrumental sound could be instantly located and fully appreciated." (https://youtu.be/neIOP1uhjpE?t=23)

The abovementioned video makes reference to instruments generally. But my request for an L1SA (Steerable Array) is to have a speaker that will accurately guide the attention of each person in the largest possible audience to the source of the most amazing instrument of them all, the human voice.

Please note, the Bose Panaray MSA12X beam steering applies to the vertical plane, not the horizontal and intended to be used for installed applications (not portable).

Horizontal Dispersion
160° H
 

Vertical Opening Angles
Software Adjustable: 1 module: up to 30°, 2-3 modules: up to 40°
 

Vertical Beam Steering Angles
/ - 20°

For horizontal steering (is that what you're asking for?) it's currently done with wave guides. (See Bose RoomMatch products for examples).

ST

"Please note, the Bose Panaray MSA12X beam steering applies to the vertical plane, not the horizontal and intended to be used for installed applications (not portable)."

I appreciate what you are saying, I own an L1 Compact (which I purchased second hand) and we use it in the church I attend. It works well for preachers in our current venue which has a raked floor. However, by the end of next year, we will move into a newly renovated building with a flat floor.

The advantages of the L1 Compact is that it's vertical beam spread is suited to a sloping floor. 

When the time comes I intend to either sell the L1 Compact and buy a second hand L1 Model S1 (thank-you Bose for designing speakers that hold their value) or buy an MSA12X and put it on a stand.

Apart from a steerable beam, the advantage of the MSA12X is that the beam can be shaped. What this means is the persons sitting close to the speaker would experience lower sound pressure than would normally be the case. Similarly, persons sitting towards the rear of the auditorium would experience higher sound pressure than would normally be the case.

So if I'm planning on putting an MSA12X on a stand why request an L1 Model 1SA? Think about it. The total net weight of an L1 Model 1S top array and bottom extension (11.3 kg) and power stand (10.7 kg) is 22 kg. The total net weight of an MSA12X (14.5 kg) and custom stand (8.5 kg) is 22 kg. In other words, an L1 Model 1SA would be just as portable as an L1 Model 1S and with the inclusion, some simple volume controls would be completely self-contained and programmable to suit venues with either raked or flat floors.

Tens of thousands of churches and other places of worship around the world use a basic L/R channel setup. An L1 Model 1SA which would be arranged to augment their existing setup to achieve an L/R Mono setup would permit prospective customers to evaluate the benefits for themselves.

"In L/R Mono you still have thee output buses but whether something is L/R or mono is a result of an output bus assignment rather than a pan. You can assign a signal to either or both outputs. If a signal is assigned L/R and panned center, it comes equally from both left and right and not from the mono output. A mono send is just that and pan does not affect it.

L/R Mono is often used to have a mono center speech speaker/cluster/array and then split left and right stereo speakers/clusters/arrays. Using a single point for the speech reinforcement can reduce the timing and localization issues that would result if the same signal is reproduced from multiple locations. At the same time, the L/R arrangement allows for greater stereo separation for stereo playback. Since the center speaker/cluster/array is typically used primarily for speech sources, the speaker array components used are often selected based on voice reproduction (maybe a 12" woofer and usually no sub) while the left and right speaker array components are typically selected based more on music reproduction." (https://forums.prosoundweb.com....msg820059#msg820059)          

Hi, Uncle John,

Check out Places of Worship on the Bose Pro site.

In the meantime, let's continue this thread as a place for L1 Feature Requests and let Bose read and be informed. 

Cheers,

ST

Hi @ST, Thanks for the link. I'm familiar with these case studies. In fact, these were my starting point when I started researching Bose products and services last year.
Thank you too for the invitation to continue the thread. I've got a few more ideas but I'll let readers digest what I've suggested for a while before I go on.
In addition to the training videos, I found this design guide (and the explanation of beam shaping etc.) to be very useful: https://assets.bose.com/conten...anaray-msa12x_en.pdf
   

Hi Uncle John,

You sort of went in a different direction than I anticipated following the first post.

When the L1 was first introduced it was highly promoted as a system designed for one person. When used in that manner, even with several onstage, it is easy to determine who is playing what and where it is coming from. The Model II and the L1s project in a pretty flat beam the height of the speaker array. The Compact is a curved array similar to, but much smaller than a 502a which serves to change the dispersion from a flat beam to one that is angled up and down slightly to provide some addition vertical dispersion.

The F1 flexible array give the user control over the vertical dispersion to match the seating or listening arrangement of the audience.

The MA12 series of speakers came about during the 10 years of L1 development, and were the first of the 12 speaker line arrays to be brought to the market. I recall seeing a pair at a Bose dealer on tri-pod stands when I was purchasing a 402 II system just before the release of the Classic.

The fact that they are still on the market and have been improved and redesigned tells us they are popular, but I don't recall ever seeing a pair, or even one, being used as a portable system outside of that dealer setup.

The M12 series have a much larger cabinet which allows them to produce lower frequencies than the L1 column, but that lower frequency range is not part of the spectrum that is steerable, and with only one column the steerable cutoff is 500 Hz. That means for music reproduction one would need a sub to supplement the bottom end if the steerable feature was critical to coverage.

Over the years I have played on a lot of different stages and have always been able to direct the L1 "beam" to my audience. In most cases a simple short 2X4 under the front or back will accomplish enough angle to get the audience within the confines of the vertical dispersion.

I recall very early, when this forum first started, we talked about the possibility of a jointed array column (a knee and an ankle) to give the user more control over the dispersion, but I think most of that was based on us, the early adopters, and Bose getting used to a brand new speaker design that had properties the engineers were still figuring out and the users didn't understand at all. 

While I could see the steerable feature something that might find value in the Model II or Model 1s, I don't think I would sacrifice the portability of either for that feature and use the MSA12X in its place. 

O..

Interesting.  But I fear the accoustics of a room could put the kabosh on these best layed plans.  By the way ST, I finally got a chance to set up both L1s and my F1 812s out doors.  Fabulous, just as I had hoped.

Hi @Oldghm,
Thanks for your comments.
I did try to explain what I meant about beam shaping in the following paragraph:

"Apart from a steerable beam, the advantage of the MSA12X is that the beam can be shaped. What this means is the persons sitting close to the speaker would experience lower sound pressure than would normally be the case. Similarly, persons sitting towards the rear of the auditorium would experience higher sound pressure than would normally be the case."

To achieve the outcomes described in the above paragraph requires more than simply inclining the speaker column. 

Hi @Rob Wright, The reason I an L1 Model 1SA is to reduce the reverberance you seem to be hinting at.
Later today I will be uploading a model of the interior of a church created using Sketchup. I will also post a link to the corresponding mdr file for Bose Modeler.
My intention is to use this basic model to create another two models, one with a tilted L1 Model 1S (as suggested by @Oldghm) and the other with an L1 Model 1SA.
Following that, I will run a simulation for each and post the results here.
How long will all this take? If I do it, probably a few months as I'm on a steep learning curve. If someone at Bose is willing to pitch in (which I hope they will), it would probably take them less than a day. 
 

@Uncle John posted:

Hi @Oldghm,
Thanks for your comments.
I did try to explain what I meant about beam shaping in the following paragraph:

"Apart from a steerable beam, the advantage of the MSA12X is that the beam can be shaped. What this means is the persons sitting close to the speaker would experience lower sound pressure than would normally be the case. Similarly, persons sitting towards the rear of the auditorium would experience higher sound pressure than would normally be the case."

To achieve the outcomes described in the above paragraph requires more than simply inclining the speaker column. 

Hi Uncle John,

Could you link to the documentation for the quote I highlighted in red? 

All of the portable line arrays lose dB at a lessor rate than typical point source speakers. I think the Model II loses volume by 3db per doubling of distance vs a typical two way speaker losing at a rate of 6db per doubling of distance.

O..

 

Hi @Oldghm, I was quoting myself from earlier in this discussion ( https://www.bosepro.community/...96#56492378163831796 
I used to work as a technical author. The understanding expressed here is based mostly on what I took away from the Bose online education center course material at:
https://pro.bose.com/en_us/res...learning-center.html

Course: Bose Array Tool.
5. Vertical Beam Shape Types  

Hi All

WOW!!

What an interesting thread. I wonder where the S1 Pro stands in all these technical analogies?

Or does it?

Harpo

Hi Harpo,

The S1 is the shortest of the Bose speakers with "line arrays". Length of throw and how well the array carries volume are both relative to the length, (among other factors) or height of the array. A Model II will carry more volume a longer distance than a Model 1s, a 1s will carry more volume a longer distance than a Compact, and the Compact will carry more volume a longer distance than a S1.

O..

@Uncle John posted:

Hi @Oldghm,
Thanks for your comments.
I did try to explain what I meant about beam shaping in the following paragraph:

"Apart from a steerable beam, the advantage of the MSA12X is that the beam can be shaped. What this means is the persons sitting close to the speaker would experience lower sound pressure than would normally be the case. Similarly, persons sitting towards the rear of the auditorium would experience higher sound pressure than would normally be the case."

To achieve the outcomes described in the above paragraph requires more than simply inclining the speaker column. 

Hi Uncle John,

Please understand my comments come from a very basic layman's understanding of the principles of line array technology. I am not an engineer  or highly skilled technical person.

After spending a fair amount of time looking, I failed to find documentation to support the hypothesis you have presented.

While I believe it is true that "beams", when there are at least two, from one or more stacked modules can have separate gain, the property that you speak of about sound pressure levels is not unique to, or directly related to the steerable beam feature of the MSA12X. If I am wrong I am open to being corrected.

When compared to traditional style speakers, the Bose L1 and MA series all offer a more even sound field, front to back. This even sound is a product of the line array, a stack of speakers arranged very close together, not a product of the steerable feature.

The steerable feature allows the narrow vertical coverage of the array to be directed to an audience that is seated in an arrangement that exceeds the normal vertical coverage of the MA 12 series.

It is my understanding that line arrays present problems that are overcome by DSP. When placing speakers close together there is both constructive and destructive interference between the output of individual transducers. Using DSP to modify this interference is what makes the line array usable. I'm just guessing here, but I suspect the steerable feature is born from the continued research of how to make line arrays work better in the most difficult of venues.

I believe that if, or when, this steerable feature of a line array becomes consumer usable in a portable system, Bose will be the first to include that feature in their products.

O..

 

I've been thinking about any possible negatives of a DSP speaker such as the MSA 12X as compared to say the L1 Model 1S.
Here are two which I'd like to explore:
1. DSP introduces a delay of 5.7 ms. As I understand it this would mean that sound from the DSP speaker would seem to be coming from about 7 ft (2m) further back when compared to a non-DSP speaker. Are there any significant negative aspects related to this if a DSP speaker is placed where an L1 speaker is intended to be placed, ie. behind the performer?
2. The L1 Compact has a line-level input impedance of 800 kohm (1/4 inch). The MSA 12X has an input impedance of 20 kohm. Can the L1 Compact line-level output be used successfully as a source for the MSA 12X? I'm proposing to operate such a setup with the array section of the L1 Compact disconnected.    

 

Hi Uncle John,

 

Latency is a product of digital signal processing. I don't think that there is a fixed number for latency in a digital speaker system. Some might be more, some less. Generally speaking latency of 10 milliseconds or less is not detrimental to a vocal performance.

 

Problems occur when there are multiple sound sources different distances from a listeners ears. Then distance and delay must be managed.

 

The MA 12 series of speakers like many other of Bose products require active eq controllers to provide best results.

I am not familiar enough with the X series to offer an opinion on using the Compact line out to feed one. I'll read some and return If I learn something worth sharing.

 

O..

 

Hi Uncle John,

Well, the MSA 12X has an analog, line level input so I see no technical reason that the Compact cannot be used as an interface.

 

I have to ask, why?

 

O..