I have been tasked with "sorting out" the appalling sound system in a large rectangular school assembly hall. Seats 600 people. Wooden floors, concrete and glass walls. Recommendation has been to put two big speakers at front and some more half way down so that "front speakers" don't have to be so loud they create distortion echo etc.
Having been following the L1 for some time now it seems that an option would be to use L1s as the sound system.
My children are musicians who would benefit from better sound in the hall.
I believe echo etc is caused by having to have current speakers up loud enough to be heard at back.

Main use is people standing up at front of hall talking to crowds of students etc, performances by small groups of musicians. back ground music and announcers at functions..


Any thoughts as to whether this is a viable option. The people looking to sell ussound systems had never heard of the L1s. New Zealand is along way away.

Greg

Hi Greg D,

I am glad that you found your way here. Welcome.

quote:

Seats 600 people. Wooden floors, concrete and glass walls.

It seems that these kinds of conditions are not nearly as challenging for the L1™ system if only because we tend not to have to run them as loud as other systems - and because of the limited vertical dispersion. You can read about that here: Physics: Spherical, Cylindrical, Plane-Wave Sources in the wiki.

quote:

Recommendation has been to put two big speakers at front and some more half way down so that "front speakers" don't have to be so loud they create distortion echo etc.

Good thoughts for this space.

quote:

Having been following the L1 for some time now it seems that an option would be to use L1s as the sound system.

Agreed.

quote:

My children are musicians who would benefit from better sound in the hall.
I believe echo etc is caused by having to have current speakers up loud enough to be heard at back.

Aha - like minds. Seriously, I have found that turning down the volume can alleviate excessive reverberation. But there is only so much you can do if there is a lot of ambient noise (students stirring).

quote:

Main use is people standing up at front of hall talking to crowds of students etc, performances by small groups of musicians. back ground music and announcers at functions..


Any thoughts as to whether this is a viable option. The people looking to sell ussound systems had never heard of the L1s. New Zealand is along way away.

Let's get some details.

Can you get the dimensions of the room. This will give us an idea about whether you might need more L1™s acting as "satellite" systems part-way down the wall.

Also - can you tell us a little more about the space?

Is there a separate stage?
Is it elevated?
Dimensions?

Are there any architectural features you haven't mentioned (alcoves or balconies).

Do you have any pictures of the room?

Where are you?

Something to consider if you go with putting speakers halfway down the hall...I read many years ago that you should plug those speakers into a digital delay (100% wet) and set the delay so that those sitting at the back don't have sound from the front of the hall and sound from the second set of speakers arriving at different times.

i.e., since sound travels at 1000 feet per second at sea level (give or take), if you've got a hall that's 100 feet long with speakers at the front and half way down, then you should delay the second speakers by roughly 50 milliseconds.

I have no direct experience with this, but it makes sense to me.

Hi Andrew,

Here's a note we did for another application (Talker/Lecturer in a large hotel ballroom).

quote:

Originally posted by ST:
This is a revised conceptual view of how you can incorporate a mixer for several inputs including a source for background music (shown as old style iPod).

L1 ™ System is located near the stage.

L1 ™ System (the Remote System) is at least 50 feet or more away - probably around half-way along the longest wall in the room.

The digital delay is set at approximately 1 msec per foot between the two L1™ Systems.


-- click image to make changes to the live version --

Codes:
Orange numbers are Systems and Inputs using those Systems.
Blue ringed numbers are Channels on the Systems.
Green numbers are for general notes about the Sketch and connections to non-Bose gear.

Connections to mixer
- all inputs panned up the center.
- Three (or more) wireless mics (receivers go to mixer)
- iPod

Mixer Outputs
Right: goes to L1™ System
Left goes to - digital delay - then to wireless transmitter (or wire to System 2)

L1™ System requires
Wireless receiver from
Output from wireless receiver goes to L1™ System

see it in context

Hi Andrew,

You are correct in pointing out that a Digital Delay Line (DDL) should be used in situations where speakers need to be positioned at a substantial distance from the main source.

The formula is Feet divided by 1130 then multiplied by 1000. So for 100 feet the delay would be 88.5 msec (90 msec). It is standard practice to delay the sound a little bit more so the sound leaves the delayed speakers slightly after the sound arrives from the main source to keep the perceived image up front. An additional 10 milliseconds would suffice. Some DDLs allow the delay time to be set in feet. Also note that most digital consoles have output delay built in. It is also customary to set the level of a delayed speaker lower as its sound will add to the original.

But... I haven't totally wrapped my head around the fact that since the L1 radiates nearly 180 degrees, placement of the delayed speakers could be a concern. If they are placed next to a wall, reflection could be an issue but rotating an L1 to reduce the reflections would send sound towards the source Lets wait for Greg D's response to ST's questions before we delve deeper into this. It would be a lot simpler if delayed L1s are not required. Based on many testimonials in other threads, delayed L1s will not likely be required. Further information from Greg will help in determining that.

Again, Andrew is correct in pointing out that delay time is an important factor in retaining the clarity of sound we almost take for granted from the L1 when placing additional L1s or other speaker farther away from the source.

I know that I was somewhat repetitive in the way I presented this information. This is an attempt on my part not to confuse

Thanks for the responses.
At my son's school I have put my name forward to drive the replacement of the school assembly hall's sound system. This is to last a few years while we raise funds for a "Performing Arts" centre.
I will get dimensions of hall etc
BUT my key thought is.
Why go down the traditional path when in some areas the L1 has changed the rules? I don't see any postings about being used as a "permanent" sound system in school auditoriums
(but I don't see any about Harp/violin combos either). Is this because a rectangular school hall with acoustic problems. ie is people talking through microphones are difficult to hear properly etc is not an area where an L1 will be a star?

In NZ we don't have the 45 day trial, so I can't order one and test it.

I would love the L1s to be a viable option - I like the idea of ground breaking technology that overcomes problems that have been around for years.


Background: Music {performance) is a big thing for my 13 yr old son and 16 yr old daughter. At their schools they get performance opportunities all the time. Outside of school they are in church and orchestral groups. Main instruments Harp and violin. But I was at school concerts/practices this week with them playing sax, piano, flute, guitar and double bass. They are now getting asked to play at wedinds and functions. - When they get older they'll probbably start getting paid to do it. At the moment it's just an amazing musical journey for them.

I am "amusical". I have observed them perfoming in amplified situations from someone shoving a mike in front of the violin or harp and hoping for the best to my daughter playing a harp solo in the Great Hall of the People" in Beijing with 2 or three sound engineers spending 20 minutes getting the sound right for the performance. A proud parent - and a lucky one.

So I began researching portable sound systems and immediately came to Bose.

I fit into the category of someone with no experience of sound - so no preconceived ideas. I am waiting for new model to become available in NZ before "taking the plunge"

I know a few "longtime musicians" acquantances who are very much still involved in the NZ music scene, organising shows, producing, ecordingplaying etc and none of them have delved into the L1.

Background: Music {performance) is a big thing for my 13 yr old son and 16 yr old daughter. At their schools they get performance opportunities all the time. Outside of school they are in church and orchestral groups. Main instruments Harp and violin. But I was at school concerts/practices this week with them playing sax, piano, flute, guitar and double bass. They are now getting asked to play at wedinds and functions. - When they get older they'll probbably start getting paid to do it. At the moment it's just an amazing musical journey for them.

I am "amusical". I have observed them perfoming in amplified situations from someone shoving a mike in front of the violin or harp and hoping for the best to my daughter playing a harp solo in the Great Hall of the People" in Beijing with 2 or three sound engineers spending 20 minutes getting the sound right for the performance. A proud parent - and a lucky one.

So I began researching portable sound systems and immediately came to Bose.

I fit into the category of someone with no experience of sound - so no preconceived ideas. I am waiting for new model to become available in NZ before "taking the plunge"

I know a few "longtime musicians" acquantances who are very much still involved in the NZ music scene, organising shows, producing, ecordingplaying etc and none of them have delved into the L1.

Greg D, yes we are already using the L1 system in a school hall situation in New Zealand.
I have recently supplied a system to Onslow College here in Wellington and also fitted two other very reverberant school areas with systems using the BOSE MA12 loudspeakers which were developed as a result of the research and development work involved in the L1 system.
All work a treat.
If you would like to try one of the systems in your space then please contact me.
Ian Hull-Brown...email... bose at goldenhorn.co.nz or phone me on 04 479-4111

GregD:

*Do* get in touch with Ian; he'll be of great help -- particularly in choosing whether to go with an installed system (with MA12's, of course), L1's, or some combination of the two.

For performing, and the flexibility of using sound reinforcement in places other than just the assembly hall, the L1 will be great.

Unless the hall is really long and narrow, you probably will not need more than Systems at the front.

Keep us posted!

quote:

Originally posted by Andrew Douglas:
Something to consider if you go with putting speakers halfway down the hall...I read many years ago that you should plug those speakers into a digital delay (100% wet) and set the delay so that those sitting at the back don't have sound from the front of the hall and sound from the second set of speakers arriving at different times.

i.e., since sound travels at 1000 feet per second at sea level (give or take), if you've got a hall that's 100 feet long with speakers at the front and half way down, then you should delay the second speakers by roughly 50 milliseconds.

I have no direct experience with this, but it makes sense to me.

You can buy a number of delay processors that you set by the number of feet or meters from the original source to the delay stack.
a reliable cheap-o is the Behringer Shark these are multi purpose boxes single channel for around $60 a shot. Digitech an ART are also cheap units that offer multi channel operation with the ease of measure and set. Depending on the response of the room you may only want to use the radiators on the delay lines without the B1's.
Good luck